Category Archives: PKC

Geniposide –Penta-acetyl Geniposide (Ac)5GP

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

Action: Cytostatic, induces apoptosis

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

Hepatocarcinogenesis, Glioma

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

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

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

Induces Apoptosis

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

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

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

Glioma

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

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

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

Melanoma

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

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

Hepatoma, Prostate Cancer, Cervical Cancer

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

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

References

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


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


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


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


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

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.

Artemisinin

Cancer: Breast, leukemia, gastric

Action: Anti-cancer

Artemisinin is isolated from Artemisia annua (L.).

Anti-cancer

Artemisinin and related compounds (artemisinins) is a frontline treatment for malaria. According to experimental evidence from more than 400 literature studies, 558 key proteins were derived and the artemisinins-rewired protein interaction network was constructed. Topological properties were analyzed to show that the protein network was a scale-free biological system. Five key pathways including PI3K-Akt, T cell receptor, Toll-like receptor, TGF-beta and insulin signaling pathways were involved in artemisinins-mediated anti-cancer effects (Huang et al., 2013).

Breast Cancer

Artemisinin has previously been shown to have selective toxicity towards cancer cells in vitro. The potential of artemisinin to prevent breast cancer development has been investigated in rats treated with a single oral dose (50 mg/kg) of 7,12-dimethylbenz[a]anthracene (DMBA), known to induce multiple breast tumors. Starting from the day immediately after DMBA treatment, one group of rats was provided with a powdered rat-chow containing 0.02% artemisinin, whereas a control group was provided with plain powdered food. For 40 weeks, both groups of rats were monitored for breast tumors.

Oral artemisinin significantly delayed (P<.002) and in some animals prevented (57% of artemisinin-fed versus 96% of the controls developed tumors, P<.01) breast cancer development in the monitoring period. In addition, breast tumors in artemisinin-fed rats were significantly fewer (P<.002) and smaller in size (P<.05) when compared with controls. Since artemisinin is a relatively safe compound that causes no known side-effects even at high oral doses, the present data indicate that artemisinin may be a potent chemoprevention agent (Lai, 2006).

Leukemia

Artemisinin is also a well-known anti-leukemic agent. The effect of artemisinin on cellular differentiation in the human promyelocytic leukemia HL-60 cell culture system has been investigated. Artemisinin markedly increased the degree of HL-60 leukemia cell differentiation when simultaneously combined with low doses of 1α,25-dihydoxyvitamin D3 [1,25-(OH)2D3] or all-trans retinoic acid (all-trans RA).

Extracellular-regulated kinase (ERK) inhibitors markedly inhibited HL-60 cell differentiation induced by artemisinin in combination with 1,25-(OH)2D3 or all-trans RA, whereas phosphatidylinositol 3-kinase (PI3-K) inhibitors did not. Particularly, protein kinase C (PKC) inhibitors inhibited HL-60 cell differentiation induced by artemisinin in combination with 1,25-(OH)2D3 but not with all-trans RA. Artemisinin enhanced PKC activity and protein level of PKCβI isoform in only 1,25-(OH)2D3-treated HL-60 cells.

Taken together, these results indicate that artemisinin strongly enhances the action of low doses of 1α,25-dihydoxyvitamin D3 [1,25-(OH)2D3] and all-trans retinoic acid in leukemia cell differentiation (Kim, 2003).

Gastric Cancer

Zhang et al. (2013) found that artemisinin inhibited growth and modulated expression of cell-cycle regulators in gastric cancer cells (AGS and MKN74 cells). Treatment with artemisinin was also associated with induction of p27kip1 and p21kip1, two negative cell-cycle regulators. Furthermore, we revealed that artemisinin treatment led to an increased expression of p53.

The side-effects from the artemisinin class of medications are similar to the symptoms of malaria: nausea, vomiting, anorexia, and dizziness. Mild blood abnormalities have also been noted. A rare but serious adverse effect is allergic reaction (Leonardi et al., 2001).

References

Huang C, Ba Q, Yue Q, et al. (2013). Artemisinin rewires the protein interaction network in cancer cells: network analysis, pathway identification, and target prediction. Mol Biosyst. Kim SH, Kim HJ, Kim TS. (2003). Differential involvement of protein kinase C in human promyelocytic leukemia cell differentiation enhanced by artemisinin. European Journal of Pharmacology, 482(1–3):67–76. doi:10.1016/j.ejphar.2003.09.057.


Lai H, Singh NP. (2006). Oral artemisinin prevents and delays the development of 7, 12-dimethylbenz [a] anthracene (DMBA)-induced breast cancer in the rat. Cancer Letters, 231(1):43–48. doi: 10.1016/j.canlet.2005.01.019.


Leonardi E, Gilvary G, White NJ, Nosten F. (2001). Severe allergic reactions to oral artesunate: a report of two cases'. Trans. R. Soc. Trop. Med. Hyg, 95(2):182–3. doi:10.1016/S0035-9203(01)90157-9.


Sun H, Meng X, Han J, et al. (2013) Anti-cancer activity of DHA on gastric cancer-an in vitro and in vivo study. Tumor Biol.


Zhang HT, Wang YL, Zhang J, Zhang QX. (2013). Artemisinin inhibits gastric cancer cell proliferation through up-regulation of p53. Tumor Biol.

Aloe-emodin (See also Emodin)

Cancer:
Nasopharyngeal., ER α degradation, Lung, breast, oral., glioblastoma, liver cancer prevention

Action: Cytostatic, radio-sensitizing, chemo-sensitizing

Nasopharyngeal Carcinoma

Aloe-emodin (AE), a natural., biologically active compound from Aloe vera leaves has been shown to induce apoptosis in several cancer cell lines in vitro. Investigation showed that AE induced G2/M phase arrest by increasing levels of cyclin B1 bound to Cdc2, and also caused an increase in apoptosis of nasopharyngeal carcinoma (NPC) cells, which was characterized by morphological changes, nuclear condensation, DNA fragmentation, caspase-3 activation, cleavage of poly (ADP-ribose) polymerase (PARP) and increased sub-G(1) population. Treatment of NPC cells with AE also resulted in a decrease in Bcl-X(L) and an increase in Bax expression.

Collectively, results indicate that the caspase-8-mediated activation of the mitochondrial death pathway plays a critical role in AE-induced apoptosis of NPC cells (Lin et al., 2010).

Glioblastoma

Aloe emodin arrested the cell-cycle in the S phase and promoted the loss of mitochondrial membrane potential in glioblastoma U87 cells that indicated the early event of the mitochondria-induced apoptotic pathway. It plays an important role in the regulation of cell growth and death (Ismail et al., 2013).

Breast Cancer

The anthraquinones emodin and aloe-emodin are also abundant in the rhizome Rheum palmatum and can induce cytosolic estrogen receptor α (ER α) degradation; it primarily affected nuclear ER α distribution similar to the action of estrogen when protein degradation was blocked. In conclusion, our data demonstrate that emodin and aloe-emodin specifically suppress breast cancer cell proliferation by targeting ER α protein stability through distinct mechanisms (Huang et al., 2013).

Lung Cancer

Photoactivated aloe-emodin induced anoikis and changes in cell morphology, which were in part mediated through its effect on cytoskeleton in lung carcinoma H460 cells. The expression of protein kinase Cδ (PKCδ) was triggered by aloe-emodin and irradiation in H460 cells. Furthermore, the photoactivated aloe-emodin-induced cell death and translocation of PKCδ from the cytosol to the nucleus was found to be significantly inhibited by rottlerin, a PKCδ-selective inhibitor (Chang et al., 2012).

Oral Cancer; Radio-sensitizing, Chemo-sensitizing

The treatment of cancer with chemotherapeutic agents and radiation has two major problems: time-dependent development of tumor resistance to therapy (chemoresistance and radioresistance) and nonspecific toxicity toward normal cells. Many plant-derived polyphenols have been studied intensively for their potential chemo-preventive properties and are pharmacologically safe.

These compounds include genistein, curcumin, resveratrol, silymarin, caffeic acid phenethyl ester, flavopiridol, emodin, green tea polyphenols, piperine, oleandrin, ursolic acid, and betulinic acid. Recent research has suggested that these plant polyphenols might be used to sensitize tumor cells to chemotherapeutic agents and radiation therapy by inhibiting pathways that lead to treatment resistance. These agents have also been found to be protective from therapy-associated toxicities.

Treatment with aloe-emodin at 10 to 40 microM resulted in cell-cycle arrest at G2/M phase. The alkaline phosphatase (ALP) activity in KB cells increased upon treatment with aloe-emodin when compared to controls. This is one of the first studies to focus on the expression of ALP in human oral carcinomas cells treated with aloe-emodin. These results indicate that aloe-emodin has anti-cancer effect on oral cancer, which may lead to its use in chemotherapy and chemo-prevention of oral cancer (Xiao et al., 2007).

Liver Cancer Prevention

In Hep G2 cells, aloe-emodin-induced p53 expression and was accompanied by induction of p21 expression that was associated with a cell-cycle arrest in G1 phase. In addition, aloe-emodin had a marked increase in Fas/APO1 receptor and Bax expression. In contrast, with p53-deficient Hep 3B cells, the inhibition of cell proliferation of aloe-emodin was mediated through a p21-dependent manner that did not cause cell-cycle arrest or increase the level of Fas/APO1 receptor, but rather promoted aloe-emodin-induced apoptosis by enhancing expression of Bax.

These findings suggest that aloe-emodin may be useful in liver cancer prevention (Lian et al., 2005).

References

Chang WT, You BJ, Yang WH, et al. (2012). Protein kinase C delta-mediated cytoskeleton remodeling is involved in aloe-emodin-induced photokilling of human lung cancer cells. Anti-cancer Res, 32(9):3707-13.

Huang PH, Huang CY, Chen MC, et al. (2013). Emodin and Aloe-Emodin Suppress Breast Cancer Cell Proliferation through ER α Inhibition. Evid Based Complement Alternat Med, 2013:376123. doi: 10.1155/2013/376123.

Ismail S, Haris K, Abdul Ghani AR, et al. (2013). Enhanced induction of cell-cycle arrest and apoptosis via the mitochondrial membrane potential disruption in human U87 malignant glioma cells by aloe emodin. J Asian Nat Prod Res.

Lian LH, Park EJ, Piao HS, Zhao YZ, Sohn DH. (2005). Aloe Emodin‐Induced Apoptosis in Cells Involves a Mitochondria‐Mediated Pathway. Basic & Clinical Pharmacology & Toxicology, 96(6):495–502.

Lin, ML, Lu, YC, Chung, JG, et al. (2010). Aloe-emodin induces apoptosis of human nasopharyngeal carcinoma cells via caspase-8-mediated activation of the mitochondrial death pathway. Cancer Letters, 291(1), 46-58. doi: 10.1016/j.canlet.2009.09.016.

Xiao B, Guo J, Liu D, Zhang S. (2007). Aloe-emodin induces in vitro G2/M arrest and alkaline phosphatase activation in human oral cancer KB cells. Oral Oncol, 43(9):905-10.

Carnosol

Cancer: Breast, prostate, skin, colon, leukemia, stomach

Action: Anti-inflammatrory, anti-angiogenic

Carnosol is found in certain Mediterranean meats, fruits, vegetables, and olive oil. In particular, it is sourced from rosemary (Rosmarinus officinalis (L.)) and desert sage (Salvia pachyphylla (Epling ex Munz)).

Prostate Cancer, Breast Cancer, Skin Cancer, Colon Cancer, Leukemia

One agent, carnosol, has been evaluated for anti-cancer property in prostate, breast, skin, leukemia, and colon cancer with promising results. These studies have provided evidence that carnosol targets multiple deregulated pathways associated with inflammation and cancer that include nuclear factor kappa B (NFκB), apoptotic related proteins, phosphatidylinositol-3-kinase (PI3 K)/Akt, androgen and estrogen receptors, as well as molecular targets. In addition, carnosol appears to be well tolerated in that it has a selective toxicity towards cancer cells versus non-tumorigenic cells and is well tolerated when administered to animals.

This mini-review reports on the pre-clinical studies that have been performed to date with carnosol describing mechanistic, efficacy, and safety/tolerability studies as a cancer chemoprevention and anti-cancer agent (Johnson, 2011).

Literature evidence from animal and cell culture studies demonstrates the anti-cancer potential of rosemary extract, carnosol, carnosic acid, ursolic acid, and rosmarinic acid to suppress the development of tumors in several organs including the colon, breast, liver, stomach, as well as melanoma and leukemia cells (Ngo et al., 2011).

Anti-inflammatory

Treatment with retinoic acid (RA) or carnosol, two structurally unrelated compounds with anti-cancer properties, inhibited phorbol ester (PMA)-mediated induction of activator protein-1 (AP-1) activity and cyclooxygenase-2 (COX-2) expression in human mammary epithelial cells. Treatment with carnosol but not RA blocked increased binding of AP-1 to the COX-2 promoter. Carnosol but not RA inhibited the activation of PKC, ERK1/2, p38, and c-Jun NH2-terminal kinase mitogen-activated protein kinase. Overexpressing c-Jun but not CBP/p300 reversed the suppressive effect of carnosol on PMA-mediated stimulation of COX-2 promoter activity.

Carnosol inhibited the induction of COX-2 by blocking PKC signaling and thereby the binding of AP-1 to the CRE of the COX-2 promoter. Taken together, these results show that small molecules can block the activation of COX-2 transcription by distinct mechanisms (Subbaramaiah, 2002).

Breast Cancer

Two rosemary components, carnosol and ursolic acid, appear to be partly responsible for the anti-tumorigenic activity of rosemary. Supplementation of diets for 2 weeks with rosemary extract (0.5% by wt) but not carnosol (1.0%) or ursolic acid (0.5%) resulted in a significant decrease in the in vivo formation of rat mammary DMBA-DNA adducts, compared to controls. When injected intraperitoneally (i.p.) for 5 days at 200 mg/kg body wt, rosemary and carnosol, but not ursolic acid, significantly inhibited mammary adduct formation by 44% and 40%, respectively, compared to controls. Injection of this dose of rosemary and carnosol was associated with a significant 74% and 65% decrease, respectively, in the number of DMBA-induced mammary adenocarcinomas per rat, compared to controls. Ursolic acid injection had no effect on mammary tumorigenesis.

Therefore, carnosol is one rosemary constituent that can prevent DMBA-induced DNA damage and tumor formation in the rat mammary gland, and, thus, has potential for use as a breast cancer chemopreventative agent (Singletary et al., 1996).

Anti-angiogenic

The anti-angiogenic activity of carnosol and carnosic acid could contribute to the chemo-preventive, anti-tumoral and anti-metastatic activities of rosemary extracts and suggests that there is potential in the treatment of other angiogenesis-related malignancies (L-pez-JimŽnez et al., 2013).

References:

Johnson JJ. (2011). Carnosol: A promising anti-cancer and anti-inflammatory agent. Cancer Letters, 305(1):1-7. doi:10.1016/j.canlet.2011.02.005.


L-pez-JimŽnez A, Garc'a-Caballero M, Medina Mç, Quesada AR. (2013). Anti-angiogenic properties of carnosol and carnosic acid, two major dietary compounds from rosemary. Eur J Nutr, 52(1):85-95. doi: 10.1007/s00394-011-0289-x.


Ngo SN, Williams DB, Head RJ. (2011). Rosemary and cancer prevention: preclinical perspectives. Crit Rev Food Sci Nutr, 51(10):946-54. doi: 10.1080/10408398.2010.490883.


Singletary K, MacDonald C & Wallig M. (1996). Inhibition by rosemary and carnosol of 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary tumorigenesis and in vivo DMBA-DNA adduct formation. Cancer Letters, 104(1):43-8. doi: 10.1016/0304-3835(96)04227-9


Subbaramaiah K, Cole PA, Dannenberg AJ. (2002). Retinoids and Carnosol Suppress Cyclooxygenase-2 Transcription by CREB-binding Protein/p300-dependent and -independent Mechanisms. Cancer Res, 62:2522

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

Carnosol

Cancer: Breast, prostate, skin, colon, leukemia, stomach

Action: Anti-inflammatrory, anti-angiogenic

Carnosol is found in certain Mediterranean meats, fruits, vegetables, and olive oil. In particular, it is sourced from rosemary (Rosmarinus officinalis (L.)) and desert sage (Salvia pachyphylla (Epling ex Munz)).

Prostate Cancer, Breast Cancer, Skin Cancer, Colon Cancer, Leukemia

One agent, carnosol, has been evaluated for anti-cancer property in prostate, breast, skin, leukemia, and colon cancer with promising results. These studies have provided evidence that carnosol targets multiple deregulated pathways associated with inflammation and cancer that include nuclear factor kappa B (NFκB), apoptotic related proteins, phosphatidylinositol-3-kinase (PI3 K)/Akt, androgen and estrogen receptors, as well as molecular targets. In addition, carnosol appears to be well tolerated in that it has a selective toxicity towards cancer cells versus non-tumorigenic cells and is well tolerated when administered to animals.

This mini-review reports on the pre-clinical studies that have been performed to date with carnosol describing mechanistic, efficacy, and safety/tolerability studies as a cancer chemoprevention and anti-cancer agent (Johnson, 2011).

Literature evidence from animal and cell culture studies demonstrates the anti-cancer potential of rosemary extract, carnosol, carnosic acid, ursolic acid, and rosmarinic acid to suppress the development of tumors in several organs including the colon, breast, liver, stomach, as well as melanoma and leukemia cells (Ngo et al., 2011).

Anti-inflammatory

Treatment with retinoic acid (RA) or carnosol, two structurally unrelated compounds with anti-cancer properties, inhibited phorbol ester (PMA)-mediated induction of activator protein-1 (AP-1) activity and cyclooxygenase-2 (COX-2) expression in human mammary epithelial cells. Treatment with carnosol but not RA blocked increased binding of AP-1 to the COX-2 promoter. Carnosol but not RA inhibited the activation of PKC, ERK1/2, p38, and c-Jun NH2-terminal kinase mitogen-activated protein kinase. Overexpressing c-Jun but not CBP/p300 reversed the suppressive effect of carnosol on PMA-mediated stimulation of COX-2 promoter activity.

Carnosol inhibited the induction of COX-2 by blocking PKC signaling and thereby the binding of AP-1 to the CRE of the COX-2 promoter. Taken together, these results show that small molecules can block the activation of COX-2 transcription by distinct mechanisms (Subbaramaiah, 2002).

Breast Cancer

Two rosemary components, carnosol and ursolic acid, appear to be partly responsible for the anti-tumorigenic activity of rosemary. Supplementation of diets for 2 weeks with rosemary extract (0.5% by wt) but not carnosol (1.0%) or ursolic acid (0.5%) resulted in a significant decrease in the in vivo formation of rat mammary DMBA-DNA adducts, compared to controls. When injected intraperitoneally (i.p.) for 5 days at 200 mg/kg body wt, rosemary and carnosol, but not ursolic acid, significantly inhibited mammary adduct formation by 44% and 40%, respectively, compared to controls. Injection of this dose of rosemary and carnosol was associated with a significant 74% and 65% decrease, respectively, in the number of DMBA-induced mammary adenocarcinomas per rat, compared to controls. Ursolic acid injection had no effect on mammary tumorigenesis.

Therefore, carnosol is one rosemary constituent that can prevent DMBA-induced DNA damage and tumor formation in the rat mammary gland, and, thus, has potential for use as a breast cancer chemopreventative agent (Singletary et al., 1996).

Anti-angiogenic

The anti-angiogenic activity of carnosol and carnosic acid could contribute to the chemo-preventive, anti-tumoral and anti-metastatic activities of rosemary extracts and suggests that there is potential in the treatment of other angiogenesis-related malignancies (L-pez-JimŽnez et al., 2013).

References:

Johnson JJ. (2011). Carnosol: A promising anti-cancer and anti-inflammatory agent. Cancer Letters, 305(1):1-7. doi:10.1016/j.canlet.2011.02.005.


L-pez-JimŽnez A, Garc'a-Caballero M, Medina Mç, Quesada AR. (2013). Anti-angiogenic properties of carnosol and carnosic acid, two major dietary compounds from rosemary. Eur J Nutr, 52(1):85-95. doi: 10.1007/s00394-011-0289-x.


Ngo SN, Williams DB, Head RJ. (2011). Rosemary and cancer prevention: preclinical perspectives. Crit Rev Food Sci Nutr, 51(10):946-54. doi: 10.1080/10408398.2010.490883.


Singletary K, MacDonald C & Wallig M. (1996). Inhibition by rosemary and carnosol of 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary tumorigenesis and in vivo DMBA-DNA adduct formation. Cancer Letters, 104(1):43-8. doi: 10.1016/0304-3835(96)04227-9


Subbaramaiah K, Cole PA, Dannenberg AJ. (2002). Retinoids and Carnosol Suppress Cyclooxygenase-2 Transcription by CREB-binding Protein/p300-dependent and -independent Mechanisms. Cancer Res, 62:2522

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

Chung YC, Lu LC, Tsai MH, et al. (2013). The inhibitory effect of ellagic Acid on cell growth of ovarian carcinoma cells. Evid Based Complement Alternat Med, 2013(2013):306705. doi: 10.1155/2013/306705.


Edderkaoui M, Odinokova I, Ohno I, et al. (2008). Ellagic acid induces apoptosis through inhibition of nuclear factor κ B in pancreatic cancer cells. World Journal of Gastroenterology, 14(23):3672–3680.


Fjaeraa C, NŒnberg E. (2009). Effect of ellagic acid on proliferation, cell adhesion and apoptosis in SH-SY5Y human neuroblastoma cells. Biomedicine and Pharmacotherapy, 63(4):254–261.


HHLW (Ministry of Health, Labor and Welfare of Japan). (1996). List of Existing Food Additives, Notification No. 120 of the Ministry of Health and Welfare.


Ho CC, Huang AC, Yu CS, Lien JC, et al. (2013). Ellagic acid induces apoptosis in tsgh8301 human bladder cancer cells through the endoplasmic reticulum stress- and mitochondria-dependent signaling pathways. Environ Toxicol. doi: 10.1002/tox.21857.


Kim S, Liu Y, Gaber MW, Bumgardner JD, Haggard WO, Yang Y. (2009). Development of chitosan-ellagic acid films as a local drug delivery system to induce apoptotic death of human melanoma cells. Journal of Biomedical Materials Research, 90(1):145–155.


Larrosa M, Tomás-Barberán FA, Espín JC. (2006). The dietary hydrolysable tannin punicalagin releases ellagic acid that induces apoptosis in human colon adenocarcinoma Caco-2 cells by using the mitochondrial pathway. Journal of Nutritional Biochemistry, 17(9):611–625.


Li TM, Chen GW, Su CC, et al. (2005). Ellagic acid induced p53/p21 expression, G1 arrest and apoptosis in human bladder cancer T24 cells. Anti-cancer Research, 25(2 A):971–979.


Losso JN, Bansode RR, Trappey A, II, Bawadi HA, Truax R. (2004). In vitro anti-proliferative activities of ellagic acid. Journal of Nutritional Biochemistry, 15(11):672–678.


Mishra S, Vinayak M. (2013). Ellagic acid checks lymphoma promotion via regulation of PKC signaling pathway. Mol Biol Rep, 40(2):1417-28. doi: 10.1007/s11033-012-2185-8.


Malik A, Afaq S, Shahid M, Akhtar K, Assiri A. (2011). Influence of ellagic acid on prostate cancer cell proliferation: a caspase-dependent pathway. Asian Pacific Journal of Tropical Medicine, 4(7):550–555.


Mishra S, Vinayak M. (2011). Anti-carcinogenic action of ellagic acid mediated via modulation of oxidative stress regulated genes in Dalton lymphoma bearing mice. Leukemia and Lymphoma, 52(11):2155–2161.


Munagala R, Aqil F, Vadhanam MV, Gupta RC. (2013). MicroRNA 'signature' during estrogen-mediated mammary carcinogenesis and its reversal by ellagic acid intervention. Cancer Lett, S0304-3835(13)00462-X. doi: 10.1016/j.canlet.2013.06.012.


Pitchakarn P, Chewonarin T, Ogawa K, et al. (2013). Ellagic Acid inhibits migration and invasion by prostate cancer cell lines. Asian Pac J Cancer Prev, 14(5):2859-63.


Tasaki M, Umemura T, Maeda M, et al. (2008). Safety assessment of ellagic acid, a food additive, in a subchronic toxicity study using F344 rats. Food and Chemical Toxicology, 46(3):1119–1124.


Zhao M, Tang SN, Marsh JL, et al. (2013). Ellagic acid inhibits human pancreatic cancer growth in Balb c nude mice. Cancer Letters, 337(2):210–217