Category Archives: STAT3

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.

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.

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.

Cucurbitacin D (CuD) (See also Trichosanthin)

Cancer: Hepatocellular carcinoma, pancreatic, breast

Action: Apoptosis

Breast Cancer

Cucurbitacin D (CuD) isolated from Trichosanthes kirilowii induces apoptosis in several cancer cells. Constitutive signal transducer and activator of transcription 3 (STAT3), which is an oncogenic transcription factor, is often observed in many human malignant tumors, including breast cancer. Kim et al. (2013) tested whether Trichosanthes kirilowii ethanol extract (TKE) or CuD suppresses cell growth and induces apoptosis through inhibition of STAT3 activity in breast cancer cells.

They found that both TKE and CuD suppressed proliferation and induced apoptosis and G2/M cell-cycle arrest in MDA-MB-231 breast cancer cells by inhibiting STAT3 phosphorylation. In addition, both TKE and CuD inhibited nuclear translocation and transcriptional activity of STAT3. Taken together, our results indicate that TKE and its derived compound, CuD, could be potent therapeutic agents for breast cancer, blocking tumor cell proliferation and inducing apoptosis through suppression of STAT3 activity.

Hepatocellular Carcinoma

Takahashi et al. (2009) found that the anti-tumor components isolated from the extract of trichosanthes (EOT) are cucurbitacin D and dihydrocucurbitacin D, and suggest that cucurbitacin D induces apoptosis through caspase-3 and phosphorylation of JNK in hepatocellular carcinoma cells. These results suggest that cucurbitacin D isolated from Trichosanthes kirilowii could be a valuable candidate for an anti-tumor drug.

Pancreatic Cancer

Dose-response studies showed that the drug inhibited 50% growth of seven pancreatic cancer cell lines at 10−7 mol/L, whereas clonogenic growth was significantly inhibited at 5 × 10−8 mol/L. Cucurbitacin B caused dose- and time-dependent G2-M-phase arrest and apoptosis of pancreatic cancer cells. This was associated with inhibition of activated JAK2, STAT3, and STAT5, increased level of p21WAF1 even in cells with nonfunctional p53, and decrease of expression of cyclin A, cyclin B1, and Bcl-XL with subsequent activation of the caspase cascade.

Cucurbitacin B has profound in vitro and in vivo anti-proliferative effects against human pancreatic cancer cells, and the compound may potentate the anti-proliferative effect of the chemotherapeutic agent gemcitabine. Further clinical studies are necessary to confirm our findings in patients with pancreatic cancer (Thoennissen et al., 2009).

References

Kim SR, Seo HS, Choi H-S, et al. (2013). Trichosanthes kirilowii Ethanol Extract and Cucurbitacin D Inhibit Cell Growth and Induce Apoptosis through Inhibition of STAT3 Activity in Breast Cancer Cells. Evidence-Based Complementary and Alternative Medicine, 2013. http://dx.doi.org/10.1155/2013/975350


Thoennissen NH, Iwanski GB, Doan NB, et al. (2009). Cucurbitacin B Induces Apoptosis by Inhibition of the JAK/STAT Pathway and Potentiates Anti-proliferative Effects of Gemcitabine on Pancreatic Cancer Cells.   Cancer Res, 69; 5876 doi: 10.1158/0008-5472.CAN-09-0536


Takahashi N, Yoshida Y, Sugiura T, et al. (2009). Cucurbitacin D isolated from Trichosanthes kirilowii induces apoptosis in human hepatocellular carcinoma cells in vitro. International Immunopharmacology, 9(4):508–513.

Cryptotanshinone (See also Tanshinone)

Cancer:
Prostate, breast, cervical., leukemia, hepatocellular carcinoma

Action: Anti-inflammatory, cell-cycle arrest, inhibits dihydrotestosterone (DHT), anti-proliferative, hepato-protective

Cryptotanshinone is a major constituent of tanshinones from Salvia miltiorrhiza (Bunge).

Tanshinone IIA and cryptotanshinone could induce CYP3A activity (Qiu et al., 2103).

Anti-proliferative Agent

Cryptotanshinone (CPT), a natural compound, is a potential anti-cancer agent. Chen et al., (2010) have shown that CPT inhibited cancer cell proliferation by arresting cells in G(1)-G(0) phase of the cell-cycle. This is associated with the inhibition of cyclin D1 expression and retinoblastoma (Rb) protein phosphorylation.

Furthermore, they found that CPT inhibited the signaling pathway of the mammalian target of rapamycin (mTOR), a central regulator of cell proliferation. This is evidenced by the findings that CPT inhibited type I insulin-like growth factor I- or 10% fetal bovine serum-stimulated phosphorylation of mTOR, p70 S6 kinase 1, and eukaryotic initiation factor 4E binding protein 1 in a concentration- and time-dependent manner. Expression of constitutively active mTOR conferred resistance to CPT inhibition of cyclin D1 expression and Rb phosphorylation, as well as cell growth. The results suggest that CPT is a novel anti-proliferative agent.

Anti-inflammatory; COX-2, PGE2

Cyclooxygenase-2 (COX-2) is a key enzyme that catalyzes the biosynthesis of prostaglandins from arachidonic acid and plays a critical role in some pathologies including inflammation, neurodegenerative diseases and cancer. Cryptotanshinone is a major constituent of tanshinones and has well-documented anti-oxidative and anti-inflammatory effects.

This study confirmed the remarkable anti-inflammatory effect of cryptotanshinone in the carrageenan-induced rat paw edema model. Since the action of cryptotanshinone on COX-2 has not been previously described, in this study, Jin et al. (2006) examined the effect of cryptotanshinone on cyclooxygenase activity in the exogenous arachidonic acid-stimulated insect sf-9 cells, which highly express human COX-2 or human COX-1, and on cyclooxygenases expression in human U937 promonocytes stimulated by lipopolysaccharide (LPS) plus phorbolmyristate acetate (PMA).

Cryptotanshinone reduced prostaglandin E2 synthesis and reactive oxygen species generation catalyzed by COX-2, without influencing COX-1 activity in cloned sf-9 cells. In PMA plus LPS-stimulated U937 cells, cryptotanshinone had negligible effects on the expression of COX-1 and COX-2, at either a mRNA or protein level. These results demonstrate that the anti-inflammatory effect of cryptotanshinone is directed against enzymatic activity of COX-2, not against the transcription or translation of the enzyme.

Prostate Cancer

Cryptotanshinone was identified as a potent STAT3 inhibitor. Cryptotanshinone rapidly inhibited STAT3 Tyr705 phosphorylation in DU145 prostate cancer cells and the growth of the cells through 96 hours of the treatment. Inhibition of STAT3 Tyr705 phosphorylation in DU145 cells decreased the expression of STAT3 downstream target proteins such as cyclin D1, survivin, and Bcl-xL.

Cryptotanshinone can suppress Bcl-2 expression and augment Fas sensitivity in DU145 prostate cancer cells. Park et al. (2010) show that JNK and p38 MAPK act upstream of Bcl-2 expression in Fas-treated DU145 cells, and that cryptotanshinone significantly blocked activation of these kinases. Moreover, cryptotanshinone sensitized several tumor cells to a broad range of anti-cancer agents. Collectively, the data suggest that cryptotanshinone has therapeutic potential in the treatment of human prostate cancer (Park et al., 2010).

Cryptotanshinone was colocalized with STAT3 molecules in the cytoplasm and inhibited the formation of STAT3 dimers. Computational modeling showed that cryptotanshinone could bind to the SH2 domain of STAT3. These results suggest that cryptotanshinone is a potent anti-cancer agent targeting the activation STAT3 protein. It is the first report that cryptotanshinone has anti-tumor activity through the inhibition of STAT3 (Shin et al., 2009).

Prostate Cancer; Androgen Receptor Positive

Anti-androgens to reduce or prevent androgens binding to androgen receptor (AR) are widely used to suppress AR-mediated PCa growth; however, the androgen depletion therapy is only effective for a short period of time. Xu et al., (2012) found that cryptotanshinone (CTS), with a structure similar to dihydrotestosterone (DHT), can effectively inhibit the DHT-induced AR transactivation and prostate cancer cell growth. Their results indicated that 0.5 µM CTS effectively suppresses the growth of AR-positive PCa cells, but has little effect on AR negative PC-3 cells and non-malignant prostate epithelial cells.

Furthermore, data indicated that CTS could modulate AR transactivation and suppress the DHT-mediated AR target genes expression in both androgen responsive PCa LNCaP cells and castration resistant CWR22rv1 cells. The mechanistic studies indicate that CTS functions as an AR inhibitor to suppress androgen/AR-mediated cell growth and PSA expression by blocking AR dimerization and the AR-coregulator complex formation.

Furthermore, they showed that CTS effectively inhibits CWR22Rv1 cell growth and expressions of AR target genes in the xenograft animal model. The previously un-described mechanisms of CTS may explain how CTS inhibits the growth of PCa cells and help us to establish new therapeutic concepts for the treatment of PCa.

Breast Cancer, Cervical Cancer, Leukemia, Hepatocellular Carcinoma

The three tanshinone derivatives, tanshinone I, tanshinone IIA, and cryptotanshinone, exhibited significant in vitro cytotoxicity against several human carcinoma cell lines (Wang et al., 2007).

Tanshinone I was found to inhibit the growth and invasion of breast cancer cells both in vitro and in vivo through regulation of adhesion molecules including ICAM-1 and VCAM-1 (Nizamutdinova et al., 2008), and induce apoptosis of leukemia cells by interfering with the mitochondrial transmembrane potential (ΔΨm), increasing the expression of Bax, as well as activating caspase-3 (Liu et al., 2010). Tanshinone IIA has been reported to inhibit the growth of cervical cancer cells through disrupting the assembly of microtubules, and induces G2/M phase arrest and apoptosis (Pan et al., 2010).

This compound can also inhibit invasion and metastasis of hepatocellular carcinoma (HCC) cells both in vitro and in vivo, by suppressing the expression of the metalloproteinases, MMP2 and MMP9 and interfering with the NFκB signaling pathway (Xu et al., 2009).

Breast Cancer

Cryptotanshione was reported to induce cell-cycle arrest at the G1-G0 phase, which was accompanied by the inhibition of cyclin D1 expression, retinoblastoma (Rb) protein phosphorylation, and of the rapamycin (mTOR) signaling pathway (Chen et al., 2010).

Hepato-protective Effect

Cryptotanshinone (20 or 40mg/kg) was orally administered 12 and 1h prior to GalN (700mg/kg)/LPS (10µg/kg) injection. The increased mortality and TNF- α levels by GalN/LPS were declined by cryptotanshinone pre-treatment. In addition, cryptotanshinone attenuated GalN/LPS-induced apoptosis, characterized by the blockade of caspase-3, -8, and -9 activation, as well as the release of cytochrome c from the mitochondria. Furthermore, cryptotanshinone significantly inhibited the activation of NF-κB and suppressed the production of pro-inflammatory cytokines.

These findings suggest that the hepato-protective effect of cryptotanshinone is likely to be associated with its anti-apoptotic activity and the down-regulation of MAPKs and NF-κB associated at least in part with suppressing TAK1 phosphorylation (Jin et al., 2013).

References

Chen W, Luo Y, Liu L, Zhou H, Xu B, Han X, Shen T, Liu Z, Lu Y, Huang S. (2010). Cryptotanshinone Inhibits Cancer Cell Proliferation by Suppressing Mammalian Target of Rapamycin–Mediated Cyclin D1 Expression and Rb Phosphorylation. Cancer Prev Res (Phila), 3(8):1015-25. doi: 10.1158/1940-6207.CAPR-10-0020. Epub 2010 Jul 13.

Jin DZ, Yina LL, Jia XQ, Zhu XZ. (2006). Cryptotanshinone inhibits cyclooxygenase-2 enzyme activity but not its expression. European Journal of Pharmacology, 549(1-3):166-72. doi:10.1016/j.ejphar.2006.07.055

Jin VQ, Jiang S, Wu YL, et al. (2013). Hepato-protective effect of cryptotanshinone from Salvia miltiorrhiza in d-galactosamine/lipopolysaccharide-induced fulminant hepatic failure. Phytomedicine. doi:10.1016/j.phymed.2013.07.016

Liu JJ, Liu WD, Yang HZ, et al. (2010). Inactivation of PI3k/Akt signaling pathway and activation of caspase-3 are involved in tanshinone I-induced apoptosis in myeloid leukemia cells in vitro. Ann Hematol, 89:1089–1097. doi: 10.1007/s00277-010-0996-z.

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

Pan TL, Hung YC, Wang PW, et al. (2010). Functional proteomic and structural insights into molecular targets related to the growth-inhibitory effect of tanshinone IIA on HeLa cells. Proteomics,10:914–929.

Park IJ, Kim MJ, Park OJ, et al. (2010). Cryptotanshinone sensitizes DU145 prostate cancer cells to Fas(APO1/CD95)-mediated apoptosis through Bcl-2 and MAPK regulation. Cancer Lett, 298:88–98. doi: 10.1016/j.canlet.2010.06.006.

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

Shin DS, Kim HN, Shin KD, et al. (2009). Cryptotanshinone Inhibits Constitutive Signal Transducer and Activator of Transcription 3 Function through Blocking the Dimerization in DU145 Prostate Cancer Cells. Cancer Research, 69:193. doi: 10.1158/0008-5472.CAN-08-2575

Wang X, Morris-Natschke SL, Lee KH. (2007). New developments in the chemistry and biology of the bioactive constituents of Tanshen. Med Res Rev, 27:133–148. doi: 10.1002/med.20077.

Xu D, Lin TH, Li S, Da J, et al. (2012). Cryptotanshinone suppresses androgen receptor-mediated growth in androgen dependent and castration resistant prostate cancer cells. Cancer Lett, 316(1):11-22. doi: 10.1016/j.canlet.2011.10.006.

Xu YX, Feng T, Li R, Liu ZC. (2009). Tanshinone II-A inhibits invasion and metastasis of human hepatocellular carcinoma cells in vitro and in vivo. Tumori, 95:789–795.

Corosolic acid

Cancer:
Myeloid leukemia, cervical., glioblastoma, gastric, sarcoma

Action: Immunosuppressive activity

Corosolic Acid is isolated from Lagerstroemia speciosa [(L.) Pers.] and Crataegus pinnatifida var. psilosa (C. K. Schneider).

Sarcoma; Immunosuppressive Activity

The results from an in vivo study showed that Corosolic acid (CA) administration did not suppress the tumor proliferation index, but significantly impaired subcutaneous tumor development and lung metastasis.

CA administration inhibited signal transducer and activator of transcription-3 (Stat3) activation and increased in the number of infiltrating lymphocytes in tumor tissues. Ex vivo analysis demonstrated that a significant immunosuppressive effect of MDSC in tumor-bearing mice was abrogated and the mRNA expressions of cyclooxygenase-2 and CCL2 in MDSC were significantly decreased by CA administration.

Furthermore, CA enhanced the anti-tumor effects of adriamycin and cisplatin in vitro. Since Stat3 is associated with tumor progression not only in osteosarcoma, but also in other malignant tumors, these findings indicate that CA might be widely useful in anti-cancer therapy by targeting the immunosuppressive activity of MDSC and through its synergistic effects with anti-cancer agents (Horlad et al., 2013).

Cervical Cancer

Xu et al. (2009) investigated the response of human cervix adenocarcinoma HeLa cells to Corosolic acid (CRA) treatment. These results showed that CRA significantly inhibited cell viability in both a dose- and a time-dependent manner. CRA treatment induced S cell-cycle arrest and caused apoptotic death in HeLa cells. It was found that CRA increased in Bax/Bcl-2 ratios by up-regulating Bax expression, disrupted mitochondrial membrane potential and triggered the release of cytochrome c from mitochondria into the cytoplasm.

These results, taken together, indicate CRA could have strong potentials for clinical application in treating human cervix adenocarcinoma and improving cancer chemotherapy.

Glioblastoma

Tumor-associated macrophages (TAMs) of M2 phenotype promote tumor proliferation and are associated with a poor prognosis in patients with glioblastoma.

The natural compounds possessing inhibitory effects on M2 polarisation in human monocyte-derived macrophages were investigated. Among 130 purified natural compounds examined, corosolic acid significantly inhibited the expression of CD163, one of the phenotype markers of M2 macrophages, as well as suppressed the secretion of IL-10, one of the anti-inflammatory cytokines preferentially produced by M2 macrophages, thus suggesting that corosolic acid suppresses M2 polarisation of macrophages.

Furthermore, corosolic acid inhibited the proliferation of glioblastoma cells, U373 and T98G, and the activation of Signal transducer and activator of transcription-3 (STAT3) and Nuclear Factor-kappa B (NF-κB), in both human macrophages and glioblastoma cells. These results indicate that corosolic acid suppresses the M2 polarisation of macrophages and tumor cell proliferation by inhibiting both STAT3 and NF-κB activation. Therefore, corosolic acid may be a new tool for tumor prevention and therapy (Fujiwara et al., 2010).

Gastric Cancer

Corosolic acid (CRA) suppresses HER2 expression, which in turn promotes cell-cycle arrest and apoptotic cell death of gastric cancer cells, providing a rationale for future clinical trials of CRA in the treatment of HER2-positive gastric cancers. CRA combined with adriamycin and 5-fluorouracil enhanced this growth inhibition, but not with docetaxel and paclitaxel (Lee et al., 2010).

Leukemia

Corosolic acid displayed about the same potent cytotoxic activity as ursolic acid against several human cancer cell lines. In addition, the compound displayed antagonistic activity against the phorbol ester-induced morphological modification of K-562 leukemic cells, indicating the suppression of protein kinase C (PKC) activity by the cytotoxic compound (Ahn et al., 1998).

References

Ahn KS, Hahm MS, Park EJ, Lee HK, Kim IH. (1998). Corosolic acid isolated from the fruit of Crataegus pinnatifida var. psilosa is a protein kinase C inhibitor as well as a cytotoxic agent. Planta Med, 64(5):468-70.


Fujiwara Y, Komohara Y, Ikeda T, Takeya M. (2010). Corosolic acid inhibits glioblastoma cell proliferation by suppressing the activation of signal transducer and activator of transcription-3 and nuclear factor-kappa B in tumor cells and tumor-associated macrophages. Cancer Science. doi: 10.1111/j.1349-7006.2010.01772.x


Horlad H, Fujiwara Y, Takemura K, et al. (2013). Corosolic acid impairs tumor development and lung metastasis by inhibiting the immunosuppressive activity of myeloid-derived suppressor cells. Molecular Nutrition & Food Research, 57(6):1046-1054. doi: 10.1002/mnfr.201200610


Lee MS, Cha EY, Thuong PT, et al. (2010). Down-regulation of human epidermal growth factor receptor 2/neu oncogene by corosolic acid induces cell-cycle arrest and apoptosis in NCI-N87 human gastric cancer cells. Biol Pharm Bull, 33(6):931-7.


Xu YF, Ge RL, Du J, et al. (2009). Corosolic acid induces apoptosis through mitochondrial pathway and caspases activation in human cervix adenocarcinoma HeLa cells. Cancer Letters, 284(2):229-237. doi:10.1016/j.canlet.2009.04.028.

Decursin

Cancer: Prostate, breast, fibrosarcoma, sarcoma

Action: MDR, inflammation, anti-cancer, angiogenesis

Decursin is isolated from Angelica gigas (Nakai).

Angelica gigas NAKAI is used to treat dysmenorrhea, amenorrhea, menopause, abdominal pain, injuries, migraine, and arthritis. The physicochemical and toxicological characterization of compounds in A. gigas NAKAI, decursin, decursinol angelate, diketone decursin, ether decursin, epoxide decursin and oxim decursin, have been extensively studied (Mahat et al., 2012).

Sarcoma; Anti-cancer

The in vivo anti-tumor activities of decursinol angelate (1) and decursin (2) isolated from the roots of Angelica gigas were investigated. These two compounds, when administered consecutively for 9 days at 50 and 100 mg/kg i.p. in mice, caused a significant increase in the life span and a significant decrease in the tumor weight and volume of mice inoculated with Sarcoma-180 tumor cells. These results suggest that decursinol angelate (1) and decursin (2) from A. gigas have anti-tumor activities (Lee et al., 2003).

Fibrosarcoma

Decursin and related coumarin compounds in herbal extracts have a number of biological activities against inflammation, angiogenesis and cancer. The human fibrosarcoma cell line, HT1080, was treated with TNFα (tumor necrosis factor α) in the presence or absence of CSL-32. Treatment of HT1080 cells with a derivative of decursin (CSL-32) inhibited their proliferation, without affecting cell viability, and TNF α-induced expression of pro-inflammatory mediators, such as MMP-9 (matrix metalloproteinase-9) and IL-8 (interleukin-8) (Lee et al., 2012).

Prostate Cancer

Androgen and androgen receptor (AR) signaling are crucial for the genesis of prostate cancer (PCa), which can often develop into androgen-ligand-independent diseases that are lethal to patients. As current chemotherapy is largely ineffective for PCa and has serious toxic side-effects, a collaborative effort has been initiated to identify and develop novel, safe and naturally occurring agents that target AR signaling from Oriental medicinal herbs for the chemoprevention and treatment of PCa. The discovery of decursin from an Oriental formula containing Korean Angelica gigas Nakai (Dang Gui) root as a novel anti-androgen/AR agent has been highlighted and the mechanisms to account for the specific anti-AR actions have been identified: rapid block of AR nuclear translocation, inhibition of binding of 5-dihydrotestesterone to AR, and increased proteasomal degradation of AR protein. Structure-activity analyzes reveal a critical requirement of the side-chain on decursin or its structural isomer decursinol angelate for anti-AR, cell-cycle arrest and pro-apoptotic activities.

This work demonstrates the feasibility of using activity-guided fractionation in cell culture assays combined with mechanistic studies to identify novel anti-androgen/AR agents from complex herbal mixtures (Lu et al., 2007).

MDR

Combination cancer therapy is one of the attractive approaches to overcome drug resistance of cancer cells. In the present study, Jang et al (2013) investigated the synergistic effect of decursin from Angelica gigas and doxorubicin on the induction of apoptosis in three human multiple myeloma cells. The combined treatment reduced mitochondrial membrane potential., suppressed the phosphorylation of JAK2, STAT3, and Src, activated SHP-2, and attenuated the expression of cyclind-D1 and survivin in U266 cells.

Overall, the combination treatment of decursin and doxorubicin can enhance apoptotic activity via mTOR and/or STAT3 signaling pathway in multiple myeloma cells.

Breast Cancer

Decursin significantly reduced protein expression and enzymatic activity of Pin1 in MDA-MB-231 cells. Kim et al (2013) found that decursin treatment enhanced the p53 expression level and failed to down-regulate Pin1 in the cells transfected with p53 siRNA, indicating the importance of p53 in the decursin-mediated Pin1 inhibition in MDA-MB-231 cells. Decursin stimulated association between peptidyl-prolyl cis/trans isomerase Pin1 to p53. Moreover, decursin facilitated p53 transcription in MDA-MB-231 cells. Overall, the study suggests the potential of decursin as an attractive cancer therapeutic agent for breast cancer by targeting Pin1.

References

Jang J, Jeong SJ, Kwon HY, Jung JH, et al. (2013). Decursin and Doxorubicin Are in Synergy for the Induction of Apoptosis via STAT3 and/or mTOR Pathways in Human Multiple Myeloma Cells. Evid Based Complement Alternat Med. 2013:506324. doi: 10.1155/2013/506324.

Kim JH, Jung JH, Kim SH, Jeong SJ. (2013). Decursin Exerts Anti-cancer Activity in MDA-MB-231 Breast Cancer Cells Via Inhibition of the Pin1 Activity and Enhancement of the Pin1/p53 Association.Phytother Res. doi: 10.1002/ptr.4986.

Lee S, Lee YS, Jung SH, et al. (2003). Anti-tumor activities of decursinol angelate and decursin from Angelica gigas. Arch Pharm Res, 26(9):727-30.

Lee SH, Lee JH, Kim EJ, et al. (2012). A novel derivative of decursin, CSL-32, blocks migration and production of inflammatory mediators and modulates PI3K and NF- κB activities in HT1080 cells. Cell Biol Int, 36(7):683-8. doi: 10.1042/CBI20110257.

Lu JX, Kim SH, Jiang C, Lee JJ, Guo JM. (2007). Oriental herbs as a source of novel anti-androgen and prostate cancer chemo-preventive agents. Acta Pharmacologica Sinica, 28, 1365–1372. doi:10.1111/j.1745-7254.2007.00683.x

Mahat B, Chae JW, Baek IH, et al. (2012). Physicochemical characterization and toxicity of decursin and their derivatives from Angelica gigas. Biol Pharm Bull, 35(7):1084-90.

Decursin

Cancer: Prostate, breast, fibrosarcoma, sarcoma

Action: MDR, inflammation, anti-cancer, angiogenesis

Decursin is isolated from Angelica gigas (Nakai).

Angelica gigas NAKAI is used to treat dysmenorrhea, amenorrhea, menopause, abdominal pain, injuries, migraine, and arthritis. The physicochemical and toxicological characterization of compounds in A. gigas NAKAI, decursin, decursinol angelate, diketone decursin, ether decursin, epoxide decursin and oxim decursin, have been extensively studied (Mahat et al., 2012).

Sarcoma; Anti-cancer

The in vivo anti-tumor activities of decursinol angelate (1) and decursin (2) isolated from the roots of Angelica gigas were investigated. These two compounds, when administered consecutively for 9 days at 50 and 100 mg/kg i.p. in mice, caused a significant increase in the life span and a significant decrease in the tumor weight and volume of mice inoculated with Sarcoma-180 tumor cells. These results suggest that decursinol angelate (1) and decursin (2) from A. gigas have anti-tumor activities (Lee et al., 2003).

Fibrosarcoma

Decursin and related coumarin compounds in herbal extracts have a number of biological activities against inflammation, angiogenesis and cancer. The human fibrosarcoma cell line, HT1080, was treated with TNFα (tumor necrosis factor α) in the presence or absence of CSL-32. Treatment of HT1080 cells with a derivative of decursin (CSL-32) inhibited their proliferation, without affecting cell viability, and TNF α-induced expression of pro-inflammatory mediators, such as MMP-9 (matrix metalloproteinase-9) and IL-8 (interleukin-8) (Lee et al., 2012).

Prostate Cancer

Androgen and androgen receptor (AR) signaling are crucial for the genesis of prostate cancer (PCa), which can often develop into androgen-ligand-independent diseases that are lethal to patients. As current chemotherapy is largely ineffective for PCa and has serious toxic side-effects, a collaborative effort has been initiated to identify and develop novel, safe and naturally occurring agents that target AR signaling from Oriental medicinal herbs for the chemoprevention and treatment of PCa. The discovery of decursin from an Oriental formula containing Korean Angelica gigas Nakai (Dang Gui) root as a novel anti-androgen/AR agent has been highlighted and the mechanisms to account for the specific anti-AR actions have been identified: rapid block of AR nuclear translocation, inhibition of binding of 5-dihydrotestesterone to AR, and increased proteasomal degradation of AR protein. Structure-activity analyzes reveal a critical requirement of the side-chain on decursin or its structural isomer decursinol angelate for anti-AR, cell-cycle arrest and pro-apoptotic activities.

This work demonstrates the feasibility of using activity-guided fractionation in cell culture assays combined with mechanistic studies to identify novel anti-androgen/AR agents from complex herbal mixtures (Lu et al., 2007).

MDR

Combination cancer therapy is one of the attractive approaches to overcome drug resistance of cancer cells. In the present study, Jang et al (2013) investigated the synergistic effect of decursin from Angelica gigas and doxorubicin on the induction of apoptosis in three human multiple myeloma cells. The combined treatment reduced mitochondrial membrane potential., suppressed the phosphorylation of JAK2, STAT3, and Src, activated SHP-2, and attenuated the expression of cyclind-D1 and survivin in U266 cells.

Overall, the combination treatment of decursin and doxorubicin can enhance apoptotic activity via mTOR and/or STAT3 signaling pathway in multiple myeloma cells.

Breast Cancer

Decursin significantly reduced protein expression and enzymatic activity of Pin1 in MDA-MB-231 cells. Kim et al (2013) found that decursin treatment enhanced the p53 expression level and failed to down-regulate Pin1 in the cells transfected with p53 siRNA, indicating the importance of p53 in the decursin-mediated Pin1 inhibition in MDA-MB-231 cells. Decursin stimulated association between peptidyl-prolyl cis/trans isomerase Pin1 to p53. Moreover, decursin facilitated p53 transcription in MDA-MB-231 cells. Overall, the study suggests the potential of decursin as an attractive cancer therapeutic agent for breast cancer by targeting Pin1.

References

Jang J, Jeong SJ, Kwon HY, Jung JH, et al. (2013). Decursin and Doxorubicin Are in Synergy for the Induction of Apoptosis via STAT3 and/or mTOR Pathways in Human Multiple Myeloma Cells. Evid Based Complement Alternat Med. 2013:506324. doi: 10.1155/2013/506324.

Kim JH, Jung JH, Kim SH, Jeong SJ. (2013). Decursin Exerts Anti-cancer Activity in MDA-MB-231 Breast Cancer Cells Via Inhibition of the Pin1 Activity and Enhancement of the Pin1/p53 Association.Phytother Res. doi: 10.1002/ptr.4986.

Lee S, Lee YS, Jung SH, et al. (2003). Anti-tumor activities of decursinol angelate and decursin from Angelica gigas. Arch Pharm Res, 26(9):727-30.

Lee SH, Lee JH, Kim EJ, et al. (2012). A novel derivative of decursin, CSL-32, blocks migration and production of inflammatory mediators and modulates PI3K and NF- κB activities in HT1080 cells. Cell Biol Int, 36(7):683-8. doi: 10.1042/CBI20110257.

Lu JX, Kim SH, Jiang C, Lee JJ, Guo JM. (2007). Oriental herbs as a source of novel anti-androgen and prostate cancer chemo-preventive agents. Acta Pharmacologica Sinica, 28, 1365–1372. doi:10.1111/j.1745-7254.2007.00683.x

Mahat B, Chae JW, Baek IH, et al. (2012). Physicochemical characterization and toxicity of decursin and their derivatives from Angelica gigas. Biol Pharm Bull, 35(7):1084-90.

Silibinin

Cancer:
Lung, leukemia, colorectal, thyroid, breast, bladder

Action: Anti-angiogenesis, EMT, cell-cycle arrest

Cell-cycle Arrest, Colon Cancer

Silibinin, an active constituent of milk thistle (Silybum marianum [(L.) Gaertn.]), has been reported to inhibit proliferation and induce cell-cycle arrest of human colon cancer cells, Fet, Geo, and HCT116 (Hogan et al., 2007). Silibinin Up-regulates the expression of cyclin-dependent kinase inhibitors and induces cell-cycle arrest and apoptosis in human colon carcinoma HT-29 cells (Agarwal et al., 2003). Also in HT-29 cells, treatment with beta-escin, a principal component of horse chestnut, tinduces growth arrest at the G1-S phase together with an induction of Cip1/p21 and an associated reduction in the phosphorylation of retinoblastoma protein (Patlolla et al., 2006).

Lung Cancer

Silibinin also has anti-angiogenic effects on lung adenocarcinomas in vitro, as it strongly decreased both tumor number and tumor size (an anti-tumor effect that correlates with reduced anti-angiogenic activity) (Tyagi et al., 2009). Further, silibinin inhibits mouse lung tumorigenesis in vivo, in part by targeting tumor microenvironment. Tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) can be pro- or anti-tumorigenic, but in lung cancer cell lines they induce pro-inflammatory enzymes cyclooxygenase 2 (COX2) and inducible nitric oxide synthase (iNOS). Accordingly, the mechanism of silibinin action was examined on TNF-α + IFN-γ (hereafter referred as cytokine mixture) elicited signaling in tumor-derived mouse lung epithelial LM2 cells.

Both signal transducers and activators of the transcription (STAT)3 (tyr705 and ser727) and STAT1 (tyr701) were activated within 15 min of cytokine mixture exposure, while STAT1 (ser727) activated after 3 h. Cytokine mixture also activated Erk1/2 and caused an increase in both COX2 and iNOS levels. Pre-treatment of cells with a MEK, NF-κB, and/or epidermal growth factor receptor (EGFR) inhibitor inhibited cytokine mixture-induced activation of Erk1/2, NF-κB, or EGFR, respectively, and strongly decreased phosphorylation of STAT3 and STAT1 and expression of COX2 and iNOS.

Together, the results show that STAT3 and STAT1 could be valuable chemo-preventive and therapeutic targets within the lung tumor microenvironment in addition to being targets within the tumor itself, and that silibinin inhibit their activation as a plausible mechanism of its efficacy against lung cancer (Tyagi et al., 2011).

Leukemia

Silibinin also affects cellular differentiation in the human promyelocytic leukemia HL-60 cell culture system. Treatment of HL-60 cells with silibinin inhibited cellular proliferation and induced cellular differentiation in a dose-dependent manner.

Silibinin enhanced protein kinase C (PKC) activity and increased protein levels of both PKCα and PKCβ in 1,25-(OH)2D3-treated HL-60 cells. PKC and extracellular signal-regulated kinase (ERK) inhibitors significantly inhibited HL-60 cell differentiation induced by silibinin alone or in combination with 1,25-(OH)2D3, indicating that PKC and ERK may be involved in silibinin-induced HL-60 cell differentiation (Kang et al., 2001).

Thyroid Cancer, Breast Cancer

Silibinin inhibits TPA-induced cell migration and MMP-9 expression in thyroid and breast cancer cells. Matrix metalloproteinases (MMPs) play an important role in cancer metastasis, cell migration and invasion. The effects of silibinin were investigated on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cell migration and MMP-9 expression in thyroid and breast cancer cells. These results revealed that the levels of MMP-9 mRNA and protein expression were significantly increased by TPA but not MMP-2 in TPC-1 and MCF7 cells.

TPA-induced phosphorylation of MEK and ERK was also inhibited by silibinin. Taken together, these results suggest that silibinin suppresses TPA-induced cell migration and MMP-9 expression through the MEK/ERK-dependent pathway in thyroid and breast cancer cells (Oh et al., 2013).

Bladder Cancer

Silibinin induced apoptosis and inhibited proliferation of bladder cancer cells and metastasis. In the present study, Wu et al. (2013) utilized a novel highly metastatic T24-L cell model, and found that silibinin treatment not only resulted in the suppression of cell migration and invasion in vitro, but also decreased bladder cancer lung metastasis and prolonged animal survival in vivo. Inactivation of β-catenin/ZEB1 signaling by silibinin leads to dual-block of EMT and stemness.

Lung Cancer, EMT

Silibinin formulation might facilitate the design of clinical trials to test the administration of silibinin meglumine-containing injections, granules, or beverages in combination with EGFR TKIs in patients with EGFR-mutated NSCLC. Silibinin meglumine notably decreased the overall volumes of NSCLC tumors as efficiently as did the EGFR tyrosine kinase inhibitor (TKI) gefitinib. Concurrent treatment with silibinin meglumine impeded the regrowth of gefitinib-unresponsive tumors, resulting in drastic tumor growth prevention.

Because the epithelial-to-mesenchymal transition (EMT) is required by a multiplicity of mechanisms of resistance to EGFR TKIs, we evaluated the ability of silibinin meglumine to impede the EMT in vitro and in vivo. Silibinin-meglumine efficiently prevented the loss of markers associated with a polarized epithelial phenotype as well as the de novo synthesis of proteins associated with the mesenchymal morphology of transitioning cells (Cuf` et al., 2013).

Breast cancer

Myeloid-derived suppressor cells (MDSC)s increase in blood and accumulate in the tumor microenvironment of tumor-bearing animals, contributing to immune suppression in cancer. Silibinin, a natural flavonoid from the seeds of milk thistle, has been developed as an anti-inflammatory agent and supportive care agent to reduce the toxicity of cancer chemotherapy. The goals of this study were to evaluate the effect of silibinin on MDSCs in tumor-bearing mice and antitumor activity of silibinin in a mouse model of breast cancer. 4T1 luciferase-transfected mammary carcinoma cells were injected into in the mammary fat pad female BALB/c mice, and female CB17-Prkdc Scid/J mice. Silibinin treatment started on day 4 or day 14 after tumor inoculation continued every other day.

Tumor growth was monitored by bioluminescent imaging (BLI) measuring total photon flux. Flow cytometry measured total leukocytes, CD11b+ Gr-1+ MDSC, and T cells in the blood and tumors of tumor-bearing mice. The effects of silibinin on 4T1 cell viability in vitro were measured by BLI. Treatment with silibinin increased overall survival in mice harboring tumors derived from the 4T1-luciferase breast cancer cell line, and reduced tumor volumes and numbers of CD11b+Gr-1+ MDSCs in the blood and tumor, and increased the content of T cells in the tumor microenvironment.

Silibinin failed to inhibit tumor growth in immunocompromised severe combined immunodeficiency mice, supporting the hypothesis that anticancer effect of silibinin is immune-mediated. The antitumor activity of silibinin requires an intact host immune system and is associated with decreased accumulation of blood and tumor-associated MDSCs.

References

 

Agarwal C, Singh RP, Dhanalakshmi S, et al. (2003). Silibinin Up-regulates the expression of cyclin-dependent kinase inhibitors and causes cell-cycle arrest and apoptosis in human colon carcinoma HT-29 cells. Oncogene, 22:8271–8282.

 

Cufí S, Bonavia R, Vazquez-Martin A, Corominas-Faja B, et al. (2013). Silibinin meglumine, a water-soluble form of milk thistle silymarin, is an orally active anti-cancer agent that impedes the epithelial-to-mesenchymal transition (EMT) in EGFR-mutant non-small-cell lung carcinoma cells. Food Chem Toxicol, 60:360-8. doi: 10.1016/j.fct.2013.07.063.

Hogan FS, Krishnegowda NK, Mikhailova M, Kahlenberg MS. (2007). Flavonoid, silibinin, inhibits proliferation and promotes cell-cycle arrest of human colon cancer. J Surg Res, 143:58–65.

Kang SN, Lee MH, Kim KM, Cho D, Kim TS. (2001). Induction of human promyelocytic leukemia HL-60 cell differentiation into monocytes by silibinin: involvement of protein kinase C. Biochemical Pharmacology, 61(12):1487–1495

Oh SJ, Jung SP, Han J, et al. (2013). Silibinin inhibits TPA-induced cell migration and MMP-9 expression in thyroid and breast cancer cells. Oncol Rep, 29(4):1343-8. doi: 10.3892/or.2013.2252.

Patlolla JM, Raju J, Swamy MV, Rao CV. (2006). Beta-escin inhibits colonic aberrant crypt foci formation in rats and regulates the Cell-cycle growth by inducing p21(waf1/cip1) in colon cancer cells. Mol Cancer Ther, 5:1459–1466.

Tyagi A, Singh RP, Ramasamy K, et al. (2009). Growth Inhibition and Regression of Lung Tumors by Silibinin: Modulation of Angiogenesis by Macrophage-Associated Cytokines and Nuclear Factor-κ B and Signal Transducers and Activators of Transcription 3. Cancer Prev Res, 2(1):74-83

Tyagi A, Agarwal C, Dwyer-Nield LD, et al. (2011). Silibinin modulates TNF‐α and IFN ‐γ mediated signaling to regulate COX2 and iNOS expression in tumorigenic mouse lung epithelial LM2 cells. Molecular Carcinogenesis. doi: 10.1002/mc.20851.

Wu K, Ning Z, Zeng J, et al. (2013). Silibinin inhibits β -catenin/ZEB1 signaling and suppresses bladder cancer metastasis via dual-blocking epithelial-mesenchymal transition and stemness. Cell Signal, 25(12):2625-2633. doi: 10.1016/j.cellsig.2013.08.028.

Forghani P, Khorramizadeh MR & Waller EK. (2014) Silibinin inhibits accumulation of myeloid-derived suppressor cells and tumor growth of murine breast cancer. Cancer Medicine. Volume 3, Issue 2, pages 215–224, April 2014 DOI: 10.1002/cam4.186

Emodin (See also Aloe-Emodin)

Cancer:
Breast, colon, liver, chemotherapy, myeloma, oral., pancreatic, hepatocellular carcinoma, lung, leukemia

Action: MDR-1, cell-cycle arrest

Emodin is an active natural anthraquinone derivative component of a traditional Chinese and Japanese medicine isolated from the root and rhizomes of Rheum palmatum L., Senna obtusifolia [(L.) H.S.Irwin & Barneby], Fallopia japonica [Houtt. (Ronse Decr.)], Kalimeris indica (L.) Sch.Bip., Ventilago madraspatana (Gaertn.), Rumex nepalensis (Spreng.), Fallopia multiflora [(Thunb.) Haraldson], Cassia occidentalis [(L.) Link], Senna siamea [(Lam.) Irwin et Barneby] and Acalypha australis (L.).

Aloe-emodin is an active natural anthraquinone derivative, and is found in the roots and rhizomes of numerous Chinese medicinal herbs (including Rheum palmatum L) and exhibits anti-cancer effects on many types of human cancer cell lines.

Administration of rhubarb (Emodin) can effectively reverse severe acute pancreatitis (SAP) by regulating the levels of IL-15 and IL-18 (Yu & Yang, 2013).

Pancreatic Cancer

Emodin is a tyrosine kinase inhibitor that has an inhibitory effect on mammalian cell-cycle modulation in specific oncogene-overexpressing cells. Recently, there has been great progress in the preclinical study of the anti-cancer mechanisms of emodin. A recent study revealed that emodin has therapeutic effects on pancreatic cancer through various anti-tumor mechanisms. Notably, the therapeutic efficacy of emodin in combination with chemotherapy was found to be higher than the comparable single chemotherapeutic regime, and the combination therapy also exhibited fewer side-effects (Wei et al., 2013).

Hepatocellular Carcinoma, Pancreatic, Breast, Colorectal and Lung Cancers, and Leukemia

Emodin is found as an active ingredient in different Chinese herbs including Rheum palmatum and Polygonam multiflorum, and has diuretic, vasorelaxant, anti-bacterial., anti-viral., anti-ulcerogenic, anti-inflammatory, and anti-cancer effects. The anti-inflammatory effects of emodin have been exhibited in various in vitro as well as in vivo models of inflammation including pancreatitis, arthritis, asthma, atherosclerosis and glomerulonephritis. As an anti-cancer agent, emodin has been shown to suppress the growth of various tumor cell lines including hepatocellular carcinoma, pancreatic, breast, colorectal., leukemia, and lung cancers. Emodin is a pleiotropic molecule capable of interacting with several major molecular targets including NF-κB, casein kinase II, HER2/neu, HIF-1α, AKT/mTOR, STAT3, CXCR4, topoisomerase II, p53, p21, and androgen receptors which are involved in inflammation and cancer (Shrimali et al., 2013).

Hepatocellular Carcinoma

It has been found that emodin induces apoptotic responses in the human hepatocellular carcinoma cell lines (HCC) Mahlavu, PLC/PRF/5 and HepG2. The addition of emodin to these three cell lines led to inhibition of growth in a time-and dose-dependent manner. Emodin generated reactive oxygen species (ROS) in these cells which brought about a reduction of the intracellular mitochondrial transmembrane potential (ΔΨ m), followed by the activation of caspase–9 and caspase–3, leading to DNA fragmentation and apoptosis.

Preincubation of hepatoma cell lines with the hydrogen peroxide-scavenging enzyme, catalase (CAT) and cyclosporin A (CsA), partially inhibited apoptosis. These results demonstrate that enhancement of generation of ROS, DeltaPsim disruption and caspase activation may be involved in the apoptotic pathway induced by emodin (Jing et al., 2002).

Colon Cancer

In in vitro study, emodin induced cell morphological changes, decreased the percentage of viability, induced G2/M phase arrest and increased ROS and Ca(2+) productions as well as loss of mitochondrial membrane potential (ΔΨ(m)) in LS1034 cells. Emodin-triggered apoptosis was also confirmed by DAPI staining and these effects are concentration-dependent.

In in vivo study, emodin effectively suppressed tumor growth in tumor nude mice xenografts bearing LS1034. Overall, the potent in vitro and in vivo anti-tumor activities of emodin suggest that it might be developed for treatment of colon cancer in the future (Ma et al., 2012).

Myeloid Leukemia

It has been shown that emodin significantly induces cytotoxicity in the human myeloma cells through the elimination of myeloid cell leukemia 1 (Mcl-1). Emodin inhibited interleukin-6–induced activation of Janus-activated kinase 2 (JAK2) and phosphorylation of signal transducer and activator of transcription 3 (STAT3), followed by the decreased expression of Mcl-1. Activation of caspase-3 and caspase-9 was triggered by emodin, but the expression of other anti-apoptotic Bcl-2 family members, except Mcl-1, did not change in the presence of emodin. To clarify the importance of Mcl-1 in emodin-induced apoptosis, the Mcl-1 expression vector was introduced into the human myeloma cells by electroporation. Induction of apoptosis by emodin was almost abrogated in Mcl-1–overexpressing myeloma cells as the same level as in parental cells, which were not treated with emodin. Emodin therefore inhibits interleukin-6–induced JAK2/STAT3 pathway selectively and induces apoptosis in myeloma cells via down-regulation of Mcl-1, which is a good target for treating myeloma. Taken together, these results show emodin as a new potent anti-cancer agent for the treatment of multiple myeloma patients (Muto et al., 2007).

Breast Cancer; Block HER-2

The mechanism by which emodin prevents breast cancer is unknown; however the product of the HER-2/neu proto-oncogene, HER2 has been proposed to be involved. The product of the HER-2/neu proto-oncogene, HER2, is the second member of the human epidermal growth factor receptor (HER) family of tyrosine kinase receptors and has been suggested to be a ligand orphan receptor. Amplification of the HER2 gene and overexpression of the HER2 protein induces cell transformation and has been demonstrated in 10% to 40% of human breast cancer. HER2 overexpression has been suggested to associate with tumor aggressiveness, prognosis and responsiveness to hormonal and cytotoxic agents in breast cancer patients. These findings indicate that HER2 is an appropriate target for tumor-specific therapies.

A number of approaches have been investigated: (1) a humanized monoclonal antibody against HER2, rhuMAbHER2 (trastuzumab), which is already approved for clinical use in the treatment of patients with metastatic breast cancer; (2) tyrosine kinase inhibitors, such as emodin, which block HER2 phosphorylation and its intracellullar signaling; (3) active immunotherapy, such as vaccination; and (4) heat shock protein (Hsp) 90-associated signal inhibitors, such as radicicol derivatives, which induce degradation of tyrosine kinase receptors, such as HER2 (Kurebayashi, 2001).

MDR

The effects of emodin on the nucleoside transport and multi-drug resistance in cancer cells has also been investigated. Nucleoside transport inhibition was determined by thymidine incorporation assay. The cytotoxicity to cancer cells was determined by MTT assay. The pump efflux activity and the expression of P glycoprotein were examined by flow cytometric assay. Emodin was active in the inhibition of nucleoside transport, with an IC 50 value of 9 9 µmol·L -1. Emodin markedly enhanced the cytotoxicity of 5 FU, MMC and MTX against human hepatoma BEL 7402 cells and partly reversed the multi-drug resistance in human breast cancer MCF 7/Adr cells.

Emodin inhibited P-gp pump efflux activity and reduced the expression of P gp in MCF 7/Adr cells. These findings provide a biological basis for the application of emodin as a biochemical modulator to potentiate the effects of anti-tumor drugs and reverse the multi-drug resistance in cancer cells (Jiang et al., 2009).

Cell-cycle Arrest

Large quantities of emodin were isolated from the roots of Rheum emodi and a library of novel emodin derivatives 2–15 were prepared to evaluate their anti-proliferative activities against HepG2, MDA-MB-231 and NIH/3T3 cells lines. The derivatives 3 and 12 strongly inhibited the proliferation of HepG2 and MDA-MB-231 cancer cell line with an IC50 of 5.6, 13.03 and 10.44, 5.027, respectively, which is comparable to marketed drug epirubicin (III). The compounds 3 and 12 were also capable of inducing cell-cycle arrest and caspase dependent apoptosis in HepG2 cell lines and exhibit DNA intercalating activity. These emodin derivatives hold promise for developing safer alternatives to the marketed epirubicin (Narender et al., 2013).

Cell-cycle Arrest; MDR1 & AZT

3'-azido-3'-deoxythymidine (AZT) and emodin altered the cell-cycle distribution and led to an accumulation of cells in S phase. Meanwhile, the expression of MDR1 mRNA/p-gp protein was markedly decreased. These results show a synergistic growth-inhibitory effect of AZT and emodin in K562/ADM cells, which is achieved through S phase arrest. MDR1 might ultimately be responsible for these phenomena (Chen et al., 2013).

References

Chen P, Liu Y, Sun Y, et al. (2013). AZT and emodin exhibit synergistic growth-inhibitory effects on K562/ADM cells by inducing S phase cell-cycle arrest and suppressing MDR1 mRNA/p-gp protein expression. Pharm Biol.


Garg AK, Buchholz TA, Aggarwal BB. (2005). Chemo-sensitization and Radiosensitization of Tumors by Plant Polyphenols. Antioxid Redox Signal., 7(11-12):1630-47.


Jiang XF & Zhen YS. (1999). Reversal of Multi-drug resistance by emodin in cancer cells. Acta Pharmaceutica Sinica, 1999-03.


Jing X, Ueki N, Cheng J, Imanishi H, Hada T. (2002). Induction of apoptosis in hepatocellular carcinoma cell lines by emodin. Cancer Science, 93(8):874–882.


Kurebayashi J. (2001). Biological and clinical significance of HER2 overexpression in breast cancer. Breast Cancer, 8(1):45-51


Ma YS, Weng SW, Lin MW, et al. (2012). Anti-tumor effects of emodin on LS1034 human colon cancer cells in vitro and in vivo: Roles of apoptotic cell death and LS1034 tumor xenografts model. Food Chem Toxicol, 50(5): 1271–1278. doi: 10.1016/j.fct.2012.01.033.


Muto A, Hori M, Sasaki Y, et al. (2007). Emodin has a cytotoxic activity against human multiple myeloma as a Janus-activated kinase 2 inhibitor. Mol Cancer Ther. doi: 10.1158/1535-7163.MCT-06-0605.


Narender T, Sukanya P, Sharma K, et al. (2013). Preparation of novel anti-proliferative emodin derivatives and studies on their cell-cycle arrest, caspase dependent apoptosis and DNA binding interaction. Phytomedicine, 20(10):890-896.


Shrimali D, Shanmugam MK, Kumar AP, et al. (2013). Targeted abrogation of diverse signal transduction cascades by emodin for the treatment of inflammatory disorders and cancer. Cancer Lett:S0304-3835(13)00598-3. doi: 10.1016/j.canlet.2013.08.023.


Wei WT, Lin SZ, Liu DL, Wang ZH. (2013). The distinct mechanisms of the anti-tumor activity of emodin in different types of cancer (Review). Oncol Rep. doi: 10.3892/or.2013.2741.


Yu XW, Yang RZ. (2013). Effects of crude rhubarb on serum IL-15 and IL-18 levels in patients with severe acute pancreatitis. An Hui Yi Xue, 34(3): 285-287.

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.

Spica Prunellae Extract

Cancer: Colorectal

Action: Promotes apoptosis, anti-angiogenic, induces angiogenesis

Constitutive activation of STAT3 is one of the major oncogenic pathways involved in the development of various types of malignancies including colorectal cancer (CRC); and thus becomes a promising therapeutic target. Spica Prunellae has long been used as an important component in many traditional Chinese medicine formulas to clinically treat CRC. Previously, Lin et al., (2013) found that Spica Prunellae inhibits CRC cell growth through mitochondrion-mediated apoptosis. Furthermore, we demonstrated its anti-angiogenic activities in vivo and in vitro.

CRC mouse xenograft model was generated by subcutaneous injection of human colon carcinoma HT-29 cells into nude mice. Animals were given intra-gastric administration with 6 g/kg of the ethanol extract of Spica Prunellae (EESP) daily, 5 days a week for 16 days. Body weight and tumor growth were measured every two days. Tumor growth in vivo was determined by measuring the tumor volume and weight. HT-29 cell viability was examined by MTT assay. Cell apoptosis and proliferation in tumors from CRC xenograft mice was evaluated via immunohistochemical staining (IHS) for TUNEL and PCNA, and the intratumoral microvessel density (MVD) was examined by using IHS for the endothelial cell-specific marker CD31. The activation of STAT3 was evaluated by determining its phosphorylation level using IHS. The mRNA and protein expression of Bcl-2, Bax, Cyclin D1, VEGF-A and VEGFR2 was measured by RT-PCR and IHS, respectively.

EESP treatment reduced tumor volume and tumor weight but had no effect on body weight change in CRC mice; decreasedanti-angiogenic cell viability in a dose-dependent manner, suggesting that EESP displays therapeutic efficacy against colon cancer growth in vivo and in vitro, without apparent toxicity. In addition, EESP significantly inhibited the phosphorylation of STAT3 in tumor tissues, indicating its suppressive action on the activation of STAT3 signaling. Consequently, the inhibitory effect of EESP on STAT3 activation resulted in an increase in the pro-apoptotic Bax/Bcl-2 ratio, decrease in the expression of the pro-proliferative Cyclin D1 and CDK4, as well as down-regulation of pro-angiogenic VEGF-A and VEGFR-2 expression. Finally, these molecular effects led to the induction of apoptosis, the inhibition of cell proliferation and tumor angiogenesis.

Spica Prunellae possesses a broad range of anti-cancer activities due to its ability to affect STAT3 pathway, suggesting that Spica Prunellae could be a novel potent therapeutic agent for the treatment of CRC.

Reference

Lin W, Zheng L, Zhuang Q, Zhao J, et al. (2013) Spica prunellae promotes cancer cell apoptosis, inhibits cell proliferation and tumor angiogenesis in a mouse model of colorectal cancer via suppression of stat3 pathway. BMC Complement Altern Med. 2013 Jun 24;13(1):144.