Category Archives: Prostate cancer cell lines

Oleandrin

Cancer: Prostate, glioma, melanoma

Action: Radio-sensitizer

Anvirzel is an extract of Nerium oleander (L.) currently undergoing, as Anvirzelª Phase I clinical evaluation as a potential treatment for cancer. Two of the active components of Anvirzel are the cardiac glycosides, oleandrin and oleandrigenin.

Prostate Cancer

In continuing research on the anti-tumor activity of this novel plant extract, the relative abilities of oleandrin and oleandrigenin to inhibit FGF-2 export from two human prostate cancer cell lines, DU145 and PC3, were examined. An ELISA assay was utilized to determine the FGF-2 concentration in the cell culture medium before and after exposure to cardiac glycosides or the parent extract material Anvirzel.

Studies also were conducted with Anvirzel (a hot water extract of Nerium oleander, known as Anvirzelª) and ouabain (found in the ripe seeds of African plants Strophanthus gratus). Oleandrin (0.1 ng/mL) produced a 45.7% inhibition of FGF-2 release from PC3 cells and a 49.9% inhibition from DU145 cells. Non-cytotoxic concentrations (100 ng/mL) of Anvirzel produced a 51.9% and 30.8% inhibition of FGF-2 release, respectively, in the two cell lines. These results demonstrate that Anvirzel, like oleandrin, inhibited FGF-2 export in vitro from PC3 and DU145 prostate cancer cells in a concentration- and time-dependent fashion and may, therefore, contribute to the anti-tumor activity of this novel treatment for cancer (Smith et al., 2001).

Radio-sensitizers; Prostate Cancer

In the present study Nasu et al. (2002) explored the relative radio-sensitization potential of oleandrin, a cardiac glycoside contained within the plant extract known as Anvirzelª. The data show that oleandrin produces an enhancement of sensitivity of PC-3 human prostate cells to radiation; at a cell survival of 0.1, the enhancement factor was 1.32. The magnitude of radio-sensitization depended on duration of exposure of cells to drug prior to radiation treatment.

While a radio-sensitizing effect of oleandrin was evident with only 1 hour of cell exposure to drug, the effect greatly increased with 24 hours of oleandrin pre-treatment.

Activation was greatest when cells were exposed simultaneously to oleandrin and radiation. Inhibition of caspase-3 activation with Z-DEVD-FMK abrogated the oleandrin-induced enhancement of radiation response suggesting that both oleandrin and radiation share a caspase-3 dependent mechanism of apoptosis in the PC-3 cell line.

Glioma, Melanoma

Twelve human tumor cell lines were chosen to examine determinants of human tumor cell sensitivity to cardiac glycosides. In vitro cell culture models of human glioma HF U251 and U251 cells as well as human parental and modified melanoma BRO cells were also included in these studies. Cardiac glycosides such as oleandrin, ouabain and bufalin increased expression of Na+, K+ -ATPase alpha 1 and therefore total Na+, K+ -ATPase activity, which is associated with increased cellular levels of glutathione. Additionally, an increased colony-forming ability was noted in cells with high levels of Na+, K+ -ATPase alpha 1 expression, suggesting that Na+, K+ -ATPase alpha 1 isoform may be actively involved in tumor growth and cell survival (Lin, Ho, & Newman, 2010)

References

Lin Y, Ho DH, Newman RA. (2010). Human tumor cell sensitivity to oleandrin is dependent on relative expression of Na+, K+ -ATPase subunitst. J Exp Ther Oncol, 8(4):271-86.


Nasu S, Milas L, Kawabe S, Raju U, Newman R. (2002). Enhancement of radiotherapy by oleandrin is a caspase-3 dependent process. Cancer Letters, 185(2):145–151. doi:10.1016/S0304-3835(02)00263-X


Smith JA, Madden T, Vijjeswarapu M, Newman RA. (2001). Inhibition of export of fibroblast growth factor-2 (FGF-2) from the prostate cancer cell lines PC3 and DU145 by anvirzel and its cardiac glycoside component, oleandrin. Biochemical Pharmacology, 62(4):469-472. doi:10.1016/S0006-2952(01)00690-6.

I3C

Cancer: Prostate

Action: Inhibits telomerase activity, anti-cancer

Indole-3-carbinol (I3C) is a phytochemical with anti-carcinogenic properties. Telomerase activity is key in carcinogenesis. The effect of I3C on telomerase was investigated in human prostate cancer cell lines LNCaP and PC3. Cells were treated with I3C at 100 and 250 µM with and without 10-50 µM diethylstilbestrol (DES). Telomerase activity was performed using TRAPaze Telomerase Detection Kit, and hTERT gene expression by real time quantitative RT-PCR. I3C (250 µM) inhibited telomerase activity and mRNA expression of hTERT in LNCaP and PC3 cells. I3C at 250 µM combined with any concentration of DES was cytotoxic to LNCaP. Telomerase activity in PC3 cells with 250 µM of I3C and 25 or 50 µM of DES was significantly reduced or inhibited, respectively.

I3C combined with DES reduced PC3 viability and eliminated LNCaP cells. I3C significantly inhibited telomerase activity and hTERT mRNA expression in LNCaP and PC3 cells. Combination of I3C and DES enhanced the inhibitory effect on telomerase activity, gene expression, and cell viability. These results implied that I3C and DES combined might help in prostate cancer treatment (Adler et al., 2011).

Reference

Adler S, Rashid G, Klein A. (2011). Indole-3-carbinol inhibits telomerase activity and gene expression in prostate cancer cell lines. Anti-cancer Res, 31(11):3733-7.

Glycyrrhiza Uralensis: Glycyrrhizin, Isoliquiritigenin

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

Action: Induces apoptosis

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

Stomach Cancer, Hepatoma, Breast Cancer, Cervical Cancer

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

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

Prostate Cancer

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

References

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


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

Oridonin

Cancer: Prostate

Action: Growth arrest, autophagy

To investigate the mechanism of oridonin (ORI)-induced autophagy in prostate cancer PC-3 cells, PC-3 cells cultured in vitro were treated with ORI, and the inhibitory ratio of ORI on PC-3 cells was assayed by 3-4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. After ORI treatment, the proliferation of PC-3 cells was inhibited significantly in a concentration and time-dependent manner. SEM examination revealed cellular shrinkage and disappearance of surface microvilli in ORI-treated cells. Under TEM examination, the nuclei exhibited chromatin condensation and the appearance of a large number of autophagosomes with double-membrane structure in cytoplasm. AO staining showed the existence of AVOs. The expression of LC3 and the mRNA level of beclin 1 was increased by ORI. Furthermore, autophagy inhibitor 3-methyladenine reversed the increase of beclin 1 mRNA. The growth of PC-3 cells was inhibited, and autophagy was induced by ORI, indicating ORI may have a potential antitumor effect.

Source
Ye LH, Li WJ, Jiang XQ, et al. Study on the autophagy of prostate cancer PC-3 cells induced by oridonin. Anat Rec (Hoboken). 2012 Mar;295(3):417-22. doi: 10.1002/ar.21528.

 

Cancer: Multiple myeloma

Action: Inhibits proliferation and induces apoptosis

This study was purposed to investigate the antitumor effect of oridonin on human multiple myeloma cell line U266 The results showed that the oridonin obviously inhibited the growth of U266 cell in dose-and time-dependent manners. As for morphological changes, characteristic apoptotic cells presented in U266 cells treated with 10 µmol/L oridonin for 24 hours. The apoptotic rate of U266 cells increased in dose and time dependent manners; after treatment of U266 cells with oridonin the mRNA levels of FGFR3, BCL2, CCND1 and MYC as well as the their protein levels decreased. Occasionally, the oridonin up-regulated the protein levels of P53 in the same manner. It is concluded that the oridonin can exert its anti-tumor effect by inhibiting proliferation and inducing apoptosis of U266 cell in dose dependent and time dependent manners, that maybe give the clues about new program of target therapy for multiple myeloma.

Source:

Duan HQ, Li MY, Gao L, et al. Mechanism concerning antitumor effect of oridonin on multiple myeloma cell line U266. Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2014 Apr;22(2):364-9. doi: 10.7534/j.issn.1009-2137.2014.02.018.

Cancer: Multiple myeloma

Action: Induces apoptosis and autophagy

Exposure to oridonin (1-64 μmol/L) inhibited the proliferation of RPMI8266 cells in a concentration-dependent manner with an IC(50) value of 6.74 μmol/L. Exposure to oridonin (7 μmol/L) simultaneously induced caspase 3-mediated apoptosis and Beclin 1-dependent autophagy of RPMI8266 cells. Both the apoptosis and autophagy were time-dependent, and apoptosis was the main effector pathway of cell death. Exposure to oridonin (7 μmol/L) increased intracellular ROS and reduced SIRT1 nuclear protein in a time-dependent manner.

Oridonin simultaneously induces apoptosis and autophagy of human multiple myeloma RPMI8266 cells via regulation of intracellular ROS generation and SIRT1 nuclear protein. The cytotoxicity of oridonin is mainly mediated through the apoptotic pathway, whereas the autophagy protects the cells from apoptosis.

Source

Zeng R, Chen Y, Zhao S, Cui GH.Autophagy counteracts apoptosis in human multiple myeloma cells exposed to oridonin in vitro via regulating intracellular ROS and SIRT1. Acta Pharmacol Sin. 2012 Jan;33(1):91-100. doi: 10.1038/aps.2011.143.

Cancer: Prostate, acute promyelocytic leukemia, breast, non-small-cell lung (NSCL), Ehrlich ascites, P388 lymphocytic leukemia, colorectal., ovarian, esphageal

Action: Chemoresistance, Ara-C, VP-16 

Cancer cell arises in part through the acquisition of apoptotic resistance. Leukemia cells resistant to chemotherapy-induced apoptosis have been found to be sensitive to oridonin, a natural agent with potent anticancer activity. Weng et al., (2014) compared the response of human leukemia cells with oridonin and the antileukemia drugs Ara-C and VP-16. Compared with HL60 cells, K562 and K562/ADR cells displayed resistance to apoptosis stimulated by Ara-C and VP-16 but sensitivity to oridonin. Mechanistic investigations revealed that oridonin upregulated BIM-S by diminishing the expression of miR-17 and miR-20a, leading to mitochondria-dependent apoptosis. In contrast, neither Ara-C nor VP-16 could reduce miR-17 and miR-20a expression or could trigger BIM-S–mediated apoptosis.

Notably, silencing miR-17 or miR-20a expression by treatment with microRNA (miRNA; miR) inhibitors or oridonin restored sensitivity of K562 cells to VP-16. Synergistic effects of oridonin and VP-16 were documented in cultured cells as well as mouse tumor xenograft assays. Inhibiting miR-17 or miR-20a also augmented the proapoptotic activity of oridonin. Taken together, our results identify a miRNA-dependent mechanism underlying the anticancer effect of oridonin and provide a rationale for its combination with chemotherapy drugs in addressing chemoresistant leukemia cells.

Reference

Weng Hy, Huang Hl, Dong B, et al. Inhibition of miR-17 and miR-20a by Oridonin Triggers Apoptosis and Reverses Chemoresistance by Derepressing BIM-S. Cancer Res; 74(16); 1–11. doi: 10.1158/0008-5472.CAN-13-1748

Action: Induces apoptosis

Oridonin is a tetracycline diterpenoid isolated from the plant Rabdosia rubescens (RR) [(Hemsl.). Hara (Lamiaceae)] (dong ling cao) is a Chinese medicinal herb used widely in provinces including Henan. The aerial parts of RR and other species of the same genus has been reported to have the functions of clearing “heat” and “toxicity”, nourishing “yin”, removing “blood stasis”, and relieving swelling. RR has been used to treat stomach-ache, sore throat and cough.

Gastric Cancer, Esophageal Cancer, Liver Cancer, Prostate Cancer

RR and its extracts have been shown to be able to suppress disease progress, reduce tumor burden, alleviate syndrome and prolong survival in patients with gastric carcinoma, esophageal., liver and prostate cancers (Tang & Eisenbrand, 1992). Interestingly, other Isodon plants including Isodon japonicus Hara (IJ) and I. trichocarpus (IT) are also applied as home remedies for similar disorders in Japan and Korea.

Induces Apoptosis

These reports suggest that Isodon plants should have at least one essential anti-tumor component. In the 1970s, a bitter tetracycline diterpenoid compound, oridonin, was isolated from RR, IJ, and IT separately, and was shown to be a potent apoptosis inducer in a variety of cancer cells (Fujita et al., 1970; Fujita et al., 1976; Henan Medical Institute, 1978; Fujita et al., 1988).

Anti-cancer

There is currently research being undertaken regarding the relationship between the chemical structure/modifications and the molecular mechanisms underlying its anti-cancer activity, such as suppression of tumor proliferation and induction of tumor cell death, and the cell signal transduction in anti-cancer activity of oridonin (Zhang et al., 2010).

Prostate Cancer, Breast Cancer, NSCLC, Leukemia, Glioblastoma

Oridonin has been found to effectively inhibit the proliferation of a wide variety of cancer cells including those from prostate (LNCaP, DU145, PC3), breast (MCF-7, MDA-MB231), non-small-cell lung (NSCL) (NCI-H520, NCI-H460, NCI-H1299) cancers, acute promyelocytic leukemia (NB4), and glioblastoma multiforme (U118, U138).

Oridonin induced apoptosis and G0/G1 cell-cycle arrest in LNCaP prostate cancer cells. In addition, expression of p21waf1 was induced in a p53-dependent manner. Taken together, oridonin inhibited the proliferation of cancer cells via apoptosis and cell-cycle arrest with p53 playing a central role in several cancer types which express the wild-type p53 gene. Oridonin may be a novel, adjunctive therapy for a large variety of malignancies (Ikezoe et al., 2003).

Breast Cancer; Anti-metastatic

According to the flow cytometric analysis, oridonin suppressed MCF-7 cell growth by cell-cycle arrest at the G2/M phase and caused accumulation of MDA-MB-231 cells in the Sub-G1 phase. The induced apoptotic effect of oridonin was further confirmed by a morphologic characteristics assay and TUNEL assay. Meanwhile, oridonin significantly suppressed MDA-MB-231 cell migration and invasion, decreased MMP-2/MMP-9 activation and inhibited the expression of Integrin β1 and FAK. In conclusion, oridonin inhibited growth and induced apoptosis in breast cancer cells, which might be related to DNA damage and activation of intrinsic or extrinsic apoptotic pathways. Moreover, oridonin also inhibited tumor invasion and metastasis in vitro possibly via decreasing the expression of MMPs and regulating the Integrin β1/FAK pathway in MDA-MB-231 cells (Wang et al., 2013).

Gastric Cancer

The inhibitory effect of oridonin on gastric cancer HGC-27 cells was detected using the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. After treated with oridonin (0, 1.25, 2.5, 5 and 10 µg/mL), HGC-27 cells were collected for anexin V-phycoerythrin and 7-amino-actinomycin D double staining and tested by flow cytometric analysis, and oridonin- induced apoptosis in HGC-27 cells was detected.

Oridonin significantly inhibited the proliferation of HGC-27 cells in a dose- and time-dependent manner. The inhibition rates of HGC-27 treated with four different concentrations of oridonin for 24 h (1.25, 2.5, 5 and 10 µg/mL) were 1.78% ± 0.36%, 4.96% ± 1.59%, 10.35% ± 2.76% and 41.6% ± 4.29%, respectively, which showed a significant difference (P < 0.05. Cells treated with oridonin showed typical apoptotic features with acridine orange/ethidium bromide staining. After treatment with oridonin, the cells became round, shrank, and developed small buds around the nuclear membrane while forming apoptotic bodies. However, the change in the release of LDH caused by necrosis was insignificant, suggesting that the major cause of oridonin-induced HGC-27 cell death was apoptosis. Flow cytometric analysis also revealed that oridonin induced significant apoptosis compared with the controls (P < 0.05).

Apoptosis of HGC-27 induced by oridonin may be associated with differential expression of Apaf-1, caspase-3 and cytochrome c, which are highly dependent upon the mitochondrial pathway (Sun et al., 2012).

Ehrlich Ascites, Leukemia

Oridonin has been found to also increase lifespan of mice bearing Ehrlich ascites or P388 lymphocytic leukemia. Oridonin triggered apoptosis in more than 50% of t(8;21) leukemic cells in vitro at concentration of 2 M or higher accompanied by degradation of AE oncoprotein, and showed significant anti-leukemia efficacies with low adverse effects in vivo. These data suggest possible beneficial effects for patients with t(8;21) acute myeloid leukemia (AML) (Zhou et al., 2007).

Prostate Cancer, Breast Cancer, Ovarian Cancer

Oridonin exhibited anti-proliferative activity toward all cancer cell lines tested, with an IC50 estimated by the MTT cell viability assay ranging from 5.8+/-2.3 to 11.72+/-4.8 microM. The increased incidence of apoptosis, identified by characteristic changes in cell morphology, was seen in tumor lines treated with oridonin. Notably, at concentrations that induced apoptosis among tumor cells, oridonin failed to induce apoptosis in cultures of normal human fibroblasts. Oridonin up-regulated p53 and Bax and down-regulated Bcl-2 expression in a dose-dependent manner and its absorption spectrum was measured in the presence and absence of double stranded (ds) DNA. Oridonin inhibits cancer cell growth in a cell-cycle specific manner and shifts the balance between pro- and anti-apoptotic proteins in favor of apoptosis. The present data suggest that further studies are warranted to assess the potential of oridonin in cancer prevention and/or treatment (Chen et al., 2005).

Ovarian Cancer Stem Cells; Chemotherapy Resistance

Oridonin was suggested to suppress ovarian CSCs as is reflected by down-regulation of the surface marker EpCAM. Unlike NSAIDS (non-steroid anti-inflammatory drugs), well documented clinical data for phyto-active compounds are lacking. In order to evaluate objectively the potential benefit of these types of compounds in the treatment of ovarian cancer, strategically designed, large scale studies are warranted (Chen et al., 2012).

Colorectal Cancer

Oridonin induced potent growth inhibition, cell-cycle arrest, apoptosis, senescence and colony-forming inhibition in three colorectal cancer cell lines in a dose-dependent manner in vitro. Daily i.p. injection of oridonin (6.25, 12.5 or 25 mg/kg) for 28 days significantly inhibited the growth of SW1116 s.c. xenografts in BABL/C nude mice.

Oridonin possesses potent in vitro and in vivo anti-colorectal cancer activities that correlated with induction of histone hyperacetylation and regulation of pathways critical for maintaining growth inhibition and cell-cycle arrest. Therefore, oridonin may represent a novel therapeutic option in colorectal cancer treatment as it has been shown to induce apoptosis and senescence of colon cancer cells in vitro and in vivo (Gao et al., 2010).

Colon Cancer; Apoptosis

Oridonin increased intracellular hydrogen peroxide levels and reduced the glutathione content in a dose-dependent manner. N-acetylcysteine, a reactive oxygen species scavenger, not only blocked the oridonin-induced increase in hydrogen peroxide and glutathione depletion, but also blocked apoptosis and senescence induced by oridonin.

Moreover, exogenous catalase could inhibit the increase in hydrogen peroxide and apoptosis induced by oridonin, but not the glutathione depletion and senescence. Furthermore, thioredoxin reductase (TrxR) activity was reduced by oridonin in vitro and in cells, which may cause the increase in hydrogen peroxide. In conclusion, the increase in hydrogen peroxide and glutathione depletion account for oridonin-induced apoptosis and senescence in colorectal cancer cells, and TrxR inhibition is involved in this process.

Given the importance of TrxR as a novel cancer target in colon cancer, oridonin would be a promising clinical candidate (Gao et al., 2012).

Prostate Cancer; Apoptosis

Oridonin (ORI) could inhibit the proliferation and induce apoptosis in various cancer cell lines. After ORI treatment, the proliferations of human prostate cancer (HPC) cell lines PC-3 and LNCaP were inhibited in a concentration and time-dependent manner. ORI induced cell-cycle arrest at the G2/M phase. Autophagy occurred before the onset of apoptosis and protected cancer cells in ORI-treated HPC cells. P21 was involved in ORI-induced autophagy and apoptosis (Li et al., 2012).

References

Chen S, Gao J, Halicka HD, et al. (2005). The cytostatic and cytotoxic effects of oridonin (Rubescenin), a diterpenoid from Rabdosia rubescens, on tumor cells of different lineage. Int J Oncol, 26(3):579-88.

 

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

 

Fujita E, Fujita T, Katayama H, Shibuya M. (1970). Terpenoids. Part XV. Structure and absolute configuration of oridonin isolated from Isodon japonicus trichocarpus. J Chem Soc (Chem Comm), 21:1674–1681

 

Fujita E, Nagao Y, Node M, et al. (1976). Anti-tumor activity of the Isodon diterpenoids: structural requirements for the activity. Experientia, 32:203–206.

 

Fujita T, Takeda Y, Sun HD, et al. (1988). Cytotoxic and anti-tumor activities of Rabdosia diterpenoids. Planta Med, 54:414–417.

 

Henan Medical Institute, Henan Medical College, Yunnan Institute of Botany. (1978). Oridonin–a new anti-tumor subject. Chin Science Bull, 23:53–56.

 

Ikezoe T, Chen SS, Tong XJ, et al. (2003). Oridonin induces growth inhibition and apoptosis of a variety of human cancer cells. Int J Oncol, 23(4):1187-93.

 

Gao FH, Hu XH, Li W, Liu H, et al. (2010). Oridonin induces apoptosis and senescence in colorectal cancer cells by increasing histone hyperacetylation and regulation of p16, p21, p27 and c-myc. BMC Cancer, 10:610. doi: 10.1186/1471-2407-10-610.

 

Gao FH, Liu F, Wei W, et al. (2012). Oridonin induces apoptosis and senescence by increasing hydrogen peroxide and glutathione depletion in colorectal cancer cells. Int J Mol Med, 29(4):649-55. doi: 10.3892/ijmm.2012.895.

 

Li X, Li X, Wang J, Ye Z, Li JC. (2012) Oridonin up-regulates expression of P21 and induces autophagy and apoptosis in human prostate cancer cells. Int J Biol Sci. 2012;8(6):901-12. doi: 10.7150/ijbs.4554.

 

Sun KW, Ma YY, Guan TP, et al. (2012). Oridonin induces apoptosis in gastric cancer through Apaf-1, cytochrome c and caspase-3 signaling pathway. World J Gastroenterol, 18(48):7166-74. doi: 10.3748/wjg.v18.i48.7166.

 

Tang W, Eisenbrand G. (1992). Chinese drugs of plant origin: chemistry, pharmacology, and use in traditional and modern medicine. Berlin: Springer-Verlag, 817–847.

 

Wang S, Zhong Z, Wan J, et al. (2013). Oridonin induces apoptosis, inhibits migration and invasion on highly-metastatic human breast cancer cells. Am J Chin Med, 41(1):177-96. doi: 10.1142/S0192415X13500134.

 

Zhang Wj, Huang Ql, Hua Z-C. (2010). Oridonin: A promising anti-cancer drug from China. Frontiers in Biology, 5(6):540-545.

 

Zhou G-B, Kang H, Wang L, et al. (2007). Oridonin, a diterpenoid extracted from medicinal herbs, targets AML1-ETO fusion protein and shows potent anti-tumor activity with low adverse effects on t(8;21) leukemia in vitro and in vivo. Blood, 109(8):3441-3450.

Ellagic Acid

Cancer:
Pancreatic, prostate, ovarian, breast, bladder, lymphoma, oral., melanoma

Action: Anti-cancer, induces apoptosis, promoted ROS and Ca2+ productions

Ellagic acid (EA) is a polyphenol compound widely found in fruits such as berries, walnuts, pecans, pomegranate, cranberries, and longan. It is well known to have a free radical scavenging activity and has been approved in Japan as an 'existing food additive' for anti-oxidative purposes (HHLW, 1996). In vitro evidence revealed that 100µM EA represented little toxic effect on human normal cells (Losso et al., 2004; Larrosa et al., 2006). A subchronic toxicity study further demonstrated that orally feeding EA (9.4, 19.1, 39.1g/kg b.w., resp.) could not induce mortality or treatment-related clinical signs throughout the experimental period on F344 rats (Tasaki et al., 2008), indicating the low toxicity of EA to mammalians. Furthermore, EA exhibits potent anti-cancer and anti-carcinogenesis activities towards breast, colorectal., oral., prostate (Losso et al., 2004; Larrosa et al., 2006; Malik et al., 2011), pancreatic (Edderkaoui et al., 2008), bladder (Li et al., 2005), neuroblastoma (Fjaeraa et al., 2009), melanoma (Kim et al., 2009), and lymphoma cells (Mishra et al., 2011).

Pancreatic Cancer

Edderkaoui et al. (2008) show that ellagic acid, a polyphenolic compound in fruits and berries, at concentrations 10 to 50 mmol/L stimulates apoptosis in human pancreatic adenocarcinoma cells. Ellagic acid stimulates the mitochondrial pathway of apoptosis associated with mitochondrial depolarization, cytochrome C release, and the downstream caspase activation. Ellagic acid does not directly affect mitochondria. Ellagic acid dose-dependently decreased NF-kappa B binding activity.

Furthermore, inhibition of NF-kappa B activity using IkB wild type plasmid prevented the effect of ellagic acid on apoptosis.

Pancreatic Cancer (PANC-1) cells were injected subcutaneously into Balb c nude mice, and tumor-bearing mice were treated with ellagic acid (EA). Treatment of PANC-1 xenografted mice with EA resulted in significant inhibition in tumor growth which was associated with suppression of cell proliferation and caspase-3 activation, and induction of PARP cleavage. EA also reversed epithelial to mesenchymal transition by up-regulating E-cadherin and inhibiting the expression of Snail, MMP-2 and MMP-9.

These data suggest that EA can inhibit pancreatic cancer growth, angiogenesis and metastasis by suppressing Akt, Shh and Notch pathways. In view of the fact that EA could effectively inhibit human pancreatic cancer growth by suppressing Akt, Shh and Notch pathways, our findings suggest that the use of EA would be beneficial for the management of pancreatic cancer (Zhao et al., 2013).

Ovarian Cancer

Ovarian carcinoma ES-2 and PA-1 cells were treated with EA (10~100  µ M) and assessed for viability, cell-cycle, apoptosis, anoikis, autophagy, and chemosensitivity to doxorubicin and their molecular mechanisms. EA inhibited cell proliferation in a dose- and time-dependent manner by arresting both cell lines at the G1 phase of the cell-cycle, which were from elevating p53 and Cip1/p21 and decreasing cyclin D1 and E levels. EA also induced caspase-3-mediated apoptosis by increasing the Bax :  Bcl-2 ratio and restored anoikis in both cell lines.

The enhancement of apoptosis and/or inhibition of autophagy in these cells by EA assisted the chemotherapy efficacy. The results indicated that EA is a potential novel chemoprevention and treatment assistant agent for human ovarian carcinoma Chung et al., 2013).

Prostate Cancer; AR+

In the present study, Pitchakarn et al. (2013) investigated anti-invasive effects of ellagic acid (EA) in androgen-independent human (PC-3) and rat (PLS10) prostate cancer cell lines in vitro. The results indicated that non-toxic concentrations of EA significantly inhibited the motility and invasion of cells examined in migration and invasion assays. They found that EA significantly reduced proteolytic activity of collagenase/gelatinase secreted from the PLS-10 cell line. Collagenase IV activity was also concentration-dependently inhibited by EA. These results demonstrated that EA has an ability to inhibit invasive potential of prostate cancer cells through action on protease activity.

Breast Cancer

The role of estrogen (E2) in regulation of cell proliferation and breast carcinogenesis is well-known. Recent reports have associated several miRNAs with estrogen receptors in breast cancers. Investigation of the regulatory role of miRNAs is critical for understanding the effect of E2 in human breast cancer, as well as developing strategies for cancer chemoprevention.

In this study Munagala et al. (2013) used the well-established ACI rat model that develops mammary tumors upon E2 exposure and identified a 'signature' of 33 significantly modulated miRNAs during the process of mammary tumorigenesis. Several of these miRNAs were altered as early as 3 weeks after initial E2 treatment and their modulation persisted throughout the mammary carcinogenesis process, suggesting that these molecular changes are early events. This is the first systematic study examining the changes in miRNA expression associated with E2 treatment in ACI rats as early as 3weeks until tumor time point. The effect of a chemo-preventive agent, ellagic acid in reversing miRNAs modulated during E2-mediated mammary tumorigenesis is also established. These observations provide mechanistic insights into the new molecular events behind the chemo-preventive action of ellagic acid and treatment of breast cancer.

Bladder Cancer

To investigate the effects of ellagic acid on the growth inhibition of TSGH8301 human bladder cancer cells in vitro, cells were incubated with various doses of ellagic acid for different time periods. Results indicated that ellagic acid induced morphological changes, decreased the percentage of viable cells through the induction of G0/G1 phase arrest and apoptosis, and also showed that ellagic acid promoted ROS and Ca2+ productions and decreased the level of ΔΨm and promoted activities of caspase-9 and -3.

On the basis of these observations, Ho et al (2013) suggest that ellagic acid induced cytotoxic effects for causing a decrease in the percentage of viable cells via G0/G1 phase arrest and induction of apoptosis in TSGH8301 cells.

Lymphoma

Protein Kinase C (PKC) isozymes are key components involved in cell proliferation and their over activation leads to abnormal tumor growth. PKC follows signaling pathway by activation of downstream gene NF-kB and early transcription factor c-Myc. Over activation of NF-kB and c-Myc gene are also linked with unregulated proliferation of cancer cells.

Therefore any agent which can inhibit the activation of Protein kinase C, NF-kB and c-Myc may be useful in reducing cancer progression. The role of ellagic acid was tested in regulation of tumor suppressor gene Transforming growth factor-β1 (TGF-β1). DL mice were treated with three different doses (40, 60 and 80 mg/kg body weight) of ellagic acid. Ascites cells of mice were used for the experiments. Ellagic acid administration to DL mice decreased oxidative stress by reducing lipid peroxidation.

The anti-carcinogenic action of ellagic acid was also confirmed by up-regulation of TGF-β1 and down-regulation of c-Myc. Lymphoma prevention by ellagic acid is further supported by decrease in cell proliferation, cell viability, ascites fluid accumulation and increase in life span of DL mice. All these findings suggest that ellagic acid prevents the cancer progression by down- regulation of PKC signaling pathway leading to cell proliferation (Mishra et al., 2013).

References

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