Category Archives: pro-oxidative

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.

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.

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.

Hispolon

Cancer: Bladder, breast, liver, gastric

Action: Anti-inflammatory, cytostatic, cytotoxic, pro-oxidative, anti-proliferative

Hispolon is an active phenolic compound of Phellinus igniarius , a mushroom that has recently been shown to have anti-oxidant, anti-inflammatory, and anti-cancer activities.

Liver Cancer

Hispolon inhibited cellular growth of Hep3B cells in a time-dependent and dose-dependent manner, through the induction of cell-cycle arrest at S phase measured using flow cytometric analysis and apoptotic cell death, as demonstrated by DNA laddering. Exposure of Hep3B cells to hispolon resulted in apoptosis as evidenced by caspase activation, PARP cleavage, and DNA fragmentation. Hispolon treatment also activated JNK, p38 MAPK, and ERK expression. Inhibitors of ERK (PB98095), but not those of JNK (SP600125) and p38 MAPK (SB203580), suppressed hispolon-induced S-phase arrest and apoptosis in Hep3B cells.

These findings establish a mechanistic link between the MAPK pathway and hispolon-induced cell-cycle arrest and apoptosis in Hep3B cells (Huang et al., 2011).

Gastric Cancer, Breast Cancer, Bladder Cancer

Hispolon extracted from Phellinus species was found to induce epidermoid and gastric cancer cell apoptosis. Hispolon has also been found to inhibit breast and bladder cancer cell growth, regardless of p53 status. Furthermore, p21(WAF1), a cyclin-dependent kinase inhibitor, was elevated in hispolon-treated cells. MDM2, a negative regulator of p21(WAF1), was ubiquitinated and degraded after hispolon treatment.

Lu et al. (2009) also found that activated ERK1/2 (extracellular signal-regulated kinase1/2) was recruited to MDM2 and involved in mediating MDM2 ubiquitination. The results indicated that cells with higher ERK1/2 activity were more sensitive to hispolon. In addition, hispolon-induced caspase-7 cleavage was inhibited by the ERK1/2 inhibitor, U0126.

In conclusion, hispolon ubiquitinates and down-regulates MDM2 via MDM2-recruited activated ERK1/2. Therefore, hispolon may be a potential anti-tumor agent in breast and bladder cancers.

Gastric Cancer

The efficacy of hispolon in human gastric cancer cells and cell death mechanism was explored. Hispolon induced ROS-mediated apoptosis in gastric cancer cells and was more toxic toward gastric cancer cells than toward normal gastric cells, suggesting greater susceptibility of the malignant cells.

The mechanism of hispolon-induced apoptosis was that hispolon abrogated the glutathione anti-oxidant system and caused massive ROS accumulation in gastric cancer cells. Excessive ROS caused oxidative damage to the mitochondrial membranes and impaired the membrane integrity, leading to cytochrome c release, caspase activation, and apoptosis. Furthermore, hispolon potentiated the cytotoxicity of chemotherapeutic agents used in the clinical management of gastric cancer.

These results suggest that hispolon could be useful for the treatment of gastric cancer either as a single agent or in combination with other anti-cancer agents (Chen et al., 2008).

Anti-proliferative Activity

Hispolon, which lacks one aromatic unit in relation to curcumin, exhibits enhanced anti-inflammatory and anti-proliferative activities. Dehydroxy hispolon was least potent for all three activities. Overall the results indicate that the substitution of a hydroxyl group for a methoxy group at the meta positions of the phenyl rings in curcumin significantly enhanced the anti-inflammatory activity, and the removal of phenyl ring at the 7(th) position of the heptadiene back bone and addition of hydroxyl group significantly increased the anti-proliferative activity of curcumin and hispolon (Ravindran et al., 2010).

References

Chen W, Zhao Z, Li L, et al. (2008). Hispolon induces apoptosis in human gastric cancer cells through a ROS-mediated mitochondrial pathway. Free Radic Biol Med, 45(1):60-72. doi: 10.1016/j.freeradbiomed.2008.03.013.


Huang GJ, Deng JS, Huang SS, Hu ML. (2011). Hispolon induces apoptosis and cell-cycle arrest of human hepatocellular carcinoma Hep3B cells by modulating ERK phosphorylation. J Agric Food Chem, 59(13):7104-13. doi: 10.1021/jf201289e.


Lu TL, Huang GJ, Lu TJ, et al. (2009). Hispolon from Phellinus linteus has anti-proliferative effects via MDM2-recruited ERK1/2 activity in breast and bladder cancer cells. Food Chem Toxicol, 47(8):2013-21. doi: 10.1016/j.fct.2009.05.023.


Ravindran J, Subbaraju GV, Ramani MV, et al. (2010). Bisdemethylcurcumin and structurally related hispolon analogues of curcumin exhibit enhanced prooxidant, anti-proliferative and anti-inflammatory activities in vitro. Biochem Pharmacol, 79(11):1658-66. doi: 10.1016/j.bcp.2010.01.033.

Costunolide and Dehydrocostus Lactone

Cancers:
Breast, cervical., lung, ovarian, bladder, leukemia, prostate, gastric

Action: Anti-inflammatory, pro-oxidative, MDR, lymphangiogenesis inhibitor, anti-metastasis, mediates apoptosis, anti-metastatic

Components of Saussurea lappa Clarke, Vladimiria souliei (Franchet) Lingelsheim (Compositae)

Breast cancer; Anti-metastatic

It was found that costunolide inhibited the growth and telomerase activity of MCF-7 and MDA-MB-231 cells in a concentration- and time-dependent manner. The expression of hTERT mRNA was also inhibited but hTR mRNA was not. In addition, the bindings of transcription factors in hTERT promoters were significantly decreased in both cells by the treatment of costunolide. These results suggest that costunolide inhibited the growth of both MCF-7 and MDA-MB-231 cells and this effect was mediated at least in part by a significant reduction in telomerase activity (Choi et al., 2005).

Breast Cancer

Costunolide has been demonstrated to suppress tumor growth and metastases of MDA-MB-231 highly metastatic human breast cancer cells via inhibiting TNF-α induced NF-kB activation. Costunolide also inhibited MDA-MB-231 tumor growth and metastases without affecting body weights in the in vivo mouse orthotopic tumor growth assays.

In addition, costunolide inhibited in vitro TNF-α induced invasion and migration of MDA-MB-231 cells. Costunolide further suppressed TNF-α induced NF-kB signaling activation, resulting in a reduced expression of MMP-9, a well-known NF-kB-dependent gene to mediate breast cancer cell growth and metastases. Taken together, these results suggest that SLC and its derivative costunolide suppress breast cancer growth and metastases by inhibiting TNF-α induced NF-k B activation, suggesting that costunolide as well as SLC may be promising anti-cancer drugs, especially for metastatic breast cancer (Choi et al., 2013).

Several Chinese herbs, namely, Herba Taraxaci Mongolici (Pu Gong Ying), Radix Glycyrrhizae Uralensis (Gan Cao), Radix Bupleuri (Chai Hu), Radix Aucklandiae Lappae/ Radix Aucklandiae Lappae (Mu Xiang), Fructus Trichosanthis (Gua Lou) and Rhizoma Dioscoreae Bulbiferae (Huang Yao Zi) are frequently used in complex traditional Chinese medicine formulas for breast hyperplasia and breast tumor therapy.

The pharmacological effects of these Chinese herbs are all described as 'clearing heat-toxin and resolving masses' in traditional use. A bioactivity-oriented screening platform, which was based on a human breast cancer MCF-7 cellular model was developed to rapidly screen the 6 Chinese herbs. Two potential anti-breast cancer compounds, which were costunolide (Cos) and dehydrocostus lactone (Dehy), were identified in Radix Aucklandiae Lappae.

Combination of the two compounds showed a synergism on inhibiting the proliferation of MCF-7 cells in vitro, which exhibits a potential application prospect for breast cancer therapy. This bioactivity-oriented screening strategy is rapid, economical., reliable and specific for screening potential anti-breast cancer compounds in traditional Chinese medicines (Peng et al., 2013).

Dehydrocostuslactone (DHE) suppresses the expression of cyclin D, cyclin A, cyclin-dependent kinase 2, and cdc25A and increases the amount of p53 and p21, resulting in G(0)/G(1)-S phase arrest in MCF-7 cells. In contrast, DHE caused S-G(2)/M arrest by increasing p21 expression and chk1 activation and inhibiting cyclin A, cyclin B, cdc25A, and cdc25C expression in MDA-MB-231 cells. Reduction of SOCS-1 and SOCS-3 expression by small interfering RNA inhibits DHE-mediated signal transducer and activator of transcription-3 inhibition, p21 up-regulation, and cyclin-dependent kinase 2 blockade, supporting the hypothesis that DHE inhibits cell-cycle progression and cell death through SOCS-1 and SOCS-3.

Significantly, animal studies have revealed a 50% reduction in tumor volume after a 45-day treatment period. Taken together, this study provides new insights into the molecular mechanism of the DHE action that may contribute to the chemoprevention of breast cancer (Kuo et al., 2009).

ER- Breast Cancer

Costunolide induced apoptosis through the extrinsic pathway, including the activation of Fas, caspase-8, caspase-3, and degradation of PARP. However, it did not have the same effect on the intrinsic pathway as revealed by analysis of mitochondrial membrane potential (Δψ m) with JC-1 dye and expression of Bcl2 and Bax proteins level.

Furthermore, costunolide induced cell-cycle arrest in the G2/M phase via decrease in Cdc2, cyclin B1 and increase in p21WAF1 expression, independent of p53 pathway in p53-mutant MDA-MB-231 cells, and increases Cdc2-p21WAF1 binding/

Through this study it was confirmed that costunolide induces G2/M cell-cycle arrest and apoptotic cell death via extrinsic pathway in MDA-MB-231 cells, suggesting that it could be a promising anti-cancer drug especially for ER negative breast cancer (Choi et al., 2012).

Bladder Cancer

Costunolide, a member of sesquiterpene lactone family, possesses potent anti-cancer properties. The effects of costunolide were investigated on the cell viability and apoptosis in human bladder cancer T24 cells. Treatment of T24 cells with costunolide resulted in a dose-dependent inhibition of cell viability and induction of apoptosis, which was associated with the generation of ROS and disruption of mitochondrial membrane potential (Δψm).

These effects were significantly blocked when the cells were pre-treated with N-acetyl- cysteine (NAC), a specific ROS inhibitor. Exposure of T24 cells to costunolide was also associated with increased expression of Bax, down-regulation of Bcl-2, and of   survivin and significant activation of caspase-3, and its downstream target PARP. These findings provide the rationale for further in vivo and clinical investigation of costunolide against human bladder cancer (Rasul et al., 2013).

Sarcomas; MDR

Human soft tissue sarcomas represent a rare group of malignant tumors that frequently exhibit chemotherapeutic resistance and increased metastatic potential following unsuccessful treatment.

The effects on cell proliferation, cell-cycle distribution, apoptosis induction, and ABC transporter expression were analyzed. Cells treated with costunolide showed no changes in cell-cycle, little in caspase 3/7 activity, and low levels of cleaved caspase-3 after 24 and 48 hours. Dehydrocostus lactone caused a significant reduction of cells in the G1 phase and an increase of cells in the S and G2/M phase. Moreover, it led to enhanced caspase 3/7 activity, cleaved caspase-3, and cleaved PARP indicating apoptosis induction.

These data demonstrate that dehydrocostus lactone affects cell viability, cell-cycle distribution and ABC transporter expression in soft tissue sarcoma cell lines. Furthermore, it led to caspase 3/7 activity as well as caspase-3 and PARP cleavage, which are indicators of apoptosis. Therefore, this compound may be a promising lead candidate for the development of therapeutic agents against drug-resistant tumors (Kretschmer et al., 2013).

Leukemia, Lung Cancer

Costunolide, an active compound isolated from the stem bark of Magnolia sieboldii, has been found to induce apoptosis via reactive oxygen species (ROS) and Bcl-2-dependent mitochondrial permeability transition in human leukemia cells. Mitogen-activated protein kinases (MAPKs) were investigated for their involvement in the costunolide-induced apoptosis in human promonocytic leukemia U937 cells.

Treatment with costunolide resulted in the significant activation of c-Jun N-terminal kinase (JNK), but not of extracellular-signal-related kinase (ERK1/2) or p38. In vitro kinase assays showed that JNK activity was low in untreated cells but increased dramatically after 30 minutes of costunolide treatment. U937 cells co-treated with costunolide and sorbitol, a JNK activator, exhibited higher levels of cell death. In addition, inhibition of the JNK pathway using a dominant-negative mutation of c-jun and JNK inhibitor SP600125, significantly prevented costunolide-induced apoptosis.

Furthermore, pre-treatment with the anti-oxidant NAC (N-acetyl-L-cysteine) blocked the costunolide-stimulated activation of JNK while the overexpression of Bcl-2 failed to reverse JNK activation. These results indicate that costunolide-induced JNK activation acts downstream of ROS but upstream of Bcl-2, and suggest that ROS-mediated JNK activation plays a key role in costunolide-induced apoptosis. Moreover, the administration of costunolide (intraperitoneally once a day for 7 days) significantly suppressed tumor growth and increased survival in 3LL Lewis lung carcinoma-bearing model (Choi et al., 2009).

Prostate Cancer

Several pharmacological and biochemical assays were used to characterize the apoptotic-signaling pathways of costunolide in prostate cancer cells. Costunolide showed effective anti-proliferative activity against hormone dependent (LNCaP) and independent (PC-3 and DU-145) prostate cancer cells (ATCC¨) by sulforhodamine B assay, clonogenic test and flow cytometric analysis of carboxyfluorescein succinimidyl ester labeling. In PC-3 cells data showed that costunolide induced a rapid overload of nuclear Ca(2+), DNA damage response and ATR phosphorylation.

This indicated the crucial role of intracellular Ca(2+) mobilization and thiol depletion but not of reactive oxygen species production in apoptotic signaling. Data suggest that costunolide induces the depletion of intracellular thiols and overload of nuclear Ca(2+) that cause DNA damage and p21 up-regulation. The association of p21 with the cyclin dependent kinase 2/cyclin E complex blocks cyclin dependent kinase 2 activity and inhibits Rb phosphorylation, leading to G1 arrest of the cell-cycle and subsequent apoptotic cell death in human prostate cancer cells (Hsu et al., 2011).

Gastric Cancer, Prostate Cancer

Radix Aucklandiae Lappae/Saussurea lappa has been used in Chinese traditional medicine for the treatment of abdominal pain, tenesmus, nausea, and cancer; previous studies have shown that S. lappa also induces G(2) growth arrest and apoptosis in gastric cancer cells. The effects of hexane extracts of S. lappa (HESLs) on the migration of DU145 and TRAMP-C2 prostate cancer cells were investigated.

The active compound, dehydrocostus lactone (DHCL), in fraction 7 dose-dependently inhibited the basal and EGF-induced migration of prostate cancer cells. HESL and DHCL reduced matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 secretion but increased TIMP-2 levels in both the absence and presence of EGF. These results demonstrate that the inhibition of MMP-9 secretion and the stimulation of TIMP-2 secretion contribute to reduced migration of DU145 cells treated with HESL and DHCL.

This indicates that HESL containing its active principle, DHCL, has potential as an anti-metastatic agent for the treatment of prostate cancer (Kim et al., 2012).

Anti-metastatic

Lymphangiogenesis inhibitors from crude drugs used in Japan and Korea were investigated for their impact on metastasis. The three crude drugs Saussureae Radix, Psoraleae Semen and Aurantti Fructus Immaturus significantly inhibited the proliferation of temperature-sensitive rat lymphatic endothelial (TR-LE) cells in vitro.

Among isolated compounds, several compounds; costunolide, dehydrocostus lactone, psoracorylifol D, bavachinin, bakuchiol, showed an inhibitory effect on the proliferation and the capillary-like tube formation of TR-LE cells. In addition, all compounds showed selective inhibition of the proliferation of TR-LE cells compared to Hela and Lewis lung carcinoma (LLC) cells.

These compounds might offer clinical benefits as lymphangiogenesis inhibitors and may be good candidates for novel anti-cancer and anti-metastatic agents (Jeong et al., 2013).

Ovarian Cancer, MDR

The apoptosis-inducing effect of costunolide, a natural sesquiterpene lactone, was studied in platinum-resistant human ovarian cancer cells relative to cisplatin.

The MTT assay for cell viability, PI staining for cell-cycle profiling, and annexin V assay for apoptosis analysis were performed. Costunolide induced apoptosis of platinum-resistant cells in a time and dose-dependent manner and suppressed tumor growth in the SKOV3 (PT)-bearing mouse model. In addition, costunolide triggered the activation of caspase-3, caspase-8, and caspase-9. Pre-treatment with caspase inhibitors neutralized the pro-apoptotic activity of costunolide. We further demonstrated that costunolide induced a significant increase in intracellular reactive oxygen species (ROS). Moreover, costunolide synergized with cisplatin to induce cell death in platinum-resistant ovarian cancer cells.

Data suggests that costunolide, alone or in combination with cisplatin, may be of therapeutic potential in platinum-resistant ovarian cancers (Yang, Kim, Lee, & Choi, 2011).

Anti-inflammatory, Anti-oxidant, Mediates Apoptosis

Cheon et al. (2013) found that costunolide significantly inhibited RANKL-induced BMM differentiation into osteoclasts in a dose-dependent manner without causing cytotoxicity. Costunolide did not regulate the early signaling pathways of RANKL, including the mitogen-activated protein kinase and NF-κB pathways.

However, costunolide suppressed nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) expression via inhibition of c-Fos transcriptional activity without affecting RANKL-induced c-Fos expression. The inhibitory effects of costunolide were rescued by overexpression of constitutively active (CA)-NFATc1. Taken together, these results suggest that costunolide inhibited RANKL-induced osteoclast differentiation by suppressing RANKL-mediated c-Fos transcriptional activity.

References

Cheon YH, Song MJ, Kim JY, Kwak SC, Park JH, Lee CH, Kim JJ, Kim JY, Choi MK, Oh J, Kim YC, Yoon KH., Kwak HB, Lee MS. (2013). Costunolide inhibits osteoclast differentiation by suppressing c-Fos transcriptional activity. Phytotherapy, July, (6). doi: 10.1002/ptr.5034.

Choi SH, Im E, Kang HK, et al. (2005). Inhibitory effects of costunolide on the telomerase activity in human breast carcinoma cells. Cancer Lett, 227(2):153-62.


Choi JH, Lee KT. (2009). Costunolide-induced apoptosis in human leukemia cells: involvement of c-jun N-terminal kinase activation. Biol Pharm Bull, 32(10):1803-8.


Choi YK, Seo HS, Choi HS, et al. (2012). Induction of Fas-mediated extrinsic apoptosis, p21WAF1-related G2/M cell-cycle arrest and ROS generation by costunolide in estrogen receptor-negative breast cancer cells, MDA-MB-231. Mol Cell Biochem, 363(1-2):119-28. doi: 10.1007/s11010-011-1164-z.


Choi YK, Cho S-G, Woo S-M, et al. (2013). Saussurea lappa Clarke-Derived Costunolide Prevents TNF α-Induced Breast Cancer Cell Migration and Invasion by Inhibiting NF-κ B Activity. Evidence-Based Complementary and Alternative Medicine. doi:10.1155/2013/936257.


Hsu JL, Pan SL, Ho YF, Het al. (2011). Costunolide induces apoptosis through nuclear calcium2+ overload and DNA damage response in human prostate cancer. The Journal of Urology, 185(5):1967-74. doi: 10.1016/j.juro.2010.12.091.


Jeong D, Watari K, Shirouzu T, et al. (2013). Studies on lymphangiogenesis inhibitors from Korean and Japanese crude drugs. Biol Pharm Bull, 36(1):152-7.


Kim EJ, Hong JE, Lim SS, et al. (2012). The hexane extract of Saussurea lappa and its active principle, dehydrocostus lactone, inhibit prostate cancer cell migration. J Med Food, 15(1):24-32. doi: 10.1089/jmf.2011.1735.


Kretschmer N, Rinner B, Stuendl N, et al. (2012). Effect of costunolide and dehydrocostus lactone on cell-cycle, apoptosis, and ABC transporter expression in human soft tissue sarcoma cells. Planta Med, 78(16):1749-56. doi: 10.1055/s-0032-1315385.


Kuo PL, Ni WC, Tsai EM, Hsu YL. (2009). Dehydrocostuslactone disrupts signal transducers and activators of transcription 3 through up-regulation of suppressor of cytokine signaling in breast cancer cells. Mol Cancer Ther, 8(5):1328-39. doi: 10.1158/1535-7163.MCT-08-0914.


Peng ZX, Wang Y, Gu X, Wen YY, Yan C. (2013). A platform for fast screening potential anti-breast cancer compounds in traditional Chinese medicines. Biomed Chromatogr. doi: 10.1002/bmc.2990.


Rasul A, Bao R, Malhi M, et al. (2013). Induction of apoptosis by costunolide in bladder cancer cells is mediated through ROS generation and mitochondrial dysfunction. Molecules, 18(2):1418-33. doi: 10.3390/molecules18021418.


Yang YI, Kim JH, Lee KT, & Choi JH. (2011). Costunolide induces apoptosis in platinum-resistant human ovarian cancer cells by generating reactive oxygen species. Gynecologic Oncology, 123(3), 588-96. doi: 10.1016/j.ygyno.2011.08.031.