Category Archives: apoptosis

Indirubin

Cancer:
Chronic myelogenous leukemia, lung, breast, head and neck, prostate, acute myeloid leukemia, prostate

Action: Aryl hydrocarbon Receptor (AhR) regulator, inhibits angiogenesis

Indirubin is the active component of many plants from the Isatis (L.) genus, including Isatis tinctoria (L.).

Indirubin is the active ingredient of Danggui Longhui Wan, a mixture of plants that is used in traditional Chinese medicine to treat chronic diseases. Indirubin and its analogues are potent inhibitors of cyclin-dependent kinases (CDKs). The crystal structure of CDK2 in complex with indirubin derivatives shows that indirubin interacts with the kinase's ATP-binding site through van der Waals interactions and three hydrogen bonds. Indirubin-3'-monoxime inhibits the proliferation of a large range of cells, mainly through arresting the cells in the G2/M phase of the cell-cycle. These results have implications for therapeutic optimization of indigoids (Hoessel et al., 1999).

Formula; Huang Lian (Rhizoma Coptidis Recens), Huang Qin (Radix Scutellariae Baicalensis), Huang Bai (Cortex Phellodendri), Zhi Zi (Fructus Gardeniae Jasminoidis), Dang Gui (Radix Angelicae Sinensis), Lu Hui (Herba Aloes), Long Dan Cao (Radix Gentianae Longdancao), Da Huang (Radix et Rhizoma Rhei), Mu Xiang (Radix Aucklandiae Lappae), Qing Dai (Indigo Pulverata Levis), She Xiang (Secretio Moschus)

Leukemia

Indirubin, a 3, 2' bisindole isomer of indigo was originally identified as the active principle of a traditional Chinese preparation and has been proven to exhibit anti-leukemic effectiveness in chronic myelocytic leukemia. Indirubin was detected to represent a novel lead structure with potent inhibitory potential towards cyclin-dependent kinases (CDKs) resulting from high affinity binding into the enzymes ATP binding site. This seminal finding triggered research to improve the pharmacological activities of the parent molecule within comprehensive structure-activity studies. Molecular modifications made novel anti-cancer compounds accessible with strongly improved CDK inhibitory potential and with broad-spectrum anti-tumor activity.

This novel family of compounds holds strong promise for clinical anti-cancer activity and might be useful also in several important non-cancer indications, including Alzheimer's disease or diabetes (Eisenbrand et al., 2004).

Aryl Hydrocarbon Receptor (AhR) Regulator; Breast Cancer

The aryl hydrocarbon receptor (AhR), when activated by exogenous ligands such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), regulates expression of several phase I and phase II enzymes and is also involved in the regulation of cell proliferation. One putative endogenous ligand is indirubin, which was recently identified in human urine and bovine serum. We determined the effect of indirubin in MCF-7 breast cancer cells on induction of the activities of cytochromes P450 (CYP) 1A1 and 1B1. With 4 hours exposure, the effects of indirubin and TCDD at 10nM on CYP activity were comparable, but the effects of indirubin, unlike those of TCDD, were transitory. Indirubin-induced ethoxyresorufin-O-deethylase activity was maximal by 6–9 hours post-exposure and had disappeared by 24 hours, whereas TCDD-induced activities remained elevated for at least 72 hours.

Thus, if indirubin is an endogenous AhR ligand, then AhR-mediated signaling by indirubin is likely to be transient and tightly controlled by the ability of indirubin to induce CYP1A1 and CYP1B1, and hence its own metabolism (Spink et al., 2003).

Chronic Myelogenous Leukemia (CML)

Indirubin is the major active anti-tumor component of a traditional Chinese herbal medicine used for treatment of chronic myelogenous leukemia (CML). In a study investigating its mechanism of action, indirubin derivatives (IRDs) were found to potently inhibit Signal Transducer and Activator of Transcription 5 (Stat5) protein in CML cells.

Compound E804, which is the most potent in this series of IRDs, blocked Stat5 signaling in human K562 CML cells, imatinib-resistant human KCL-22 CML cells expressing the T315I mutant Bcr-Abl (KCL-22M), and CD34-positive primary CML cells from patients.

In sum, these findings identify IRDs as potent inhibitors of the SFK/Stat5 signaling pathway downstream of Bcr-Abl, leading to apoptosis of K562, KCL-22M and primary CML cells. IRDs represent a promising structural class for development of new therapeutics for wild type or T315I mutant Bcr-Abl-positive CML patients (Nam et al., 2012).

Lung Cancer

A novel indirubin derivative, 5'-nitro-indirubinoxime (5'-NIO), exhibits a strong anti-cancer activity against human cancer cells. Here, the 5'-NIO-mediated G1 cell-cycle arrest in lung cancer cells was associated with a decrease in protein levels of polo-like kinase 1 (Plk1) and peptidyl-prolyl cis/trans isomerase Pin1. These findings suggest that 5'-NIO have potential anti-cancer efficacy through the inhibition of Plk1 or/and Pin1 expression (Yoon et al., 2012).

The control lung tissue showed a normal architecture with clear alveolar spaces. Interestingly, the indirubin-3-monoxime treated groups showed reduced adenocarcinoma with appearance of alveolar spaces. Transmission Electron Microscopic (TEM) studies of lung sections of [B(α)P]-induced lung cancer mice showed the presence of phaemorphic cells with dense granules and increased mitochondria.

The lung sections of mice treated with indirubin-3-monoxime showed the presence of shrunken, fragmented, and condensed nuclei implying apoptosis. The effects were dose-dependent and prominent in 10 mg/kg/5 d/week groups, suggesting the therapeutic role of indirubin analogue against this deadly human malignancy. These results indicate that indirubin-3-monoxime brings anti-tumor effect against [B(α)P]-induced lung cancer by its apoptotic action in A/J mice (Ravichandran et al., 2010).

Head and Neck Cancer

The effects of 5'-nitro-indirubinoxime (5'-NIO), an indirubin derivative, on metastasis of head and neck cancer cells were investigated and the underlying molecular mechanisms involved in this process explored.

After treatment of head and neck cancer cells with 5'-NIO, cell metastatic behaviors such as colony formation, invasion, and migration were inhibited in a concentration-dependent manner. 5'-NIO inhibited the beta1 Integrin/FAK/Akt pathway which can then facilitate invasion and/or migration of cancer cells through the extracellular matrix (ECM). Moreover, treatment of head and neck cancer cell with Integrin β1 siRNA or FAK inhibitor effectively inhibited the invasion and migration, suggesting their regulatory role in invasiveness and migration of head and neck cancer cells. It was concluded that 5'-NIO inhibits the metastatic ability of head and neck cancer cells by blocking the Integrin β1/FAK/Akt pathway (Kim et al., 2011).

Prostate Cancer; Inhibits Angiogenesis

Indirubin, the active component of a traditional Chinese herbal medicine, Banlangen, has been shown to exhibit anti-tumor and anti-inflammation effects; however, its role in tumor angiogenesis, the key step involved in tumor growth and metastasis, and the involved molecular mechanism is unknown.

To address this shortfall in the existing research, it was identified that indirubin inhibited prostate tumor growth through inhibiting tumor angiogenesis. It was found that indirubin inhibited angiogenesis in vivo. The inhibition activity of indirubin in endothelial cell migration, tube formation and cell survival in vitro has also been shown. Furthermore, indirubin suppressed vascular endothelial growth factor receptor 2-mediated Janus kinase (JAK)/STAT3 signaling pathway. This study provided the first evidence for anti-tumor angiogenesis activity of indirubin and the related molecular mechanism.

These investigations suggest that indirubin is a potential drug candidate for angiogenesis-related diseases (Zhang et al., 2011).

Acute Myeloid Leukemia

Indirubin derivatives were identified as potent FLT3 tyrosine kinase inhibitors with anti-proliferative activity at acute myeloid leukemic cell lines, RS4;11 and MV4;11 which express FLT3-WT and FLT3-ITD mutation, respectively. Among several 5 and 5'-substituted indirubin derivatives, 5-fluoro analog, 13 exhibited potent inhibitory activity at FLT3 (IC(50)=15 nM) with more than 100-fold selectivity versus 6 other kinases and potent anti-proliferative effect for MV4;11 cells (IC(50)=72 nM) with 30-fold selectivity versus RS4;11 cells.

Cell cycle analysis indicated that compound 13 induced cell-cycle arrest at G(0)/G(1) phase in MV4;11 cells (Choi et al., 2010).

References

Choi SJ, Moon MJ, Lee SD, et al. (2010). Indirubin derivatives as potent FLT3 inhibitors with anti-proliferative activity of acute myeloid leukemic cells. Bioorg Med Chem Lett, 20(6):2033-7.


Eisenbrand G, Hippe F, Jakobs S, Muehlbeyer S. (2004). Molecular mechanisms of indirubin and its derivatives: novel anti-cancer molecules with their origin in traditional Chinese phytomedicine. J Cancer Res Clin Oncol, 130(11):627-35


Hoessel R, Leclerc S, Endicott JA, et al. (1999). Indirubin, the active constituent of a Chinese antileukaemia medicine, inhibits cyclin-dependent kinases. Nat Cell Biol, 1(1):60-7.


Kim SA, Kwon SM, Kim JA, et al. (2011). 5'-Nitro-indirubinoxime, an indirubin derivative, suppresses metastatic ability of human head and neck cancer cells through the inhibition of Integrin β 1/FAK/Akt signaling. Cancer Lett, 306(2):197-204.


Nam S, Scuto A, Yang F, et al. (2012). Indirubin derivatives induce apoptosis of chronic myelogenous leukemia cells involving inhibition of Stat5 signaling. Mol Oncol, 6(3):276-83.


Ravichandran K, Pal A, Ravichandran R. (2010). Effect of indirubin-3-monoxime against lung cancer as evaluated by histological and transmission electron microscopic studies. Microsc Res Tech, 73(11):1053-8.


Spink BC, Hussain MM, Katz BH, Eisele L, Spink DC. (2003). Transient induction of cytochromes P450 1A1 and 1B1 in MCF-7 human breast cancer cells by indirubin. Biochem Pharmacol, 66(12):2313-21.


Yoon HE, Kim SA, Choi HS, et al. (2012). Inhibition of Plk1 and Pin1 by 5'-nitro-indirubinoxime suppresses human lung cancer cells. Cancer Lett, 316(1):97-104.


Zhang X, Song Y, Wu Y, et al. (2011). Indirubin inhibits tumor growth by anti-tumor angiogenesis via blocking VEGFR2-mediated JAK/STAT3 signaling in endothelial cell. Int J Cancer, 129(10):2502-11. doi: 10.1002/ijc.25909.

Icaritin

Cancer:
Endometrial., chronic myeloid leukemia, prostate, breast

Action: Radio-sensitizer, cell-cycle arrest, ER modulator

Icaritin is a compound in several species of the genus Epimedium (L.).

Cell-cycle Arrest

Icariin and icaritin with prenyl group have been demonstrated to have selective estrogen receptor modulating activities. Icaritin-induced growth inhibition was associated with G(1) arrest (P<0.05), and G(2)-M arrest depending upon doses. Consistent with G(1) arrest, icaritin increased protein expressions of pRb, p27(Kip1) and p16(Ink4a), while showing decrease in phosphorylated pRb, Cyclin D1 and CDK4.

Comparatively, icariin has much lower effects on PC-3 cells and showed only weak G(1) arrest, suggesting a possible structure-activity relationship. These findings suggested a novel anti-cancer efficacy of icaritin mediated selectively via induction of cell-cycle arrest but not associated with estrogen receptors in PC-3 cells (Huang et al., 2007).

Estrogen Receptor (ER) Modulator; Endometrial Cancer

Icaritin has selective estrogen receptor (ER) modulating activities, and posseses anti-tumor activity. The effect of icaritin on cell growth of human endometrial cancer Hec1A cells was investigated and it was found that icaritin potently inhibited proliferation of Hec1A cells. Icaritin also induced cell apoptosis accompanied by activation of caspases. Icaritin treatment also induced expression of pro-apoptotic protein Bax with a concomitant decrease of Bcl-2 expression.

These results demonstrate that icaritin induced sustained ERK 1/2 activation and inhibited growth of endometrial cancer Hec1A cells, and provided a rationale for preclinical and clinical evaluation of icaritin for endometrial cancer therapy (Tong et al., 2011).

Breast cancer

In research carried out to probe breast cancer cell growth mechanisms, icaritin has been found to strongly inhibit the growth of breast cancer MDA-MB-453 and MCF7 cells. At concentrations of 2–3 µM, icaritin induced cell-cycle arrest at the G2/M phase accompanied by a down-regulation of the expression levels of the G2/M regulatory proteins such as cyclinB, cdc2 and cdc25C.

Icaritin at concentrations of 4–5 µM, however, induced apoptotic cell death. In addition, icaritin also induced a sustained phosphorylation of extracellular signal-regulated kinase (ERK) in these breast cancer cells.

Icaritin more potently inhibited growth of the breast cancer stem/progenitor cells compared to anti-estrogen tamoxifen. These results indicate that icaritin is a potent growth inhibitor for breast cancer cells and provides a rationale for preclinical and clinical evaluations of icaritin for breast cancer therapy (Guo et al., 2011).

Radio-sensitizer

The combination of Icaritin at 3 µM or 6 µM with 6 or 8 Gy of ionizing radiation (IR) in the clonogenic assay yielded an ER (enhancement ratio) of 1.18 or 1.28, CI (combination index) of 0.38 or 0.19 and DRI (dose reducing index) of 2.51 or 5.07, respectively. These findings strongly suggest that Icaritin exerted a synergistic killing effect with radiation on the tumor cells. It suppressed angiogenesis in chick embryo chorioallantoic membrane (CAM) assay. These results, taken together, indicate Icaritin is a new radio-sensitizer and can enhance anti-cancer effect of IR or other therapies (Hong et al., 2013).

Chronic Myeloid Leukemia (CML)

The mechanism of anti-leukemia for Icaritin is involved in the regulation of Bcr/Abl downstream signaling. Icaritin may be useful for an alternative therapeutic choice of Imatinib-resistant forms of CML. Icaritin potently inhibited proliferation of K562 cells (IC50 was 8 µM) and primary CML cells (IC50 was 13.4 µM for CML-CP and 18 µM for CML-BC), induced CML cells apoptosis, and promoted the erythroid differentiation of K562 cells in a time-dependent manner. Furthermore, Icaritin was able to suppress the growth of primary CD34+ leukemia cells (CML) and Imatinib-resistant cells, and to induce apoptosis (Zhu et al., 2011).

References

Guo YM, Zhang XT, Meng J, Wang ZY. (2011). An anti-cancer agent icaritin induces sustained activation of the extracellular signal-regulated kinase (ERK) pathway and inhibits growth of breast cancer cells. European Journal of Pharmacology, 658(2–3):114–122. doi:10.1016/j.ejphar.2011.02.005.


Hong J, Zhang Z, Lv W, et al. (2013). Icaritin Synergistically Enhances the Radiosensitivity of 4T1 Breast Cancer Cells. PLoS One, 8(8):e71347. doi: 10.1371/journal.pone.0071347.


Huang X, Zhu D, Lou Y. (2007). A novel anti-cancer agent, icaritin, induced cell growth inhibition, G1 arrest and mitochondrial transmembrane potential drop in human prostate carcinoma PC-3 cells. Eur J Pharmacol, 564(1-3):26-36.


Tong JS, Zhang QH, Huang X, et al. (2011). Icaritin Causes Sustained ERK1/2 Activation and Induces Apoptosis in Human Endometrial Cancer Cells. PLoS ONE, 6(3): e16781. doi:10.1371/journal.pone.0016781.


Zhu JF, Li ZJ, Zhang GS, et al. (2011). Icaritin shows potent anti-leukemia activity on chronic myeloid leukemia in vitro and in vivo by regulating MAPK/ERK/JNK and JAK2/STAT3 /AKT signalings. PLoS One, 6(8):e23720. doi: 10.1371/journal.pone.0023720.

Homoharringtonine/Omacetaxine

Cancer:
Leukemia, AML, CML, myelodysplastic syndrome (MDS)

Action: Induces apoptosis, anti-tumor activity

Homoharringtonine (also known as Omacetaxine mepesuccinate) is isolated from Cephalotaxus harringtonia (K.Koch).

Homoharringtonine/omacetaxine is a unique agent with a long history of research development. It has been recently approved by the Food and Drug Administration for the treatment of chronic myeloid leukemia after failure of 2 or more tyrosine kinase inhibitors. Research with this agent has spanned over 40 years (Kantarjian, O'Brien, & Cortes, 2013).

Leukemia

Homoharringtonine (HHT), first isolated from the Chinese evergreen Cephalotaxus harringtonia, has been demonstrated to have a broad anti-tumor activity in rodents and anti-leukemic effects in humans. It was found that HHT was metabolized to an acid product [HHT acid; 2'hydroxy2' (acetic acid) 6'hydroxy6'methylheptanoyl cephalotaxine] when incubated with either human plasma or mouse plasma in vitro. The HHT concentration inhibiting 50% of the growth of human leukemic HL60 cells was 20 ng/ml, while for HHT acid it was 14,500 ng/ml, indicating that the acid form was more than 700 times less cytotoxic than HHT. The lethal dose of HHT affecting 50%(LD50) of mice was 6.7 mg/kg, but HHT acid produced no apparent toxic effects at doses up to 280 mg/kg (Ni et al., 2003).

Acute Myeloid Leukemia (AML)

The response to remission induction in elderly patients with acute myeloid leukemia (AML) remains poor. Patients were treated with the HA regimen consisting of homoharringtonine (2 mg/m2/day for 7 days) and cytarabine (Ara-C, 100 mg/m2/day for 7 days). The overall response rate was 56.5% with complete remission (CR) rate of 39.1% and partial remission of 17.4%.

There was no early death in this cohort of patients. The estimated median overall survival (OS) time of all patients was (12.0 ± 3.0) months. The estimated OS time of the CR patients was 15 months. The estimated one-year OS rate of all patients treated with HA protocol was (49.3 ± 13.5) %. The estimated one-year OS rate of the CR patients was (62.5 ± 17.1) % (Wang et al., 2009).

Leukemia; Telomerase

The effect of HHT on the telomerase activity and apoptosis of human leukemia HL-60 cells was investigated. Telomerase activity of HL-60 cells was examined by the telomeric repeat amplification protocol (TRAP)–an enzyme-linked immunosorbent assay (ELISA). Apoptosis was analyzed by morphological observation, DNA agarose gel electrophoresis, flow cytometry (FCM), and TdT-mediated dUTP-biotin nick end labeling (TUNEL).

After treatment with HHT at 5-500 microg/l for 48 hours, the level of telomerase activity in HL-60 cells decreased in a dose-and time-dependent manner. Simultaneously, HL-60 cells underwent apoptosis. In conclusion, these data suggest that HHT can inhibit the telomerase content of HL- 60 cells effectively and induce apoptosis (Xie et al., 2006).

Chronic Myeloid Leukemia (CML)

Evidence confirmed HHT as an apoptosis inducer in tumor cell lines and fresh cells from cancer patients. The CR rate reported with HHT-based regimen in acute nonlymphocytic leukemia showed no statistical differences from that with DNR-based regimen, although the case number was limited.

Although with anti-growth activity in vitro and laudable achievement in acute and chronic myeloid leukemia treatment, the drug shows no beneficial effect in lymphocytic leukemia and solid tumors. The underlying mechanism for the discrepancy of efficacy remains unknown, and is a subject for further research (Luo et al., 2004).

Myelodysplastic Syndrome (MDS)

Homoharringtonine might have clinical activity in some patients with myelodysplastic syndrome (MDS) (Daver et al., 2013).

References

Daver N, Vega-Ruiz A, Kantarjian HM, et al. (2013). A phase II open-label study of the intravenous administration of homoharringtonine in the treatment of myelodysplastic syndrome. Eur J Cancer Care, 22(5):605-11. doi: 10.1111/ecc.12065.


Kantarjian HM, O'Brien S, Cortes J. (2013). Homoharringtonine/Omacetaxine mepesuccinate: the long and winding road to food and drug administration approval. Clin Lymphoma Myeloma Leuk, 13(5):530-3. doi: 10.1016/j.clml.2013.03.017.


Luo CY, Tang JY, Wang YP. (2004). Homoharringtonine: a new treatment option for myeloid leukemia. Hematology, 9(4):259-70.


Ni D, Ho DH, Vijjeswarapu M, et al. (2003). Metabolism of homoharringtonine, a cytotoxic component of the evergreen plant Cephalotaxus harringtonia. Journal of Experimental Therapeutics and Oncology, 3(1):47.


Wang J, LŸ S, Yang J, et al. (2009). A homoharringtonine-based induction regimen for the treatment of elderly patients with acute myeloid leukemia: a single center experience from China. Journal of Hematology & Oncology, 2:32. doi:10.1186/1756-8722-2-32


Xie WZ, Lin MF, Huang H, Cai Z. (2006). Homoharringtonine-induced apoptosis of human leukemia HL-60 cells is associated with down-regulation of telomerase. Am J Chin Med, 34(2):233-44.

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.

Hedyotis Diffusa Extract

Cancer: Colon

Action: CYP3A4 induction, inhibits angiogenesis

Hedyotis diffusa is a herb native to East Asia, particularly China, Japan, and Nepal.

Inhibition of tumor angiogenesis has become an attractive target of anti-cancer chemotherapy. However, drug resistance and cytotoxicity against non-tumor-associated endothelial cells limit the long-term use and the therapeutic effectiveness of angiogenesis inhibitors, thus increasing the necessity for the development of multi-target agents with minimal side effects. Hedyotis Diffusa Willd (EEHDW) has long been used as an important component in several TCM formulas to treat various types of cancer.

Inhibits Angiogenesis

The angiogenic effects of the ethanol extract of EEHDW were investigated, in order to find a molecular mechanism for its anti-cancer activity. It was found that EEHDW inhibited angiogenesis in vivo in chick embryo chorioallantoic membrane (CAM). In addition, EEHDW dose- and time-dependently inhibited the proliferation of human umbilical vein endothelial cells (HUVEC) by blocking the cell-cycle G1 to S progression.

Moreover, EEHDW inhibited the migration and tube formation of HUVECs. Furthermore, EEHDW treatment down-regulated the mRNA and protein expression levels of VEGF-A in HT-29 human colon carcinoma cells and HUVECs. These findings suggest that inhibiting tumor angiogenesis is one of the mechanisms by which EEHDW is involved in cancer therapy (Lin et al., 2011).

Colorectal Cancer

Hedyotis diffusa Willd has been used as a major component in several Chinese medicine formulas for the clinical treatment of colorectal cancer (CRC). The ethanol extract of Hedyotis diffusa Willd (EEHDW) reduced tumor volume and tumor weight, and suppressed STAT3 phosphorylation in tumor tissues, which in turn resulted in the promotion of cancer cell apoptosis and inhibition of proliferation. Moreover, EEHDW treatment altered the expression pattern of several important target genes of the STAT3 signaling pathway, i.e., decreased expression of Cyclin D1, CDK4 and Bcl-2 as well as up-regulated p21 and Bax (Cai et al., 2012).

EEHDW reduced HT-29 cell viability and survival in a dose- and time-dependent manner. Lin et al. (2012) observed that EEHDW treatment blocked the cell-cycle, preventing G1 to S progression, and reduced mRNA expression of pro-proliferative PCNA, Cyclin D1 and CDK4, but increased that of anti-proliferative p21 (Lin et al., 2012).

Recently, Lin et al. (2013) reported that HDW could inhibit colorectal cancer growth in vivo and in vitro via suppression of the STAT3 pathway. EEHDW could significantly reduce intratumoral microvessel density (MVD), indicating its activity of anti-tumor angiogenesis in vivo. EEHDW suppressed the activation of SHH signaling in CRC xenograft tumors since it significantly decreased the expression of key mediators of SHH pathway. EEHDW treatment inhibited the expression of the critical SHH signaling target gene VEGF-A as well as its specific receptor VEGFR2 (Lin et al., 2013).

CYP3A4 Induction

Patients are warned against the concomitant use of Oldenlandia diffusa and Rehmannia glutinosa, which could result in induction of CYP3A4, leading to a reduced efficacy of drugs that are CYP3A4 substrates and have a narrow therapeutic window (Lau et al., 2013).

References

Cai Q, Lin J, Wei L, Zhang L, et al. (2012). Hedyotis diffusa Willd Inhibits Colorectal Cancer Growth in Vivo via Inhibition of STAT3 Signaling Pathway. Int J Mol Sci, 13(5):6117-28. doi: 10.3390/ijms13056117.


Lau C, Mooiman KD, Maas-Bakker RF, et al. (2013). Effect of Chinese herbs on CYP3A4 activity and expression in vitro. J Ethnopharmacol, 149(2):543-9. doi: 10.1016/j.jep.2013.07.014.


Lin J, Wei L, Xu W, et al. (2011). Effect of Hedyotis Diffusa Willd extract on tumor angiogenesis. Mol Med Report, 4(6):1283-8. doi: 10.3892/mmr.2011.577.


Lin M, Lin J, Wei L, et al. (2012). Hedyotis diffusa Willd extract inhibits HT-29 cell proliferation via cell-cycle arrest. Exp Ther Med, 4(2):307-310.


Lin J, Wei L, Shen A, et al. (2013). Hedyotis diffusa Willd extract suppresses Sonic hedgehog signaling leading to the inhibition of colorectal cancer angiogenesis. Int J Oncol, 42(2):651-6. doi: 10.3892/ijo.2012.1753.

Gypenosides

Cancer: Leukemia, colorectal., oral., esophageal

Action: Apoptosis,inhibits cell proliferation and migration

Gypenosides (Gyp), found in Gynostemma pentaphyllum Makino [(Thunb) Makino], have been used as folk medicine for centuries and have exhibited diverse pharmacological effects, including anti-leukemia effects in vitro and in vivo.

Gyp have been used to examine effects on cell viability, cell-cycle, and induction of apoptosis in vitro. They were administered in the diet to mice injected with WEHI-3 cells in vivo. Gyp inhibited the growth of WEHI-3 cells. These effects were associated with the induction of G0/G1 arrest, morphological changes, DNA fragmentation, and increased sub-G1 phase. Gyp promoted the production of reactive oxygen species, increased Ca2+ levels, and induced the depolarization of the mitochondrial membrane potential.

The effects of Gyp were dose- and time-dependent. Moreover, Gyp increased levels of the pro-apoptotic protein Bax, reduced levels of the anti-apoptotic proteins Bcl-2, and stimulated release of cytochrome c, AIF (apoptosis-inducing factor), and Endo G (endonuclease G) from mitochondria. The levels of GADD153, GRP78, ATF6-α, and ATF4-α were increased by Gyp, resulting in ER (endoplasmic reticular) stress in WEHI-3 cells. Oral consumption of Gyp increased the survival rate of mice injected with WEHI-3 cells used as a mouse model of leukemia.

Results of these experiments provide new information on understanding mechanisms of Gyp-induced effects on cell-cycle arrest and apoptosis in vitro and in an in vivo animal model (Hsu et al., 2011).

Inhibits Cell Proliferation and Migration

Results indicated that Gypenosides (Gyp) inhibited cell proliferation and migration in SW620 and Eca-109 cells in dose- and time-dependent manner. Gyp elevated intracellular ROS level, decreased the Δψ m, and induced apoptotic morphology such as cell shrinkage and chromatin condensation, suggesting oxidative stress and mitochondria-dependent cell apoptosis that might be involved in Gyp-induced cell viability loss in SW620 and Eca-109 cells. The findings indicate Gyp may have valuable application in clinical colon cancer and esophageal cancer treatments (Yan et al., 2013).

Gyp-induced cell death occurs through caspase-dependent and caspase-independent apoptotic signaling pathways, and the compound reduced tumor size in a xenograft nu/nu mouse model of oral cancer.

Gyp induced morphological changes, decreased the percentage of viable cells, caused G0/G1 phase arrest, and triggered apoptotic cell death in SAS cells. Cell-cycle arrest induced by Gyp was associated with apoptosis. The production of ROS, increased intracellular Ca(2+) levels, and the depolarization of ΔΨ(m) were observed. Gyp increased levels of the pro-apoptotic protein Bax but inhibited the levels of the anti-apoptotic proteins Bcl-2 and Bcl-xl. Gyp also stimulated the release of cytochrome c and Endo G. Translocation of GADD153 to the nucleus was stimulated by Gyp. Gyp in vivo attenuated the size and volume of solid tumors in a murine xenograft model of oral cancer (Lu et al., 2012).

Cell-cycle Arrest

Lin et al. (2011) have shown that gypenosides (Gyp) induced cell-cycle arrest and apoptosis in many human cancer cell lines. In the present study the effects of Gyp on cell morphological changes and viability, cell-cycle arrest and induction of apoptosis in vitro and effects on Gyp in an in vivo murine xenograft model were demonstrated. Results indicated that Gyp induced morphological changes, decreased cell viability, induced G0/G1 arrest, DNA fragmentation and apoptosis (sub-G1 phase) in HL-60 cells. Gyp increased reactive oxygen species production and Ca(2+) levels but reduced mitochondrial membrane potential in a dose- and time-dependent manner.

Oral consumption of Gyp reduced tumor size of HL-60 cell xenograft mode mice in vivo. These results provide new information on understanding mechanisms by which Gyp induces cell-cycle arrest and apoptosis in vitro and in vivo (Lin et al., 2011).

References

Hsu HY, Yang JS, Lu KW, et al. (2011). An Experimental Study on the Anti-leukemia Effects of Gypenosides In Vitro and In Vivo. Integr Cancer Ther, 10(1):101-12. doi: 10.1177/1534735410377198.


Lin JJ, Hsu HY, Yang JS, et al. (2011). Molecular evidence of anti-leukemia activity of gypenosides on human myeloid leukemia HL-60 cells in vitro and in vivo using a HL-60 cells murine xenograft model. Phytomedicine,18(12):1075-85. doi: 10.1016/j.phymed.2011.03.009.


Lu KW, Chen JC, Lai TY, et al. (2012). Gypenosides suppress growth of human oral cancer SAS cells in vitro and in a murine xenograft model: the role of apoptosis mediated by caspase-dependent and caspase-independent pathways. Integr Cancer Ther, 11(2):129-40. doi: 10.1177/1534735411403306.


Yan H, Wang X, Wang Y, Wang P, Xiao Y. (2013). Antiproliferation and anti-migration induced by gypenosides in human colon cancer SW620 and esophageal cancer Eca-109 cells. Hum Exp Toxicol.

Guggulsterones

Cancer: Leukemia, cervical cancer

Action: MDR

Guggulsterones are isolated from Commiphora wightii [(Arn.) Bhandari].

Leukemia

The anti-leukemic effects of three isomeric pregnadienedione steroids, cis-guggulsterone, trans-guggulsterone, and 16-dehydroprogesterone, were investigated in HL60 and U937 cells as well as in primary leukemic blasts in culture. Results showed that all three compounds inhibited the proliferation of HL60 and U937 cells, with IC50s ranging from 3.6 to 10.9 µmol/L after treatment for 6 days. These growth-inhibitory effects correlated with externalization of phosphatidylserine and loss of mitochondrial membrane potential., suggesting that these isomeric steroids induce apoptosis in leukemia cells. z-VAD-fmk prevented phosphatidylserine externalization but not mitochondrial membrane potential loss, indicating that mitochondrial dysfunction occurred in the absence of caspase activation.

Interestingly, although all three compounds increased the generation of reactive oxygen species and decreased phosphorylation of extracellular signal-regulated kinase, only cis-guggulsterone induced a rapid depletion of reduced glutathione levels and oxidation of the mitochondrial phospholipid cardiolipin.

Guggulsterones and 16-dehydroprogesterone hence exert anti-leukemic effects via the induction of apoptosis and differentiation and, more importantly, identifies the pregnadienedione structure as a potential chemotherapeutic scaffold (Samudio et al., 2005).

Multi-drug Resistance

Natural phytosterols, such as beta-sitosterol, campesterol, stigmasterol, fucosterol, and z-guggulsterone, are found in foods, herbs, and dietary supplements. The effects of dietary plant sterols on human drug efflux transporters P-glycoprotein (P-gp, ABCB1) and multi-drug resistance protein 1 (MRP1, ABCC1) were investigated using P-gp-overexpressing human carcinoma KB-C2 cells and human MRP1 gene-transfected KB/MRP cells.

The accumulation of daunorubicin or rhodamine 123, fluorescent substrates of P-gp, increased in the presence of guggulsterone in KB-C2 cells. The efflux of rhodamine 123 from KB-C2 cells was inhibited by guggulsterone. Guggulsterone also increased the accumulation of calcein, a fluorescent substrate of MRP1, in KB/MRP cells. The ATPase activities of P-gp and MRP1 were stimulated by guggulsterone.

These results suggest that guggulsterone, a natural dietary hypolipidemic agent, have dual inhibitory effects on P-gp and MRP1 and the potencies to cause food-drug interactions.

References

Nabekura T, Yamaki T, Ueno K, Kitagawa S. (2008). Effects of plant sterols on human Multi-drug transporters ABCB1 and ABCC1. Biochemical and Biophysical Research Communications, 369(2), 363-368. doi: 10.1016/j.bbrc.2008.02.026.


Samudio I, Konopleva M, Safe S, et al. (2005). Guggulsterones induce apoptosis and differentiation in acute myeloid leukemia: identification of isomer-specific antileukemic activities of the pregnadienedione structure. Mol Cancer Ther, 4:1982. doi: 10.1158/1535-7163.MCT-05-0247.

Glycyrrhiza Uralensis: Glycyrrhizin, Isoliquiritigenin

Cancer:
Cervical., breast, stomach, liver, hepatoma, prostate

Action: Induces apoptosis

The active components of Glycyrrhiza uralensis include the total flavones extracted from Chinese licorice, Glycyrrhiza uralensis Fisch.

Stomach Cancer, Hepatoma, Breast Cancer, Cervical Cancer

The anti-proliferation effect of glycyrrhizhin and total flavones extracted from Chinese licorice, Glycyrrhiza uralensis Fisch, on four kinds of human cancer cells (cervix tumor cell; Hela, breast tumor cell; Bcap-37, stomach tumor cell; MGC-803 and hepatoma cell; Bel-7404) were studied. MTT showed that the anti-proliferation effect of glycyrrhizin was concentration-dependent; higher concentration of glycyrrhizin (1000µg/ml) had obvious anti-tumor effect; within certain concentrations of (200~1000µg/ml), inhibitory effect of total flavones was also concentration dependent; the lower concentration (200µg/ml) was of the highest inhibitory effect: its inhibiting rates on Bcap-37, Hela, Bel-7404, MGC-803 were 79.55%, 79.98%, 67.91% and 37.86% respectively.

Both glycyrrhizin and total flavones have stronger apoptosis-inducing effects on the four kinds of tumor cells (Ma et al., 2008).

Prostate Cancer

Kanazawa et al. (2003) investigated the anti-tumor effect of isoliquiritigenin on prostate cancer in vitro. DU145 and LNCaP prostate cancer cell lines were used as targets. The effects of isoliquiritigenin were examined on cell proliferation, cell-cycle regulation and cell-cycle-regulating gene expression. Further, they investigated the effects of isoliquiritigenin on the GADD153 mRNA and protein expression, and promoter activity. Isoliquiritigenin significantly inhibited the proliferation of prostate cancer cell lines in a dose-dependent and time-dependent manner. These findings suggest that isoliquiritigenin is a candidate agent for the treatment of prostate cancer and GADD153 may play an important role in isoliquiritigenin-induced cell-cycle arrest and cell growth inhibition.

References

Kanazawa M, Satomi Y, Mizutani Y, et al. (2003). Isoliquiritigenin inhibits the growth of prostate cancer. Eur Urol. 43(5):580-6.


Ma M, Zhou X-l, Hu Y-l, et al. (2008). Lishizhen Medicine and Materia Medica Research. doi: CNKI:SUN:SZGY.0.2008-01-006

Germacrone

Cancer: Breast, stomach

Action: Cell-cycle arrest

Traditional medicinal herbs are an untapped source of potential pharmaceutical compounds. Germacrone is a natural product isolated from Rhizoma curcuma longa (L.).

Breast Cancer

Germacrone has been investigated for its inhibition on the proliferation of breast cancer cell lines. Germacrone treatment significantly inhibited cell proliferation, increased lactate dehydrogenase (LDH) release, and induced mitochondrial membrane potential (ΔΨ m) depolarization in both MCF-7 and MDA-MB-231 cells in a dose-dependent manner. Germacrone induced MDA-MB-231 and MCF-7 cell-cycle arrest at the G0/G1 and G2/M phases respectively and induced MDA-MB-231 cell apoptosis.

In addition, germacrone treatment induced caspase-3, 7, 9, PARP cleavage. It was therefore concluded that germacrone inhibited the proliferation of breast cancer cell lines by inducing cell-cycle arrest and apoptosis through mitochondria-mediated caspase pathway. These results might provide some molecular basis for the anti-tumor activity of Rhizoma curcuma (Zhong et al., 2011).

Stomach Cancer

Germacrone, contained in zedoary oil from Rhizoma curcuma, significantly decreased the cell viability of AGS cells (P < 0.01) and MGC 803 cells (P < 0.01), and the inhibitory effects were attenuated by elevated concentrations of FBS. At high concentrations (>=90 mug/mL), zedoary oil killed GES-1 cells. At low concentrations (<=60 mug/mL), zedoary oil was less inhibitory toward gastric cancer cell lines. In AGS cells, zedoary oil inhibited cell proliferation in a dose- and time-dependent manner, with decreased PCNA protein expression in the zedoary oil-treated cells, and arrested the cell-cycle at S, G2/M and G0/G1 stages after treatment for 6–48 hours. At concentrations of 30, 60 and 90 mug/mL, which resulted in significant inhibition of proliferation and cell-cycle arrest, zedoary oil induced cell apoptosis.

Zedoary oil up-regulated the ratio of Bax/Bcl-2 protein expression (P < 0.01). Zedoary oil which contains germacrone was hence found to inhibit AGS cell proliferation through cell-cycle arrest and cell apoptosis promotion, which are related to Bax/Bcl-2 protein expression.

References

Shi H, Tan B, Ji G, et al. (2013). Zedoary oil (Ezhu You) inhibits proliferation of AGS cells. Chin Med, 8(1):13.


Zhong Z, Chen X, Tan W, et al. (2011). Germacrone inhibits the proliferation of breast cancer cell lines by inducing cell-cycle arrest and promoting apoptosis. Eur J Pharmacol, 667(1-3):50-55. doi:10.1016/j.ejphar.2011.03.041.

Geraniin

Cancer: Melanoma, T cell leukemia, cervical

Action: Causes cell-cycle arrest

Melanoma

Geraniin, a form of tannin separated from Geranium genus (including Geranium niveum (S. Watson)), causes cell death through induction of apoptosis. Geraniin triggered cell death by caspase-3-mediated cleavage of FAK and was associated with the up-regulation of Fas ligand expression, the activation of caspase-8, the cleavage of Bid, and the induction of cytochrome c release from mitochondria to the cytosol in human melanoma cells (Lee et al., 2008).

Leukemia, Cervical Cancer

Different concentrations of geraniin, the level of expression of the client proteins c-Raf, pAkt, and EGFR, was strongly down-regulated. Geraniin was able to inhibit in vitro the Hsp90α ATPase activity in a dose-dependent manner, with an inhibitory efficiency comparable to that measured for 17-AAG. In addition, this compound compromised the chaperone activity of Hsp90α, monitored by the citrate synthase thermal induced aggregation assay. Geraniin decreased the viability of HeLa and Jurkat cell lines and caused an arrest in G2/M phase. These results, along with the finding that geraniin did not exert any appreciable cytotoxicity on normal cells, encourage further studies on this compound as a promising chemical scaffold for the design of new Hsp90 inhibitors (Vassallo et al., 2013).

References

Lee JC, Tsai CY, Kao JY, et al. (2008). Geraniin-mediated apoptosis by cleavage of focal adhesion kinase through up-regulation of Fas ligand expression in human melanoma cells. Mol Nutr Food Res, 52(6):655-63.


Vassallo A, Vaccaro MC, De Tommasi N, Dal Piaz F, Leone A. (2013). Identification of the plant compound geraniin as a novel hsp90 inhibitor. PLoS One, 8(9):e74266. doi: 10.1371/journal.pone.0074266.

Gentianaceae

Cancer: Prostate, breast, lung, pancreatic

Action: Causes cell-cycle arrest

Gentianaceae is a naturally occurring alkaloid isolated from Sophora flavescens (Aiton).

Prostate Cancer; AR-

Gentianaceae has shown anti-proliferative properties in a number of types of cancer, including breast, gastric, lung and pancreatic tumors. Gentianaceae was also found to promote apoptosis and inhibit invasion of cancer cells.

The anti-tumor effects of gentianaceae were evaluated on androgen-independent PC-3 prostate cancer cells. The effects of gentianaceae on cell-cycle progression and apoptosis of PC-3 cells were tested. Gentianaceae-treated PC-3 cells underwent G0/G1 cell-cycle arrest. There was a significant reduction in the number of S phase and G2/M phase cells in the treated group when compared to untreated cells.

There was also an increase in the number of necrotic cells in the gentianaceae-treated group when compared to untreated cells. Gentianaceae treatment resulted in increased levels of caspase-3 and Bax and decreased levels of Bcl-2. The data suggest that gentianaceae inhibits the proliferation of androgen-independent prostate cancer cells by causing G0/G1 cell-cycle arrest and promoting apoptosis. Gentianaceae-induced apoptosis was mediated by down-regulation of Bcl-2/Bax ratios and up-regulation of caspase-3 levels (Zhang et al., 2012).

Reference

Zhang P, Wang Z, Chong T, Ji Z. (2012). Matrine inhibits proliferation and induces apoptosis of the androgen “American Typewriter”; “American Typewriter”;‑ independent prostate cancer cell line PC-3. Mol Med Report, 5(3):783-7. doi: 10.3892/mmr.2011.701.

Geniposide –Penta-acetyl Geniposide (Ac)5GP

Cancers:
Glioma, melanoma, liver, hepatocarcinogenesis, hepatoma, prostate, cervical

Action: Cytostatic, induces apoptosis

Gardenia, the fruit of Gardenia jasminoides Ellis, has been widely used to treat liver and gall bladder disorders in Chinese medicine. It has been shown recently that geniposide, the main ingredient of Gardenia fructus , exhibits anti-tumor effect.

Hepatocarcinogenesis, Glioma

It has been demonstrated that (Ac)5GP plays more potent roles than geniposide in chemoprevention. (Ac)5GP decreased DNA damage and hepatocarcinogenesis, induced by aflatoxin B1 (AFB1), by activating the phase II enzymes glutathione S-transferase (GST) and GSH peroxidase (GSH-Px). It reduced the growth and development of inoculated C6 glioma cells, especially in pre-treated rats. In addition to the preventive effect, (Ac)5GP exerts its actions on apoptosis and growth arrest.

Treatment of (Ac)5GP caused DNA fragmentation of glioma cells. (Ac)5GP induced sub- G1 peak through the activation of apoptotic cascades PKCdelta/JNK/Fas/caspase8 and caspase 3. It arrested the cell-cycle at G0/ G1 by inducing the expression of p21, thus suppressing the cyclin D1/cdk4 complex formation and the phosphorylation of E2F.

Data from in vivo experiments indicated that (Ac)5GP is not harmful to the liver, heart and kidney. (Ac)5GP is strongly suggested to be an anti-tumor agent for development in the future (Peng, Huang, & Wang, 2005).

Induces Apoptosis

Previous studies have demonstrated the apoptotic cascades protein kinase C (PKC) delta/c-Jun NH2-terminal kinase (JNK)/Fas/caspases induced by penta-acetyl geniposide [(Ac)5GP]. However, the upstream signals mediating PKCdelta activation have not yet been clarified. Ceramide, mainly generated from the degradation of sphingomyelin, was hypothesized upstream above PKCdelta in (Ac)5GP-transduced apoptosis.

After investigation, (Ac)5GP was shown to activate neutral sphingomyelinase (N-SMase) immediately, with its maximum at 15 min. The NGF and p75 enhanced by (Ac)5GP was inhibited when combined with GW4869, the N-SMase inhibitor, indicating NGF/p75 as the downstream signals of N-SMase/ceramide. To evaluate whether N-SMase is involved in (Ac)5GP-transduced apoptotic pathway, cells were treated with (Ac)5GP, alone or combined with GW4869. It was demonstrated that N-SMase inhibition blocked FasL expression and caspase 3 activation. Similarly, p75 antagonist peptide attenuated the FasL/caspase 3 expression. It indicated that N-SMase activation is pivotal in (Ac)5GP-mediated apoptosis.

SMase and NGF/p75 are suggested to mediate upstream above PKCdelta, thus transducing FasL/caspase cascades in (Ac)5GP-induced apoptosis (Peng, Huang, Hsu, & Wang, 2006).

Glioma

Penta-acetyl geniposide [(Ac)(5)GP], an acetylated geniposide product from Gardenia fructus, has been known to have hepato-protective properties and recent studies have revealed its anti-proliferative and apoptotic effect on C6 glioma cells. The anti-metastastic effect of (Ac)(5)GP in the rat neuroblastoma line C6 glioma cells were investigated.

Further (Ac)(5)GP also exerted an inhibitory effect on phosphoinositide 3-kinase (PI3K) protein expression, phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and inhibition of activation of transcription factor nuclear factor kappa B (NF-kappaB), c-Fos, c-Jun.

Findings suggest (Ac)(5)GP is highly likely to be an inhibiting cancer migration agent to be further developed in the future (Huang et al., 2009).

Melanoma

A new iridoid glycoside, 10-O-(4'-O-methylsuccinoyl) geniposide, and two new pyronane glycosides, jasminosides Q and R, along with nine known iridoid glycosides, and two known pyronane glycosides, were isolated from a MeOH extract of Gardeniae Fructus, the dried ripe fruit of Gardenia jasminoides (Rubiaceae).

The structures of new compounds were elucidated on the basis of extensive spectroscopic analyzes and comparison with literature. Upon evaluation of these compounds on the melanogenesis in B16 melanoma cells induced with α-melanocyte-stimulating hormone (α-MSH), three compounds, i.e., 6-O-p-coumaroylgeniposide (3), 7, and 6'-O-sinapoyljasminoside (12), exhibited inhibitory effects with 21.6-41.0 and 37.5-47.7% reduction of melanin content at 30 and 50 µM, respectively, with almost no toxicity to the cells (83.7-106.1% of cell viability at 50 µM) (Akisha et al., 2012).

Hepatoma, Prostate Cancer, Cervical Cancer

Genipin is a metabolite of geniposide isolated from an extract of Gardenia fructus. Some observations suggested that genipin could induce cell apoptosis in hepatoma cells and PC3 human prostate cancer cells. Genipin could remarkably induce cytotoxicity in HeLa cells and inhibit its proliferation. Induction of the apoptosis by genipin was confirmed by analysis of DNA fragmentation and induction of sub-G(1) peak through flow cytometry.

The results also showed that genipin-treated HeLa cells cycle was arrested at G(1) phase. Western blot analysis revealed that the phosphorylated c-Jun NH(2)-terminal kinase (JNK) protein, phospho-Jun protein, p53 protein and bax protein significantly increased in a dose-dependent manner after treatment of genipin for 24 hours; the activation of JNK may result in the increase of the p53 protein level; the increase of the p53 protein led to the accumulation of bax protein; and bax protein further induced cell apoptotic death eventually (Cao et al., 2010).

References

Akihisa T, Watanabe K, Yamamoto A, et al. (2012). Melanogenesis inhibitory activity of monoterpene glycosides from Gardeniae Fructus. Chemistry & Biodiversity, 9(8), 1490-9. doi: 10.1002/cbdv.201200030.


Cao H, Feng Q, Xu W, et al. (2010). Genipin induced apoptosis associated with activation of the c-Jun NH2-terminal kinase and p53 protein in HeLa cells. Biol Pharm Bull, 33(8):1343-8.


Huang HP, Shih YW, Wu CH, et al. (2009). Inhibitory effect of penta-acetyl geniposide on C6 glioma cells metastasis by inhibiting matrix metalloproteinase-2 expression involved in both the PI3K and ERK signaling pathways. Chemico-biological Interactions, 181(1), 8-14. doi: 10.1016/j.cbi.2009.05.009.


Peng CH, Huang CN, Hsu SP, Wang CJ. (2006). Penta-acetyl geniposide induce apoptosis in C6 glioma cells by modulating the activation of neutral sphingomyelinase-induced p75 nerve growth factor receptor and protein kinase Cdelta pathway. Molecular Pharmacology, 70(3), 997-1004.


Peng CH, Huang CN, Wang CJ. (2005). The anti-tumor effect and mechanisms of action of penta-acetyl geniposide. Current Cancer Drug Targets, 5(4), 299-305.

Ferula Gummosa Boiss Extract

Cancer: Gastric

Action: Anti-oxidant, Anti-hemolytic

Ferula gummosa Boiss. (Barije) is an Iranian endemic plant growing in the northern mountainous regions. The gum extracted from the aerial parts of the plant has been traditionally used in the treatment of wounds, stomach pain and chorea. For the first time, anti-proliferative activity and apoptosis-inducing effects of ethanol extracts of the F. gummosa Boiss. leaf and flower were examined.

Gastric Cancer

The ethanol extracts were examined for their anti-proliferative and apoptosis inducing activity in human gastric cancer cell line, AGS, using concentrations from 10–70µg/mL.   F. gummosa Boiss. extracts inhibited the cell proliferation of AGS cell line in a dose-dependent manner with an IC50 of 37.47µg/mL for flower and 32.99µg/mL for leaf extracts. F. gummosa Boiss. extracts also induced apoptosis as shown by analysis of DNA fragmentation and plasma membrane translocation of phosphatidyl serine. F. gummosa Boiss. extracts exerted anti-proliferative as well as apoptosis induction effect in gastric cancer cell line. Further studies are needed for elucidation of the biochemical performance details and biological activity of the oleo gum-resin from Ferula gummosa Boiss which has shown acetylcholinesterase (AChE) inhibitory activity (Adhami et al., 2013).

Anti-oxidant, Anti-hemolytic activities

F. gummosa Boiss root showed different level anti-oxidant and anti-hemolytic activities. Biological effects may be attributed, at least in part, to the presence of phenols and flavonoids in the extract (Ebrahimzadeh et al., 2011).

References

Adhami HR, Scherer U, Kaehlig H, et al. (2013). Combination of bioautography with HPTLC-MS/NMR: a fast identification of acetylcholinesterase inhibitors from galbanum( ). Phytochem Anal., 24(4):395-400. doi: 10.1002/pca.2422.


Ebrahimzadeh MA, Nabavi SM, Nabavi SF, Dehpour AA. (2011). Anti-oxidant activity of hydroalcholic extract of Ferula gummosa Boiss roots. Eur Rev Med Pharmacol Sci, 15(6):658-64.


Gharaei R, Akrami H, Heidari S, Asadib MH, Jalilic A. (2013). The suppression effect of Ferula gummosa Boiss. extracts on cell proliferation through apoptosis induction in gastric cancer cell line. European Journal of Integrative Medicine, 5(3):241-247.

Eugenol

Cancer:
Melanoma, osteosarcoma, leukemia, gastric, colon, liver, oral., lung

Action: Radio-protective

Eugenol is a natural compound available in honey and various plants extracts; in particular, cloves (Syzygium aromaticum (L.) Merrill & Perry).

Melanoma, Skin Tumors, Osteosarcoma, Leukemia, Gastric Cancer

Eugenol (4-allyl-2-methoxyphenol), a phenolic phytochemicals, is the active component of Syzigium aromaticum (cloves). Aromatic plants like nutmeg, basil, cinnamon and bay leaves also contain eugenol. Eugenol has a wide range of applications like perfumeries, flavorings, essential oils and in medicine as a local antiseptic and anesthetic. Increasing volumes of literature show eugenol possesses anti-oxidant, anti-mutagenic, anti-genotoxic, anti-inflammatory and anti-cancer properties.

The molecular mechanism of eugenol-induced apoptosis in melanoma, skin tumors, osteosarcoma, leukemia, gastric and mast cells has been well documented and highlights the anti-proliferative activity and molecular mechanism of eugenol-induced apoptosis against the cancer cells and animal model (Jaganathan et al., 2012).

Colon Cancer

Since most of the drugs used in cancer are apoptosis-inducers, the apoptotic effect and anti-cancer mechanism of eugenol were investigated against colon cancer cells. MTT assay signified the anti-proliferative nature of eugenol against the tested colon cancer cells. PI staining indicated increasing accumulation of cells at sub-G1-phase. Eugenol treatment resulted in reduction of intracellular non-protein thiols and increase in the earlier lipid layer break. Further events like dissipation of MMP and generation of ROS (reactive oxygen species) were accompanied in the eugenol-induced apoptosis. Augmented ROS generation resulted in the DNA fragmentation of treated cells as shown by DNA fragmentation and TUNEL assay. Further activation of PARP (polyadenosine diphosphate-ribose polymerase), p53 and caspase-3 were observed in Western blot analyzes.

These results demonstrate the molecular mechanism of eugenol-induced apoptosis in human colon cancer cells. This research will further enhance eugenol as a potential chemo-preventive agent against colon cancer (Jaganathan et al., 2011).

Radio-protective, Skin Cancer, Liver Cancer, Oral Cancer, Lung Cancer

Ocimum sanctum L. or Ocimum tenuiflorum L , commonly known as Holy Basil in English or Tulsi in the various Indian languages, is an important medicinal plant in the various traditional and folk systems of medicine in Southeast Asia, and another plant from which eugenol is extracted. Scientific studies have shown it to possess anti-inflammatory, analgesic, anti-pyretic, anti-diabetic, hepato-protective, hypolipidemic, anti-stress, and immunomodulatory activities. Preclinical studies have also shown that Ocimum and some of its phytochemicals including eugenol prevented chemical-induced skin, liver, oral., and lung cancers and to mediate these effects by increasing the anti-oxidant activity, altering the gene expressions, inducing apoptosis, and inhibiting angiogenesis and metastasis.

The aqueous extract of Ocimum and its flavanoids, orintin and vicenin, are shown to protect mice against γ-radiation-induced sickness and mortality and to selectively protect the normal tissues against the tumoricidal effects of radiation. This action is related to the important phytochemicals it contains like eugenol, which are also shown to prevent radiation-induced DNA damage.

References

Baliga MS, Jimmy R, Thilakchan KR, et al. (2013). Ocimum sanctum L (Holy Basil or Tulsi) and its phytochemicals in the prevention and treatment of cancer. Nutr Cancer, 65(1):26-35. doi: 10.1080/01635581.2013.785010.


Jaganathan SK, Mazumdar A, Mondhe D, Mandal M. (2011). Apoptotic effect of eugenol in human colon cancer cell lines. Cell Biol Int, 35(6):607-15. doi: 10.1042/CBI20100118.


Jaganathan SK, Supriyanto E. (2012). Anti-proliferative and Molecular Mechanism of Eugenol-Induced Apoptosis in Cancer Cells. Molecules, 17(6):6290-6304. doi:10.3390/molecules17066290.

EGCG, ECG, CG, EC

Cancer: Breast, pancreatic, lung, colorectal

Action: Chemo-preventive effects, metastasis

(-)-Epigallocatechin gallate (EGCG) is isolated from Camellia sinensis [(L.) Kuntze].

Epidemiological evidence suggests tea (Camellia sinensis L.) has chemo-preventive effects against various tumors. (-)-Epigallocatechin gallate (EGCG), a catechin polyphenol compound, represents the main ingredient of green tea extract and is chemo-preventive and an anti-oxidant. EGCG shows growth inhibition of various cancer cell lines, such as lung, mammary, and stomach.

Breast Cancer, Colorectal Cancer

Although EGCG has been shown to be growth-inhibitory in a number of tumor cell lines, it is not clear whether the effect is cancer-specific. The effect of EGCG on the growth of SV40 virally transformed WI38 human fibroblasts (WI38VA) was compared with that of normal WI38 cells. The IC50 value of EGCG was estimated to be 120 and 10 microM for WI38 and WI38VA cells, respectively. Similar differential growth inhibition was also observed between a human colorectal cancer cell line (Caco-2), a breast cancer cell line (Hs578T) and their respective normal counterparts.

EGCG at a concentration range of 40-200 microM induced a significant amount of apoptosis in WI38VA cultures, but not in WI38 cultures, as determined by terminal deoxynucleotidyl transferase assay. It is possible that differential modulation of certain genes, such as c-fos and c-myc, may cause differential effects of EGCG on the growth and death of cancer cells (Chen et al., 1998).

Breast Cancer

Green tea contains many polyphenols, including epigallocatechin-3 gallate (EGCG), which possess anti-oxidant qualities. Reduction of chemically-induced mammary gland carcinogenesis by green tea in a carcinogen-induced rat model has been suggested previously, but the results reported were not statistically significant. Green tea significantly increased mean latency to the first tumor, and reduced tumor burden and number of invasive tumors per tumor-bearing animal; however, it did not affect tumor number in female rats.

Furthermore, we show that proliferation and/or viability of cultured Hs578T and MDA-MB-231 estrogen receptor-negative breast cancer cell lines was reduced by EGCG treatment. Similar negative effects on proliferation were observed with the DMBA-transformed D3-1 cell line. Growth inhibition of Hs578T cells correlated with induction of p27Kip1 cyclin-dependent kinase inhibitor (CKI) expression.

Thus, green tea had significant chemo-preventive effects on carcinogen-induced mammary tumorigenesis in female S-D rats. In culture, inhibition of human breast cancer cell proliferation by EGCG was mediated in part via induction of the p27Kip1 (Kavanagh et al., 2001).

Pancreatic Cancer

The in vitro anti-tumoral properties of EGCG were investigated in human PDAC (pancreatic ductal adenocarcinoma) cells PancTu-I, Panc1, Panc89 and BxPC3 in comparison with the effects of two minor components of green tea catechins, catechin gallate (CG) and epicatechin gallate (ECG). It was found that all three catechins inhibited proliferation of PDAC cells in a dose- and time-dependent manner.

Interestingly, CG and ECG exerted much stronger anti-proliferative effects than EGCG. Importantly, catechins, in particular ECG, inhibited TNFα-induced activation of NF-κB and consequently secretion of pro-inflammatory and invasion promoting proteins like IL-8 and uPA.

Overall, these data show that green tea catechins ECG and CG exhibit potent and much stronger anti-proliferative and anti-inflammatory activities on PDAC cells than the most studied catechin EGCG (KŸrbitz et al., 2011).

Okabe et al. (1997) assessed the ability of EGCG to inhibit HGF signaling in the immortalized, nontumorigenic breast cell line, MCF10A, and the invasive breast carcinoma cell line, MDA-MB-231. The ability of alternative green tea catechins to inhibit HGF-induced signaling and motility was investigated. (-)-Epicatechin-3-gallate (ECG) functioned similarly to EGCG by completely blocking HGF-induced signaling as low as 0.6 muM and motility at 5 muM in MCF10A cells; whereas, (-)-epicatechin (EC) was unable to inhibit HGF-induced events at any concentration tested. (-)-Epigallocatechin (EGC), however, completely repressed HGF-induced AKT and ERK phosphorylation at concentrations of 10 and 20 muM, but was incapable of blocking Met activation. Despite these observations, EGC did inhibit HGF-induced motility in MCF10A cells at 10 muM.

Metastsis Inhibition

These observations suggest that the R1 galloyl and the R2 hydroxyl groups are important in mediating the green tea catechins' inhibitory effect towards HGF/Met signaling. These combined in vitro studies reveal the possible benefits of green tea polyphenols as cancer therapeutic agents to inhibit Met signaling and potentially block invasive cancer growth (Bigelow et al., 2006).

Colorectal Cancer

Panaxadiol (PD) is a purified sapogenin of ginseng saponins, which exhibits anti-cancer activity. Epigallocatechin gallate (EGCG), a major catechin in green tea, is a strong botanical anti-oxidant. Effects of selected compounds on HCT-116 and SW-480 human colorectal cancer cells were evaluated by a modified trichrome stain cell proliferation analysis. Cell-cycle distribution and apoptotic effects were analyzed by flow cytometry after staining with PI/RNase or annexin V/PI. Cell growth was suppressed after treatment with PD (10 and 20  µm) for 48 h. When PD (10 and 20  µm) was combined with EGCG (10, 20, and 30  µm), significantly enhanced anti-proliferative effects were observed in both cell lines.

Combining 20  µm of PD with 20 and 30   µm of EGCG significantly decreased S-phase fractions of cells. In the apoptotic assay, the combination of PD and EGCG significantly increased the percentage of apoptotic cells compared with PD alone (p  < 0.01).

Data from this study suggested that apoptosis might play an important role in the EGCG-enhanced anti-proliferative effects of PD on human colorectal cancer cells (Du et al., 2013).

Action: Anti-inflammatory, antioxidant

Green tea catechins, especially epigallocatechin-3-gallate (EGCG), have been associated with cancer prevention and treatment. This has resulted in an increased number of studies evaluating the effects derived from the use of this compound in combination with chemo/radiotherapy. Most of the studies on this subject up to date are preclinical. Relevance of the findings, impact factor, and date of publication were critical parameters for the studies to be included in the review.

Additive and synergistic effects of EGCG when combined with conventional cancer therapies have been proposed, and its anti-inflammatory and antioxidant activities have been related to amelioration of cancer therapy side effects. However, antagonistic interactions with certain anticancer drugs might limit its clinical use.

The use of EGCG could enhance the effect of conventional cancer therapies through additive or synergistic effects as well as through amelioration of deleterious side effects. Further research, especially at the clinical level, is needed to ascertain the potential role of EGCG as adjuvant in cancer therapy.

Cancer: Pancreatic ductal adenocarcinoma

Action: Anti-proliferative and anti-inflammatory

In the present study, Kürbitz et al., (2011) investigated the in vitro anti-tumoral properties of EGCG on human PDAC (pancreatic ductal adenocarcinoma) cells PancTu-I, Panc1, Panc89 and BxPC3 in comparison with the effects of two minor components of green tea catechins catechin gallate (CG) and epicatechin gallate (ECG). We found that all three catechins inhibited proliferation of PDAC cells in a dose- and time-dependent manner. Interestingly, CG and ECG exerted much stronger anti-proliferative effects than EGCG. Western blot analyses performed with PancTu-I cells revealed catechin-mediated modulation of cell cycle regulatory proteins (cyclins, cyclin-dependent kinases [CDK], CDK inhibitors). Again, these effects were clearly more pronounced in CG or ECG than in EGCG treated cells. Importantly, catechins, in particular ECG, inhibited TNFα-induced activation of NF-κB and consequently secretion of pro-inflammatory and invasion promoting proteins like IL-8 and uPA. Overall, our data show that green tea catechins ECG and CG exhibit potent and much stronger anti-proliferative and anti-inflammatory activities on PDAC cells than the most studied catechin EGCG.

References

Bigelow RLH, & Cardelli JA. (2006). The green tea catechins, (-)-Epigallocatechin-3-gallate (EGCG) and (-)-Epicatechin-3-gallate (ECG), inhibit HGF/Met signaling in immortalized and tumorigenic breast epithelial cells. Oncogene, 25:1922–1930. doi:10.1038/sj.onc.1209227

Chen ZP, Schell JB, Ho CT, Chen KY. (1998). Green tea epigallocatechin gallate shows a pronounced growth-inhibitory effect on cancerous cells but not on their normal counterparts. Cancer Lett,129(2):173-9.


Du GJ, Wang CZ, Qi LW, et al. (2013). The synergistic apoptotic interaction of panaxadiol and epigallocatechin gallate in human colorectal cancer cells. Phytother Res, 27(2):272-7. doi: 10.1002/ptr.4707.


Kavanagh KT, Hafer LJ, Kim DW, et al. (2001). Green tea extracts decrease carcinogen-induced mammary tumor burden in rats and rate of breast cancer cell proliferation in culture. Journal of Cellular Biochemistry, 82(3):387-98. doi:10.1002/jcb.1164


KŸrbitz C, Heise D, Redmer T, et al. (2011). Epicatechin gallate and catechin gallate are superior to epigallocatechin gallate in growth suppression and anti-inflammatory activities in pancreatic tumor cells. Cancer Science, 102(4):728-734. doi: 10.1111/j.1349-7006.2011.01870.x


Okabe S, Suganuma M, Hayashi M, et al. (1997). Mechanisms of Growth Inhibition of Human Lung Cancer Cell Line, PC-9, by Tea Polyphenols. Cancer Science, 88(7):639–643. doi: 10.1111/j.1349-7006.1997.tb00431.x

Lecumberri E, Dupertuis YM, Miralbell R, Pichard C. (2013) Green tea polyphenol epigallocatechin-3-gallate (EGCG) as adjuvant in cancer therapy. Clinical Nutrition. Volume 32, Issue 6, December 2013, Pages 894–903.

Kürbitz C, Heise D, Redmer T, Goumas F, et al. Cancer Science. Online publication Jan 2011. DOI: 10.1111/j.1349-7006.2011.01870.x

Diosgenin

Cancer: Breast, colon, prostate, leukemia, stomach

Action: HER-2, apoptosis, chemo-enhancing

Diosgenin is a plant-derived steroid isolated from Trigonella foenum-graecum (L.).

Breast Cancer; Chemo-enhancing

Diosgenin preferentially inhibited proliferation and induced apoptosis in HER2-overexpressing cancer cells. Furthermore, diosgenin inhibited the phosphorylation of Akt and mTOR, and enhanced phosphorylation of JNK.

The use of pharmacological inhibitors revealed that the modulation of Akt, mTOR and JNK phosphorylation was required for diosgenin-induced FAS suppression. Finally, it was shown that diosgenin could enhance paclitaxel-induced cytotoxicity in HER2-overexpressing cancer cells. These results suggested that diosgenin has the potential to advance as chemo-preventive or chemotherapeutic agent for cancers that overexpress HER2 (Chiang et al., 2007).

Colon Cancer

On 24 hours exposure to diosgenin, MTT cytotoxicity activity reduced by ³50% was achieved at the higher concentrations (i.e., ³80 µmol/L). However, compared with the control, 20 to 60 µmol/L diosgenin reduced the MTT activity only by 5% to 30%. Diosgenin caused a significant time-dependent and dose-dependent decrease in the proliferation of HT-29 cells. Twenty four hours exposure to diosgenin (20 to 100 µmol/L) inhibited cell proliferation compared with untreated cell growth. The in vitro experiment results indicated that diosgenin inhibits cell growth and induces apoptosis in the HT-29 human colon cancer cell line in a dose-dependent manner.

Furthermore, diosgenin induces apoptosis in HT-29 cells at least in part by inhibition of bcl-2 and by induction of caspase-3 protein expression (Raju et al., 2004).

Breast Cancer

The electrochemical behavior of breast cancer cells was studied on a graphite electrode by cyclic voltammetry (CV) and potentiometric stripping analysis (PSA) in unexposed and diosgenin exposed cells. In both cases, only one oxidative peak at approximately +0.75 V was observed. The peak area in PSA was used to study the growth of the cells and the effect of diosgenin on MCF-7 cells. The results showed that diosgenin can effectively inhibit the viability and proliferation of the breast cancer cells (Li et al., 2005).

Leukemia

Cell viability was assessed via an MTT assay. Apoptosis was investigated in terms of nuclear morphology, DNA fragmentation, and phosphatidylserine externalization. Cell cycle analysis was performed via PI staining and flow cytometry (FCM). Western blotting and immunofluorescence methods were used to determine the levels of p53, cell-cycle-related proteins and Bcl-2 family members. Cell cycle analysis showed that diosgenin caused G2/M arrest independently of p53. The levels of cyclin B1 and p21Cip1/Waf1 were decreased, whereas cdc2 levels were increased. The anti-apoptotic Bcl-2 and Bcl-xL proteins were down-regulated, whereas the pro-apoptotic Bax was upregulated.

Diosgenin was hence found to inhibit K562 cell proliferation via cell-cycle G2/M arrest and apoptosis, with disruption of Ca2+ homeostasis and mitochondrial dysfunction playing vital roles (Liu et al., 2005).

In recent years, Akt signaling has gained recognition for its functional role in more aggressive, therapy-resistant malignancies. As it is frequently constitutively active in cancer cells, several drugs are being investigated for their ability to inhibit Akt signaling. Diosgenin (fenugreek), a dietary compound, was examined for its action on Akt signaling and its downstream targets on estrogen receptor positive (ER+) and estrogen receptor negative (ER-) breast cancer (BCa) cells. Additionally, in vivo tumor studies indicate diosgenin significantly inhibits tumor growth in both MCF-7 and MDA-231 xenografts in nude mice. Thus, these results suggest that diosgenin might prove to be a potential chemotherapeutic agent for the treatment of BCa (Srinivasan et al., 2009).

Leukemia, Stomach Cancer

Protodioscin (PD) was purified from fenugreek (Trigonella foenumgraecum L.) and identified by mass spectrometry, and 1H- and 13C-NMR. The effects of PD on cell viability in human leukemia HL-60 and human stomach cancer KATO III cells were investigated. PD displayed strong growth-inhibitory effect against HL-60 cells, but weak growth-inhibitory effect on KATO III cells.

These findings suggest that growth inhibition by PD of HL-60 cells results from the induction of apoptosis by this compound in HL-60 cells (Hibasami et al., 2003).

References

Chiang CT, Way TD, Tsai SJ, Lin JK. (2007). Diosgenin, a naturally occurring steroid, suppresses fatty acid synthase expression in HER2-overexpressing breast cancer cells through modulating Akt, mTOR and JNK phosphorylation. FEBS letters, 581(30), 5735-42. doi:     10.1016/j.febslet.2007.11.021.


Hibasami H, Moteki H, Ishikawa K, et al. (2003). Protodioscin isolated from fenugreek (Trigonella foenumgraecum L.) induces cell death and morphological change indicative of apoptosis in leukemic cell line H-60, but not in gastric cancer cell line KATO III. Int J Mol Med, 11(1):23-6.


Li J, Liu X, Guo M, et al. (2005). Electrochemical Study of Breast Cancer Cells MCF-7 and Its Application in Evaluating the Effect of Diosgenin. Analytical Sciences, 21(5), 561. doi:10.2116/analsci.21.561


Liu MJ, Wang Z, Ju Y, Wong RNS, Wu QY. (2005). Diosgenin induces cell-cycle arrest and apoptosis in human leukemia K562 cells with the disruption of Ca2+ homeostasis. Cancer Chemotherapy and Pharmacology, 55(1), 79-90, doi: 10.1007/s00280-004-0849-3


Raju J, Patlolla JMR, Swamy MV, Rao CV. (2004). Diosgenin, a Steroid Saponin of Trigonella foenum graecum (Fenugreek), Inhibits Azoxymethane-Induced Aberrant Crypt Foci Formation in F344 Rats and Induces Apoptosis in HT-29 Human Colon Cancer Cells. Cancer Epidemiol Biomarkers Prev, 13; 1392.


Srinivasan S, Koduru S, Kumar R, et al. (2009). Diosgenin targets Akt-mediated prosurvival signaling in human breast cancer cells. International Journal of Cancer, 125(4), 961–967. doi: 10.1002/ijc.24419

Dietary Flavones

Cancer:
Prostate, colorectal., breast, pancreatic, bladder, ovarian, leukemia, liver, glioma, osteosarcoma, melanoma

Action: Anti-inflammatory, TAM resistance, cancer stem cells, down-regulate COX-2, apoptosis, cell-cycle arrest, anti-angiogenic, chemo-sensitzer, adramycin (ADM) resistance

Sulforaphane, Phenethyl isothiocyanate (PEITC), quercetin, epicatechin, catechin, Luteolin, apigenin

Anti-inflammatory

The anti-inflammatory activities of celery extracts, some rich in flavone aglycones and others rich in flavone glycosides, were tested on the inflammatory mediators tumor necrosis factor α (TNF-α) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in lipopolysaccharide-stimulated macrophages. Pure flavone aglycones and aglycone-rich extracts effectively reduced TNF-α production and inhibited the transcriptional activity of NF-κB, while glycoside-rich extracts showed no significant effects.

Celery diets with different glycoside or aglycone contents were formulated and absorption was evaluated in mice fed with 5% or 10% celery diets. Relative absorption in vivo was significantly higher in mice fed with aglycone-rich diets as determined by HPLC-MS/MS (where MS/MS is tandem mass spectrometry). These results demonstrate that deglycosylation increases absorption of dietary flavones in vivo and modulates inflammation by reducing TNF-α and NF-κB, suggesting the potential use of functional foods rich in flavones for the treatment and prevention of inflammatory diseases (Hostetler et al., 2012).

Colorectal Cancer

Association between the 6 main classes of flavonoids and the risk of colorectal cancer was examined using data from a national prospective case-control study in Scotland, including 1,456 incident cases and 1,456 population-based controls matched on age, sex, and residence area.

Dietary, including flavonoid, data were obtained from a validated, self-administered food frequency questionnaire. Risk of colorectal cancer was estimated using conditional logistic regression models in the whole sample and stratified by sex, smoking status, and cancer site and adjusted for established and putative risk factors.

The significant dose-dependent reductions in colorectal cancer risk that were associated with increased consumption of the flavonols quercetin, catechin, and epicatechin, remained robust after controlling for overall fruit and vegetable consumption or for other flavonoid intake. The risk reductions were greater among nonsmokers, but no interaction beyond a multiplicative effect was present.

This was the first of several a priori hypotheses to be tested in this large study and showed strong and linear inverse associations of flavonoids with colorectal cancer risk (Theodoratou et al., 2007).

Anti-angiogenic, Prostate Cancer

Luteolin is a common dietary flavonoid found in fruits and vegetables. The anti-angiogenic activity of luteolin was examined using in vitro, ex vivo, and in vivo models. Angiogenesis, the formation of new blood vessels from pre-existing vascular beds, is essential for tumor growth, invasion, and metastasis; hence, examination of this mechanism of tumor growth is essential to understanding new chemo-preventive targets. In vitro studies using rat aortic ring assay showed that luteolin at non-toxic concentrations significantly inhibited microvessel sprouting and proliferation, migration, invasion and tube formation of endothelial cells, which are key events in the process of angiogenesis. Luteolin also inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay (CAM) and matrigel plug assay.

Pro-inflammatory cytokines such as IL-1β, IL-6, IL-8, and TNF-α level were significantly reduced by the treatment of luteolin in PC-3 cells. Luteolin (10 mg/kg/d) significantly reduced the volume and the weight of solid tumors in prostate xenograft mouse model, indicating that luteolin inhibited tumorigenesis by targeting angiogenesis. Moreover, luteolin reduced cell viability and induced apoptosis in prostate cancer cells, which were correlated with the down-regulation of AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 expressions.

Taken together, these findings demonstrate that luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis (Pratheeshkumar et al., 2012).

Pancreatic Cancer; Chemo-sensitizer

The potential of dietary flavonoids apigenin (Api) and luteolin (Lut) were assessed in their ability to enhance the anti-proliferative effects of chemotherapeutic drugs on BxPC-3 human pancreatic cancer cells; additionally, the molecular mechanism of the action was probed.

Simultaneous treatment with either flavonoid (0,13, 25 or 50µM) and chemotherapeutic drugs 5-fluorouracil (5-FU, 50µM) or gemcitabine (Gem, 10µM) for 60 hours resulted in less-than-additive effect (p<0.05). Pre-treatment for 24 hours with 13µM of either Api or Lut, followed by Gem for 36 hours was optimal to inhibit cell proliferation. Pre-treatment of cells with 11-19µM of either flavonoid for 24 hours resulted in 59-73% growth inhibition when followed by Gem (10µM, 36h). Lut (15µM, 24h) pre-treatment followed by Gem (10µM, 36h), significantly decreased protein expression of nuclear GSK-3β and NF-κB p65 and increased pro-apoptotic cytosolic cytochrome c. Pre-treatment of human pancreatic cancer cells BxPC-3 with low concentrations of Api or Lut hence effectively aid in the anti-proliferative activity of chemotherapeutic drugs (Johnson et al., 2013).

Breast Cancer; Chemo-sensitizer, Tamoxifen

The oncogenic molecules in human breast cancer cells are inhibited by luteolin treatment and it was found that the level of cyclin E2 (CCNE2) mRNA was higher in tumor cells than in normal paired tissue samples as assessed using real-time reverse-transcriptase polymerase chain reaction (RT-PCR) analysis (n=257).

Combined treatment with 4-OH-TAM and luteolin synergistically sensitized the TAM-R cells to 4-OH-TAM. These results suggest that luteolin can be used as a chemo-sensitizer to target the expression level of CCNE2 and that it could be a novel strategy to overcome TAM resistance in breast cancer patients (Tu et al., 2013).

Breast Cancer

Consumers of higher levels of Brassica vegetables, particularly those of the genus Brassica (broccoli, Brussels sprouts and cabbage), reduce their susceptibility to cancer at a variety of organ sites. Brassica vegetables contain high concentrations of glucosinolates that can be hydrolyzed by the plant enzyme, myrosinase, or intestinal microflora to isothiocyanates, potent inducers of cytoprotective enzymes and inhibitors of carcinogenesis. Oral administration of either the isothiocyanate, sulforaphane, or its glucosinolate precursor, glucoraphanin, inhibits mammary carcinogenesis in rats treated with 7,12-dimethylbenz[a]anthracene. To determine whether sulforaphane exerts a direct chemo-preventive action on animal and human mammary tissue, the pharmacokinetics and pharmacodynamics of a single 150 µmol oral dose of sulforaphane were evaluated in the rat mammary gland.

Sulforaphane metabolites were detected at concentrations known to alter gene expression in cell culture. Elevated cytoprotective NAD(P)H:quinone oxidoreductase (NQO1) and heme oxygenase-1 (HO-1) gene transcripts were measured using quantitative real-time polymerase chain reaction. An observed 3-fold increase in NQO1 enzymatic activity, as well as 4-fold elevated immunostaining of HO-1 in rat mammary epithelium, provide strong evidence of a pronounced pharmacodynamic action of sulforaphane. In a subsequent pilot study, eight healthy women undergoing reduction mammoplasty were given a single dose of a broccoli sprout preparation containing 200 µmol of sulforaphane. Following oral dosing, sulforaphane metabolites were readily measurable in human breast tissue enriched for epithelial cells. These findings provide a strong rationale for evaluating the protective effects of a broccoli sprout preparation in clinical trials of women at risk for breast cancer (Cornblatt et al., 2007).

In a proof of principle clinical study, the presence of disseminated tumor cells (DTCs) was demonstrated in human breast tissue after a single dose of a broccoli sprout preparation containing 200 µmol of sulforaphane. Together, these studies demonstrate that sulforaphane distributes to the breast epithelial cells in vivo and exerts a pharmacodynamic action in these target cells consistent with its mechanism of chemo-protective efficacy.

Such efficacy, coupled with earlier randomized clinical trials revealing the safety of repeated doses of broccoli sprout preparations , supports further evaluation of broccoli sprouts in the chemoprevention of breast and other cancers (Cornblatt et al., 2007).

CSCs

Recent research into the effects of sulforaphane on cancer stem cells (CSCs) has drawn a great deal of interest. CSCs are suggested to be responsible for initiating and maintaining cancer, and to contribute to recurrence and drug resistance. A number of studies have indicated that sulforaphane may target CSCs in different types of cancer through modulation of NF- κB, SHH, epithelial-mesenchymal transition and Wnt/β-catenin pathways. Combination therapy with sulforaphane and chemotherapy in preclinical settings has shown promising results (Li et al., 2013).

Anti-inflammatory

Sulforaphane has been found to down-regulate COX-2 expression in human bladder transitional cancer T24 cells at both transcriptional- and translational levels. Cyclooxygenase-2 (COX-2) overexpression has been associated with the grade, prognosis and recurrence of transitional cell carcinoma (TCC) of the bladder. Sulforaphane (5-20 microM) induced nuclear translocation of NF-kappaB and reduced its binding to the COX-2 promoter, a key mechanism for suppressing COX-2 expression by sulforaphane. Moreover, sulforaphane increased expression of p38 and phosphorylated-p38 protein. Taken together, these data suggest that p38 is essential in sulforaphane-mediated COX-2 suppression and provide new insights into the molecular mechanisms of sulforaphane in the chemoprevention of bladder cancer (Shan et al., 2009).

Bladder Cancer

An aqueous extract of broccoli sprouts potently inhibits the growth of human bladder carcinoma cells in culture and this inhibition is almost exclusively due to the isothiocyanates. Isothiocyanates are present in broccoli sprouts as their glucosinolate precursors and blocking their conversion to isothiocyanates abolishes the anti-proliferative activity of the extract.

Moreover, the potency of isothiocyanates in the extract in inhibiting cancer cell growth was almost identical to that of synthetic sulforaphane, as judged by their IC50 values (6.6 versus 6.8 micromol/L), suggesting that other isothiocyanates in the extract may be biologically similar to sulforaphane and that nonisothiocyanate substances in the extract may not interfere with the anti-proliferative activity of the isothiocyanates. These data show that broccoli sprout isothiocyanate extract is a highly promising substance for cancer prevention/treatment and that its anti-proliferative activity is exclusively derived from isothiocyanates (Tang et al., 2006).

Ovarian Cancer

Sulforaphane is an extract from the mustard family recognized for its anti-oxidation abilities, phase 2 enzyme induction, and anti-tumor activity. The cell-cycle arrest in G2/M by sulforaphane and the expression of cyclin B1, Cdc2, and the cyclin B1/CDC2 complex in PA-1 cells using Western blotting and co-IP Western blotting. The anti-cancer effects of dietary isothiocyanate sulforaphane on ovarian cancer were investigated using cancer cells line PA-1.

Sulforaphane -treated cells accumulated in metaphase by CDC2 down-regulation and dissociation of the cyclin B1/CDC2 complex.

These findings suggest that, in addition to the known effects on cancer prevention, sulforaphane may also provide anti-tumor activity in established ovarian cancer (Chang et al., 2013).

Leukemia Stem Cells

Isolated leukemia stem cells (LSCs) showed high expression of Oct4, CD133, β-catenin, and Sox2 and imatinib (IM) resistance. Differentially, CD34(+)/CD38(-) LSCs demonstrated higher BCR-ABL and β-catenin expression and IM resistance than CD34(+)/CD38(+) counterparts. IM and sulforaphane (SFN) combined treatment sensitized CD34(+)/CD38(-) LSCs and induced apoptosis, shown by increased caspase 3, PARP, and Bax while decreased Bcl-2 expression. Mechanistically, imatinib (IM) and sulforaphane (SFN) combined treatment resensitized LSCs by inducing intracellular reactive oxygen species (ROS). Importantly, β-catenin-silenced LSCs exhibited reduced glutathione S-transferase pi 1 (GSTP1) expression and intracellular GSH level, which led to increased sensitivity toward IM and sulforaphane.

It was hence demonstrated that IM and sulforaphane combined treatment effectively eliminated CD34(+)/CD38(-) LSCs. Since SFN has been shown to be well tolerated in both animals and human, this regimen could be considered for clinical trials (Lin et al., 2012).

DCIS Stem Cells

A miR-140/ALDH1/SOX9 axis has been found to be critical to basal cancer stem cell self-renewal and tumor formation in vivo, suggesting that the miR-140 pathway may be a promising target for preventive strategies in patients with basal-like Ductal Carcinoma in Situ (DCIS). The dietary compound sulforaphane has been found to decrease Transcription factor SOX-9 and Acetaldehyde dehydrogenases (ALDH1), and thereby reduced tumor growth in vivo (Li et al., 2013).

Glioma, Prostate Cancer, Colon Cancer, Breast Cancer, Liver Cancer

Phenethyl isothiocyanate (PEITC), a natural dietary isothiocyanate, inhibits angiogenesis. The effects of PEITC were examined under hypoxic conditions on the intracellular level of the hypoxia inducible factor (HIF-1α) and extracellular level of the vascular endothelial growth factor (VEGF) in a variety of human cancer cell lines. Gupta et al., (2013) observed that PEITC suppressed the HIF-1α accumulation during hypoxia in human glioma U87, human prostate cancer DU145, colon cancer HCT116, liver cancer HepG2, and breast cancer SkBr3 cells. PEITC treatment also significantly reduced the hypoxia-induced secretion of VEGF.

Suppression of HIF-1α accumulation during treatment with PEITC in hypoxia was related to PI3K and MAPK pathways.

Taken together, these results suggest that PEITC inhibits the HIF-1α expression through inhibiting the PI3K and MAPK signaling pathway and provide a new insight into a potential mechanism of the anti-cancer properties of PEITC.

Breast Cancer Metastasis

Breast tumor metastasis is a leading cause of cancer-related deaths worldwide. Breast tumor cells frequently metastasize to brain and initiate severe therapeutic complications. The chances of brain metastasis are further elevated in patients with HER2 overexpression. The MDA-MB-231-BR (BR-brain seeking) breast tumor cells stably transfected with luciferase were injected into the left ventricle of mouse heart and the migration of cells to brain was monitored using a non-invasive IVIS bio-luminescent imaging system.

Results demonstrate that the growth of metastatic brain tumors in PEITC treated mice was about 50% less than that of control. According to Kaplan Meir's curve, median survival of tumor-bearing mice treated with PEITC was prolonged by 20.5%. Furthermore, as compared to controls, we observed reduced HER2, EGFR and VEGF expression in the brain sections of PEITC treated mice. These results demonstrate the anti-metastatic effects of PEITC in vivo in a novel breast tumor metastasis model and provides the rationale for further clinical investigation (Gupta et al., 2013).

Osteosarcoma, Melanoma

Phenethyl isothiocyanate (PEITC) has been found to induce apoptosis in human osteosarcoma U-2 OS cells. The following end points were determined in regard to human malignant melanoma cancer A375.S2 cells: cell morphological changes, cell-cycle arrest, DNA damage and fragmentation assays and morphological assessment of nuclear change, reactive oxygen species (ROS) and Ca2+ generations, mitochondrial membrane potential disruption, and nitric oxide and 10-N-nonyl acridine orange productions, expression and activation of caspase-3 and -9, B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), Bcl-2, poly (adenosine diphosphate-ribose) polymerase, and cytochrome c release, apoptosis-inducing factor and endonuclease G. PEITC

It was therefore concluded that PEITC-triggered apoptotic death in A375.S2 cells occurs through ROS-mediated mitochondria-dependent pathways (Huang et al., 2013).

Prostate Cancer

The glucosinolate-derived phenethyl isothiocyanate (PEITC) has recently been demonstrated to reduce the risk of prostate cancer (PCa) and inhibit PCa cell growth. It has been shown that p300/CBP-associated factor (PCAF), a co-regulator for the androgen receptor (AR), is upregulated in PCa cells through suppression of the mir-17 gene. Using AR-responsive LNCaP cells, the inhibitory effects of PEITC were observed on the dihydrotestosterone-stimulated AR transcriptional activity and cell growth of PCa cells.

Expression of PCAF was upregulated in PCa cells through suppression of miR-17. PEITC treatment significantly decreased PCAF expression and promoted transcription of miR-17 in LNCaP cells. Functional inhibition of miR-17 attenuated the suppression of PCAF in cells treated by PEITC. Results indicate that PEITC inhibits AR-regulated transcriptional activity and cell growth of PCa cells through miR-17-mediated suppression of PCAF, suggesting a new mechanism by which PEITC modulates PCa cell growth (Yu et al., 2013).

Bladder Cancer; Adramycin (ADM) Resistance

The role of PEITC on ADM resistance reversal of human bladder carcinoma T24/ADM cells has been examined, including an increased drug sensitivity to ADM, cell apoptosis rates, intracellular accumulation of Rhodamine-123 (Rh-123), an increased expression of DNA topoisomerase II (Topo-II), and a decreased expression of multi-drug resistance gene (MDR1), multi-drug resistance-associated protein (MRP1), bcl-2 and glutathione s transferase π (GST-π). The results indicated that PEITC might be used as a potential therapeutic strategy to ADM resistance through blocking Akt and activating MAPK pathway in human bladder carcinoma (Tang et al., 2013).

Breast Cancer; Chemo-enhancing

The synergistic effect between paclitaxel (taxol) and phenethyl isothiocyanate (PEITC) on the inhibition of breast cancer cells has been examined. Two drug-resistant breast cancer cell lines, MCF7 and MDA-MB-231, were treated with PEITC and taxol. Cell growth, cell-cycle, and apoptosis were examined.

The combination of PEITC and taxol significantly decreased the IC50 of PEITC and taxol over each agent alone. The combination also increased apoptosis by more than 2-fold over each single agent in both cell lines. A significant increase of cells in the G2/M phases was detected. Taken together, these results indicated that the combination of PEITC and taxol exhibits a synergistic effect on growth inhibition in breast cancer cells. This combination deserves further study in vivo (Liu et al., 2013).

References

Chang CC, Hung CM, Yang YR, Lee MJ, Hsu YC. (2013). Sulforaphane induced cell-cycle arrest in the G2/M phase via the blockade of cyclin B1/CDC2 in human ovarian cancer cells. J Ovarian Res, 6(1):41. doi: 10.1186/1757-2215-6-41


Cornblatt BS, Ye LX, Dinkova-Kostova AT, et al. (2007). Preclinical and clinical evaluation of sulforaphane for chemoprevention in the breast. Carcinogenesis, 28(7):1485-1490. doi: 10.1093/carcin/bgm049


Gupta B, Chiang L, Chae K, Lee DH. (2013). Phenethyl isothiocyanate inhibits hypoxia-induced accumulation of HIF-1 α and VEGF expression in human glioma cells. Food Chem, 141(3):1841-6. doi: 10.1016/j.foodchem.2013.05.006.


Gupta P, Adkins C, Lockman P, Srivastava SK. (2013). Metastasis of Breast Tumor Cells to Brain Is Suppressed by Phenethyl Isothiocyanate in a Novel In Vivo Metastasis Model. PLoS One, 8(6):e67278. doi:10.1371/journal.pone.0067278


Hostetler G, Riedl K, Cardenas H, et al. (2012). Flavone deglycosylation increases their anti-inflammatory activity and absorption. Molecular Nutrition & Food Research, 56(4):558-569. doi: 10.1002/mnfr.201100596


Huang SH, Hsu MH, Hsu SC, et al. (2013). Phenethyl isothiocyanate triggers apoptosis in human malignant melanoma A375.S2 cells through reactive oxygen species and the mitochondria-dependent pathways. Hum Exp Toxicol. doi: 10.1177/0960327113491508


Johnson JL, Gonzalez de Mejia E. (2013). Interactions between dietary flavonoids apigenin or luteolin and chemotherapeutic drugs to potentiate anti-proliferative effect on human pancreatic cancer cells, in vitro. Food Chem Toxicol, 60:83-91. doi: 10.1016/j.fct.2013.07.036.


Li Q, Yao Y, Eades G, Liu Z, Zhang Y, Zhou Q. (2013). Down-regulation of miR-140 promotes cancer stem cell formation in basal-like early stage breast cancer. Oncogene. doi: 10.1038/onc.2013.226.


Li Y, Zhang T. (2013). Targeting cancer stem cells with sulforaphane, a dietary component from broccoli and broccoli sprouts. Future Oncol, 9(8):1097-103. doi: 10.2217/fon.13.108.


Lin LC, Yeh CT, Kuo CC, et al. (2012). Sulforaphane potentiates the efficacy of imatinib against chronic leukemia cancer stem cells through enhanced abrogation of Wnt/ β-catenin function. J Agric Food Chem, 60(28):7031-9. doi: 10.1021/jf301981n.


Liu K, Cang S, Ma Y, Chiao JW. (2013). Synergistic effect of paclitaxel and epigenetic agent phenethyl isothiocyanate on growth inhibition, cell-cycle arrest and apoptosis in breast cancer cells. Cancer Cell Int, 13(1):10. doi: 10.1186/1475-2867-13-10.


Pratheeshkumar P, Son YO, Budhraja A, et al. (2012). Luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis. PLoS One, 7(12):52279. doi: 10.1371/journal.pone.0052279.


Tang K, Lin Y, Li LM. (2013). The role of phenethyl isothiocyanate on bladder cancer ADM resistance reversal and its molecular mechanism. Anat Rec (Hoboken), 296(6):899-906. doi: 10.1002/ar.22677.


Tang L, Zhang Y, Jobson HE, et al. (2006). Potent activation of mitochondria-mediated apoptosis and arrest in S and M phases of cancer cells by a broccoli sprout extract. Mol Cancer Ther, 5(4):935-44. doi: 10.1158/1535-7163.MCT-05-0476


Theodoratou E, Kyle J, Cetnarskyj R, et al. (2007). Dietary flavonoids and the risk of colorectal cancer. Cancer Epidemiol Biomarkers Prev,16(4):684-93.


Tu SH, Ho CT, Liu MF, et al. (2013). Luteolin sensitizes drug-resistant human breast cancer cells to tamoxifen via the inhibition of cyclin E2 expression. Food Chem, 141(2):1553-61. doi: 10.1016/j.foodchem.2013.04.077.


Shan Y, Wu K, Wang W, et al. (2009). Sulforaphane down-regulates COX-2 expression by activating p38 and inhibiting NF-kappaB-DNA-binding activity in human bladder T24 cells. Int J Oncol, 34(4):1129-34.


Yu C, Gong AY, Chen D, et al. (2013). Phenethyl isothiocyanate inhibits androgen receptor-regulated transcriptional activity in prostate cancer cells through suppressing PCAF. Mol Nutr Food Res. doi: 10.1002/mnfr.201200810.

Dehydrocostus (See also costunolide)

Cancers: Breast, cervical., lung, prostate, sarcoma

Action: Anti-metastatic, cytostatic, lymphangiogenesis inhibitors

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 G2 growth arrest and apoptosis in gastric cancer cells.

Prostate Cancer

The effects of hexane extracts of S. lappa (HESLs) on the migration of DU145 and TRAMP-C2 prostate cancer cells were investigated. DU145 and TRAMP-C2 cells were cultured in the presence of 0-4 µg/mL HESL with or without 10 ng/mL epidermal growth factor (EGF).

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.

Results demonstrated 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 in the treatment of prostate cancer (Kim et al., 2012).

Sarcoma

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 of the costunolide and dehydrocostus lactone, which have been isolated from Saussurea lappa using activity-guided isolation, were studied on three soft tissue sarcoma cell lines of various origins. The effects on cell proliferation, cell-cycle distribution, apoptosis induction, and ABC transporter expression were analyzed. Both compounds inhibited cell viability dose- and time-dependently.

IC50 values ranged from 6.2 µg/mL to 9.8 µg/mL. 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.

These data demonstrate for the first time 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., 2012).

The effects of the sesquiterpene lactones, costunolide and dehydrocostus, on the cell-cycle, MMP expression, and invasive potential of three human STS cell lines of various origins. Both compounds reduced cell proliferation in a time- and dose-dependent manner.

Dehydrocostus lactone significantly inhibited cell proliferation, arrested the cells at the G2/M interface and caused a decrease in the expression of the cyclin-dependent kinase CDK2 and the cyclin-dependent kinase inhibitor p27 (Kip1).

In the presence of costunolide, MMP-2 and MMP-9 levels were significantly increased in SW-982 and TE-671 cells. Dehydrocostus lactone treatment significantly reduced MMP-2 and MMP-9 expression in TE-671 cells, but increased MMP-9 level in SW-982 cells. In addition, the invasion potential was significantly reduced after treatment with both sesquiterpene lactones as investigated by the HTS FluoroBlock insert system (Lohberger et al., 2013).

Breast Cancer

Several Chinese herbs, namely, pu gong ying (Taraxacum officinale), gan cao (Glycyrrhizae uralensis), chai hu (Bupleurum chinense), mu xiang (Auklandia lappa), gua lou (Trichosanthes kirilowii) and huang yao zi (Dioscoreae bulbiferae), are frequently used in complex traditional Chinese medicine formulas, for breast hyperplasia and breast tumor therapy. The effects of these Chinese herbs are all described as 'clearing heat-toxin and resolving masses' in traditional use. However, the chemical profiles of anti-breast cancer constituents in these herbs have not been investigated thus far.

Two potential anti-breast cancer compounds, costunolide (Cos) and dehydrocostus lactone (Dehy), were identified in mu xiang. The combination of the two compounds showed a synergistic effect on inhibiting the proliferation of MCF-7 cells in vitro, exhibiting potential application in the treatment of breast cancer (Peng, Wang, Gu, Wen & Yan, 2013).

Lymphangiogenesis Inhibitors

In this study, we investigated lymphangiogenesis inhibitors from crude drugs used in Japan and Korea. 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. These compounds might offer clinical benefits as lymphangiogenesis inhibitors and may be good candidates for novel anti-cancer and anti-metastatic agents (Jeong, 2013).

References

Jeong D, Watari K, Shirouzu T, et al. (2013). Studies on lymphangiogenesis inhibitors from Korean and Japanese crude drugs. Biological & Pharmaceutical Bulletin, 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. Journal of Medicinal 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 Medica, 78(16), 1749-1756. doi: 10.1055/s-0032-1315385.


Lohberger B, Rinner B, Stuendl N, et al. (2013). Sesquiterpene lactones downregulate g2/m cell-cycle regulator proteins and affect the invasive potential of human soft tissue sarcoma cells. PLoS One, 8(6), e66300. doi: 10.1371/journal.pone.0066300.


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. Biomedical Chromatography. doi: 10.1002/bmc.2990.

Dauricine

Cancer: Prostate, urinary system, breast, lung

Action: MDR

Lung Cancer

Menispermum dauricum DC (Moonseed) contains several alkaloids, of which dauricine can account for as much as 50% of the alkaloids present. In human lung adenocarcinoma A549 cells, these alkaloids activate caspase-3 by activating caspases-8 and -9. Accordingly, these alkaloids induce apoptosis through the apoptosis death receptor and mitochondrial pathways (Wang et al., 2011).

Prostate Cancer

The anti-tumor effects of asiatic moonseed rhizome extraction-dauricine were explored on bladder cancer EJ cell strain, prostate cancer PC-3Mcell strain and primary cell culture system. The main effective component, phenolic alkaloids of Menispermum dauricum, was extracted and separated from asiatic moonseed rhizome by chemical method.

Dauricine had an obvious proliferation inhibition effect on the main tumor cells in urinary system. The minimum drug sensitivity concentration was between 3.81-5.15 µg/mL, and the inhibition ratio increased with the increased concentration. Dauricine, the main effective component extracted from asiatic moonseed rhizome, had good inhibition effect on tumor cells in the urinary system. At the same time, Dauricine has certain inhibition effects on the primary cultured tumor cell (Wang et al., 2012).

Breast Cancer

Serum-starved MCF-7 cells were pretreated for 1 h with different concentrations of dauricine (Dau), followed by incubation with IGF-I for 6 h. Dau significantly inhibited IGF-I-induced HIF-1alpha protein expression but had no effect on HIF-1alpha mRNA expression. However, Dau remarkably suppressed VEGF expression at both protein and mRNA levels in response to IGF-I. Mechanistically, Dau suppressed IGF-I-induced HIF-1alpha and VEGF protein expression mainly by blocking the activation of PI-3K/AKT/mTOR signaling pathway.

Dau inhibits human breast cancer angiogenesis by suppressing HIF-1alpha protein accumulation and VEGF expression, which may provide a novel potential mechanism for the anti-cancer activities of Dau in human breast cancer (Tang et al., 2009).

Breast Cancer; MDR

The potentiation of vincristine-induced apoptosis by tetrandrine, neferine and dauricine isolated from Chinese medicinal plants in the human mammary MCF-7 Multi-drug-resistant cells was investigated. The apoptotic cells induced by vincristine alone accounted for about 10% of all the cancer cells, while the percentage of apoptotic cells induced by a combination of vincristine with tetrandrine, neferine, or dauricine was found to be significantly higher than that by vincristine alone, and their reversal effects were positively correlated with the drug concentration and the exposure time.

In addition, tetrandrine was shown to be the most potent in the reversal efficacy among the three compounds to be tested for apoptosis in vitro. Tetrandrine, neferine and dauricine showed obvious potentiation of vincristine-induced apoptosis in the human mammary MCF-7 multi-drug-resistant cells (Ye et al., 2001).

MDR

Bisbenzylisoquinoline alkaloids are a large family of natural phytochemicals with great potential for clinical use. The interaction between breast cancer resistant protein (BCRP), sometimes called ATP binding cassette protein G2 (ABCG2), and 5 bisbenzylisoquinoline alkaloids (neferine, isoliensinine, liensinine, dauricine and tetrandrine) was evaluated using LLC-PK1/BCRP cell model.

The intracellular accumulation and bi-directional transport studies were conducted, and then molecular docking analysis was carried out employing a homology model of BCRP. This data indicates that BCRP could mediate the excretion of liensinine and dauricine, and thus influence their pharmacological activity and disposition (Tian et al., 2013).

References

Tang XD, Zhou X, Zhou KY. (2009). Dauricine inhibits insulin-like growth factor-I-induced hypoxia inducible factor 1alpha protein accumulation and vascular endothelial growth factor expression in human breast cancer cells. Acta Pharmacol Sin, 30(5):605-16. doi: 10.1038/aps.2009.8.

Tian Y, Qian S, Jiang Y, et al. (2013). The interaction between human breast cancer resistance protein (BCRP) and five bisbenzylisoquinoline alkaloids. Int J Pharm, 453(2):371-9. doi: 10.1016/j.ijpharm.2013.05.053.

Wang J, Li Y, Zu XB, Chen MF, Qi L. (2012). Dauricine can inhibit the activity of proliferation of urinary tract tumor cells. Asian Pac J Trop Med, 5(12):973-6. doi: 10.1016/S1995-7645(12)60185-0.

Wang YG, Sun S, Yang WS, Sun FD, Liu Q. (2011). Extract of Menispermum Dauricum induces apoptosis of human lung cancer cell line A549. J Pract Oncol (Chin), 26:343-346.

Ye ZG, Wang JH, Sun AX, et al. (2001). Potentiation of vincristine-induced apoptosis by tetrandrine, neferine and dauricine in the human mammary MCF-7 Multi-drug-resistant cells. Yao Xue Xue Bao, 36(2):96-9.

Dandelion Root Extract (Taraxacum)

Cancer:
Pancreatic, Chronic Myelomonocytic Leukemia, leukemia, liver, hepatocellular carcinoma

Action: Induces cytotoxicity, induces apoptosis

Dandelion root is extracted from Taraxacum officinale (F.H. Wigg).

Hepatocellular Carcinoma

Taraxacum officinale (TO) has been frequently used as a remedy for women's diseases (e.g. breast and uterus cancer) and disorders of the liver and gallbladder. Several earlier studies have indicated that TO exhibits anti-tumor properties. TO decreased the cell viability by 26%, and significantly increased the tumor necrosis factor (TNF)-alpha and interleukin (IL)-1alpha production compared with media control (about 1.6-fold for TNF-alpha, and 2.4-fold for IL-1alpha, P < 0.05). Also, TO strongly induced apoptosis of Hep G2 cells as determined by flow cytometry. Increased amounts of TNF-alpha and IL-1alpha contributed to TO-induced apoptosis. Anti-TNF-alpha and IL-1alpha antibodies almost abolished it. These results suggest that TO induces cytotoxicity through TNF-alpha and IL-1alpha secretion in Hep G2 cells (Koo et al., 2004).

Pancreatic Cancer

The efficacy of dandelion root extract (DRE) in inducing apoptosis and autophagy in aggressive and resistant pancreatic cancer cells, known to have a high rate of mortality, have been investigated. The effect of DRE was evaluated using WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate) assay.

This extract induces selective apoptosis in a dose- and time-dependent manner. Dandelion root extract caused the collapse of the mitochondrial membrane potential., leading to prodeath autophagy. Normal human fibroblasts were resistant at similar doses. It was demonstrated that DRE has the potential to induce apoptosis and autophagy in human pancreatic cancer cells with no significant effect on noncancerous cells. This will provide a basis on which further research in cancer treatment through DRE can be executed (Ovadje et al., 2012a).

Chronic Myelomonocytic Leukemia

Chronic myelomonocytic leukemia (CMML) is a heterogeneous disease that is not only hard to diagnose and classify, but is also highly resistant to treatment. Available forms of therapy for this disease have not shown significant effects and patients rapidly develop resistance early on in therapy. These factors lead to the very poor prognosis observed with CMML patients, with median survival duration between 12 and 24 months after diagnosis. This study is therefore centered around evaluating the selective efficacy of a natural extract from dandelion roots, in inducing programmed cell death in aggressive and resistant CMML cell lines.

The results from this study indicate that Dandelion Root Extract (DRE) is able to efficiently and selectively induce apoptosis and autophagy in these cell lines in a dose and time-dependent manner, with no significant toxicity on non-cancerous peripheral blood mononuclear cells. More importantly, we observed early activation of initiator caspase-8, which led to mitochondrial destabilization and the induction of autophagy, suggesting that DRE acts through the extrinsic pathway of apoptosis (Ovadje et al., 2012b).

Leukemia

A study by Ovadje et al. (2011) determined the anti-cancer activity of dandelion root extract (DRE) against human leukemia, and evaluated the specificity and mechanism of DRE-induced apoptosis. Aqueous DRE contains components that act to induce apoptosis selectively in cultured leukemia cells, emphasizing the importance of this traditional medicine and thus presents a potential novel non-toxic alternative to conventional leukemia therapy.

References

Koo HN, Hong SH, Song BK, et al. (2004). Taraxacum officinale induces cytotoxicity through TNF-alpha and IL-1alpha secretion in Hep G2 cells. Life Sci, 74(9):1149-57.


Ovadje P, Chatterjee S, Griffin C, et al. (2011). Selective induction of apoptosis through activation of caspase-8 in human leukemia cells (Jurkat) by dandelion root extract. J Ethnopharmacol, 133(1):86-91. doi: 10.1016/j.jep.2010.09.005.


Ovadje P, Chochkeh M, Akbari-Asl P, Hamm C, Pandey S. (2012). Selective Induction of Apoptosis and Autophagy Through Treatment With Dandelion Root Extract in Human Pancreatic Cancer Cells. Pancreas, 41(7),1039-47. doi: 10.1097/MPA.0b013e31824b22a2.


Ovadje P, Hamm C, Pandey S. b (2012). Efficient induction of extrinsic cell death by dandelion root extract in human chronic myelomonocytic leukemia (CMML) cells. PLoS One. 2012;7(2):e30604. doi: 10.1371/journal.pone.0030604.