Category Archives: Pathway

Zerumbone

Cancer:
Colorectal, renal carcinoma, glioblastoma, ovarian and cervical

Action: CSCs, anti-inflammatory

Zerumbone is isolated from Zingiber zerumbet [(L.) Roscoe ex Sm.].

Colorectal Cancer

Numerous agents from 'mother nature' (also called nutraceuticals) that have potential to both prevent and treat CRC have been identified. The most significant discoveries relate to compounds such as cardamonin, celastrol, curcumin, deguelin, diosgenin, thymoquinone, tocotrienol, ursolic acid, and zerumbone. Unlike pharmaceutical drugs, these agents modulate multiple targets, including transcription factors, growth factors, tumor cell survival factors, inflammatory pathways, and invasion and angiogenesis linked closely to CRC. We describe the potential of these dietary agents to suppress the growth of human CRC cells in culture and to inhibit tumor growth in animal models (Aggarwal et al., 2013).

Cancer Stem Cells (CSCs)

Cancer stem cells (CSCs) are a major cause of cancer treatment failure, relapse, and drug resistance and are known to be responsible for cancer cell invasion and metastasis. The Sonic hedgehog (Shh) signaling pathway is crucial to embryonic development. Intriguingly, the aberrant activation of the Shh pathway plays a critical role in developing CSCs and leads to angiogenesis, migration, invasion, and metastasis. Natural compounds and chemical structure modified derivatives from complementary and alternative medicine have received increasing attention as cancer chemo-preventives, and their anti-tumor effects have been demonstrated both in vitro and in vivo.

Compounds cyclopamine, curcumin, epigallocatechin-3-gallate, genistein, resveratrol, zerumbone, norcantharidin, and arsenic trioxide, with a focus on Shh signaling blockade, were reviewed by Huang et al. (2013) and given that Shh signaling antagonism has been clinically proven as an effective strategy against CSCs, this review may be exploitable for the development of novel anti-cancer agents from complementary and alternative medicine.

Renal Carcinoma

Sun et al. (2013) reported that zerumbone, a monosesquiterpine, shows anti-cancer effects on human RCC cells via induction of apoptosis in vitro. Human renal clear cell carcinoma 786-0 and 769-P cell lines were used as the model system. Exposure of RCC cells to zerumbone resulted in cell viability inhibition, accompanied by DNA fragmentation and increased apoptotic index. Mechanically, treatment of RCC cells with zerumbone activated caspase-3 and caspase-9 finally led to cleavage of PARR.

Taken together, our studies provided the first evidence that zerumbone imparted strong inhibitory and apoptotic effects on human RCC cells. The zerumbone-induced apoptosis might be related to the activation of the caspase cascade and deregulation of the Gli-1/Bcl-2 pathway. Our results suggest that zerumbone merit further investigation as an apoptosis inducer as well as a novel RCC chemotherapeutic agent in the clinical setting.

Glioblastoma

Zerumbone (10~50 µM) induced death of human glioblastoma multiforme (GBM8401) cells in a dose-dependent manner. Flow cytometry studies showed that zerumbone increased the percentage of apoptotic GBM cells. Zerumbone also caused caspase-3 activation and poly (ADP-ribose) polymerase (PARP) production. N-benzyloxycarbonyl -Val-Ala-Asp- fluoromethylketone (zVAD-fmk), a broad-spectrum caspase inhibitor, hindered zerumbone-induced cell death. Moreover, transfection of GBM8401 cells with WT IKKα reduced the zerumbone-induced decrease in Akt and FOXO1 phosphorylation. However, transfection with WT Akt decreased FOXO1, but not IKKα, phosphorylation.

The results suggest that inactivation of IKKα, followed by Akt and FOXO1 phosphorylation and caspase-3 activation, contributes to zerumbone-induced GBM cell apoptosis (Weng et al., 2012).

Ovarian and Cervical Cancer

A study by Abdelwahab et al., (2012) was designed to investigate the role of IL-6 and IL6 receptors in the cytotoxic effects of zerumbone in ovarian and cervical cancer cell lines (Caov-3 and HeLa, respectively). Exposure of both cancer cells to zerumbone or cisplatin demonstrated growth inhibition in a dose-dependent manner as determined by the MTT reduction assay. The studies conducted seem to suggest that zerumbone induces cell death by stimulating apoptosis better than cisplatin, based on the significantly higher percentage of apoptotic cells in zerumbone's treated cancer cells as compared to cisplatin. In addition, zerumbone and cisplatin arrest cancer cells at G2/M phase as analyzed by flow cytometry. These results indicated that zerumbone significantly decreased the levels of IL-6 secreted by both cancer cells.

This study concludes that the compound, zerumbone, inhibits cancer cell growth through the induction of apoptosis, arrests cell-cycle at G2/M phase and inhibits the secretion levels of IL-6 in both cancer cells.

References

Abdelwahab SI, Abdul AB, Zain ZN, Hadi AH. (2012). Zerumbone inhibits interleukin-6 and induces apoptosis and cell-cycle arrest in ovarian and cervical cancer cells. Int Immunopharmacol,12(4):594-602. doi: 10.1016/j.intimp.2012.01.014.


Aggarwal B, Prasad S, Sung B, Krishnan S, Guha S. (2013). Prevention and Treatment of Colorectal Cancer by Natural Agents From Mother Nature. Curr Colorectal Cancer Rep, 9(1):37-56.


Huang YC, Chao KS, Liao HF, Chen YJ. (2013). Targeting sonic hedgehog signaling by compounds and derivatives from natural products. Evid Based Complement Alternat Med, 2013:748587. doi: 10.1155/2013/748587.


Sun Y, Sheng Q, Cheng Y, et al. (2013). Zerumbone induces apoptosis in human renal cell carcinoma via Gli-1/Bcl-2 pathway. Pharmazie, 68(2):141-5.


Weng HY, Hsu MJ, Wang CC, et al. (2012). Zerumbone suppresses IKK α , Akt, and FOXO1 activation, resulting in apoptosis of GBM 8401 cells. J Biomed Sci, 19:86. doi: 10.1186/1423-0127-19-86.

Wogonin

Cancer:
Breast, lung (NSCLC), gallbladder carcinoma, osteosarcoma, colon, cervical

Action: Neuro-protective, anti-lymphangiogenesis, anti-angiogenic, anti-estrogenic, chemo-sensitizer, pro-oxidative, hypoxia-induced drug resistance, anti-metastatic, anti-tumor, anti-inflammatory

Wogonin is a plant monoflavonoid isolated from Scutellaria rivularis (Benth.) and Scutellaria baicalensis (Georgi).

Breast Cancer; ER+ & ER-

Effects of wogonin were examined in estrogen receptor (ER)-positive and -negative human breast cancer cells in culture for proliferation, cell-cycle progression, and apoptosis. Cell growth was attenuated by wogonin (50-200 microM), independently of its ER status, in a time- and concentration-dependent manner. Apoptosis was enhanced and accompanied by up-regulation of PARP and Caspase 3 cleavages as well as pro-apoptotic Bax protein. Akt activity was suppressed and reduced phosphorylation of its substrates, GSK-3beta and p27, was observed. Suppression of Cyclin D1 expression suggested the down-regulation of the Akt-mediated canonical Wnt signaling pathway.

ER expression was down-regulated in ER-positive cells, while c-ErbB2 expression and its activity were suppressed in ER-negative SK-BR-3 cells. Wogonin feeding to mice showed inhibition of tumor growth of T47D and MDA-MB-231 xenografts by up to 88% without any toxicity after 4 weeks of treatment. As wogonin was effective both in vitro and in vivo, our novel findings open the possibility of wogonin as an effective therapeutic and/or chemo-preventive agent against both ER-positive and -negative breast cancers, particularly against the more aggressive and hormonal therapy-resistant ER-negative types (Chung et al., 2008).

Neurotransmitter Action

Kim et al. (2011) found that baicalein and wogonin activated the TREK-2 current by increasing the opening frequency (channel activity: from 0.05 ± 0.01 to 0.17 ± 0.06 in baicalein treatment and from 0.03 ± 0.01 to 0.29 ± 0.09 in wogonin treatment), while leaving the single-channel conductance and mean open time unchanged. Baicalein continuously activated TREK-2, whereas wogonin transiently activated TREK-2. Application of baicalein and wogonin activated TREK-2 in both cell attached and excised patches, suggesting that baicalein and wogonin may modulate TREK-2 either directly or indirectly with different mechanisms. These results suggest that baicalein- and wogonin-induced TREK-2 activation help set the resting membrane potential of cells exposed to pathological conditions and thus may give beneficial effects in neuroprotection.

Anti-metastasic

The migration and invasion assay was used to evaluate the anti-metastasis effect of wogonin. Wogonin at the dose of 1–10 µM, which did not induce apoptosis, significantly inhibited the mobility and invasion activity of human gallbladder carcinoma GBC-SD cells. In addition, the expressions of matrix metalloproteinase (MMP)-2, MMP-9 and phosphorylated extracellular regulated protein kinase 1/2 (ERK1/2) but not phosphorylated Akt were dramatically suppressed by wogonin in a concentration-dependent manner. Furthermore, the metastasis suppressor maspin was confirmed as the downstream target of wogonin.

These findings suggest that wogonin inhibits cell mobility and invasion by up-regulating the metastasis suppressor maspin. Together, these data provide novel insights into the chemo-protective effect of wogonin, a main active ingredient of Chinese medicine Scutellaria baicalensis (Dong et al., 2011).

Anti-tumor and Anti-metastatic

Kimura & Sumiyoshi (2012) examined the effects of wogonin isolated from Scutellaria baicalensis roots on tumor growth and metastasis using a highly metastatic model in osteosarcoma LM8-bearing mice. Wogonin (25 and 50mg/kg, twice daily) reduced tumor growth and metastasis to the lung, liver and kidney, angiogenesis (CD31-positive cells), lymphangiogenesis (LYVE-1-positive cells), and TAM (F4/80-positive cell) numbers in the tumors of LM8-bearing mice. Wogonin (10–100µM) also inhibited increases in IL-1β production and cyclooxygenase (COX)-2 expression induced by lipopolysaccharide in THP-1 macrophages. The anti-tumor and anti-metastatic actions of wogonin may be associated with the inhibition of VEGF-C-induced lymphangiogenesis through a reduction in VEGF-C-induced VEGFR-3 phosphorylation by the inhibition of COX-2 expression and IL-1β production in Tumor-associated macrophages (TAMs).

Anti-inflammatory

Wogonin extracted from Scutellariae baicalensis and S. barbata is a cell-permeable and orally available flavonoid that displays anti-inflammatory properties. Wogonin is reported to suppress the release of NO by iNOS, PGE2 by COX-2, pro-inflammatory cytokines, and MCP-1 gene expression and NF-kB activation (Chen et al., 2008).

Hypoxia-Induced Drug Resistance (MDR)

Hypoxia-induced drug resistance is a major obstacle in the development of effective cancer therapy. The reversal abilities of wogonin on   hypoxia resistance were examined and the underlying mechanisms discovered. MTT assay revealed that hypoxia increased maximal 1.71-, 2.08-, and 2.15-fold of IC50 toward paclitaxel, ADM, and DDP in human colon cancer cell lines HCT116, respectively. Furthermore, wogonin showed strong reversal potency in HCT116 cells in hypoxia and the RF reached 2.05. Hypoxia-inducible factor-1α (HIF-1α) can activate the expression of target genes involved in glycolysis. Wogonin decreased the expression of glycolysis-related proteins (HKII, PDHK1, LDHA), glucose uptake, and lactate generation in a dose-dependent manner.

In summary, wogonin could be a good candidate for the development of a new multi-drug resistance (MDR) reversal agent and its reversal mechanism probably is due to the suppression of HIF-1α expression via inhibiting PI3K/Akt signaling pathway (Wang et al., 2013).

NSCLC

Wogonin, a flavonoid originated from Scutellaria baicalensis Georgi, has been shown to enhance TRAIL-induced apoptosis in malignant cells in in vitro studies. In this study, the effect of a combination of TRAIL and wogonin was tested in a non-small-cell lung cancer xenografted tumor model in nude mice. Consistent with the in vitro study showing that wogonin sensitized A549 cells to TRAIL-induced apoptosis, wogonin greatly enhanced TRAIL-induced suppression of tumor growth, accompanied with increased apoptosis in tumor tissues as determined by TUNEL assay.

The down-regulation of these antiapoptotic proteins was likely mediated by proteasomal degradation that involved intracellular reactive oxygen species (ROS), because wogonin robustly induced ROS accumulation and ROS scavengers butylated hydroxyanisole (BHA) and N-acetyl-L-cysteine (NAC) and the proteasome inhibitor MG132 restored the expression of these antiapoptotic proteins in cells co-treated with wogonin and TRAIL.

These results show for the first time that wogonin enhances TRAIL's anti-tumor activity in vivo, suggesting this strategy has an application potential for clinical anti-cancer therapy (Yang et al., 2013).

Colon Cancer

Following treatment with baicalein or wogonin, several apoptotic events were observed, including DNA fragmentation, chromatin condensation and increased cell-cycle arrest in the G1 phase. Baicalein and wogonin decreased Bcl-2 expression, whereas the expression of Bax was increased in a dose-dependent manner compared with the control. Furthermore, the induction of apoptosis was accompanied by an inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt in a dose-dependent manner.

The administration of baicalein to mice resulted in the inhibition of the growth of HT-29 xenografts without any toxicity following 5 weeks of treatment. The results indicated that baicalein induced apoptosis via Akt activation in a p53-dependent manner in the HT-29 colon cancer cells and that it may serve as a chemo-preventive or therapeutic agent for HT-29 colon cancer (Kim et al., 2012).

Breast

The involvement of insulin-like growth factor-1 (IGF-1) and estrogen receptor α (ERα) in the inhibitory effect of wogonin on the breast adenocarcinoma growth was determined. Moreover, the effect of wogonin on the angiogenesis of chick chorioallantoic membrane (CAM) was also investigated. The results showed wogonin and ICI182780 both exhibited a potent ability to blunt IGF-1-stimulated MCF-7 cell growth. Either of wogonin and ICI182780 significantly inhibited ERα and p-Akt expressions in IGF-1-treated cells. The inhibitory effect of wogonin showed no difference from that of ICI182780 on IGF-1-stimulated expressions of ERα and p-Akt. Meanwhile, wogonin at different concentrations showed significant inhibitory effect on CAM angiogenesis.

These results suggest the inhibitory effect of wogonin on breast adenocarcinoma growth via inhibiting IGF-1-mediated PI3K-Akt pathway and regulating ERα expression. Furthermore, wogonin has a strong anti-angiogenic effect on CAM model (Ma et al., 2012).

Chemoresistance; Cervical Cancer, NSCLC

Chemoresistance to cisplatin is a major limitation of cisplatin-based chemotherapy in the clinic. The combination of cisplatin with other agents has been recognized as a promising strategy to overcome cisplatin resistance. Previous studies have shown that wogonin (5,7-dihydroxy-8-methoxyflavone), a flavonoid isolated from the root of the medicinal herb Scutellaria baicalensis Georgi, sensitizes cancer cells to chemotheraputics such as etoposide, adriamycin, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and TNF.

In this study, the non-small-cell lung cancer cell line A549 and the cervical cancer cell line HeLa were treated with wogonin or cisplatin individually or in combination. It was found for the first time that wogonin is able to sensitize cisplatin-induced apoptosis in both A549 cells and HeLa cells as indicated by the potentiation of activation of caspase-3, and cleavage of the caspase-3 substrate PARP in wogonin and cisplatin co-treated cells.

Results provided important new evidence supporting the potential use of wogonin as a cisplatin sensitizer for cancer therapy (He et al., 2012).

References

Chen LG, Hung LY, Tsai KW, et al. (2008). Wogonin, a bioactive flavonoid in herbal tea, inhibits inflammatory cyclooxygenase-2 gene expression in human lung epithelial cancer cells. Mol Nutr Food Res. 52:1349-1357.


Chung H, Jung YM, Shin DH, et al. (2008). Anti-cancer effects of wogonin in both estrogen receptor-positive and -negative human breast cancer cell lines in vitro and in nude mice xenografts. Int J Cancer, 122(4):816-22.


Dong P, Zhang Y, Gu J, et al. (2011). Wogonin, an active ingredient of Chinese herb medicine Scutellaria baicalensis, inhibits the mobility and invasion of human gallbladder carcinoma GBC-SD cells by inducing the expression of maspin. J Ethnopharmacol, 137(3):1373-80. doi: 10.1016/j.jep.2011.08.005.


He F, Wang Q, Zheng XL, et al. (2012). Wogonin potentiates cisplatin-induced cancer cell apoptosis through accumulation of intracellular reactive oxygen species. Oncology Reports, 28(2), 601-605. doi: 10.3892/or.2012.1841.


Kim EJ, Kang D, Han J. (2011). Baicalein and wogonin are activators of rat TREK-2 two-pore domain K+ channel. Acta Physiologica, 202(2):185–192. doi: 10.1111/j.1748-1716.2011.02263.x.


Kim SJ, Kim HJ, Kim HR, et al. (2012). Anti-tumor actions of baicalein and wogonin in HT-29 human colorectal cancer cells. Mol Med Rep, 6(6):1443-9. doi: 10.3892/mmr.2012.1085.


Kimura Y & Sumiyoshi M. (2012). Anti-tumor and anti-metastatic actions of wogonin isolated from Scutellaria baicalensis roots through anti-lymphangiogenesis. Phytomedicine, 20(3-4):328-336. doi:10.1016/j.phymed.2012.10.016


Ma X, Xie KP, Shang F, et al. (2012). Wogonin inhibits IGF-1-stimulated cell growth and estrogen receptor α expression in breast adenocarcinoma cell and angiogenesis of chick chorioallantoic membrane. Sheng Li Xue Bao, 64(2):207-12.


Wang H, Zhao L, Zhu LT, et al. (2013). Wogonin reverses hypoxia resistance of human colon cancer HCT116 cells via down-regulation of HIF-1α and glycolysis, by inhibiting PI3K/Akt signaling pathway. Mol Carcinog. doi: 10.1002/mc.22052.


Yang L, Wang Q, Li D, et al. (2013). Wogonin enhances anti-tumor activity of tumor necrosis factor-related apoptosis-inducing ligand in vivo through ROS-mediated down-regulation of cFLIPL and IAP proteins. Apoptosis, 18(5):618-26. doi: 10.1007/s10495-013-0808-8.

Wedelia Chinensis Extract: indole-3-carboxylaldehyde, wedelolactone, luteolin, apigenin

Cancer: Prostate

Action: Anti-inflammatory

Wedelia chinensis [(Osbeck) Merr.], also known as Chinese Wedelia, is widespread throughout China, India, Indochina, Indonesia, Philippines, Japan and Malaysia.

Prostate Cancer; AR Negative

The in vivo efficacy and mechanisms of action of oral administration of a standardized extract of W. chinensis were analyzed in animals bearing a subcutaneous or orthotopic prostate cancer xenograft. Exposure of prostate cancer cells to W. chinensis extract induced apoptosis selectively in androgen receptor (AR)-positive prostate cancer cells and shifted the proportion in each phase of cell-cycle toward G(2)-M phase in AR-negative prostate cancer cells. Oral herbal extract (4 or 40 mg/kg/d for 24–28 days) attenuated the growth of prostate tumors in nude mice implanted at both subcutaneous (31% and 44%, respectively) and orthotopic (49% and 49%, respectively) sites. The tumor suppression effects were associated with increased apoptosis and lower proliferation in tumor cells as well as reduced tumor angiogenesis. The anti-tumor effect of W. chinensis extract was correlated with accumulation of the principal active compounds, wedelolactone, luteolin, and apigenin, in vivo.

Anti-cancer action of W. chinensis extract was due to three active compounds that inhibit the AR signaling pathway. Oral administration of W. chinensis extract impeded prostate cancer tumorigenesis. Future studies of W. chinensis for chemoprevention or complementary medicine against prostate cancer in humans are thus warranted (Tsai et al., 2009).

Prostate Cancer; AR Positive

Reduction of inflammation is an important anti-cancer therapeutic opportunity, and chronic inflammation can augment tumor development in various types of cancers, including prostate cancer (PCa). Four anti-proliferative phytocompounds in Wedelia chinensis have been identified through their ability to modulate the androgen receptor (AR) activation of transcription from prostate-specific antigen promoter in PCa cells. The 50% inhibition concentration values of indole-3-carboxylaldehyde, wedelolactone, luteolin and apigenin, were 34.9, 0.2, 2.4 and 9.8 muM, respectively.

A formula that combined the phytocompounds in the same proportions as in the herbal extract decreased the dosage of each compound required to achieve maximal AR inhibition. In correlation with the AR suppression effect, these active compounds specifically inhibited the growth of AR-dependent PCa cells and as a combination formula they also synergistically suppressed growth in AR-dependent PCa cells. Our study has identified synergistic effects of active compounds in W. chinensis and demonstrated their potential in PCa prevention and therapy (Lin et al., 2007).

References

Lin FM, Chen LR, Lin EH, et al. (2007). Compounds from Wedelia chinensis synergistically suppress androgen activity and growth in prostate cancer cells. Carcinogenesis, 28(12):2521-9.


Tsai CH, Lin FM, Yang YC, et al. (2009). Herbal extract of Wedelia chinensis attenuates androgen receptor activity and orthotopic growth of prostate cancer in nude mice. Clin Cancer Res, 15(17):5435-44.

Waltonitone

Cancer: Hepatocellular carcinoma, lung

Action: Induces cell-cycle arrest

Hepatocellular Carcinoma

Waltonitone, a new ursane-type pentacyclic triterpene isolated from Gentian waltonii Burkill, significantly inhibited human hepatocellular carcinoma BEL-7402 cells growth. Apoptosis induced by waltonitone was characterized by AO/EB staining and flow cytometric analysis. Apoptosis microarray assay results showed BCL-2 family genes might especially play an important role in waltonitone-induced apoptosis.

These studies demonstrated that waltonitone might inhibit hepatocellular carcinoma cell growth and induce apoptosis in vitro and in vivo (Zhang et al., 2009a).

Adenocarcinomic Lung Cancer

Natural compounds are a great source of cancer chemotherapeutic agents. An investigation by Zhang et al. (2012) indicates that waltonitone (WT), a triterpene extracted from medicinal plants, inhibits the proliferation of A549 cells in a concentration- and time-dependent manner.

Furthermore, the treatment of A549 cells with waltonitone altered the expression of miRNAs. It was found that 27 miRNAs were differentially expressed in waltonitone-treated cells, of which 8 miRNAs target genes related to cell proliferation and apoptosis.

In summary, results demonstrate that waltonitone has a significant inhibitory effect on the proliferation of A549 cells. It is possible that up-regulation of Bax/Bcl-2 and regulation of expression of specific miRNAs play a role in inhibition of proliferation and induction of apoptosis in waltonitone-treated cells. Waltonitone can be applied to lung carcinoma as a chemotherapeutic candidate.

Hepatocellular Carcinoma

WT could inhibit the BEL-7402 cells growth, induce the S-phase cell-cycle arrest, and activate Akt and ERK1/2 phosporylation. Moreover, the cell growth inhibition and S-phase cell-cycle arrest induction of WT on BEL-7402 cells could be blocked by Akt and ERK1/2 inhibitors.

WT induces cell-cycle arrest and inhibits the cell growth on BEL-7402 cells by modulating Akt and ERK1/2 phosphorylation (Zhang et al., 2009b).

References

Zhang Y, Zhang GB, Xu XM, et al. (2012). Suppression of growth of A549 lung cancer cells by waltonitone and its mechanisms of action. Oncol Rep, 28(3):1029-35. doi: 10.3892/or.2012.1869.


Zhang Z, Wang S, Qiu H, Duan C, Ding K, Wang Z (a). (2009). Waltonitone induces human hepatocellular carcinoma cells apoptosis in vitro and in vivo. Cancer Lett, 286(2):223-31. doi: 10.1016/j.canlet.2009.05.023.


Zhang Z, Duan C, Ding K, Wang Z (b). (2009). WT inhibit human hepatocellular carcinoma BEL-7402 cells growth by modulating Akt and ERK1/2 phosphorylation. Zhongguo Zhong Yao Za Zhi, 34(24):3277-80.

Ursolic acid

Cancer:
Glioblastoma, Lung, breast, colorectal, gastric, esophageal squamous carcinoma, prostate

Action:

Mitochondrial function, reactive oxygen species (ROS) generation.

Cytostatic, anti-inflammatory, chemo-prevention, COX-2 inhibitor, suppresses NF- κ B, induces IL-1 β , induces apoptosis

Ursolic acid, a pentacyclic triterpene acid found ubiquitously in the plant kingdom, including Rosmarinus officinalis (L.), Salvia officinalis (L.), Prunella vulgaris (L.), Psychotria serpens (L.) and Hyptis capitata (Jacq.). It has been shown to suppress the expression of several genes associated with tumorigenesis resulting in anti-inflammatory, anti-tumorigenic and chemo-sensitizing effects (Liu, 1995).

Glioblastoma Cancer

Ursolic acid, a natural pentacyclic triterpenic acid, possesses anticancer potential and diverse biological effects, but its correlation with glioblastoma multiforme cells and different modes of cell death is unclear. We studied the cellular actions of human GBM DBTRG-05MG cells after ursolic acid treatment and explored cell-selective killing effect of necrotic death as a cell fate.

Ursolic acid effectively reversed TMZ resistance and reduced DBTRG-05MG cell viability. Surprisingly, ursolic acid failed to stimulate the apoptotic and autophagic-related signaling networks. The necrotic death was characterized by annexin V/PI double-positive detection and release of HMGB1 and LDH. These ursolic acid-elicited responses were accompanied by ROS generation and glutathione depletion. Rapid mitochondrial dysfunction was paralleled by the preferential induction of necrosis, rather than apoptotic death. MPT is a phenomenon to provide the onset of mitochondrial depolarization during cellular necrosis. The opening of MPT pores that were mechanistically regulated by CypD, and ATP decline occurred in treated necrotic DBTRG-05MG cells. Cyclosporine A (an MPT pore inhibitor) prevented ursolic acid-provoked necrotic death and -involved key regulators.

The study by Lu et al., (2014) is the first to report that ursolic acid-modified mitochondrial function triggers defective death by necrosis in DBTRG-05MG cells rather than augmenting programmed death.

Gastric Cancer

Ursolic acid (UA) inhibits growth of BGC-803 cells in vitro in dose-dependent and time-dependent manner. Treated with UA in vivo, tumor cells can be arrested to G0/G1 stage. The apoptotic rate was significantly increased in tumor cells treated with UA both in vitro and in vivo. These results indicated that UA inhibits growth of tumor cells both in vitro and in vivo by decreasing proliferation of cells and inducing apoptosis (Wang et al., 2011).

Esophageal Squamous Carcinoma

The anti-neoplastic effects of combinations of anti-cancer drugs (5-fluorouracil, irinotecan and cisplatin) and triterpenes (ursolic acid, betulinic acid, oleanolic acid and a Japanese apricot extract (JAE) containing triterpenes) on esophageal squamous carcinoma cells were examined by the WST-8 (2-(2-methoxy- 4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt) assay in vitro and by an animal model in vivo. Triterpenes and JAE showed additive and synergistic cytotoxic effects, respectively, on esophageal squamous carcinoma cells (YES-2 cells) by combinational use of 5-fluorouracil. JAE and 5-fluorouracil induced cell-cycle arrest at G2/M phase and at S phase, respectively, and caused apoptosis in YES-2 cells.

These results suggest that triterpenes, especially JAE, are effective supplements for enhancing the chemotherapeutic effect of 5-fluorouracil on esophageal cancer (Yamai et al., 2009).

COX-2 Inhibitor

Subbaramaiah et al. (2000) studied the effects of ursolic acid, a chemo-preventive agent, on the expression of cyclooxygenase-2 (COX-2). Treatment with ursolic acid suppressed phorbol 12-myristate 13-acetate (PMA)-mediated induction of COX-2 protein and synthesis of prostaglandin E2. Ursolic acid also suppressed the induction of COX-2 mRNA by PMA. Increased activator protein-1 activity and the binding of c-Jun to the cyclic AMP response element of the COX-2 promoter, effects were blocked by ursolic acid (Subbaramaiah et al., 2000).

Lung Cancer, Suppresses NF- κB

In terms of general anti-cancer mechanism, ursolic acid has also been found to suppress NF-κB activation induced by various carcinogens through the inhibition of the DNA binding of NF-κB. Ursolic acid also inhibits IκBα kinase and p65 phosphorylation (Shishodia et al., 2003). In particular, ursolic acid has been found to block cell-cycle progression and trigger apoptosis in lung cancer and may hence act as a chemoprevention agent for lung cancer (Hsu et al., 2004).

Breast Cancer

Ursolic acid is a potent inhibitor of MCF-7 cell proliferation. This triterpene exhibits both cytostatic and cytotoxic activity. It exerts an early cytostatic effect at G1 followed by cell death. Results suggest that alterations in cell-cycle phase redistribution of MCF-7 human breast cancer, by ursolic acid, may significantly influence MTT (colorimetric assays) reduction to formazan (Es-Saady et al., 1996).

Induces IL-1 β

Interleukin (IL)-1beta is a pro-inflammatory cytokine responsible for the onset of a broad range of diseases, such as inflammatory bowel disease and rheumatoid arthritis. It has recently been found that aggregated ursolic acid (UA), a triterpene carboxylic acid, is recognized by CD36 for generating reactive oxygen species (ROS) via NADPH oxidase (NOX) activation, thereby releasing IL-1beta protein from murine peritoneal macrophages (pMphi) in female ICR mice. In the present study, Ikeda et al. (2008) investigated the ability of UA to induce IL-1beta production in pMphi from 4 different strains of female mice as well as an established macrophage line. In addition, the different susceptibilities to UA-induced IL-1beta release were suggested to be correlated with the amount of superoxide anion (O2-) generated from the 5 different types of Mphi.

Notably, intracellular, but not extracellular, O2- generation was indicated to play a major role in UA-induced IL-1beta release. Together, these results indicate that the UA-induced IL-1beta release was strain-dependent, and the expression status of CD36 and gp91phox is strongly associated with inducibility.

Induces Apoptosis: Breast Cancer, Prostate Cancer

Ursolic acid (UA) induced apoptosis and modulated glucocorticoid receptor (GR) and Activator Protein-1 (AP-1) in MCF-7 breast cancer cells. UA is a GR modulator and may be considered as a potential anti-cancer agent in breast cancer (Kassi et al., 2009).

UA induces apoptosis via both extrinsic and intrinsic signaling pathways in cancer cells (Kwon et al., 2010). In PC-3 cells, UA inhibits proliferation by activating caspase-9 and JNK as well as FasL activation and Akt inhibition (Zhang et al., 2010). A significant proliferation inhibition and invasion suppression in both a dose- and time-dependent manner is observed in highly metastatic breast cancer MDA-MB-231 cells; this inhibition is related to the down-regulation of MMP2 and u-PA expression (Yeh et al., 2010).

Ursolic acid additionally stimulates the release of cytochrome C in HL-60 cells and breast cancer MCF-7 cells. The activation of caspase-3 in a cytochrome C-dependent manner induces apoptosis via the mitochondrial pathway (Qian et al., 2011).

Colorectal Cancer

Ursolic acid (UA) has strong anti-proliferative and apoptotic effects on human colon cancer HT-29 cells. UA dose-dependently decreased cell proliferation and induced apoptosis, accompanied by activation of caspase 3, 8 and 9. The effects may be mediated by alkaline sphingomyelinase activation (Andersson et al., 2003).

Ursolic acid (UA), using the colorectal cancer (CRC) mouse xenograft model and the HT-29 human colon carcinoma cell line, was evaluated for its efficacy against tumor growth in vivo and in vitro, and its molecular mechanisms were investigated. It was found that UA inhibits cancer growth without apparent toxicity. Furthermore, UA significantly suppresses the activation of several CRC-related signaling pathways and alters the expression of critical target genes. These molecular effects lead to the induction of apoptosis and inhibition of cellular proliferation.

These data demonstrate that UA possesses a broad range of anti-cancer activities due to its ability to affect multiple intracellular targets, suggesting that UA could be a novel multipotent therapeutic agent for cancer treatment (Lin et al., 2013).

Action: Anti-tumor, inhibits tumor cell migration and invasion

Ursolic acid (UA) is a sort of pentacyclic triterpenoid carboxylic acid purified from natural plant. UA has a series of biological effects such as sedative, anti-inflammatory, anti-bacterial, anti-diabetic, antiulcer, etc. It is discovered that UA has a broad-spectrum anti-tumor effect in recent years, which has attracted more and more scholars’ attention. This review explained anti-tumor actions of UA, including (1) the protection of cells’ DNA from different damages; (2) the anti-tumor cell proliferation by the inhibition of epidermal growth factor receptor mitogen-activated protein kinase signal or of FoxM1 transcription factors, respectively; (3) antiangiogenesis, (4) the immunological surveillance to tumors; (5) the inhibition of tumor cell migration and invasion; (6) the effect of UA on caspase, cytochromes C, nuclear factor kappa B, cyclooxygenase, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or mammalian target of rapamycin signal to induce tumor cell apoptosis respectively, and etc. Moreover, UA has selective toxicity to tumor cells, basically no effect on normal cells.

Inhibition of Epidermal Growth Factor Receptor/ Mitogen-Activated Protein Kinase Pathway
Activation of mitogen-activated protein kinase (MAPK) allows cell excessive proliferation involved in the carcinogenic process (Park et al., 1999). Subfamilies of MAPK, metastasis.(24) Otherwise, UA suppresses the activation of NF-κB and down-regulation of the MMP-9 protein, which in turn contributes to its inhibitory effects on IL-1β or tumor necrosis factor α (TNF-α)-induced C6 glioma cell invasion (Huang et al., 2009).

U A suppresses inter cellular adhesion molecules-1 (ICAM-1) expression of non-small cell lung cancer (NSCLC) H3255, A549, Calu-6 cells, and significantly inhibits fibronectin expression in a concentration-dependent way. UA significantly suppresses the expression of MMP-9 and MMP-2 and inhibits protein kinase C activity in test cell lines, at the same time, UA reduces cell invasion in a concentration-dependent manner (Huang et al., 2011).

Cancer: Multiple myeloma

Action: Anti-inflammatory, down-regulates STAT3

When dealing with the multiple myeloma, by the way of activating the proto-oncogene-mediated c-Src, JAK1, JAK2, and ERKs, ursolic acid (UA) can not only inhibit the expression of IL-6-induced STAT3 but also downregulates the STAT3 by regulating gene products, such as cyclin D1, Bcl-2, Bcl-xL, surviving, Mcl-1 and VEGF. Above all, UA can inhibit the proliferation of multiple myeloma cells and induce apoptosis, to arrest cells at G1 phase and G0 phase of cell cycle (Pathak et al., 2007).

The essential oils of ginger (Zingiber officinale) and turmeric (Curcuma longa) contain a large variety of terpenoids, some of which possess anticancer, anti-ulcer, and antioxidant properties. Despite their importance, only four terpene synthases have been identified from the Zingiberaceae family: (+)-germacrene D synthase and (S)-β-bisabolene synthase from ginger rhizome, and α-humulene synthase and β-eudesmol synthase from shampoo ginger (Zingiber zerumbet) rhizome (Koo et al., 2012).

Cancer: Colorectal

Wong et al., have previously reported Signal Transducer and Activator of Transcription 3 (STAT3) to be constitutively activated in aldehyde dehydrogenase (ALDH)(+)/cluster of differentiation-133 (CD133)(+) colon cancer-initiating cells. In the present study they tested the efficacy of inhibiting STAT3 signaling in human colon cancer-initiating cells by ursolic acid (UA), which exists widely in fruits and herbs.

ALDH(+)/CD133(+) colon cancer-initiating cells. UA also reduced cell viability and inhibited tumor sphere formation of colon cancer-initiating cells, more potently than two other natural compounds, resveratrol and capsaicin. UA also inhibited the activation of STAT3 induced by interleukin-6 in DLD-1 colon cancer cells. Furthermore, daily administration of UA suppressed HCT116 tumor growth in mice in vivo.

Their results suggest STAT3 to be a target for colon cancer prevention. UA, a dietary agent, might offer an effective approach for colorectal carcinoma prevention by inhibiting persistently activated STAT3 in cancer stem cells.

References

 

Andersson D, Liu JJ, Nilsson A, Duan RD. (2003). Ursolic acid inhibits proliferation and stimulates apoptosis in HT29 cells following activation of alkaline sphingomyelinase. Anti-cancer Research, 23(4):3317-22.

 

Es-Saady D, Simon A, Jayat-Vignoles C, Chulia AJ, Delage C. (1996). MCF-7 cell-cycle arrested at G1 through ursolic acid, and increased reduction of tetrazolium salts. Anti-cancer Research, 16(1):481-6.

 

Hsu YL, Kuo PL, Lin CC. (2004). Proliferative inhibition, cell-cycle dysregulation, and induction of apoptosis by ursolic acid in human non-small-cell lung cancer A549 cells. Life Sciences, 75(19), 2303-2316.

 

Ikeda Y, Murakami A, Ohigashi H. (2008). Strain differences regarding susceptibility to ursolic acid-induced interleukin-1beta release in murine macrophages. Life Sci, 83(1-2):43-9. doi: 10.1016/j.lfs.2008.05.001.

 

Kassi E, Sourlingas TG, Spiliotaki M, et al. (2009). Ursolic Acid Triggers Apoptosis and Bcl-2 Down-regulation in MCF-7 Breast Cancer Cells. Cancer Investigation, 27(7):723-733. doi:10.1080/07357900802672712.

 

Kwon SH, Park HY, Kim JY, et al. (2010). Apoptotic action of ursolic acid isolated from Corni fructus in RC-58T/h/SA#4 primary human prostate cancer cells. Bioorg Med Chem Lett, 20:6435–6438. doi: 10.1016/j.bmcl.2010.09.073.

 

Lin J, Chen Y, Wei L, et al. (2013). Ursolic acid promotes colorectal cancer cell apoptosis and inhibits cell proliferation via modulation of multiple signaling pathways. Int J Oncol, (4):1235-43. doi: 10.3892/ijo.2013.2040.

 

Liu J. (1995). Pharmacology of oleanolic acid and ursolic acid. Journal of Ethnopharmacology, 49(2), 57-68.

 

Shishodia S, Majumdar S, Banerjee S, Aggarwal BB. (2003). Ursolic Acid Inhibits Nuclear Factor-OE ∫ B Activation Induced by Carcinogenic Agents through Suppression of IOE ∫ BOE± Kinase and p65 Phosphorylation. Cancer Research, 63(15), 4375-4383.

 

Subbaramaiah K, Michaluart P, Sporn MB, Dannenberg AJ. (2000). Ursolic Acid Inhibits Cyclooxygenase-2 Transcription in Human Mammary Epithelial Cells. Cancer Res, 60:2399

 

Qian J, Li X, Guo GY, et al. (2011). Potent anti-tumor activity of emodin on CNE cells in vitro through apoptosis. J Zhejiang Sci-Tech Univ (Chin), 42:756-759

 

Wang X, Zhang F, Yang L, et al. (2011). Ursolic Acid Inhibits Proliferation and Induces Apoptosis of Cancer Cells In Vitro and In Vivo. J Biomed Biotechnol, 2011:419343. doi: 10.1155/2011/419343.

 

Yamai H, et al. (2009). Triterpenes augment the inhibitory effects of anti-cancer drugs on growth of human esophageal carcinoma cells in vitro and suppress experimental metastasis in vivo. Int J Cancer, 125(4):952-60. doi: 10.1002/ijc.24433.

 

Yeh CT, Wu CH, Yen GC. (2010). Ursolic acid, a naturally occurring triterpenoid, suppresses migration and invasion of human breast cancer cells by modulating c-Jun N-terminal kinase, Akt and mammalian target of rapamycin signaling. Mol Nutr Food Res, 54:1285–1295. doi: 10.1002/mnfr.200900414.

 

Zhang Y, Kong C, Zeng Y, et al. (2010). Ursolic acid induces PC-3 cell apoptosis via activation of JNK and inhibition of Akt pathways in vitro. Mol Carcinog, 49:374–385.

 

Zhang LL, Wu BN, Lin Y et al. (2014) Research Progress of Ursolic Acid’s Anti-Tumor Actions. Chin J Integr Med 2014 Jan;20(1):72-79

 

Reference

 

Huang HC, Huang CY, Lin-Shiau SY, Lin JK. Ursolic acid inhibits IL-1beta or TNF-alpha-induced C6 glioma invasion through suppressing the association ZIP/p62 with PKC-zeta and downregulating the MMP-9 expression. Mol Carcinog 2009;48:517-531

 

Huang CY, Lin CY, Tsai CW, Yin MC. Inhibition of cell proliferation, invasion and migration by ursolic acid in human lung cancer cell lines. Toxicol In Vitro 2011;25:1274-1280.

 

Park KS, Kim NG, Kim JJ, Kim H, Ahn YH, Choi KY. Differential regulation of MAP kinase cascade in human colorectal tumorigenesis. Br J Cancer 1999;81:1116-1121.

 

 

Pathak AK, Bhutani M, Nair AS, Ahn KS, Chakraborty A, Kadara H, et al. Ursolic acid inhibits STAT3 activation pathway leading to suppression of proliferation and chemosensitization of human multiple myeloma cells. Mol Cancer Res 2007;5:943-595

 

 

Koo HJ, Gang DR. (2012) Suites of terpene synthases explain differential terpenoid production in ginger and turmeric tissues. PLoS One. 2012;7(12):e51481. doi: 10.1371/journal.pone.0051481.

 

 

Wang W, Zhao C, Jou D, Lü J, Zhang C, Lin L, Lin J. (2013) Ursolic acid inhibits the growth of colon cancer-initiating cells by targeting STAT3. Anticancer Res. 2013 Oct;33(10):4279-84.

 
Lu C-C, Huang B-R, Liao P-J, Yen G-C. Ursolic acid triggers a non-programmed death (necrosis) in human glioblastoma multiforme DBTRG-05MG cells through MPT pore opening and ATP decline. Molecular Nutrition & Food Research. 2014 DOI: 10.1002/mnfr.201400051

 

 

 

Trichosanthin (TCS)

Cancer:
Lung, leukemia, cervical, breast, leukemia/lymphoma, choriocarcinoma

Action: Demethylation, anti-tumor immunity, induces apoptosis

Breast

The 27-kDa trichosanthin (TCS) is a ribosome inactivating protein purified from tubers of the Chinese herbal plant Trichosanthes kirilowii Maximowicz (tian hua fen). Fang et al. (2012) extended the potential medicinal applications of TCS from HIV, ferticide, hydatidiform moles, invasive moles, to breast cancer. They found that TCS manifested anti-proliferative and apoptosis-inducing activities in both estrogen-dependent human MCF-7 cells and estrogen-independent MDA-MB-231 cells.

Leukemia/Lymphoma, Cervical Cancer, Choriocarcinoma

Trichosanthin (TCS) as a midterm abortifacient medicine has been used clinically in traditional Chinese medicine for centuries. Additionally, TCS manifests a host of pharmacological properties, for instance, anti-HIV and anti-tumor activities. TCS has been reported to inhibit cell growth of a diversity of cancers, including cervical cancer, choriocarcinoma, and leukemia/lymphoma, etc. Sha et al. (2013) reviewed the various anti-tumor activities of TCS and the mechanism of apoptosis it induced in these tumor cells.

Lung, Anti-tumor Immunity

In this study, Cai et al. (2011) focused on the effect of TCS on murine anti-tumor immune response in the 3LL Lewis lung carcinoma tumor model and explored the possible molecular pathways involved. In addition to inhibiting cell proliferation and inducing apoptosis in the 3LL tumor, TCS retarded tumor growth and prolonged mouse survival more significantly in C57BL/6 immunocompetent mice than in nude mice. Data demonstrate that TCS not only affects tumor cells directly, but also enhances anti-tumor immunity via the interaction between TSLC1 and CRTAM.

Induce Apoptosis

Over the past 20 years, TCS has been the subject of much research because of its potential anti-tumor activities. Many reports have revealed that TCS is cytotoxic in a variety of tumor cell lines in vitro and in vivo. Monoclonal antibody-conjugated TCS could enhance its anti-tumor efficacy; thus, TCS is considered to be a potential biological agent for cancer treatment. TCS is able to inhibit protein synthesis and consequently induce necrosis. Recent studies have demonstrated that TCS does indeed induce apoptosis in several tumor cell lines (Li et al., 2010).

Leukemia

Cultured human leukemia K562 cells treated with trichosanthin were examined. Analysis of the cells by single laser flow cytometry showed the sub-G1 peak. DNA extracted from these cells formed a characteristic 'ladder' on agarose gel electrophoresis. Under electromicroscope, typical morphological changes of apoptosis were also observed. From all of these findings, Kang et al. (1998) concluded that trichosanthin was able to induce apoptosis in K562 cells.

Cervical Cancer, Demethylation Activity

Epigenetic silencing of tumor suppressor genes is a well-established oncogenic process and the reactivation of tumor suppressor genes that have been silenced by promoter methylation is an attractive molecular target for cancer therapy. In this study, Huang et al. (2012) investigated the demethylation activity of trichosanthin and its possible mechanism of action in cervical cancer cell lines. HeLa human cervical adenocarcinoma and CaSki human cervical squamous carcinoma cells were treated with various concentrations (0, 20, 40 and 80 µg/ml) of TCS for 48 hours and the mRNA and protein expression levels of the tumor suppressor genes adenomatous polyposis coli (APC) and tumor suppressor in lung cancer 1 (TSLC1) were detected using reverse transcription (RT)-PCR and Western blotting, respectively.

TCS induced demethylation in HeLa and CaSki cells and this demethylation activity was accompanied by the decreased expression of DNMT1 and reduced DNMT1 enzyme activity. Results demonstrate for the first time that TCS is capable of restoring the expression of methylation-silenced tumor suppressor genes and is potentially useful as a demethylation agent for the clinical treatment of human cervical cancer.

References:

Cai YC, Xiong SD, Zheng YJ, et al. (2011). Trichosanthin enhances anti-tumor immune response in a murine Lewis lung cancer model by boosting the interaction between TSLC1 and CRTAM. Cellular & Molecular Immunology, (2011)8:359–367. doi:10.1038/cmi.2011.12.


Fang EF, Zhang CZ, Zhang L, et al. (2012). Trichosanthin inhibits breast cancer cell proliferation in both cell lines and nude mice by promotion of apoptosis. PLoS One, 7(9):e41592. doi: 10.1371/journal.pone.0041592.


Huang Y, Song H, Hu H, et al. (2012). Trichosanthin inhibits DNA methyltransferase and restores methylation-silenced gene expression in human cervical cancer cells. Mol Med Rep, 6(4):872-8. doi: 10.3892/mmr.2012.994.


Kong M, Ke YB, Zhou MY, et al. (1998). Study on Trichosanthin induced apoptosis of leukemia K562 cells. Shi Yan Sheng Wu Xue Bao, 31(3):233-43.


Li M, Li X, Li JC. (2010). Possible mechanisms of trichosanthin-induced apoptosis of tumor cells. Anat Rec (Hoboken), 293(6):986-92. doi: 10.1002/ar.21142.


Sha O, Niu J, Ng TB, et al. (2013). Anti-tumor action of trichosanthin, a type 1 ribosome-inactivating protein, employed in traditional Chinese medicine: a mini review. Cancer Chemother Pharmacol, 71(6):1387-93. doi: 10.1007/s00280-013-2096-y.

Theaflavin-2

Cancer: none noted

Action: Anti-inflammatory, induces apoptosis

Apoptosis

Theaflavin-2 (TF-2), a major component of black tea extract (Camellia sinensis [(L.) Kuntze]), induces apoptosis of human colon cancer cells and suppresses serum-induced cyclooxygenase-2 (COX-2) expression 1. The mechanisms of TF-2 for the activation of apoptosis were examined, and the impact on inflammatory genes in a broader panel of cells was evaluated and tested for whether topical anti-inflammatory effects could be observed in vivo. TF-2 triggered apoptosis in five other transformed cancer cell lines, inducing cell shrinkage, membrane blebbing, and mitochondrial clustering within 3 h of treatment. Topical application with TF-2 significantly reduced ear edema and produced a pattern of gene down-regulation similar to that observed in the cell model. These results suggest that the anti-inflammatory and pro-apoptotic activity of TF-2 may be exploited therapeutically in cancer and other diseases associated with inflammation (Gosslau et al., 2011).

Reference

Gosslau A, En Jao DL, Huang MT et al. (2011). Effects of the black tea polyphenol theaflavin-2 on apoptotic and inflammatory pathways in vitro and in vivo. Molecular Nutrition & Food Research, 55(2):198–208. doi: 10.1002/mnfr.201000165

Tetrandrine

Cancer:
Breast, leukemia, Oral cancer, renal cell carcinoma, colon

Action: Anti-inflammatory, tamoxifen resistance, cell-cycle arrest, anti-metastatic, MDR

Tetrandrine, a bisbenzylisoquinoline alkaloid from the root of Stephania tetrandra (S, Moore), exhibits a broad range of pharmacological activities, including immunomodulating, anti-hepatofibrogenetic, anti-inflammatory, anti-arrhythmic, anti-portal hypertension, anti-cancer and neuro-protective activities (Li, Wang, & Lu, 2001; Ji, 2011). Tetrandrine has anti-inflammatory and anti-fibrogenic actions, which make tetrandrine and related compounds potentially useful in the treatment of lung silicosis, liver cirrhosis, and rheumatoid arthritis (Kwan & Achike, 2002).

Tetrandrine generally presents its anti-cancer effects in micromolar concentrations. Tetrandrine induces different phases of cell-cycle arrest, depends on cancer cell types (Kuo & Lin, 2003; Meng et al., 2004; Ng et al., 2006) and also induces apoptosis in many human cancer cells, including leukemia, bladder, colon, hepatoma, and lung (Lai et al., 1998; Ng et al., 2006; Wu et al., 2010; He et al., 2011).

In vivo experiments have also demonstrated the potential value of tetrandrine against cancer activity. For example, the survival of mice subcutaneously inoculated with CT-26 cells is extended after daily oral gavage of 50 mg/kg or 150  mg/kg of tetrandrine (Wu et al., 2010). Tetrandrine also inhibits the expression of VEGF in glioma cells, has cytotoxic effect on ECV304 human umbilical vein endothelial cells, and suppresses in vivo angiogenesis (Chen et al., 2009). Tetrandrine-treated mice (10  mg/kg/day) have fewer metastases than vehicle-treated mice, and no acute toxicity or obvious changes can be observed in the body weight of both groups (Chang et al., 2004).

Leukemia

Tetrandrine citrate is a novel orally active tetrandrine salt with potent anti-tumor activity against IM-resistant K562 cells and chronic myeloid leukemia. Tetrandrine citrate-induced growth inhibition of leukemia cells may be involved in the depletion of p210Bcr-Abl mRNA and β-catenin protein (Xu et al., 2012).

Comparative in vitro studies show that tetrandrine has significantly greater suppressive effects on adherence, locomotion and 3H-deoxyglucose uptake of neutrophils, as well as the mitogen-induced lymphocyte responses and mixed lymphocyte reactions. By contrast, berbamine demonstrated a significantly greater capacity for inhibition of NK cell cytotoxicity. These results show that tetrandrine is superior to berbamine in most aspects of anti-inflammatory and immunosuppressive activity.

Since these two alkaloids differ by only one substitution in the side chain of one of the benzene rings, these findings may provide further insight into structure-activity relationships and clues to the synthesis and development of active analogues of this promising class of drugs for the treatment of chronic inflammatory diseases (Li et al., 1989).

MDR, Breast Cancer

Tetrandrine also has been found to have extensive pharmacological activity, including positive ion channel blockade and inhibition of multiple drug resistance proteins. These activities are very similar to that of salinomycin, a known drug targeting breast cancer initiation cells (TICs). Tetrandrine has been probed for this activity, targeting of breast cancer TICs. SUM-149, an inflammatory breast cancer cell line, and SUM-159, a non-inflammatory metaplastic breast cancer cell line, were used in these studies.

In summary, tetrandrine demonstrates significant efficacy against in vitro surrogates for inflammatory and aggressive breast cancer TICs (Xu et al., 2011).

Leukemia, MDR

The potential mechanism of the chemotherapy resistance in acute myeloid leukemia (AML) is the multi-drug resistance (MDR-1) gene product P-glycoprotein (P-gp), which is often overexpressed in myeloblasts from acute myeloid leukemia. In a multi-center clinical trial, 38 patients with poor risk forms of AML were treated with tetrandrine (TET), a potent inhibitor of the MDR-1 efflux pump, combined with daunorubicin (DNR), etoposide and cytarabine (TET–DEC). Overall, postchemotherapy marrow hypoplasia was achieved in 36 patients. Sixteen patients (42%) achieved complete remission or restored chronic phase, 9 achieved partial remission (PR) and 13 failed therapy.

These data indicate that TET–DEC was relatively well tolerated in these patients with poor risk AML, and had encouraging anti-leukemic effects (Xu et al., 2006).

Tamoxifen

Tetrandrine (Tet) had a significant reversal of tamoxifen drug resistance breast cancer cells resistant (MCF-7/TAM). The non-cytotoxic dose (0. 625 microg/mL) reversed the resistance by 2.0 folds. MRP1 was reduced at gene (P <0.05) and protein levels when Tet effected on MCF-7ITAM cells. Tet could reverse the drug resistance of MCF-7/TAM cells, and the reverse mechanism may be related to down-regulating MRP1 expression (Chen & Chen, 2013).

Colon Cancer

Tetrandrine (TET) exhibits anti-colon cancer activity. Gao et al. (2013) compared TET with chemotherapy drug doxorubicin in 4T1 tumor-bearing BALB/c mice model and found that TET exhibits anti-cancer metastatic and anti-angiogenic activities better than those of doxorubicin. Local blood perfusion of tumor was markedly decreased by TET after 3 weeks.

Mechanistically, TET treatment leads to a decrease in p-ERK level and an increase in NF- κ B levels in HUVECs. TET also regulated metastatic and angiogenic related proteins, including vascular endothelial growth factor, hypoxia-inducible factor-1 α, integrin β 5, endothelial cell specific molecule-1, and intercellular adhesion molecule-1 in vivo (Chen & Chen, 2013).

Tetrandrine significantly decreased the viability of SAS human oral cancer cells in a concentration- and time-dependent manner. Tet induced nuclear condensation, demonstrated by DAPI staining, and induces apoptosis and autophagy of SAS human cancer cells via caspase-dependent and LC3-I and LC3-II “American Typewriter”; “American Typewriter”;‑dependent pathways (Huang et al., 2013).

Renal Cancer

Tetrandrine treatment showed growth-inhibitory effects on human renal cell carcinoma (RCC) in a time- and dose-dependent manner. Additionally, flow cytometric studies revealed that tetrandrine was capable of inducing G1 cell-cycle arrest and apoptosis in RCC cells. Tet triggered apoptosis and cell-cycle arrest in RCC 786-O, 769-P and ACHN cells in vitro; these events are associated with caspase cascade activation and up-regulation of p21 and p27 (Chen, Ji, & Chen, 2013).

References

Chang KH, Liao HF, Chang HH, et al. (2004). Inhibitory effect of tetrandrine on pulmonary metastases in CT26 colorectal adenocarcinoma-bearing BALB/c mice. American Journal of Chinese Medicine, 32(6):863–872.


Chen HY, Chen XY. (2013). Tetrandrine reversed the resistance of tamoxifen in human breast cancer MCF-7/TAM cells: an experimental research. Zhongguo Zhong Xi Yi Jie He Za Zhi, 33(4):488-91.


Chen T, Ji B, Chen Y. (2013). Tetrandrine triggers apoptosis and cell-cycle arrest in human renal cell carcinoma cells. J Nat Med.


Chen Y, Chen JC, Tseng SH. (2009). Tetrandrine suppresses tumor growth and angiogenesis of gliomas in rats. International Journal of Cancer, 124(10):2260–2269.


Gao JL, Ji X, He TC, et al. (2013). Tetrandrine Suppresses Cancer Angiogenesis and Metastasis in 4T1 Tumor-bearing Mice. Evid Based Complement Alternat Med, 2013:265061. doi: 10.1155/2013/265061.


He BC, Gao JL, Zhang BQ, et al. (2011). Tetrandrine inhibits Wnt/beta-catenin signaling and suppresses tumor growth of human colorectal cancer. Molecular Pharmacology, 79(2):211–219.


Huang AC, Lien JC, Lin MW, et al. (2013). Tetrandrine induces cell death in SAS human oral cancer cells through caspase activation-dependent apoptosis and LC3-I and LC3-II activation-dependent autophagy. Int J Oncol, 43(2):485-94. doi: 10.3892/ijo.2013.1952.


Ji YB. (2011). Active Ingredients of Traditional Chinese Medicine: Pharmacology and Application, People's Medical Publishing House Co., LTD, 2011.


Kwan CY, Achike FI. (2002). Tetrandrine and related bis-benzylisoquinoline alkaloids from medicinal herbs: cardiovascular effects and mechanisms of action. Acta Pharmacol Sin, 23(12):1057-68.


Kuo PL and Lin CC. (2003). Tetrandrine-induced cell-cycle arrest and apoptosis in Hep G2 cells. Life Sciences, 73(2):243–252.


Lai YL, Chen YJ, Wu TY, et al. (1998). Induction of apoptosis in human leukemic U937 cells by tetrandrine. Anti-Cancer Drugs, 9(1):77–81.


Li SY, Ling LH, The BS, Seow WK and Thong YH. (1989). Anti-inflammatory and immunosuppressive properties of the bis-benzylisoquinolines: In vitro comparisons of tetrandrine and berbamine. International Journal of Immunopharmacology, 11(4):395-401 doi:10.1016/0192-0561(89)90086-6.


Meng LH, Zhang H, Hayward L, et al. (2004). Tetrandrine induces early G1 arrest in human colon carcinoma cells by down-regulating the activity and inducing the degradation of G 1-S-specific cyclin-dependent kinases and by inducing p53 and p21Cip1. Cancer Research, 64(24):9086–9092.


Ng LT, Chiang LC, Lin YT, and C. C. Lin CC. (2006). Anti-proliferative and apoptotic effects of tetrandrine on different human hepatoma cell lines. American Journal of Chinese Medicine, 34(1):125–135.


Wu JM, Chen Y, Chen JC, Lin TY, Tseng SH. (2010). Tetrandrine induces apoptosis and growth suppression of colon cancer cells in mice. Cancer Letters, 287(2):187–195.


Xu WL, Shen HL, Ao ZF, et al. (2006). Combination of tetrandrine as a potential-reversing agent with daunorubicin, etoposide and cytarabine for the treatment of refractory and relapsed acute myelogenous leukemia. Leukemia Research, 30(4):407-413.


Xu W, Debeb BG, Lacerda L, Li J, Woodward WA. (2011). Tetrandrine, a Compound Common in Chinese Traditional Medicine, Preferentially Kills Breast Cancer Tumor Initiating Cells (TICs) In Vitro. Cancers, 3:2274-2285; doi:10.3390/cancers3022274.


Xu XH, Gan YC, Xu GB, et al. (2012). Tetrandrine citrate eliminates imatinib-resistant chronic myeloid leukemia cells in vitro and in vivo by inhibiting Bcr-Abl/ β-catenin axis. Journal of Zhejiang University SCIENCE B, 13(11):867-874.

Teng Long Bu Zhong Tang

Cancer: Colon

Action: Induces apoptosis, inhibits angiogenesis

CT26 colon carcinoma was established in BALB/c mice and treated with Teng Long Bu Zhong Tang (TLBZT), 5-Fu, or TLBZT plus 5-Fu. The tumor volumes were observed. TLBZT significantly inhibited CT26 colon carcinoma growth. TLBZT elicited apoptosis in CT26 colon carcinoma, accompanied by Caspase-3, 8, and 9 activation and PARP cleavage, and down-regulation of XIAP and Survivin. TLBZT also induced cell senescence in CT26 colon carcinoma, with concomitant up-regulation of p16 and p21 and down-regulation of RB phosphorylation.

In addition, angiogenesis and VEGF expression in CT26 colon carcinoma was significantly inhibited by TLBZT treatment. TLBZT exhibited significant anti-cancer effect, and enhanced the effects of 5-Fu in CT26 colon carcinoma, which may correlate with induction of apoptosis and cell senescence, and angiogenesis inhibition (Deng et al., 2013).

Reference

Deng S, Hu B, An HM, et al. (2013). Teng-Long-Bu-Zhong-Tang, a Chinese herbal formula, enhances anti-cancer effects of 5 – Fluorouracil in CT26 colon carcinoma. BMC Complement Altern Med, 13:128. doi: 10.1186/1472-6882-13-128.

Subamolide A

Cancer: Lung, urothelial carcinoma

Action: Increases cellular reactive oxygen species (ROS) production, decreases glutathione level

Lung Cancer

Subamolide A is isolated from Cinnamomum subavenium (Miq.). The anti-cancer effects of subamolide A (Sub-A) were investigated on human nonsmall cell lung cancer cell lines A549 and NCI-H460. Treatment of cancer cells with Sub-A resulted in decreased cell viability of both lung cancer cell lines. Sub-A induced lung cancer cell death by triggering mitotic catastrophe with apoptosis. It triggered oxidant stress, indicated by increased cellular reactive oxygen species (ROS) production and decreased glutathione level.

Therefore, Sub-A may be a novel anti-cancer agent for the treatment of non-small-cell lung cancer. Human lung cancer cells A549 and NCI-H460 are highly sensitive to Sub-A-induced mitotic catastrophe and apoptosis, mainly via ROS elevation that induces ATM and ATF3 activation, subsequently leading to p53-mediated cell death. Sub-A also causes cell growth inhibition in an in vivo xenograft model. The elucidated molecular bases and processes may provide a new strategy for developing more effective chemotherapeutic regimens for lung cancer treatment (Hung et al., 2013).

Urothelial Carcinoma

A study by Liu et al. (2011) demonstrated that subamolide A triggered the mitochondria-dependent apoptotic pathways and p53 and ERK1/2 activation in the human urothelial carcinoma cell line NTUB1. In addition, subamolide A synergistically enhanced cytotoxic effect of CDDP and Gem in NTUB1. These data suggested that subamolide A exhibited a potent anti-proliferation activity.

Subamolide A selectively induced apoptosis in two cancerous human urothelial carcinoma cell lines (NTUB1 and T24) in comparison with normal immortalized uroepithelial cells (SV-HUC-1). Subamolide A reduced mitochondrial membrane potential (Δψm) and caused apoptosis of NTUB1 cells. Subamolide A increased Bax/Bcl-2 ratios, the amount of cytochrome c released from the mitochondria, caspase-3 and PARP cleavage, activated p53 and ERK1/2 and ultimately led to apoptosis in NTUB1 cells. Furthermore, a higher dose (10µM) of subamolide A synergistically enhanced the cytotoxicity of cisplatin and gemcitabine in NTUB1 cells.

References

Hung JY, Wen CW, Hsu YL, et al. (2013). Subamolide A Induces Mitotic Catastrophe Accompanied by Apoptosis in Human Lung Cancer Cells. Evidence-Based Complementary and Alternative Medicine, 2013: 828143. doi:10.1155/2013/828143.


Liu CH, Chen CY, Huang AM, Li JH. (2011) Subamolide A, a component isolated from Cinnamomum subavenium, induces apoptosis mediated by mitochondria-dependent, p53 and ERK1/2 pathways in human urothelial carcinoma cell line NTUB1. J Ethnopharmacol,137(1):503-11. doi: 10.1016/j.jep.2011.06.001.

Sophoridine (See also oxymatrine,Matrine)

Cancer: Colorectal, lung

Action: Cell-cycle arrest

Cell-cycle Arrest

Matrine, sophoridine and oxymatrine are isolates from Sophora Flavescens (Aiton).

Sophoridine (SRI) inhibited the growth of SW620 cells significantly in a dose-and time-dependent manner, and morphological characteristics of apoptosis were observed with condensation of the nucleus, cytoplasmic bubbling, and DNA fragmentation. A DNA ladder pattern of inter-nucleosomal fragmentation was observed. Compared with that of the control group, the percentage of the G0/G1 phase and the S phase cells increased after treatment by SRI. Apoptosis was induced in SW620 cells and underwent G0/G1 arrest with exposure to SRI as evidenced by flow cytometry results. Sophoridine could induce the inhibition of cell growth by means of apoptosis in a dose-and time-dependent manner, and cellcycle arrest at G0/G1 (Liang et al., 2008).

Colorectal Cancer

The anti-proliferation of sophoridine (SRI) in human colorectal cells SW480 was detected by3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The pathology and ultrastructure of xenograft tumors treated with SRI were also observed. SRI significantly inhibited the growth of SW480 cells, and the administration of SRI significantly inhibited the growth of xenograft tumors without apparent toxicity. SRI's mechanism of action involved the induction of apoptosis.

These results suggest that SRI produces obvious anti-tumor effects in vitro and in vivo. It supports the viability of developing SRI as a novel therapeutic prodrug for colorectal cancer treatment, as well as providing a method for identifying new anti-tumor drugs in traditional Chinese medicine (Liang et al., 2012).

Sophoridine can inhibit the growth of transplanted solid tumor of human colon cancer SW480 cell line, the mechanism of which involves the inhibition of p53 and VEGF expression. The volume and weight of the tumor xenograft in sophoridine group decreased in comparison with those in the control group. Sophoridine treatment resulted in lowered expressions of p53 and VEGF at both the protein and mRNA levels in the tumor explants as compared with the control group, with a tumor inhibition rate of 34.07% in nude mice (Wang et al., 2010).

References

Liang L, Zhang XH, Wang XY, Chen Y, Deng HZ. (2008). Effect of sophoridine on proliferation and apoptosis of human colon adenocarcinoma cells (SW620). Zhong Guo Yao Li Xue Tong Bao, 24(6): 782-787.


Liang W, Wang XY, Zhang XH, et al. (2012). Sophoridine exerts an anti-colorectal carcinoma effect through apoptosis induction in vitro and in vivo. Life Sciences, 91(25–26):1295–1303


Wang QR, Li CH, Fu XQ, et al. (2010). Effects of sophoridine on the growth and expressions of p53 and vascular endothelial growth factor of transplanted solid tumor SW480 in nude mice. Nan Fang Yi Ke Da Xue Xue Bao, 30(7):1593-6.

Solanum incanum, solamargine alkaloid

Cancer: Squamous cell

Action: Apoptosis

Solanum incanum is nightshade native to Sub-Saharan Arica and the Middle East.

SR-T100, extracted from the Solanum incanum, contains solamargine alkaloid as the main active ingredient. Thirteen patients, who suffered with 14 actinic keratoses (AKs) were treated with once-daily topical SR-T100 gel and 10 AKs cured after 16 weeks, showing negligible discomforts. Our studies indicate that SR-T100 induces apoptosis of SCC cells via death receptors and the mitochondrial death pathway. The high efficacy of SR-T100 in these preclinical trials suggests that SR-T100 is a highly promising herb for AKs and related disorders (Wu et al., 2011).

Induces Apoptosis

Solamargine (SM), a steroidal glycoalkaloid isolated from the Chinese herb Solanum incanum, has been shown to inhibit the growth of some cancer cell lines and induce significant apoptosis.

SM at concentrations that induce P-gp down-regulation triggered cytotoxicity and apoptosis in MDR K562/A02 cells (Li et al., 2011).

References

Li X, Zhao Y, Ji M, Liu SS, et al. (2011). Induction of actin disruption and down-regulation of P-glycoprotein expression by solamargine in Multi-drug-resistant K562/A02 cells. Chin Med J, 124(13):2038-2044


Wu CH, Liang CH, Shiu LY, et al. (2011). Solanum incanum extract (SR-T100) induces human cutaneous squamous cell carcinoma apoptosis through modulating tumor necrosis factor receptor signaling pathway. J Dermatol Sci, 63(2):83-92.


Yu M, Liu X, Xu B, et al. (2008). Mechanism reversing MDR of K562/A02 by garlicin combined with erythromycin. Zhongguo Shi Yan Xue Ye Xue Za Zhi, 16(5):1044-9.

Scutellaria (See also apigenin, baicalein, baicalin, chrysin, scutellarein, wogonin, scutellarin, carthamidin, isocarthamidin, wogonin)

Cancer: General anti-cancer, colon, breast, glioma,

Action: Scutellaria Anti-cancer, cell-cycle arrest

Malignant Glioma, Breast Carcinoma and Prostate Cancer

The extracts and individual flavonoids inhibited the proliferation of malignant glioma and breast carcinoma cells without affecting primary or non-malignant cells. The flavonoids exhibited different mechanisms of anti-tumor activity as well as positive interactions. The anti-tumor mechanisms involved induction of apoptosis and cell-cycle arrest at G1/G2. Of the extracts tested, leaf extracts of S. angulosa, S. integrifolia, S. ocmulgee and S. scandens were found to have strong anti-cancer activity (Parajuli et al., 2009).

Anti-Cancer

Scutellaria is a traditional herbal remedy with potential anti-cancer activity. The anti-cancer mechanisms of thirteen Scutellaria species were examined, and their leaf, stem and root extracts analyzed for levels of common biologically active flavonoids: apigenin, baicalein, baicalin, chrysin, scutellarein, and wogonin. Malignant glioma, breast carcinoma and prostate cancer cells were used to determine tumor-specific effects of Scutellaria on cell proliferation, apoptosis and cell-cycle progression, via the MTT assay and flow cytometry-based apoptosis and Cell cycle analysis. The extracts and individual flavonoids inhibited the proliferation of malignant glioma and breast carcinoma cells without affecting primary or non-malignant cells. The flavonoids exhibited different mechanisms of anti-tumor activity as well as positive interactions.

The anti-tumor mechanisms involved induction of apoptosis and cell-cycle arrest at G1/G2. Of the extracts tested, leaf extracts of S. angulosa, S. integrifolia, S. ocmulgee and S. scandens were found to have strong anti-cancer activity. This study provides basis for further mechanistic and translational studies into adjuvant therapy of malignant tumors using Scutellaria leaf tissues (Parajuli et al., 2009).

Colon

Scutellaria barbata (SB) is a medicinal plant that contains flavonone compounds such as scutellarein, scutellarin, carthamidin, isocarthamidin, and wogonin. A functional proteomic approach was used to study the inhibitory effects of a chemically standardized extract from SB in human colon adrencarcinoma, LoVo. Results suggest that the chemically standardized extract from SB can induce cell death in the human colon cancer cell line. Goh, Lee, & Ong (2005) showed that the proposed platform provided a rapid approach to study the molecular mechanism because of the inhibitory effects of different doses of the botanical extracts on LoVo cell lines. This included a network of proteins involved in metabolism, regulation of the cell-cycle, and transcription-factor activity.

References

Goh D, Lee YH, Ong ES. (2005). Inhibitory effects of a chemically standardized extract from Scutellaria barbata in human colon cancer cell lines, LoVo. J Agric Food Chem, 53(21):8197-204.


Parajuli P, Joshee N, Rimando AM, Mittal S, Yadav AK. (2009). In vitro anti-tumor mechanisms of various Scutellaria extracts and constituent flavonoids. Planta Med, 75(1):41-8. doi: 10.1055/s-0028-1088364.

Schisandrin

Cancer: Leukemia, breast

Action: Anti-metastatic, cardio-protective, MDR, CYP3A, cell-cycle arrest

Leukemia

Schisandrin B (Sch B) has previously been demonstrated to be a novel P-glycoprotein (P-gp) inhibitor. Recent investigation revealed that Sch B was also an effective inhibitor of the multi-drug resistance-associated protein 1 (MRP1). Sch B's ability to reverse MRP1-mediated drug resistance was tested using HL60/ADR and HL60/MRP human promyelocytic leukemia cell lines, with the overexpression of MRP1 but not P-gp. At the equimolar concentration, Sch B demonstrated significantly stronger potency than the drug probenecid, a MRP1 inhibitor (Sun, Xu, Lu, Pan & Hu, 2007).

Up-regulates CYP3A

The ability of Schisandrin B (Sch B) to modulate cytochrome P450 3A activity (CYP3A) and alter the pharmacokinetic profiles of CYP3A substrate (midazolam) was investigated in vivo in treated rats. Rats were routinely administered with physiological saline (negative control group), ketoconazole (75mg/kg, positive control group), or varying doses of Sch B (experimental groups) for 3 consecutive days. Thereafter, changes in hepatic microsomal CYP3A activity and the pharmacokinetic profiles of midazolam and 1′-hydroxy midazolam in plasma were studied to evaluate CYP3A activity.

The results indicated that Sch B had a significant dose-dependent effect on inhibition of rat hepatic microsomal CYP3A activity. These results suggest that a 3-day treatment of Sch B could increase concentration and oral bioavailability of drugs metabolized by CYP3A (Li, Xin, Yu, & Wu, 2013).

Attenuates Metastasis

NADPH oxidase 4 (NOX4) is a potential target for intervention of cancer metastasis, as reactive oxygen species (ROS) generated by this enzyme plays important roles in TGF-β signaling, an important inducer of cancer metastasis. Zhang, Liu & Hu (2013) show that TGF-β induces ROS production in breast cancer 4T1 cells and enhances cell migration; that the effect of TGF- β depends on NOX4 expression; and that knockdown of NOX4 via RNAi significantly decreases the migration ability of 4T1 cells in the presence or absence of TGF-β and significantly attenuates distant metastasis of 4T1 cells to lung and bone.

Sch B significantly suppresses the lung and bone metastasis of 4T1 cells via inhibiting EMT, suggesting its potential application in targeting the process of cancer metastasis. Sch B significantly suppressed the spontaneous lung and bone metastasis of 4T1 cells inoculated s.c. without significant effect on primary tumor growth and significantly extended the survival time of the mice. Sch B did not inhibit lung metastasis of 4T1 cells that were injected via tail vein. Delayed start of treatment with Sch B in mice with pre-existing tumors did not reduce lung metastasis. These results suggested that Sch B acted at the step of local invasion (Liu et al., 2012).

Cardiotoxicity Protective/ Attenuates Metastasis

Sch B is capable of protecting Dox-induced chronic cardiotoxicity and enhancing its anti-cancer activity. To the best of our knowledge, Sch B is the only molecule ever proved to function as a cardio-protective agent as well as a chemotherapeutic sensitizer, which is potentially applicable for cancer treatment.

Pre-treatment with Sch B significantly attenuated Dox-induced loss of cardiac function and damage of cardiomyocytic structure. Sch B substantially enhanced Dox cytotoxicities toward S180 in vitro and in vivo in mice, and increased Dox cytotoxcity against 4T1 in vitro. Although we did not observe this enhancement against the implanted 4T1 primary tumor, the spontaneous metastasis to lung was significantly reduced in combined treatment group compared to Dox alone group (Xu et al., 2011).

Cell-cycle Arrest/Breast Cancer

Schizandrin inhibits cell proliferation through the induction of cell-cycle arrest with modulating cell-cycle-related proteins in human breast cancer cells. Schizandrin exhibited growth-inhibitory activities in cultured human breast cancer cells, and the effect was the more profound in estrogen receptor (ER)-positive T47D cells than in ER-negative MDA-MB-231 cells. When treated with the compound in T47D cells, schizandrin induced the accumulation of a cell population in the G0/G1 phase, which was further demonstrated by the induction of CDK inhibitors p21 and p27 and the inhibition of the expression of cell-cycle checkpoint proteins including cyclin D1, cyclin A, CDK2 and CDK4 (Kim et al., 2010).

References

Kim SJ, Min HY, Lee EJ, et al. (2010). Growth inhibition and cell-cycle arrest in the G0/G1 by schizandrin, a dibenzocyclooctadiene lignan isolated from Schisandra chinensis, on T47D human breast cancer cells. Phytother Res, 24(2):193-7. doi: 10.1002/ptr.2907.


Li WL, Xin HW, Yu AR, Wu XC. (2013). In vivo effect of Schisandrin B on cytochrome P450 enzyme activity. Phytomedicine, 20(8), 760-765


Liu Z, Zhang B, Liu K, Ding Z, Hu X. (2012). Schisandrin B attenuates cancer invasion and metastasis via inhibiting epithelial-mesenchymal transition. PLoS One, 7(7):e40480. doi: 10.1371/journal.pone.0040480.


Sun M, Xu X, Lu Q, Pan Q, Hu X. (2007). Schisandrin B: A dual inhibitor of P-glycoprotein and Multi-drug resistance-associated protein 1. Cancer Letters, 246(1-2), 300-307.


Xu Y, Liu Z, Sun J, et al. (2011). Schisandrin B prevents doxorubicin-induced chronic cardiotoxicity and enhances its anti-cancer activity in vivo. PLoS One, 6(12):e28335. doi: 10.1371/journal.pone.0028335.


Zhang B, Liu Z, Hu X. (2013). Inhibiting cancer metastasis via targeting NAPDH oxidase 4. Biochem Pharmacol, 86(2):253-66. doi: 10.1016/j.bcp.2013.05.011.

Sanguinarine (See also chelerythrine)

Cancer:
Prostate, bladder, breast, colon, melanoma, leukemia

Action: Pro-oxidative, anti-inflammatory, apoptosis induction

AR+/AR- Prostate Cancer

Sanguinarine, a benzophenanthridine alkaloid derived from the bloodroot plant Sanguinaria canadensis (L.), has been shown to possess anti-microbial, anti-inflammatory, anti-cancer and anti-oxidant properties. It has been shown that sanguinarine possesses strong anti-proliferative and pro-apoptotic properties against human epidermoid carcinoma A431 cells and immortalized human HaCaT keratinocytes. Employing androgen-responsive human prostate carcinoma LNCaP cells and androgen-unresponsive human prostate carcinoma DU145 cells, the anti-proliferative properties of sanguinarine against prostate cancer were also examined.

The mechanism of the anti-proliferative effects of sanguinarine against prostate cancer were examined by determining the effect of sanguinarine on critical molecular events known to regulate the cell-cycle and the apoptotic machinery.

A highlight of this study was the fact that sanguinarine induced growth-inhibitory and anti-proliferative effects in human prostate carcinoma cells irrespective of their androgen status. To our knowledge, this is the first study showing the involvement of cyclin kinase inhibitor-cyclin-cyclin-dependent kinase machinery during cell-cycle arrest and apoptosis of prostate cancer cells by sanguinarine. These results suggest that sanguinarine may be developed as an agent for the management of prostate cancer (Adhami et al., 2004).

Breast Cancer

The effects of this compound were examined on reactive oxygen species (ROS) production and its association with apoptotic tumor cell death using a human breast carcinoma MDA-MB-231 cell line. Cytotoxicity was evaluated by trypan blue exclusion methods. Apoptosis was detected using DAPI staining, agarose gel electrophoresis and flow cytometer. The expression levels of proteins were determined by Western blot analyzes and caspase activities were measured using colorimetric assays.

These observations clearly indicate that ROS is involved in the early molecular events in the sanguinarine-induced apoptotic pathway. Data suggests that sanguinarine-induced ROS are key mediators of MMP collapse, which leads to the release of cytochrome c followed by caspase activation, culminating in apoptosis (Choi, Kim, Lee & Choi, 2008).

Leukemia

Sanguinarine, chelerythrine and chelidonine are isoquinoline alkaloids derived from the greater celandine. They possess a broad spectrum of pharmacological activities. It has been shown that their anti-tumor activity is mediated via different mechanisms, which can be promising targets for anti-cancer therapy.

This study focuses on the differential effects of these alkaloids upon cell viability, DNA damage, and nucleus integrity in mouse primary spleen and lymphocytic leukemic cells, L1210. Sanguinarine and chelerythrine produced a dose-dependent increase in DNA damage and cytotoxicity in both primary mouse spleen cells and L1210 cells. Chelidonine did not show a significant cytotoxicity or damage DNA in both cell types, but completely arrested growth of L1210 cells.

Data suggests that cytotoxic and DNA-damaging effects of chelerythrine and sanguinarine are more selective against mouse leukemic cells and primary mouse spleen cells, whereas chelidonine blocks proliferation of L1210 cells. The action of chelidonine on normal and tumor cells requires further investigation (Kaminsky, Lin, Filyak, & Stoika, 2008).

T-lymphoblastic Leukemia

Apoptogenic and DNA-damaging effects of chelidonine (CHE) and sanguinarine (SAN), two structurally related benzophenanthridine alkaloids isolated from Chelidonium majus, were compared. Both alkaloids induced apoptosis in human acute T-lymphoblastic leukemia MT-4 cells. Apoptosis induction by CHE and SAN in these cells were accompanied by caspase-9 and -3 activation and an increase in the pro-apoptotic Bax protein. An elevation in the percentage of MT-4 cells possessing caspase-3 in active form after their treatment with CHE or SAN was in parallel to a corresponding increase in the fraction of apoptotic cells.

The involvement of the mitochondria in apoptosis induction by both alkaloids was supported by cytochrome C elevation in cytosol, with an accompanying decrease in cytochrome C content in the mitochondrial fraction. At the same time, two alkaloids under study differed drastically in their cell-cycle phase-specific effects, since only CHE arrested MT-4 cells at the G2/M phase. It was previously demonstrated, that CHE, in contrast to SAN, does not interact directly with DNA. (Philchenkov, Kaminskyy, Zavelevich, & Stoika, 2008).

Sanguinarine, chelerythrine and chelidonine possess prominent apoptotic effects towards cancer cells. This study found that sanguinarine and chelerythrine induced apoptosis in human CEM T-leukemia cells, accompanied by an early increase in cytosolic cytochrome C that precedes caspases-8, -9 and -3 processing. Effects of sanguinarine and chelerythrine on mitochondria were confirmed by clear changes in morphology (3h), however chelidonine did not affect mitochondrial integrity.

Sanguinarine and chelerythrine also caused marked DNA damage in cells after 1h, but a more significant increase in impaired cells occurred after 6h. Chelidonine induced intensive DNA damage in 15–20% cells after 24h. Results demonstrated that rapid cytochrome C release in CEM T-leukemia cells exposed to sanguinarine or chelerythrine was not accompanied by changes in Bax, Bcl-2 and Bcl-X((L/S)) proteins in the mitochondrial fraction, and preceded activation of the initiator caspase-8 (Kaminskyy, Kulachkovskyy & Stoika, 2008).

Colorectal Cancer

The effects of sanguinarine, a benzophenanthridine alkaloid, was examined on reactive oxygen species (ROS) production, and the association of these effects with apoptotic cell death, in a human colorectal cancer HCT-116 cell line. Sanguinarine generated ROS, followed by a decrease in mitochondrial membrane potential (MMP), activation of caspase-9 and -3, and down-regulation of anti-apoptotic proteins, such as Bcl2, XIAP and cIAP-1. Sanguinarine also promoted the activation of caspase-8 and truncation of Bid (tBid).

Observations clearly indicate that ROS, which are key mediators of Egr-1 activation and MMP collapse, are involved in the early molecular events in the sanguinarine-induced apoptotic pathway acting in HCT-116 cells (Han, Kim, Yoo, & Choi, 2013).

Bladder Cancer

Although the effects of sanguinarine, a benzophenanthridine alkaloid, on the inhibition of some kinds of cancer cell growth have been established, the underlying mechanisms are not completely understood. This study investigated possible mechanisms by which sanguinarine exerts its anti-cancer action in cultured human bladder cancer cell lines (T24, EJ, and 5637). Sanguinarine treatment resulted in concentration-response growth inhibition of the bladder cancer cells by inducing apoptosis.

Taken together, the data provide evidence that sanguinarine is a potent anti-cancer agent, which inhibits the growth of bladder cancer cells and induces their apoptosis through the generation of free radicals (Han et al., 2013).

Melanoma

Sanguinarine is a natural isoquinoline alkaloid derived from the root of Sanguinaria canadensis and from other poppy fumaria species, and is known to have a broad spectrum of pharmacological properties. Current study has found that sanguinarine, at low micromolar concentrations, showed a remarkably rapid killing activity against human melanoma cells. Sanguinarine disrupted the mitochondrial transmembrane potential (ΔΨ m), released cytochrome C and Smac/DIABLO from mitochondria to cytosol, and induced oxidative stress. Thus, pre-treatment with the thiol anti-oxidants NAC and GSH abrogated the killing activity of sanguinarine. Collectively, data suggests that sanguinarine is a very rapid inducer of human melanoma caspase-dependent cell death that is mediated by oxidative stress (Burgeiro, Bento, Gajate, Oliveira, & Mollinedo, 2013).

References

Adhami YM, Aziz MH, Reagan-Shaw SR, et al. (2004). Sanguinarine causes cell-cycle blockade and apoptosis of human prostate carcinoma cells via modulation of cyclin kinase inhibitor-cyclin-cyclin-dependent kinase machinery. Mol Cancer Ther, 3:933


Burgeiro A, Bento AC, Gajate C, Oliveira PJ, Mollinedo F. (2013). Rapid human melanoma cell death induced by sanguinarine through oxidative stress. European Journal of Pharmacology, 705(1-3), 109-18. doi: 10.1016/j.ejphar.2013.02.035.


Choi WY, Kim GY, Lee WH, Choi YH. (2008). Sanguinarine, a benzophenanthridine alkaloid, induces apoptosis in MDA-MB-231 human breast carcinoma cells through a reactive oxygen species-mediated mitochondrial pathway. Chemotherapy, 54(4), 279-87. doi: 10.1159/000149719.


Han MH, Kim GY, Yoo YH, Choi YH. (2013). Sanguinarine induces apoptosis in human colorectal cancer HCT-116 cells through ROS-mediated Egr-1 activation and mitochondrial dysfunction. Toxicology Letters, 220(2), 157-66. doi: 10.1016/j.toxlet.2013.04.020.


Han MH, Park C, Jin CY, et al. (2013). Apoptosis induction of human bladder cancer cells by sanguinarine through reactive oxygen species-mediated up-regulation of early growth response gene-1. PLoS One, 8(5), e63425. doi: 10.1371/journal.pone.0063425.


Kaminskyy V, Lin KW, Filyak Y, Stoika R. (2008). Differential effect of sanguinarine, chelerythrine and chelidonine on DNA damage and cell viability in primary mouse spleen cells and mouse leukemic cells. Cell Biology International, 32(2), 271-277.


Kaminskyy V, Kulachkovskyy O, Stoika R. (2008) A decisive role of mitochondria in defining rate and intensity of apoptosis induction by different alkaloids. Toxicology Letters, 177(3), 168-81. doi: 10.1016/j.toxlet.2008.01.009.


Philchenkov A, Kaminskyy V, Zavelevich M, Stoika R. (2008). Apoptogenic activity of two benzophenanthridine alkaloids from Chelidonium majus L. does not correlate with their DNA-damaging effects. Toxicology In Vitro, 22(2), 287-95.

Salvianolic acid-B / Salvinal

Cancer:
Head and neck squamous cell carcinoma, oral squamous cell carcinoma, glioma

Action: MDR, reduction of cardiotoxicity, COX-2 inhibitor, inflammatory-associated tumor development, anti-cancer

Salvia miltiorrhiza contains a variety of anti-tumor active ingredients, such as the water-soluble components, salvianolic acid A, salvianolic acid B, salvinal, and liposoluble constituents, tanshinone I, tanshinone IIA, dihydrotanshinone I, miltirone, cryptotanshinone, ailantholide, neo-tanshinlactone, and nitrogen-containing compounds. These anti-tumor active components play important roles in the different stages of tumor evolution, progression and metastasis (Zhang & Lu, 2010).

Anti-cancer/MDR

Aqueous extracts of Salvia miltiorrhizae Bunge have been extensively used in the treatment of cardiovascular disorders and cancer in Asia. Recently, a compound, 5-(3-hydroxypropyl)-7-methoxy-2-(3'-methoxy-4'-hydroxyphenyl)-3-benzo[b]furancarbaldehyde (salvinal), isolated from this plant showed inhibitory activity against tumor cell growth and induced apoptosis in human cancer cells. In the present study, we investigated the cytotoxic effect and mechanisms of action of salvinal in human cancer cell lines. Salvinal caused inhibition of cell growth (IC50 range, 4-17 microM) in a variety of human cancer cell lines.

In particular, salvinal exhibited similar inhibitory activity against parental KB, P-glycoprotein-overexpressing KB vin10 and KB taxol-50 cells, and multi-drug resistance-associated protein (MRP)-expressing etoposide-resistant KB 7D cells.

Taken together, our data demonstrate that salvinal inhibits tubulin polymerization, arrests cell-cycle at mitosis, and induces apoptosis. Notably, Salvinal is a poor substrate for transport by P-glycoprotein and MRP. Salvinal may be useful in the treatment of human cancers, particularly in patients with drug resistance (Chang et al., 2004).

Glioma

Salvianolic acid B (SalB) has been shown to exert anti-cancer effect in several cancer cell lines. SalB increased the phosphorylation of p38 MAPK and p53 in a dose-dependent manner. Moreover, blocking p38 activation by specific inhibitor SB203580 or p38 specific siRNA partly reversed the anti-proliferative and pro-apoptotic effects, and ROS production induced by SalB treatment.

These findings extended the anti-cancer effect of SalB in human glioma cell lines, and suggested that these inhibitory effects of SalB on U87 glioma cell growth might be associated with p38 activation mediated ROS generation. Thus, SalB might be concerned as an effective and safe natural anti-cancer agent for glioma prevention and treatment (Wang et al., 2013).

Reduced Cardiotoxicity

Clinical attempts to reduce the cardiotoxicity of arsenic trioxide (ATO) without compromising its anti-cancer activities remain an unresolved issue. In this study, Wang et al., (2013b) determined that Sal B can protect against ATO-induced cardiac toxicity in vivo and increase the toxicity of ATO toward cancer cells.

The combination treatment significantly enhanced the ATO-induced cytotoxicity and apoptosis of HepG2 cells and HeLa cells. Increases in apoptotic marker cleaved poly (ADP-ribose) polymerase and decreases in procaspase-3 expressions were observed through Western blot. Taken together, these observations indicate that the combination treatment of Sal B and ATO is potentially applicable for treating cancer with reduced cardiotoxic side effects.

Oral Cancer

Sal B has inhibitory effect on oral squamous cell carcinoma (OSCC) cell growth. The anti-tumor effect can be attributed to anti-angiogenic potential induced by a decreased expression of some key regulator genes of angiogenesis. Sal B may be a promising modality for treating oral squamous cell carcinoma.

Sal B induced growth inhibition in OSCC cell lines but had limited effects on premalignant cells. A total of 17 genes showed a greater than 3-fold change when comparing Sal B treated OSCC cells to the control. Among these genes, HIF-1α, TNFα and MMP9 are specifically inhibited; expression of THBS2 was up-regulated (Yang et al., 2011).

Head and Neck Cancer

Overexpression of cyclooxygenase-2 (COX-2) in oral mucosa has been associated with increased risk of head and neck squamous cell carcinoma (HNSCC). Celecoxib is a non-steroidal anti-inflammatory drug, which inhibits COX-2 but not COX-1. This selective COX-2 inhibitor holds promise as a cancer-preventive agent. Concerns about the cardiotoxicity of celecoxib limit its use in long-term chemo-prevention and therapy. Salvianolic acid B (Sal-B) is a leading bioactive component of Salvia miltiorrhiza Bge, which is used for treating neoplastic and chronic inflammatory diseases in China.

Tumor volumes in Sal-B treated group were significantly lower than those in celecoxib treated or untreated control groups (p < 0.05). Sal-B inhibited COX-2 expression in cultured HNSCC cells and in HNSCC cells isolated from tumor xenografts. Sal-B also caused dose-dependent inhibition of prostaglandin E(2) synthesis, either with or without lipopolysaccharide stimulation. Taking these results together, Sal-B shows promise as a COX-2 targeted anti-cancer agent for HNSCC prevention and treatment (Hao et al., 2009).

Inflammatory-associated tumor development

A half-dose of daily Sal-B (40 mg/kg/d) and celecoxib (2.5 mg/kg/d) significantly inhibited JHU-013 xenograft growth relative to mice treated with a full dose of Sal-B or celecoxib alone. The combination was associated with profound inhibition of COX-2 and enhanced induction of apoptosis. Taken together, these results strongly suggest that a combination of Sal-B, a multifunctional anti-cancer agent, with low-dose celecoxib holds potential as a new preventive strategy in targeting inflammatory-associated tumor development (Zhao et al., 2010).

Squamous Cell Carcinoma

The results showed that Sal B significantly decreased the squamous cell carcinoma (SCC) incidence from 64.7 (11/17) to 16.7% (3/18) (P=0.004); angiogenesis was inhibited in dysplasia and SCC (P<0.01), with a simultaneous decrease in the immunostaining of hypoxia-inducible factor 1alpha and vascular endothelium growth factor protein (P<0.05). The results suggested that Sal B had inhibitory effect against the malignant transformation of oral precancerous lesion and such inhibition may be related to the inhibition of angiogenesis (Zhou, Yang, & Ge, 2006).

References

Chang JY, Chang CY, Kuo CC, et al. (2004). Salvinal, a novel microtubule inhibitor isolated from Salvia miltiorrhizae Bunge (Danshen), with antimitotic activity in Multi-drug-sensitive and -resistant human tumor cells. Mol Pharmacol, 65(1):77-84.


Hao Y, Xie T, Korotcov A, et al. (2009). Salvianolic acid B inhibits growth of head and neck squamous cell carcinoma in vitro and in vivo via cyclooxygenase-2 and apoptotic pathways. Int J Cancer, 124(9):2200-9. doi: 10.1002/ijc.24160.


Wang ZS, Luo P, Dai SH, et al., (2013a). Salvianolic acid B induces apoptosis in human glioma U87 cells through p38-mediated ROS generation. Cell Mol Neurobiol, 33(7):921-8. doi: 10.1007/s10571-013-9958-z.


Wang M, Sun G, Wu P, et al. (2013b). Salvianolic Acid B prevents arsenic trioxide-induced cardiotoxicity in vivo and enhances its anti-cancer activity in vitro. Evid Based Complement Alternat Med, 2013:759483. doi: 10.1155/2013/759483.


Yang Y, Ge PJ, Jiang L, Li FL, Zhum QY. (2011). Modulation of growth and angiogenic potential of oral squamous carcinoma cells in vitro using salvianolic acid B. BMC Complement Altern Med, 11:54. doi: 10.1186/1472-6882-11-54.


Zhang W, Lu Y. (2010). Advances in studies on anti-tumor activities of compounds in Salvia miltiorrhiza. Zhongguo Zhong Yao Za Zhi, 35(3):389-92.


Zhao Y, Hao Y, Ji H, Fang Y, et al. (2010). Combination effects of salvianolic acid B with low-dose celecoxib on inhibition of head and neck squamous cell carcinoma growth in vitro and in vivo. Cancer Prev Res (Phila), 3(6):787-96. doi: 10.1158/1940-6207.CAPR-09-0243.


Zhou ZT, Yang Y, Ge JP. (2006). The preventive effect of salvianolic acid B on malignant transformation of DMBA-induced oral premalignant lesion in hamsters. Carcinogenesis, 27(4):826-32.

Saikosaponin

Cancers:
Cervical, colon, liver, lung, ovarian, liver, breast, hepatocellular

Action: Anti-angiogenic, anti-metastatic, chemo-sensitizer, pro-oxidative, cell-cycle arrest

T cell-mediated autoimmune, induces apoptosis, immune regulating, radio-sensitizer

Induces Apoptosis

Long dan xie gan tang, a well known Chinese herbal formulation, is commonly used by patients with chronic liver disease in China. Accumulated anecdotal evidence suggests that Long dan tang may have beneficial effects in patients with hepatocellular carcinoma. Long dan tang is comprised of five herbs: Gentiana root, Scutellaria root, Gardenia fruit, Alisma rhizome, and Bupleurum root. The cytotoxic effects of compounds from the five major ingredients isolated from the above plants, i.e. gentiopicroside, baicalein, geniposide, alisol B acetate and saikosaponin-d, respectively, on human hepatoma Hep3B cells, were investigated.

Annexin V immunofluorescence detection, DNA fragmentation assays and FACScan analysis of propidium iodide-staining cells showed that gentiopicroside, baicalein, and geniposide had little effect, whereas alisol B acetate and saikosaponin-d profoundly induced apoptosis in Hep3B cells. Alisol B acetate, but not saikosaponin-d, induced G2/M arrest of the cell-cycle as well as a significant increase in caspase-3 activity. Interestingly, baicalein by itself induced an increase in H(2)O(2) generation and the subsequent NF-kappaB activation; furthermore, it effectively inhibited the transforming growth factor-beta(1) (TGF-beta(1))-induced caspase-3 activation and cell apoptosis.

Results suggest that alisol B acetate and saikosaponin-d induced cell apoptosis through the caspase-3-dependent and -independent pathways, respectively. Instead of inducing apoptosis, baicalein inhibits TGF-beta(1)-induced apoptosis via increase in cellular H(2)O(2) formation and NF-kappaB activation in human hepatoma Hep3B cells (Chou, Pan, Teng & Guh, 2003).

Breast

Saikosaponin-A treatment of MDA-MB-231 for 3 hours and of MCF-7 cells for 2 hours, respectively, caused an obvious increase in the sub G1 population of cell-cycles.

Apoptosis in MDA-MB-231 cells was independent of the p53/p21 pathway mechanism and was accompanied by an increased ratio of Bax to Bcl-2 and c-myc levels and activation of caspase-3. In contrast, apoptosis of MCF-7 cells may have been initiated by the Bcl-2 family of proteins and involved p53/p21 dependent pathway mechanism, and was accompanied by an increased level of c-myc protein. The apoptosis of both MDA-MB-231 and MCF-7 cells showed a difference worthy of further research (Chen, Chang, Chung, & Chen, 2003).

Hepatocellular Carcinoma

The signaling pathway mediating induction of p15(INK4b) and p16(INK4a) during HepG2 growth inhibition triggered by the phorbol ester tumor promoter TPA (12-O-tetradecanoylphorbol 13-acetate) and the Chinese herbal compund Saikosaponin A was investigated.

Expressions of proto-oncogene c-jun, junB and c-fos were induced by TPA and Saikosaponin A between 30 minutes to 6 hours of treatment. Pre-treatment of 20 microg/ml PD98059, an inhibitor of MEK (the upstream kinase of ERK), prevents the TPA and Saikosaponin A triggered HepG2 growth inhibition by 50% and 30%, respectively. In addition, AP-1 DNA-binding assay, using non-isotopic capillary electrophoresis and laser-induced fluorescence (CE/LIF), demonstrated that the AP-1-related DNA-binding activity was significantly induced by TPA and Saikosaponin A, which can be reduced by PD98059 pre-treatment.

Results suggest that activation of ERK, together with its downstream transcriptional machinery, mediated p15(INK4b) and p16(INK4a) expression that led to HepG2 growth inhibition (Wen-Sheng, 2003).

The effects of Saikosaponin D (SSd) on syndecan-2, matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases-2 (TIMP-2) in livers of rats with hepatocellular carcinoma (HCC) was investigated.

The model group had more malignant nodules than the SSd group. Model-group HCC cells were grade III; SSd-group HCC cells were grades I-II. Controls showed normal hepatic cell phenotypes and no syndecan-2+ staining. Syndecan-2+ staining was greater in the model group (35.2%, P < or = 0.001) than in controls or the SSd group (16.5%, P < or = 0.001). The model group had more intense MMP-2+ staining than controls (0.37 vs 0.27, P< or =0.01) or the SSd group (0.31 vs 0.37, P< or =0.05); and higher MMP-13+ staining (72.55%) than in controls (12.55%, P< or =0.001) and SSd group (20.18%, P< or =0.01).

The model group also had more TIMP-2+ staining (57.2%) than controls (20.9%, P< or =0.001) and SSd group (22.7%, P< or=0.001). Controls and SSd group showed no difference in TIMP-2+ rates.

SSd inhibited HCC development, and downregulated expression of syndecan-2, MMP-2, MMP-13 and TIMP-2 in rat HCC liver tissue (Jia et al., 2012).

T Cell-mediated Autoimmune

Saikosaponin-d (Ssd) is a triterpene saponin derived from the medicinal plant, Bupleurum falcatum L. (Umbelliferae). Previous findings showed that Ssd exhibits a variety of pharmacological and immunomodulatory activities including anti-inflammatory, anti-bacterial, anti-viral and anti-cancer effects.

Results demonstrated that Ssd not only suppressed OKT3/CD28-costimulated human T cell proliferation, it also inhibited PMA, PMA/Ionomycin and Con A-induced mouse T cell activation in vitro. The inhibitory effect of Ssd on PMA-induced T cell activation was associated with down-regulation of NF-kappaB signaling through suppression of IKK and Akt activities. In addition, Ssd suppressed both DNA binding activity and the nuclear translocation of NF-AT and activator protein 1 (AP-1) of the PMA/Ionomycin-stimulated T cells. The cell surface markers, such as IL-2 receptor (CD25), were also down-regulated along with decreased production of pro-inflammatory cytokines of IL-6, TNF-alpha and IFN-gamma.

Results indicate that the NF-kappaB, NF-AT and AP-1 (c-Fos) signaling pathways are involved in the T cell inhibition evoked by Ssd. Ssd could be a potential candidate for further study in treating T cell-mediated autoimmune conditions (Wong, Zhou, Cheung, Li, & Liu, 2009).

Cervical Cancer

Saikosaponin-a and -d, two naturally occurring compounds derived from Bupleurum radix, have been shown to exert anti-cancer activity in several cancer cell lines. However, the effect of a combination of saikosaponins with chemotherapeutic drugs have never been addressed. Investigated as to whether these two saikosaponins have chemo-sensitization effect on cisplatin-induced cancer cell cytotoxicity was carried out.

Two cervical cancer cell lines, HeLa and Siha, an ovarian cancer cell line, SKOV3, and a non-small-cell lung cancer cell line, A549, were treated with saikosaponins or cisplatin individually or in combination. Cell death was quantitatively detected by the release of lactate dehydrogenase (LDH) using a cytotoxicity detection kit. Cellular ROS was analyzed by flow cytometry. Apoptosis was evaluated by AO/EB staining, flow cytometry after Anexin V and PI staining, and Western blot for caspase activation. ROS scavengers and caspase inhibitor were used to determine the roles of ROS and apoptosis in the effects of saikosaponins on cisplatin-induced cell death.

Both saikosaponin-a and -d sensitized cancer cells to cisplatin-induced cell death in a dose-dependent manner, which was accompanied with induction of reactive oxygen species (ROS) accumulation.

Results suggest that saikosaponins sensitize cancer cells to cisplatin through ROS-mediated apoptosis, and the combination of saikosaponins with cisplatin could be an effective therapeutic strategy (Wang et al., 2010).

Colon Cancer

Saikosaponin-a (SSa)-induced apoptosis of HCC cells was associated with proteolytic activation of caspase-9, caspase-3, and PARP cleavages and decreased levels of IAP family members, such as XIAP and c-IAP-2, but not of survivin. SSa treatment also enhanced the activities of caspase-2 and caspase-8, Bid cleavage, and the conformational activation of Bax. Moreover, inhibition of caspase-2 activation by the pharmacological inhibitor z-VDVAD-fmk, or by knockdown of protein levels using a si-RNA, suppressed SSa-induced caspase-8 activation, Bid cleavage, and the conformational activation of Bax. Although caspase-8 is an initiator caspase like caspase-2, the inhibition of caspase-8 activation by knockdown using a si-RNA did not suppress SSa-induced caspase-2 activation.

Results suggest that sequential activation of caspase-2 and caspase-8 is a critical step in SSa-induced apoptosis (Kim & Hong, 2011).

Immune Regulating

Tumor necrosis factor-alpha (TNF- α ) was reported as an anti-cancer therapy due to its cytotoxic effect against an array of tumor cells. However, its undesirable responses of TNF- α on activating NF- κB signaling and pro-metastatic property limit its clinical application in treating cancers. Therefore, sensitizing agents capable of overcoming this undesirable effect must be valuable for facilitating the usage of TNF- α -mediated apoptosis therapy for cancer patients. Previously, saikosaponin-d (Ssd), a triterpene saponin derived from the medicinal plant, Bupleurum falcatum L. (Umbelliferae), exhibited a variety of pharmacological activities such as anti-inflammatory, anti-bacterial, anti-viral and anti-cancer.

Investigation found that Ssd could potentially inhibit activated T lymphocytes via suppression of NF- κ B, NF-AT and AP-1 signaling. Ssd significantly potentiated TNF- α -mediated cell death in HeLa and HepG2 cancer cells via suppression of TNF- α -induced NF- κ B activation and its target genes expression involving cancer cell proliferation, invasion, angiogenesis and survival. Also, Ssd revealed a significant potency in abolishing TNF- α -induced cancer cell invasion and angiogenesis in HUVECs while inducing apoptosis via enhancing the loss of mitochondrial membrane potential in HeLa cells.

Collectively, findings indicate that Ssd has significant potential to be developed as a combined adjuvant remedy with TNF- α for cancer patients (Wong et al., 2013).

Radio-sensitizer

Saikosaponin-d (SSd), a monomer terpenoid purified from the Chinese herbal drug Radix bupleuri, has multiple effects, including anti-cancer properties. Treatment with SSd alone and radiation alone inhibited cell growth and increased apoptosis rate at the concentration used. These effects were enhanced when SSd was combined with radiation. Moreover, SSd potentiated the effects of radiation to induce G0/G1 arrest in SMMC-7721 hepatocellular carcinoma cells, and reduced the G2/M-phase population under hypoxia. SSd potentiates the effects of radiation on SMMC-7721 cells; thus, it is a promising radio-sensitizer. The radio-sensitizing effect of SSd may contribute to its effect on the G0/G1 and G2/M checkpoints of the cell-cycle (Wang et al., 2013).

References

Chen JC, Chang NW, Chung JG, Chen KC. (2003). Saikosaponin-A induces apoptotic mechanism in human breast MDA-MB-231 and MCF-7 cancer cells. The American Journal of Chinese Medicine, 31(3), 363-77.


Chou CC, Pan SL, Teng CM, Guh JH. (2003). Pharmacological evaluation of several major ingredients of Chinese herbal medicines in human hepatoma Hep3B cells. European Journal of Pharmaceutical Sciences, 19(5), 403-12.


Jia X, Dang S, Cheng Y, et al. (2012). Effects of saikosaponin-d on syndecan-2, matrix metalloproteinases and tissue inhibitor of metalloproteinases-2 in rats with hepatocellular carcinoma. Journal of Traditional Chinese Medicine, 32(3), 415-22.


Kim BM, Hong SH. (2011). Sequential caspase-2 and caspase-8 activation is essential for saikosaponin a-induced apoptosis of human colon carcinoma cell lines. Apoptosis, 16(2), 184-197. doi: 10.1007/s10495-010-0557-x.


Wang BF, Dai ZJ, Wang XJ, et al. (2013). Saikosaponin-d increases the radiosensitivity of smmc-7721 hepatocellular carcinoma cells by adjusting the g0/g1 and g2/m checkpoints of the cell-cycle. BMC Complementary and Alternative Medicine, 13:263. doi:10.1186/1472-6882-13-263


Wang Q, Zheng XL, Yang L, et al. (2010). Reactive oxygen species-mediated apoptosis contributes to chemo-sensitization effect of saikosaponins on cisplatin-induced cytotoxicity in cancer cells. Journal of Experimental & Clinical Cancer Research, 9(29), 159. doi: 10.1186/1756-9966-29-159.


Wen-Sheng, W. (2003). ERK signaling pathway is involved in p15INK4b/p16INK4a expression and HepG2 growth inhibition triggered by TPA and Saikosaponin A. Oncogene, 22(7), 955-963.


Wong VK, Zhang MM, Zhou H, et al. (2013). Saikosaponin-d Enhances the Anti-cancer Potency of TNF- α via Overcoming Its Undesirable Response of Activating NF-Kappa B Signaling in Cancer Cells. Evidence-based Complementary and Alternative Medicine, 2013(2013), 745295. doi: 10.1155/2013/745295.


Wong VK, Zhou H, Cheung SS, Li T, Liu L. (2009). Mechanistic study of saikosaponin-d (Ssd) on suppression of murine T lymphocyte activation. Journal of Cellular Biochemistry, 107(2), 303-15. doi: 10.1002/jcb.22126.

Rosmarinic Acid

Cancer: Leukemia

Action: Anti-oxidative, MDR

Leukemia

Because tumor necrosis factor-alpha (TNF-alpha) is well known to induce inflammatory responses, its clinical use is limited in cancer treatment. Rosmarinic acid (RA), a naturally occurring polyphenol flavonoid, has been reported to inhibit TNF-alpha-induced NF-kappaB activation in human dermal fibroblasts. Investigation found that RA treatment significantly sensitizes TNF-alpha-induced apoptosis in human leukemia U937 cells through the suppression of nuclear transcription factor-kappaB (NF-kappaB) and reactive oxygen species (ROS). This inhibition was correlated with suppression of NF-kappaB-dependent anti-apoptotic proteins (IAP-1, IAP-2, and XIAP). RA treatment also normalized TNF-alpha-induced ROS generation. Additionally, ectopic Bcl-2 expressing U937 reversed combined treatment-induced cell death, cytochrome c release into cytosol, and collapse of mitochondrial potential.

Results demonstrated that RA inhibits TNF-alpha-induced ROS generation and NF-kappaB activation, and enhances TNF-alpha-induced apoptosis (Moon, Kim, Lee, Choi, & Kim, 2010).

MDR

The intracellular accumulation of adriamycin, rhodamine123 (Rh123), and the expression of P-glycoprotein (P-gp) were assayed by flow cytometry. The influence of RA on the transcription of MDR1 gene was determined by reverse transcription-polymerase chain reaction. The results showed that RA could reverse the MDR of SGC7901/Adr cells, increase the intracellular accumulation of Adr and Rh123, and decrease the transcription of MDR1 gene and the expression of P-gp in SGC7901/Adr cells (Li et al., 2013).

Anti-cancer

Rosmarinic acid (RA), one of the major components of polyphenol, possesses attractive remedial features. Supplementation with RA significantly reduced the formation of aberrant crypt foci (ACF) and ACF multiplicity in 1,2-dimethylhydrazine (DMH) treated rats. Moreover RA supplementation prevented the alterations in circulatory anti-oxidant enzymes and colonic bacterial enzymes activities. Overall, results showed that all three doses of RA inhibited carcinogenesis, though the effect of the intermediary dose of 5 mg/kg b.w. was more pronounced (Karthikkumar et al., 2012).

References

Karthikkumar V, Sivagami G, Vinothkumar R, Rajkumar D, Nalini N. (2012). Modulatory efficacy of rosmarinic acid on premalignant lesions and anti-oxidant status in 1,2-dimethylhydrazine induced rat colon carcinogenesis. Environ Toxicol Pharmacol, 34(3):949-58. doi: 10.1016/j.etap.2012.07.014.


Li FR, Fu YY, Jiang DH, et al. (2013). Reversal effect of rosmarinic acid on Multi-drug resistance in SGC7901/Adr cell. J Asian Nat Prod Res, 15(3):276-85. doi: 10.1080/10286020.2012.762910.


Moon DO, Kim MO, Lee JD, Choi YH, Kim GY. (2010). Rosmarinic acid sensitizes cell death through suppression of TNF-alpha-induced NF-kappaB activation and ROS generation in human leukemia U937 cells. Cancer Letters, 288(2), 183-191. doi: 10.1016/j.canlet.2009.06.033.

RG3 (See also Ginsenosides)

Cancer: Glioblastoma, prostate, breast, colon

Action: Anti-angiogenesis, MDR, enhances chemotherapy, MDR, enhanced paclitaxel absorption, anti-metastatic

RG3 is a ginsenoside isolated from red ginseng (Panax ginseng (L.)), after being peeled, heated, and dried.

Angiosuppressive Activity

Aberrant angiogenesis is an essential step for the progression of solid tumors. Thus anti-angiogenic therapy is one of the most promising approaches to control tumor growth.

Rg3 was found to inhibit the proliferation of human umbilical vein endothelial cells (HUVEC) with an IC50 of 10 nM in Trypan blue exclusion assay.

Rg3 (1-10(3) nM) also dose-dependently suppressed the capillary tube formation of HUVEC on the Matrigel in the presence or absence of 20 ng/ml vascular endothelial growth factor (VEGF). The Matrix metalloproteinases (MMPs), such as MMP-2 and MMP-9, which play an important role in the degradation of basement membrane in angiogenesis and tumor metastasis present in the culture supernatant of Rg3-treated aortic ring culture were found to decrease in their gelatinolytic activities. Taken together, these data underpin the anti-tumor properties of Rg3 through its angiosuppressive activity (Yue et al., 2006).

Glioblastoma

Rg3 has been reported to exert anti-cancer activities through inhibition of angiogenesis and cell proliferation. The mechanisms of apoptosis by ginsenoside Rg3 were related with the MEK signaling pathway and reactive oxygen species. Our data suggest that ginsenoside Rg3 is a novel agent for the chemotherapy of glioblastoma multiforme (GBM) (Choi et al., 2013).

Sin, Kim, & Kim (2012) report that chronic treatment with Rg3 in a sub-lethal concentration induced senescence-like growth arrest in human glioma cells. Rg3-induced senescence was partially rescued when the p53/p21 pathway was inactivated. Data indicate that Rg3 induces senescence-like growth arrest in human glioma cancer through the Akt and p53/p21-dependent signaling pathways.

MDR/Enhanced Paclitaxel Absorption

The penetration of paclitaxel through the Caco-2 monolayer from the apical side to the basal side was facilitated by 20(s)-ginsenoside Rg3 in a concentration-dependent manner. Rg3 also inhibited P-glycoprotein (P-gp), and the maximum inhibition was achieved at 80 µM (p < 0.05). The relative bioavailability (RB)% of paclitaxel with 20(s)-ginsenoside Rg3 was 3.4-fold (10 mg/kg) higher than that of the control. Paclitaxel (20 mg/kg) co-administered with 20(s)-ginsenoside Rg3 (10 mg/kg) exhibited an effective anti-tumor activity with the relative tumor growth rate (T/C) values of 39.36% (p <0.05).

The results showed that 20(s)-ginsenoside Rg3 enhanced the oral bioavailability of paclitaxel in rats and improved the anti-tumor activity in nude mice, indicating that oral co-administration of paclitaxel with 20(s)-ginsenoside Rg3 could provide an effective strategy in addition to the established i.v. route (Yang et al., 2012).

Prostate Cancer

The anti-proliferation effect of Rg3 on prostate cancer cells has been well reported. Rg3 treatment triggered the activation of p38 MAPK; and SB202190, a specific inhibitor of p38 MAPK, antagonized the Rg3-induced regulation of AQP1 and cell migration, suggesting a crucial role for p38 in the regulation process. Rg3 effectively suppresses migration of PC-3M cells by down-regulating AQP1 expression through p38 MAPK pathway and some transcription factors acting on the AQP1 promoter (Pan et al., 2012).

Enhances Chemotherapy

The clinical use of cisplatin (cis-diamminedichloroplatinum II) has been limited by the frequent emergence of cisplatin-resistant cell populations and numerous other adverse effects. Therefore, new agents are required to improve the therapy and health of cancer patients. Oral administration of ginsenoside Rg3 significantly inhibited tumor growth and promoted the anti-neoplastic efficacy of cisplatin in mice inoculated with CT-26 colon cancer cells. In addition, Rg3 administration remarkably inhibited cisplatin-induced nephrotoxicity, hepatotoxicity and oxidative stress.

Rg3 promotes the efficacy of cisplatin by inhibiting HO-1 and NQO-1 expression in cancer cells and protects the kidney and liver against tissue damage by preventing cisplatin-induced intracellular ROS generation (Lee et al., 2012).

Colon Cancer

Rg3-induced apoptosis in HT-29 cells is mediated via the AMPK signaling pathway, and that 20(S)-Rg3 is capable of inducing apoptosis in colon cancer. Rg3-treated cells displayed several apoptotic features, including DNA fragmentation, proteolytic cleavage of poly (ADP-ribose) polymerase (PARP) and morphological changes. 20(S)-Rg3 down-regulated the expression of anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl2), up-regulated the expression of pro-apoptotic protein of p53 and Bcl-2-associated X protein (Bax), and caused the release of mitochondrial cytochrome c, PARP, caspase-9 and caspase-3 (Yuan et al., 2010).

Anti-metastatic

Studies have linked Rg3 with anti-metastasis of cancer in vivo and in vitro and the CXC receptor 4 (CXCR4) is a vital molecule in migration and homing of cancer to the docking regions. At a dosage without obvious cytotoxicity, Rg3 treatment elicits a weak CXCR4 stain color, decreases the number of migrated cells in CXCL12-elicited chemotaxis and reduces the width of the scar in wound healing and Rg3 is a new CXCR4 inhibitor (Chen et al., 2011).

References

Chen XP, Qian LL, Jiang H, Chen JH. (2011). Ginsenoside Rg3 inhibits CXCR4 expression and related migrations in a breast cancer cell line. Int J Clin Oncol, 16(5):519-23. doi: 10.1007/s10147-011-0222-6.


Choi YJ, Lee HJ, Kang DW, et al. (2013). Ginsenoside Rg3 induces apoptosis in the U87MG human glioblastoma cell line through the MEK signaling pathway and reactive oxygen species. Oncol Rep. doi: 10.3892/or.2013.2555.


Lee CK, Park KK, Chung AS, Chung WY. (2012). Ginsenoside Rg3 enhances the chemosensitivity of tumors to cisplatin by reducing the basal level of nuclear factor erythroid 2-related factor 2-mediated heme oxygenase-1/NAD(P)H quinone oxidoreductase-1 and prevents normal tissue damage by scavenging cisplatin-induced intracellular reactive oxygen species. Food Chem Toxicol, 50(7):2565-74. doi: 10.1016/j.fct.2012.01.005.


Pan XY, Guo H, Han J, et al. (2012). Ginsenoside Rg3 attenuates cell migration via inhibition of aquaporin 1 expression in PC-3M prostate cancer cells. Eur J Pharmacol, 683(1-3):27-34. doi: 10.1016/j.ejphar.2012.02.040.


Sin S, Kim SY, Kim SS. (2012). Chronic treatment with ginsenoside Rg3 induces Akt-dependent senescence in human glioma cells. Int J Oncol., 41(5):1669-74. doi: 10.3892/ijo.2012.1604.


Yang LQ, Wang B, Gan H, et al. (2012). Enhanced oral bioavailability and anti-tumor effect of paclitaxel by 20(s)-ginsenoside Rg3 in vivo. Biopharm Drug Dispos., 33(8):425-36. doi: 10.1002/bdd.1806.


Yuan HD, Quan HY, Zhang Y, et al. (2010). 20(S)-Ginsenoside Rg3-induced apoptosis in HT-29 colon cancer cells is associated with AMPK signaling pathway. Mol Med Rep., 3(5):825-31. doi: 10.3892/mmr.2010.328.


Yue PY, Wong DY, Wu PK, et al. (2006). The angiosuppressive effects of 20 (R)-ginsenoside Rg3. Biochem Pharmacol, 72(4):437-45.

Retinoids

Cancer: none noted

Action: Down-regulates,epidermal growth factor receptor

Human papillomavirus (HPV) is an important etiological agent in the genesis of cervical cancer. HPV-positive cervical tumors and human papillomavirus-positive cell lines display increased epidermal growth factor receptor (EGFR) expression, which is associated with increased cell proliferation. ECE16-1 cells are an HPV-immortalized human ectocervical epithelial cell line that is a model of HPV-associated cervical neoplasia and displays elevated EGFR levels.

The effects of receptor-selective retinoid ligands on EGFR-associated signal transduction were examined. It has been shown that retinoic acid receptor (RAR)-selective ligands reduce EGFR level and the magnitude and duration of EGFR activation in EGF-stimulated cells.

These effects are reversed by co-treatment with an RAR antagonist. To identify the mechanism, Sah et al. (2002) examined the effects of retinoid treatments on EGF-dependent signaling. Stimulation with EGF causes a biphasic activation of the ERK1/2 MAPK.

This effect is specific as retinoid treatment does not alter the level or activity of other EGFR-regulated kinases, including AKT and the MAPKs p38 and JNK. Retinoid X receptor-selective ligands, in contrast, did not regulate these responses. These results suggest that RAR ligand-associated down-regulation of EGFR activity reduces cell proliferation by reducing the magnitude and duration of EGF-dependent ERK1/2 activation.

All-trans retinoic acid (RA), through binding to the retinoic acid receptors (RARs), alters interactions of the RARs with various protein components of the transcription complex at numerous genes in stem cells, and some of these protein components of the transcription complex then either place or remove epigenetic marks on histones or on DNA, altering chromatin structure and leading to an exit from the self-renewing, pluripotent stem cell state.

Different epigenetic mechanisms, i.e. first, primarily H3K27me3 marks and then DNA methylation, may be employed by embryonic stem cells and other stem cells for control of early vs. late stages of cell differentiation. Creating these stable epigenetic changes requires the actions of many molecules, including tet1, polycomb protein complexes (PRCs), miRNAs, DNA methyltransferases (DNMTs), and telomerase reverse transcriptase (Gudas, 2013).

References

Gudas LJ. (2013). Retinoids induce stem cell differentiation via epigenetic changes. Semin Cell Dev Biol, S1084-9521(13)00102-X. doi: 10.1016/j.semcdb.2013.08.002.


Sah JF, Eckert RL, Chandraratna RA, Rorke EA. (2002). Retinoids suppress epidermal growth factor-associated cell proliferation by inhibiting epidermal growth factor receptor-dependent ERK1/2 activation. J Biol Chem, 277(12):9728-35.