Category Archives: AMPK

RG3 (See also Ginsenosides)

Cancer: Glioblastoma, prostate, breast, colon

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

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

Angiosuppressive Activity

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

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

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

Glioblastoma

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

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

MDR/Enhanced Paclitaxel Absorption

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

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

Prostate Cancer

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

Enhances Chemotherapy

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

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

Colon Cancer

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

Anti-metastatic

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

References

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


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


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


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


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


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


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


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

Puerarin

Cancer: Colon, breast, acute myeloid leukemia

Action: MDR, aromatase inhibition, induces apoptosis

Induces Apoptosis, Colorectal Cancer

Puerarin is isolated from Pueraria radix (Pueraria lobata [(Willd.) Ohwi]) and has beneficial effects on cardiovascular, neurological, and hyperglycemic disorders, as well as anti-cancer properties. Puerariae radix (PR) is a popular natural herb and a traditional food in Asia, which has anti-thrombotic and anti-allergic properties and stimulates estrogenic activity.

Methyl thiazolyl tetrazolium assay (MTT) assay revealed a dose-dependent reduction of HT-29 cellular growth in response to puerarin treatment. Apoptosis was observed following treatments with ³ 25µM puerarin, as reflected by the appearance of the subdiploid fraction and NDA fragmentations. Puerarin also affects the expression of apoptosis-associated genes, revealing an increase of bax and decreases of c-myc and bcl-2.

Finally, puerarin treatment significantly increased the activation of caspase-3, a key executioner of apoptosis. These findings indicate that puerarin may act as a chemo-preventive and/or chemotherapeutic agent in colon cancer cells by reducing cell viability and inducing apoptosis (Li, et al., 2006).

Induces Apoptosis, Breast Cancer

Puerarin exhibits a dose-dependent inhibition of cell growth in HS578T, MDA-MB-231, and MCF-7 cell lines. Results from cell-cycle distribution and apoptosis assays revealed that puerarin induced cell apoptosis through a caspase-3-dependent pathway and mediated cell-cycle arrest in the G2/M phase. It is therefore suggested that puerarin may act as a chemo-preventive and/or chemotherapeutic agent against breast cancer by reducing cell viability and inducing apoptosis (Lin et al., 2009).

Breast Cancer, MDR

Purearin down-regulates MDR1 expression in MCF-7/adriamycin (MCF-7/adr), a human breast MDR cancer cell line. Multi-drug resistance (MDR) is a major obstacle in cancer chemotherapy and its inhibition is an effective way to reverse cancer drug resistance. Puerarin treatment significantly inhibited MDR1 expression, MDR1 mRNA and MDR1 promoter activity in MCF-7/adr cells. The suppression of MDR1 was accompanied by partial recovery of intracellular drug accumulation, leading to increased toxicity of adriamycin and fluorescence of rhodamine 123, indicating that puerarin reversed the MDR phenotype by inhibiting the drug efflux function of MDR1. Puerarin stimulated AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase and glycogen synthase kinase-3beta phosphorylation, but puerarin decreased cAMP-responsive element-binding protein phosphorylation.

The puerarin-induced suppression of MDR1 expression was reduced by AMPK inhibitor (compound C). Furthermore, both MDR1 protein expression and the transcriptional activity of cAMP-responsive element (CRE) were inhibited by puerarin and protein kinase A/CRE inhibitor (H89). Taken together, these results suggested that puerarin down-regulated MDR1 expression via nuclear factor kappa-B and CRE transcriptional activity-dependent up-regulation of AMPK in MCF-7/adr cells (Hien et al., 2010).

Acute Myeloid Leukemia (AML)

The results showed that a certain concentration of puerarin (PR) could inhibit the proliferation of these four cell lines effectively in time-and dose-dependent manners, and the intensity of inhibition on four kinds of acute myeloid leukemia (AML) cell lines was from high to low as follows: NB4>Kasumi-1>U937>HL-60. Meanwhile, PR could also change cycle process, cell proportion in G1/G0 phase decreased, cells in S phase increased and Sub-diploid peak also appeared. It is concluded that PR can selectively inhibit the proliferation of four AML cell lines and block cell-cycle process, especially for NB4 cells (Shao et al., 2010).

Aromatase Inhibition

Aromatase P450 (P450 (arom)) is overexpressed in endometriosis, endometrial cancers and uterine fibroids. With weak estrogen agonists/antagonists and some other enzymatic activities, isoflavones are increasingly advocated as a natural alternative to estrogen replacement therapy (ERT) and are available as dietary supplements. Puerarin is a major isoflavonoid compound isolated from Pueraria lobata (ge gen).

Yu et al. (2008) found that puerarin exerted a time-course effect on the inhibition of c-jun mRNA, which parallelled that of P450(arom). The suppression of P450(arom) expression and activity by puerarin treatment may associate with the down-regulation of transcription factor AP-1 or c-jun.

References

Hien TT, Kim HG, Han EH, Kang KW, Jeong HG. (2010). Molecular mechanism of suppression of MDR1 by puerarin from Pueraria lobata via NF- κ B pathway and cAMP-responsive element transcriptional activity-dependent up-regulation of AMP-activated protein kinase in breast cancer MCF-7/adr cells. Mol Nutr Food Res, 54(7):918-28. doi: 10.1002/mnfr.200900146.


Lin YJ, Hou YC, Lin CH, et al. (2009). Puerariae radix isoflavones and their metabolites inhibit growth and induce apoptosis in breast cancer cells. Biochemical and Biophysical Research Communications, 378(4):683-8. doi:10.1016/j.bbrc.2008.10.178


Shao HM, Tang YH, Jiang PJ, et al. (2010). Inhibitory effect of flavonoids of puerarin on proliferation of different human acute myeloid leukemia cell lines in vitro. Zhongguo Shi Yan Xue Ye Xue Za Zhi, 18(2):296-9.


Yu C, Li Y, Chen H, Yang S, Xie G. (2008). Decreased expression of aromatase in the Ishikawa and RL95-2 cells by the isoflavone, puerarin, is associated with inhibition of c-jun expression and AP-1 activity. Food Chem Toxicol, 46(12):3671-6. doi: 10.1016/j.fct.2008.09.045.


Yu Z, Li WJ. (2006). Induction of apoptosis by puerarin in colon cancer HT-29 cells. Cancer Letters, 238(1):53-60.

Magnolol

Cancer:
Bladder, breast, colon, prostate, glioblastoma, ovarian, leukemia, lung

Action: Anti-inflammatory, apoptosis, inhibits angiogenesis, anti-metastatic

Magnolol (Mag), an active constituent isolated from the Chinese herb hou po (Magnolia officinalis (Rehder & Wilson)) has long been used to suppress inflammatory processes. It has anti-cancer activity in colon, hepatoma, and leukemia cell lines.

Anti-inflammatory

Magnolol (Mag) suppressed IL-6-induced promoter activity of cyclin D1 and monocyte chemotactic protein (MCP)-1 for which STAT3 activation plays a role. Pre-treatment of ECs with Mag dose-dependently inhibited IL-6-induced Tyr705 and Ser727 phosphorylation in STAT3 without affecting the phosphorylation of JAK1, JAK2, and ERK1/2. Mag pre-treatment of these ECs dose-dependently suppressed IL-6-induced promoter activity of intracellular cell adhesion molecule (ICAM)-1 that contains functional IL-6 response elements (IREs).

In conclusion, our results indicate that Mag inhibits IL-6-induced STAT3 activation and subsequently results in the suppression of downstream target gene expression in ECs. These results provide a therapeutic basis for the development of Mag as an anti-inflammatory agent for vascular disorders including atherosclerosis (Chen et al., 2006).

Bladder Cancer; Inhibits Angiogenesis

In the present study, Chen et al. (2013) demonstrated that magnolol significantly inhibited angiogenesis in vitro and in vivo, evidenced by the attenuation of hypoxia and vascular endothelial growth factor (VEGF)-induced tube formation of human umbilical vascular endothelial cells, vasculature generation in chicken chorioallantoic membrane, and Matrigel plug.

In hypoxic human bladder cancer cells (T24), treatment with magnolol inhibited hypoxia-stimulated H2O2 formation, HIF-1α induction including mRNA, protein expression, and transcriptional activity as well as VEGF secretion. Interestingly, magnolol also acts as a VEGFR2 antagonist, and subsequently attenuates the downstream AKT/mTOR/p70S6K/4E-BP-1 kinase activation both in hypoxic T24 cells and tumor tissues. As expected, administration of magnolol greatly attenuated tumor growth, angiogenesis and the protein expression of HIF-1α, VEGF, CD31, a marker of endothelial cells, and carbonic anhydrase IX, an endogenous marker for hypoxia, in the T24 xenograft mouse model.

Collectively, these findings strongly indicate that the anti-angiogenic activity of magnolol is, at least in part, mediated by suppressing HIF-1α/VEGF-dependent pathways, and suggest that magnolol may be a potential drug for human bladder cancer therapy.

Colon Cancer; Induces Apoptosis

Emerging evidence has suggested that activation of AMP-activated protein kinase (AMPK), a potential cancer therapeutic target, is involved in apoptosis in colon cancer cells. However, the effects of magnolol on human colon cancer through activation of AMPK remain unexplored.

Magnolol displayed several apoptotic features, including propidium iodide labeling, DNA fragmentation, and caspase-3 and poly(ADP-ribose) polymerase cleavages. Park et al. (2012) showed that magnolol induced the phosphorylation of AMPK in dose- and time-dependent manners.

Magnolol down-regulated expression of the anti-apoptotic protein Bcl2, up-regulated expression of pro-apoptotic protein p53 and Bax, and caused the release of mitochondrial cytochrome c. Magnolol-induced p53 and Bcl2 expression was abolished in the presence of compound C. Magnolol inhibited migration and invasion of HCT-116 cells through AMPK activation. These findings demonstrate that AMPK mediates the anti-cancer effects of magnolol through apoptosis in HCT-116 cells.

Ovarian Cancer

Treatment of HER-2 overexpressing ovarian cancer cells with magnolol down-regulated the HER-2 downstream PI3K/Akt signaling pathway, and suppressed the expression of downstream target genes, vascular endothelial growth factor (VEGF), matrix metalloproteinase 2 (MMP2) and cyclin D1. Consistently, magnolol-mediated inhibition of MMP2 activity could be prevented by co-treatment with epidermal growth factor. Migration assays revealed that magnolol treatment markedly reduced the motility of HER-2 overexpressing ovarian cancer cells. These findings suggest that magnolol may act against HER-2 and its downstream PI3K/Akt/mTOR-signaling network, thus resulting in suppression of HER-2mediated transformation and metastatic potential in HER-2 overexpressing ovarian cancers. These results provide a novel mechanism to explain the anti-cancer effect of magnolol (Chuang et al., 2011).

Lung Cancer

Magnolol has been found to inhibit cell growth, increase lactate dehydrogenase release, and modulate cell cycle in human lung carcinoma A549 cells. Magnolol induced the activation of caspase-3 and cleavage of Poly-(ADP)-ribose polymerase, and decreased the expression level of nuclear factor-κB/Rel A in the nucleus. In addition, magnolol inhibited basic fibroblast growth factor-induced proliferation and capillary tube formation of human umbilical vein endothelial cells. These data indicate that magnolol is a potential candidate for the treatment of human lung carcinoma (Seo et al., 2011).

Prostate Cancer; Anti-metastatic

Matrix metalloproteinases (MMPs) are enzymes involved in various steps of metastasis development. The objective of this study was to study the effects of magnolol on cancer invasion and metastasis using PC-3 human prostate carcinoma cells. Magnolol inhibited cell growth in a dose-dependent manner. In an invasion assay conducted in Transwell chambers, magnolol showed 33 and 98% inhibition of cancer cell at 10 microM and 20 microM concentrations, respectively, compared to the control. The protein and mRNA levels of both MMP-2 and MMP-9 were down-regulated by magnolol treatment in a dose-dependent manner.

These results demonstrate the anti-metastatic properties of magnolol in inhibiting the adhesion, invasion, and migration of PC-3 human prostate cancer cells (Hwang et al., 2010).

Glioblastoma Cancer

Magnolol has been found to concentration-dependently (0-40 microM) decrease the cell number in a cultured human glioblastoma cancer cell line (U373) and arrest the cells at the G0/G1 phase of the cell-cycle.

Pre-treatment of U373 with p21/Cip1 specific antisense oligodeoxynucleotide prevented the magnolol-induced increase of p21/Cip1 protein levels and the decrease of DNA synthesis. Magnolol at a concentration of 100 microM induced DNA fragmentation in U373. These findings suggest the potential applications of magnolol in the treatment of human brain cancers (Chen et al. 2011).

Inhibits Angiogenesis

Magnolol inhibited VEGF-induced Ras activation and subsequently suppressed extracellular signal-regulated kinase (ERK), phosphatidylinositol-3-kinase (PI3K)/Akt and p38, but not Src and focal adhesion kinase (FAK). Interestingly, the knockdown of Ras by short interfering RNA produced inhibitory effects that were similar to the effects of magnolol on VEGF-induced angiogenic signaling events, such as ERK and Akt/eNOS activation, and resulted in the inhibition of proliferation, migration, and vessel sprouting in HUVECs.

In combination, these results demonstrate that magnolol is an inhibitor of angiogenesis and suggest that this compound could be a potential candidate in the treatment of angiogenesis-related diseases (Kim et al., 2013).

References

Chen LC, Liu YC, Liang YC, Ho YS, Lee WS. (2009). Magnolol inhibits human glioblastoma cell proliferation through up-regulation of p21/Cip1. J Agric Food Chem, 57(16):7331-7. doi: 10.1021/jf901477g.


Chen MC, Lee CF, Huang WH, Chou TC. (2013). Magnolol suppresses hypoxia-induced angiogenesis via inhibition of HIF-1 α /VEGF signaling pathway in human bladder cancer cells. Biochem Pharmacol, 85(9):1278-87. doi: 10.1016/j.bcp.2013.02.009.


Chen SC, Chang YL, Wang DL, Cheng JJ. (2006). Herbal remedy magnolol suppresses IL-6-induced STAT3 activation and gene expression in endothelial cells. Br J Pharmacol, 148(2): 226–232. doi: 10.1038/sj.bjp.0706647


Chuang TC, Hsu SC, Cheng YT, et al. (2011). Magnolol down-regulates HER2 gene expression, leading to inhibition of HER2-mediated metastatic potential in ovarian cancer cells. Cancer Lett, 311(1):11-9. doi: 10.1016/j.canlet.2011.06.007.


Hwang ES, Park KK. (2010). Magnolol suppresses metastasis via inhibition of invasion, migration, and matrix metalloproteinase-2/-9 activities in PC-3 human prostate carcinoma cells. Biosci Biotechnol Biochem, 74(5):961-7.


Kim KM, Kim NS, Kim J, et al. (2013). Magnolol Suppresses Vascular Endothelial Growth Factor-Induced Angiogenesis by Inhibiting Ras-Dependent Mitogen-Activated Protein Kinase and Phosphatidylinositol 3-Kinase/Akt Signaling Pathways. Nutr Cancer.


Park JB, Lee MS, Cha EY, et al. (2012). Magnolol-induced apoptosis in HCT-116 colon cancer cells is associated with the AMP-activated protein kinase signaling pathway. Biol Pharm Bull, 35(9):1614-20.


Seo JU, Kim MH, Kim HM, Jeong HJ. (2011). Anti-cancer potential of magnolol for lung cancer treatment. Arch Pharm Res, 34(4):625-33. doi: 10.1007/s12272-011-0413-8.

Mollugin

Cancer: Breast, ovarian

Action: Multi-drug resistance, anti-inflammatory, blocks neurotoxicity

Mollugin originally isolated from Rubia cordifolia (L.) is a pharmacological compound for its anti-inflammation, anti-cancer, and anti-viral activity. Mollugin-caused inhibition of phenacetin O-deethylation was concentration-dependent in hierarchical linear models (HLMs), but not time-dependent. In addition, the Lineweaver-Burk plot indicated a typical competitive inhibition. Inhibitory effects of mollugin on human recombinant cDNA-expressed CYP1A1 and 1A2 were comparable. Taken together, the results suggested that mollugin might cause herb-drug interaction through selective inhibition of CYP1A2 in humans receiving herbal medications, including R. cordifolia (Kim et al., 2013).

MDR, Anti-inflammatory

Mollugin treatment significantly inhibited MDR1 expression by blocking MDR1 transcription. P-glycoprotein (P-gp), an important efflux transporter, is encoded by the MDR1 class of genes and is a central element of the multi-drug resistance (MDR) phenomenon in cancer cells. The suppression of MDR1 promoter activity and protein expression was mediated through mollugin-induced activation of AMP-activated protein kinase (AMPK). Furthermore, mollugin inhibited MDR1 expression through the suppression of NF-κB and cAMP-response element binding protein (CREB) activation. These results suggest that mollugin treatment enhanced suppression of P-gp expression by inhibiting the NF-κB signaling pathway and COX-2 expression, as well as attenuating cAMP-response element (CRE) transcriptional activity through AMPK activation (Tran et al., 2013).

Breast Cancer; Ovarian Cancer

Mollugin exhibited potent inhibitory effects on cancer cell proliferation, especially in HER2-overexpressing SK-BR-3 human breast cancer cells and SK-OV-3 human ovarian cancer cells in a dose- and time-dependent manner without affecting immortalized normal mammary epithelial cell line MCF-10A. Mollugin treatment caused a dose-dependent inhibition of HER2 gene expression at the transcriptional level, potentially in part through suppression of NF-κB activation. The combination of mollugin with a MEK1/2 inhibitor may be required in order to achieve optimal efficacy in HER2-overexpressing cancers.

These findings suggest that mollugin is a novel modulator of the HER2 pathway in HER2-overexpressing cancer cells with a potential role in the treatment and prevention of human breast and ovarian cancer with HER2 overexpression (Do et al., 2013).

Blocks Neurotoxicity, Anti-inflammatory

Mollugin also has effects as a neuro-protective agent in glutamate-induced neurotoxicity in the mouse hippocampal HT22 cell line and as an anti-inflammatory agent in lipopolysaccharide-induced microglial activation in BV2 cells. Mollugin showed potent neuro-protective effects against glutamate-induced neuro-toxicity and reactive oxygen species generation in mouse hippocampal HT22 cells.

In addition, the anti-inflammatory effects of mollugin were demonstrated by the suppression of pro-inflammatory mediators, including pro-inflammatory enzymes (inducible nitric oxide synthase and cyclooxygenase-2) and cytokines (tumor necrosis factor-α and interleukin-6). Furthermore, mollugin also activated the p38 mitogen-activated protein kinase (MAPK) pathway both in HT22 and BV2 cells. These results suggest that mollugin may be a promising candidate for the treatment of neurodegenerative diseases related to neuroinflammation (Jeong et al., 2011).

References

Do MT, Hwang YP, Kim HG, et al. (2013). Mollugin inhibits proliferation and induces apoptosis by suppressing fatty acid synthase in HER2-overexpressing cancer cells. Journal of Cellular Physiology, 228(5):1087–1097. doi: 10.1002/jcp.24258.


Jeong GS, Lee DS, Kim DC, et al. (2011). Neuroprotective and anti-inflammatory effects of mollugin via up-regulation of heme oxygenase-1 in mouse hippocampal and microglial cells. Eur J Pharmacol, 654(3):226-34. doi: 10.1016/j.ejphar.2010.12.027.


Kim H, Choi HK, Jeong TC, et al. (2013). Selective inhibitory effects of mollugin on CYP1A2 in human liver microsomes. Food Chem Toxicol, 51:33-7. doi: 10.1016/j.fct.2012.09.013.


Tran TP, Kim HG, Choi JH, et al. (2013). Reversal of P-glycoprotein-mediated Multi-drug resistance is induced by mollugin in MCF-7/adriamycin cells. Phytomedicine. doi:10.1016/j.phymed.2013.01.014.

Tanshinone II A & Tanshinone A (See also Cryptotanshinone)

Cancer:
Leukemia, prostate, breast, gastric, colorectal, nasopharyngeal carcinoma

Action: Chemo-sensitizer, cytostatic, cancer stem cells, anti-cancer, autophagic cell death, cell-cycle arrest

Anti-cancer

Tanshinone IIA and cryptotanshinone could induce CYP3A4 activity (Qiu et al., 2103).

Tanshinone II-A (Tan IIA) is the most abundant diterpene quinone isolated from Danshen (Salvia miltiorrhiza), which has been used in treating cardiovascular diseases for more than 2,000 years in China. Interest in its versatile protective effects in cardiovascular, metabolic, neurodegenerative diseases, and cancers has been growing over the last decade.

Tan IIA is a multi-target drug, whose molecular targets include transcription factors, scavenger receptors, ion channels, kinases, pro- and anti-apoptotic proteins, growth factors, inflammatory mediators, microRNA, and others. More recently, enhanced or synergistic effects can be observed when Tan IIA is used in combination therapy with cardio-protective and anti-cancer drugs (Xu & Liu, 2013).

Leukemia

The in vitro anti-proliferation and apoptosis-inducing effects of Tanshinone IIA on leukemia THP-1 cell lines and its mechanisms of action were investigated. MTT assay was used to detect the cell growth-inhibitory rate; cell apoptotic rate and the mitochondrial membrane potential (Deltapsim) were investigated by flow cytometry (FCM); apoptotic morphology was observed by Hoechst 33258 staining and DNA fragmentation analysis.

It was therefore concluded that Tanshinone IIA has significant growth inhibition effects on THP-1 cells by induction of apoptosis, and that Tanshinone IIA-induced apoptosis on THP-1 cells is mainly related to the disruption of Deltapsim and activation of caspase-3 as well as down-regulation of anti-apoptotic protein Bcl-2, survivin and up-regulation of pro-apoptotic protein Bax. The results indicate that Tanshinone IIA may serve as a potential anti-leukemia agent (Liu et al., 2009).

Prostate Cancer

Chiu et al. (2013) explored the mechanisms of cell death induced by Tan-IIA treatment in prostate cancer cells in vitro and in vivo. Results showed that Tan-IIA caused prostate cancer cell death in a dose-dependent manner, and cell-cycle arrest at G0/G1 phase was noted, in LNCaP cells. The G0/G1 phase arrest correlated with increased levels of CDK inhibitors (p16, p21 and p27) and decrease of the checkpoint proteins. Tan-IIA also induced ER stress in prostate cancer cells: activation and nuclear translocation of GADD153/CCAAT/enhancer-binding protein-homologous protein (CHOP) were identified, and increased expression of the downstream molecules GRP78/BiP, inositol-requiring protein-1α and GADD153/CHOP were evidenced. Blockage of GADD153/CHOP expression by siRNA reduced Tan-IIA-induced cell death in LNCaP cells.

Gastric Cancer

Tan IIA can reverse the malignant phenotype of SGC7901 gastric cancer cells, indicating that it may be a promising therapeutic agent.

Tan IIA (1, 5, 10 µg/ml) exerted powerful inhibitory effects on cell proliferation (P < 0.05, and P < 0.01), and this effect was time- and dose-dependent. FCM results showed that Tan IIA induced apoptosis of SGC7901 cells, reduced the number of cells in S phase and increased those in G0/G1 phase. Tan IIA also significantly increased the sensitivity of SGC7901 gastric cancer cells to ADR and Fu. Moreover, wound-healing and transwell assays showed that Tan IIA markedly decreased migratory and invasive abilities of SGC7901 cells (Xu et al., 2013).

Cell-cycle Arrest

MTT and SRB assays were applied to measure the effects of tanshinone A on cell viability. Cell-cycle distribution and apoptosis were assessed via flow cytometry using PI staining and the Annexin V/PI double staining method respectively. Changes to mitochondrial membrane potential was also detected by flow cytometry. The spectrophotometric method was utilized to detect changes of caspase-3 activity. Western blotting assay was used to evaluate the expression of Bcl-2, Bax and c-Myc proteins.

Results indicated that Tan-IIA displayed significant inhibitory effect on the growth of K562 cells in a dose- and time- dependent manner, and displayed only minimal damage to hepatic LO2 cells.

Tan-IIA could arrest K562 cells in the G0/G1 phase and induce apoptosis, decrease mitochondrial transmembrane potential, and the expressions of Bcl-2 and c-Myc proteins, increase the expression of Bax protein and activity of caspase-3. Accordingly, it was presumed that the induction of apoptosis may be through the endogenous pathway. Subsequently, tanshinone A could be a promising candidate in the development of a novel anti-tumor agent (Zhen et al., 2011).

Prostate Cancer, Chemo-sensitizer

Treatment with a combination of Chinese herbs and cytotoxic chemotherapies has shown a higher survival rate in clinical trials.

Tan-IIA displayed synergistic anti-tumor effects on human prostate cancer PC3 cells and LNCaP cells, when combined with cisplatin in vitro. Anti-proliferative effects were detected via MTT assay. Cell-cycle distribution and apoptosis were detected by flow cytometer. Protein expression was detected by Western blotting. The intracellular concentration of cisplatin was detected by high performance liquid chromatography (HPLC).

Results demonstrated that tanshinone II A significantly enhanced the anti-proliferative effects of cisplatin on human prostate cancer PC3 cells and LNCaP cells with an increase in the intracellular concentration of cisplatin. These effects were correlated with cell-cycle arrest at the S phase and induction of cell apoptosis. Apoptosis could potentially be achieved through the death receptor and mitochondrial pathways, decreased expression of Bcl-2.

Collectively, results indicated that the combination of tanshinone II A and cisplatin had a better treatment effect, in vitro, not only on androgen-dependent LNCaP cells but also on androgen-independent PC3 cells (Hou, Xu, Hu, & Xie, 2013).

Autophagic Cell Death, CSCs

Tan IIA significantly increased the expression of microtubule-associated protein light chain 3 (LC3) II as a hallmark of autophagy in Western blotting and immunofluorescence staining. Tan IIA augmented the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and attenuated the phosphorylation of mammalian target of rapamycin (mTOR) and p70 S6K in a dose-dependent manner.Tan IIA dramatically activated the extracellular signal regulated kinase (ERK) signaling pathway including Raf, ERK and p90 RSK in a dose-dependent and time-dependent manner. Consistently, ERK inhibitor PD184352 suppressed LC3-II activation induced by Tan IIA, whereas PD184352 and PD98059 did not affect poly (ADP-ribose) polymerase cleavage and sub-G1 accumulation induced by Tan IIA in KBM-5 leukemia cells.

Tan IIA induces autophagic cell death via activation of AMPK and ERK and inhibition of mTOR and p70 S6K in KBM-5 cells as a potent natural compound for leukemia treatment (Yun et al., 2013).

Cancer stem cells (CSCs) are maintained by inflammatory cytokines and signaling pathways. Tanshinone IIA (Tan-IIA) possesses anti-cancer and anti-inflammatory activities. The purpose of this study is to confirm the growth inhibition effect of Tan-IIA on human breast CSCs growth in vitro and in vivo and to explore the possible mechanism of its activity. After Tan-IIA treatment, cell proliferation and mammosphere formation of CSCs were decreased significantly; the expression levels of IL-6, STAT3, phospho-STAT3 (Tyr705), NF-κBp65 in nucleus and cyclin D1 proteins were decreased significantly; the tumor growth and mean tumor weight were reduced significantly.

Tan-IIA has the potential to target and kill CSCs, and can inhibit human breast CSCs growth both in vitro and in vivo through attenuation of IL-6/STAT3/NF-kB signaling pathways (Lin et al., 2013).

Colorectal Cancer

Tan II-A can effectively inhibit tumor growth and angiogenesis of human colorectal cancer via inhibiting the expression level of COX-2 and VEGF. Angiogenesis plays a significant role in colorectal cancer (CRC) and cyclooxygenase-2 (COX-2) appears to be involved with multiple aspects of CRC angiogenesis (Zhou et al., 2012). The results showed that Tan IIA inhibited the proliferation of inflammation-related colon cancer cells HCT116 and HT-29 by decreasing the production of inflammatory cytokines tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), which are generated by macrophage RAW264.7 cell line.

Treatment with TanshinoneIIA prevented increased PU.1, a transcriptional activator of miR-155, and hence increased miR-155, whereas aspirin could not. These findings support that the interruption of signal conduction between activated macrophages and colon cancer cells could be considered as a new therapeutic strategy and miR-155 could be a potential target for the prevention of inflammation-related cancer (Tu et al., 2012).

Breast Cancer

The proliferation rate of T47D and MDA-MB-231 cells influenced by 1×10-6 mol·L-1 and 1×10-7 mol·L-1 Tanshinone IIA was analyzed by MTT assay. Estrogen receptor antagonist ICI182, 780 was employed as a tool. Level of ERα and ERβ mRNA in T47D cells was quantified by Real-time RT-PCR assay. Expression of ERα and ERβ protein was measured by flow cytometry. The proliferation rates of T47D cells treated with Tanshinone IIA decreased significantly. Such effects could be partly blocked by ICI182, 780.

Meanwhile, the proliferation rates of MDA-MB-231 cells treated with Tanshinone IIA decreased much more dramatically. Real-time RT-PCR and flow cytometry results showed that Tanshinone IIA could induce elevation of ERα and ERβ, especially ERα mRNA, and protein expression level in T47D cells. Tanshinone IIA shows inhibitory effects on proliferation of breast cancer cell lines (Zhao et al., 2010).

The role of cell adhesion molecules in the process of inflammation has been studied extensively, and these molecules are critical components of carcinogenesis and cancer metastasis. This study investigated the effect of tanshinone I on cancer growth, invasion and angiogenesis on human breast cancer cells MDA-MB-231, both in vitro and in vivo. Tanshinone I dose-dependently inhibited ICAM-1 and VCAM-1 expressions in human umbilical vein endothelial cells (HUVECs) that were stimulated with TNF-α for 6 h.

Additionally, reduction of tumor mass volume and decrease of metastasis incidents by tanshinone I were observed in vivo. In conclusion, this study provides a potential mechanism for the anti-cancer effect of tanshinone I on breast cancer cells, suggesting that tanshinone I may serve as an effective drug for the treatment of breast cancer (Nizamutdinova et al., 2008).

Nasopharyngeal Carcinoma

To investigate anti-cancer effect and potential mechanism of tanshinone II(A) (Tan II(A)) on human nasopharyngeal carcinoma cell line CNE cells, the anti-proliferative effect of Tan II(A) on CNE cells was evaluated by morphological examination, cell growth curves, colonial assay and MTT assay. Tan II(A) could inhibit CNE cell proliferation in dose- and time-dependent manner. After treatment with Tan II(A), intracellular Ca2+ concentration of CNE cells was increased, mitochondria membrane potential of the cells was decreased, relative mRNA level of Bad and MT-1A was up-regulated. Tan II(A) had an anti-cancer effect on CNE cells through apoptosis via a calcineurin-dependent pathway and MT-1A down-regulation, and may be the next generation of chemotherapy (Dai et al., 2011).

References

Chiu SC, Huang SY, Chen SP, et al. (2013). Tanshinone IIA inhibits human prostate cancer cells growth by induction of endoplasmic reticulum stress in vitro and in vivo. Prostate Cancer Prostatic Dis. doi: 10.1038/pcan.2013.38.


Dai Z, Huang D, Shi J, Yu L, Wu Q, Xu Q. (2011). Apoptosis inducing effect of tanshinone II(A) on human nasopharyngeal carcinoma CNE cells. Zhongguo Zhong Yao Za Zhi, 36(15):2129-33.


Hou LL, Xu QJ, Hu GQ, Xie SQ. (2013). Synergistic anti-tumor effects of tanshinone II A in combination with cisplatin via apoptosis in the prostate cancer cells. Acta Pharmaceutica Sinica, 48(5), 675-679.


Lin C, Wang L, Wang H, et al. (2013). Tanshinone IIA inhibits breast cancer stem cells growth in vitro and in vivo through attenuation of IL-6/STAT3/NF-kB signaling pathways. J Cell Biochem, 114(9):2061-70. doi: 10.1002/jcb.24553.


Liu JJ, Zhang Y, Lin DJ, Xiao RZ. (2009). Tanshinone IIA inhibits leukemia THP-1 cell growth by induction of apoptosis. Oncol Rep, 21(4):1075-81.


Nizamutdinova IT, Lee GW, Lee JS, et al. (2008). Tanshinone I suppresses growth and invasion of human breast cancer cells, MDA-MB-231, through regulation of adhesion molecules. Carcinogenesis, 29(10):1885-1892. doi:10.1093/carcin/bgn151


Qiu F, Jiang J, Ma Ym, et al. (2013). Opposite Effects of Single-Dose and Multidose Administration of the Ethanol Extract of Danshen on CYP3A in Healthy Volunteers. Evidence-Based Complementary and Alternative Medicine, 2013(2013) http://dx.doi.org/10.1155/2013/730734


Tu J, Xing Y, Guo Y, et al. (2012). TanshinoneIIA ameliorates inflammatory microenvironment of colon cancer cells via repression of microRNA-155. Int Immunopharmacol, 14(4):353-61. doi: 10.1016/j.intimp.2012.08.015.


Xu M, Cao FL, Li NY, et al. (2013). Tanshinone IIA reverses the malignant phenotype of SGC7901 gastric cancer cells. Asian Pac J Cancer Prev, 14(1):173-7.


Xu S, Liu P. (2013). Tanshinone II-A: new perspectives for old remedies. Expert Opin Ther Pat, 23(2):149-53. doi: 10.1517/13543776.2013.743995.


Yun SM, Jung JH, Jeong SJ, et al. (2013). Tanshinone IIA Induces Autophagic Cell Death via Activation of AMPK and ERK and Inhibition of mTOR and p70 S6K in KBM-5 Leukemia Cells. Phytother Res. doi: 10.1002/ptr.5015.


Zhen X, Cen J, Li YM, Yan F, Guan T, Tang, XZ. (2011). Cytotoxic effect and apoptotic mechanism of tanshinone A, a novel tanshinone derivative, on human erythroleukemic K562 cells. European Journal of Pharmacology, 667(1-3), 129-135. doi: 10.1016/j.ejphar.2011.06.004.


Zhao PW, Niu JZ, Wang JF, Hao QX, Yu J, et al. (2010). Research on the inhibitory effect of Tanshinone IIA on breast cancer cell proliferation. Zhong Guo Yao Li Xue Tong Bao, 26(7):903-906.


Zhou LH, Hu Q, Sui H, et al. (2012). Tanshinone II–a inhibits angiogenesis through down regulation of COX-2 in human colorectal cancer. Asian Pac J Cancer Prev, 13(9):4453-8.

Kaempferol

Cancer:
Pancreatic, osteosarcoma, metastasis, ovarian cancer

Action: Anti-oxidation, anti-inflammatory, cell-cycle arrest, blood sugar regulation, estrogen receptor modulator, metastasis

Kaempferol is a flavonol compound present in various plants and Chinese medicinal herbs, including Allium cepa (L.).

Blood Sugar Regulation

It has been found that kaempferol, a flavonol compound present in various Chinese medicinal herbs, has cyto-protective effects on cultured clonal beta-cells and pancreatic human islets. Kaempferol treatment dose-dependently promoted viability, inhibited cellular apoptosis, and reduced caspase-3 activity in beta-cells and human islets exposed to chronic high glucose, with 10 µM kaempferol exerting the maximum effect. In addition, kaempferol treatment improved the expression of anti-apoptotic proteins Akt and Bcl-2, that was significantly reduced in beta-cells and human islets chronically exposed to hyperglycemia.

Furthermore, exposure of beta-cells and human islets to kaempferol restored high glucose-attenuated intracellular cAMP and ATP production. Inhibition of protein kinase A or Akt activation ablated the anti-apoptotic effect of kaempferol. These cytoprotective effects of kaempferol were associated with improved insulin secretory function and synthesis in beta-cells and human islets.

These findings provide evidence that kaempferol may be a naturally occurring anti-diabetic compound through protecting pancreatic beta-cell survival and function in a hostile environment that would otherwise lead to type 2 diabetes (Zhang et al., 2011).

Ovarian Cancer

Recent studies indicate that apigenin, genistein, kaempferol, luteolin, and quercetin potently inhibit VEGF production and suppress ovarian cancer cell metastasis in vitro. Unlike NSAIDS (non-steroid anti-inflammatory drugs), well-documented clinical data for phyto-active compounds are lacking. In order to evaluate objectively the potential benefit of these compounds in the treatment of ovarian cancer, strategically designed, large scale studies are warranted (Chen et al., 2012).

Estrogen Receptor Modulator

Kaempferol is a dietary flavonoid that can function as a selective estrogen receptor modulator (SERM). Estrogen-related receptors alpha and gamma (ERR α and ERRγ) are orphan nuclear receptors that play important roles in mitochondrial biogenesis and cancer development. Wang, Gao, & Wang (2013) have shown that kaempferol can functionally antagonize the activities of ERRs based on both response element reporter systems and target gene analysis. Kaempferol modulation of mitochondrial function and suppression of cancer cell growth has been confirmed. These findings suggest that kaempferol may exert its anti-cancer activities through antagonizing ERRs activity.

Osteosarcoma; Metastasis

Kaempferol displayed inhibitory effects on the invasion and adhesion of U-2 osteosarcoma (OS) cells in a concentration-dependent manner and it also inhibited the migration of U-2 OS cells in a concentration-dependent manner. Kaempferol treatment reduced the enzymatic activities and protein levels of matrix metalloproteinase (MMP)-2, MMP-9 and urokinase plasminogen activator (uPA) and furthermore, kaempferol was able to reduce the protein phosphorylation of ERK, p38 and JNK. Results suggest a potential role for kaempferol in the therapy of tumor metastasis of OS (Chen et al., 2013).

Cell-cycle Arrest

Kaempferol decreased cell viability as determined by MTT assays and induced a G2/M phase cell-cycle arrest in a concentration-dependent manner. CDK1/cyclin B expression and the AMPK and AKT signaling pathways contributed to kaempferol-induced G2/M cell-cycle arrest and autophagic cell death in SK-HEP-1 human hepatic cancer cells (Huang et al., 2013).

References

Chen SS, Michael A, Butler-Manuel SA. (2012). Advances in the treatment of ovarian cancer: a potential role of anti-inflammatory phytochemicals. Discov Med, 13(68):7-17.


Chen HJ, Lin CM, Lee CY, et al. (2013). Kaempferol suppresses cell metastasis via inhibition of the ERK-p38-JNK and AP-1 signaling pathways in U-2 OS human osteosarcoma cells. Oncol Rep, 30(2):925-32. doi: 10.3892/or.2013.2490.


Huang WW, Tsai SC, Peng SF, et al. (2013). Kaempferol induces autophagy through AMPK and AKT signaling molecules and causes G2/M arrest via down-regulation of CDK1/cyclin B in SK-HEP-1 human hepatic cancer cells. Int J Oncol, 42(6):2069-77. doi: 10.3892/ijo.2013.1909.


Wang H, Gao M, Wang J. (2013). Kaempferol inhibits cancer cell growth by antagonizing estrogen-related receptor α and γ activities. Cell Biol Int. doi: 10.1002/cbin.10152.


Zhang Y, Liu D. (2011). Flavonol kaempferol improves chronic hyperglycemia-impaired pancreatic beta-cell viability and insulin secretory function. Eur J Pharmacol, 670(1):325-32. doi: 10.1016/j.ejphar.2011.08.011.