Category Archives: p65

Ursolic acid

Cancer:
Glioblastoma, Lung, breast, colorectal, gastric, esophageal squamous carcinoma, prostate

Action:

Mitochondrial function, reactive oxygen species (ROS) generation.

Cytostatic, anti-inflammatory, chemo-prevention, COX-2 inhibitor, suppresses NF- κ B, induces IL-1 β , induces apoptosis

Ursolic acid, a pentacyclic triterpene acid found ubiquitously in the plant kingdom, including Rosmarinus officinalis (L.), Salvia officinalis (L.), Prunella vulgaris (L.), Psychotria serpens (L.) and Hyptis capitata (Jacq.). It has been shown to suppress the expression of several genes associated with tumorigenesis resulting in anti-inflammatory, anti-tumorigenic and chemo-sensitizing effects (Liu, 1995).

Glioblastoma Cancer

Ursolic acid, a natural pentacyclic triterpenic acid, possesses anticancer potential and diverse biological effects, but its correlation with glioblastoma multiforme cells and different modes of cell death is unclear. We studied the cellular actions of human GBM DBTRG-05MG cells after ursolic acid treatment and explored cell-selective killing effect of necrotic death as a cell fate.

Ursolic acid effectively reversed TMZ resistance and reduced DBTRG-05MG cell viability. Surprisingly, ursolic acid failed to stimulate the apoptotic and autophagic-related signaling networks. The necrotic death was characterized by annexin V/PI double-positive detection and release of HMGB1 and LDH. These ursolic acid-elicited responses were accompanied by ROS generation and glutathione depletion. Rapid mitochondrial dysfunction was paralleled by the preferential induction of necrosis, rather than apoptotic death. MPT is a phenomenon to provide the onset of mitochondrial depolarization during cellular necrosis. The opening of MPT pores that were mechanistically regulated by CypD, and ATP decline occurred in treated necrotic DBTRG-05MG cells. Cyclosporine A (an MPT pore inhibitor) prevented ursolic acid-provoked necrotic death and -involved key regulators.

The study by Lu et al., (2014) is the first to report that ursolic acid-modified mitochondrial function triggers defective death by necrosis in DBTRG-05MG cells rather than augmenting programmed death.

Gastric Cancer

Ursolic acid (UA) inhibits growth of BGC-803 cells in vitro in dose-dependent and time-dependent manner. Treated with UA in vivo, tumor cells can be arrested to G0/G1 stage. The apoptotic rate was significantly increased in tumor cells treated with UA both in vitro and in vivo. These results indicated that UA inhibits growth of tumor cells both in vitro and in vivo by decreasing proliferation of cells and inducing apoptosis (Wang et al., 2011).

Esophageal Squamous Carcinoma

The anti-neoplastic effects of combinations of anti-cancer drugs (5-fluorouracil, irinotecan and cisplatin) and triterpenes (ursolic acid, betulinic acid, oleanolic acid and a Japanese apricot extract (JAE) containing triterpenes) on esophageal squamous carcinoma cells were examined by the WST-8 (2-(2-methoxy- 4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt) assay in vitro and by an animal model in vivo. Triterpenes and JAE showed additive and synergistic cytotoxic effects, respectively, on esophageal squamous carcinoma cells (YES-2 cells) by combinational use of 5-fluorouracil. JAE and 5-fluorouracil induced cell-cycle arrest at G2/M phase and at S phase, respectively, and caused apoptosis in YES-2 cells.

These results suggest that triterpenes, especially JAE, are effective supplements for enhancing the chemotherapeutic effect of 5-fluorouracil on esophageal cancer (Yamai et al., 2009).

COX-2 Inhibitor

Subbaramaiah et al. (2000) studied the effects of ursolic acid, a chemo-preventive agent, on the expression of cyclooxygenase-2 (COX-2). Treatment with ursolic acid suppressed phorbol 12-myristate 13-acetate (PMA)-mediated induction of COX-2 protein and synthesis of prostaglandin E2. Ursolic acid also suppressed the induction of COX-2 mRNA by PMA. Increased activator protein-1 activity and the binding of c-Jun to the cyclic AMP response element of the COX-2 promoter, effects were blocked by ursolic acid (Subbaramaiah et al., 2000).

Lung Cancer, Suppresses NF- κB

In terms of general anti-cancer mechanism, ursolic acid has also been found to suppress NF-κB activation induced by various carcinogens through the inhibition of the DNA binding of NF-κB. Ursolic acid also inhibits IκBα kinase and p65 phosphorylation (Shishodia et al., 2003). In particular, ursolic acid has been found to block cell-cycle progression and trigger apoptosis in lung cancer and may hence act as a chemoprevention agent for lung cancer (Hsu et al., 2004).

Breast Cancer

Ursolic acid is a potent inhibitor of MCF-7 cell proliferation. This triterpene exhibits both cytostatic and cytotoxic activity. It exerts an early cytostatic effect at G1 followed by cell death. Results suggest that alterations in cell-cycle phase redistribution of MCF-7 human breast cancer, by ursolic acid, may significantly influence MTT (colorimetric assays) reduction to formazan (Es-Saady et al., 1996).

Induces IL-1 β

Interleukin (IL)-1beta is a pro-inflammatory cytokine responsible for the onset of a broad range of diseases, such as inflammatory bowel disease and rheumatoid arthritis. It has recently been found that aggregated ursolic acid (UA), a triterpene carboxylic acid, is recognized by CD36 for generating reactive oxygen species (ROS) via NADPH oxidase (NOX) activation, thereby releasing IL-1beta protein from murine peritoneal macrophages (pMphi) in female ICR mice. In the present study, Ikeda et al. (2008) investigated the ability of UA to induce IL-1beta production in pMphi from 4 different strains of female mice as well as an established macrophage line. In addition, the different susceptibilities to UA-induced IL-1beta release were suggested to be correlated with the amount of superoxide anion (O2-) generated from the 5 different types of Mphi.

Notably, intracellular, but not extracellular, O2- generation was indicated to play a major role in UA-induced IL-1beta release. Together, these results indicate that the UA-induced IL-1beta release was strain-dependent, and the expression status of CD36 and gp91phox is strongly associated with inducibility.

Induces Apoptosis: Breast Cancer, Prostate Cancer

Ursolic acid (UA) induced apoptosis and modulated glucocorticoid receptor (GR) and Activator Protein-1 (AP-1) in MCF-7 breast cancer cells. UA is a GR modulator and may be considered as a potential anti-cancer agent in breast cancer (Kassi et al., 2009).

UA induces apoptosis via both extrinsic and intrinsic signaling pathways in cancer cells (Kwon et al., 2010). In PC-3 cells, UA inhibits proliferation by activating caspase-9 and JNK as well as FasL activation and Akt inhibition (Zhang et al., 2010). A significant proliferation inhibition and invasion suppression in both a dose- and time-dependent manner is observed in highly metastatic breast cancer MDA-MB-231 cells; this inhibition is related to the down-regulation of MMP2 and u-PA expression (Yeh et al., 2010).

Ursolic acid additionally stimulates the release of cytochrome C in HL-60 cells and breast cancer MCF-7 cells. The activation of caspase-3 in a cytochrome C-dependent manner induces apoptosis via the mitochondrial pathway (Qian et al., 2011).

Colorectal Cancer

Ursolic acid (UA) has strong anti-proliferative and apoptotic effects on human colon cancer HT-29 cells. UA dose-dependently decreased cell proliferation and induced apoptosis, accompanied by activation of caspase 3, 8 and 9. The effects may be mediated by alkaline sphingomyelinase activation (Andersson et al., 2003).

Ursolic acid (UA), using the colorectal cancer (CRC) mouse xenograft model and the HT-29 human colon carcinoma cell line, was evaluated for its efficacy against tumor growth in vivo and in vitro, and its molecular mechanisms were investigated. It was found that UA inhibits cancer growth without apparent toxicity. Furthermore, UA significantly suppresses the activation of several CRC-related signaling pathways and alters the expression of critical target genes. These molecular effects lead to the induction of apoptosis and inhibition of cellular proliferation.

These data demonstrate that UA possesses a broad range of anti-cancer activities due to its ability to affect multiple intracellular targets, suggesting that UA could be a novel multipotent therapeutic agent for cancer treatment (Lin et al., 2013).

Action: Anti-tumor, inhibits tumor cell migration and invasion

Ursolic acid (UA) is a sort of pentacyclic triterpenoid carboxylic acid purified from natural plant. UA has a series of biological effects such as sedative, anti-inflammatory, anti-bacterial, anti-diabetic, antiulcer, etc. It is discovered that UA has a broad-spectrum anti-tumor effect in recent years, which has attracted more and more scholars’ attention. This review explained anti-tumor actions of UA, including (1) the protection of cells’ DNA from different damages; (2) the anti-tumor cell proliferation by the inhibition of epidermal growth factor receptor mitogen-activated protein kinase signal or of FoxM1 transcription factors, respectively; (3) antiangiogenesis, (4) the immunological surveillance to tumors; (5) the inhibition of tumor cell migration and invasion; (6) the effect of UA on caspase, cytochromes C, nuclear factor kappa B, cyclooxygenase, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or mammalian target of rapamycin signal to induce tumor cell apoptosis respectively, and etc. Moreover, UA has selective toxicity to tumor cells, basically no effect on normal cells.

Inhibition of Epidermal Growth Factor Receptor/ Mitogen-Activated Protein Kinase Pathway
Activation of mitogen-activated protein kinase (MAPK) allows cell excessive proliferation involved in the carcinogenic process (Park et al., 1999). Subfamilies of MAPK, metastasis.(24) Otherwise, UA suppresses the activation of NF-κB and down-regulation of the MMP-9 protein, which in turn contributes to its inhibitory effects on IL-1β or tumor necrosis factor α (TNF-α)-induced C6 glioma cell invasion (Huang et al., 2009).

U A suppresses inter cellular adhesion molecules-1 (ICAM-1) expression of non-small cell lung cancer (NSCLC) H3255, A549, Calu-6 cells, and significantly inhibits fibronectin expression in a concentration-dependent way. UA significantly suppresses the expression of MMP-9 and MMP-2 and inhibits protein kinase C activity in test cell lines, at the same time, UA reduces cell invasion in a concentration-dependent manner (Huang et al., 2011).

Cancer: Multiple myeloma

Action: Anti-inflammatory, down-regulates STAT3

When dealing with the multiple myeloma, by the way of activating the proto-oncogene-mediated c-Src, JAK1, JAK2, and ERKs, ursolic acid (UA) can not only inhibit the expression of IL-6-induced STAT3 but also downregulates the STAT3 by regulating gene products, such as cyclin D1, Bcl-2, Bcl-xL, surviving, Mcl-1 and VEGF. Above all, UA can inhibit the proliferation of multiple myeloma cells and induce apoptosis, to arrest cells at G1 phase and G0 phase of cell cycle (Pathak et al., 2007).

The essential oils of ginger (Zingiber officinale) and turmeric (Curcuma longa) contain a large variety of terpenoids, some of which possess anticancer, anti-ulcer, and antioxidant properties. Despite their importance, only four terpene synthases have been identified from the Zingiberaceae family: (+)-germacrene D synthase and (S)-β-bisabolene synthase from ginger rhizome, and α-humulene synthase and β-eudesmol synthase from shampoo ginger (Zingiber zerumbet) rhizome (Koo et al., 2012).

Cancer: Colorectal

Wong et al., have previously reported Signal Transducer and Activator of Transcription 3 (STAT3) to be constitutively activated in aldehyde dehydrogenase (ALDH)(+)/cluster of differentiation-133 (CD133)(+) colon cancer-initiating cells. In the present study they tested the efficacy of inhibiting STAT3 signaling in human colon cancer-initiating cells by ursolic acid (UA), which exists widely in fruits and herbs.

ALDH(+)/CD133(+) colon cancer-initiating cells. UA also reduced cell viability and inhibited tumor sphere formation of colon cancer-initiating cells, more potently than two other natural compounds, resveratrol and capsaicin. UA also inhibited the activation of STAT3 induced by interleukin-6 in DLD-1 colon cancer cells. Furthermore, daily administration of UA suppressed HCT116 tumor growth in mice in vivo.

Their results suggest STAT3 to be a target for colon cancer prevention. UA, a dietary agent, might offer an effective approach for colorectal carcinoma prevention by inhibiting persistently activated STAT3 in cancer stem cells.

References

 

Andersson D, Liu JJ, Nilsson A, Duan RD. (2003). Ursolic acid inhibits proliferation and stimulates apoptosis in HT29 cells following activation of alkaline sphingomyelinase. Anti-cancer Research, 23(4):3317-22.

 

Es-Saady D, Simon A, Jayat-Vignoles C, Chulia AJ, Delage C. (1996). MCF-7 cell-cycle arrested at G1 through ursolic acid, and increased reduction of tetrazolium salts. Anti-cancer Research, 16(1):481-6.

 

Hsu YL, Kuo PL, Lin CC. (2004). Proliferative inhibition, cell-cycle dysregulation, and induction of apoptosis by ursolic acid in human non-small-cell lung cancer A549 cells. Life Sciences, 75(19), 2303-2316.

 

Ikeda Y, Murakami A, Ohigashi H. (2008). Strain differences regarding susceptibility to ursolic acid-induced interleukin-1beta release in murine macrophages. Life Sci, 83(1-2):43-9. doi: 10.1016/j.lfs.2008.05.001.

 

Kassi E, Sourlingas TG, Spiliotaki M, et al. (2009). Ursolic Acid Triggers Apoptosis and Bcl-2 Down-regulation in MCF-7 Breast Cancer Cells. Cancer Investigation, 27(7):723-733. doi:10.1080/07357900802672712.

 

Kwon SH, Park HY, Kim JY, et al. (2010). Apoptotic action of ursolic acid isolated from Corni fructus in RC-58T/h/SA#4 primary human prostate cancer cells. Bioorg Med Chem Lett, 20:6435–6438. doi: 10.1016/j.bmcl.2010.09.073.

 

Lin J, Chen Y, Wei L, et al. (2013). Ursolic acid promotes colorectal cancer cell apoptosis and inhibits cell proliferation via modulation of multiple signaling pathways. Int J Oncol, (4):1235-43. doi: 10.3892/ijo.2013.2040.

 

Liu J. (1995). Pharmacology of oleanolic acid and ursolic acid. Journal of Ethnopharmacology, 49(2), 57-68.

 

Shishodia S, Majumdar S, Banerjee S, Aggarwal BB. (2003). Ursolic Acid Inhibits Nuclear Factor-OE ∫ B Activation Induced by Carcinogenic Agents through Suppression of IOE ∫ BOE± Kinase and p65 Phosphorylation. Cancer Research, 63(15), 4375-4383.

 

Subbaramaiah K, Michaluart P, Sporn MB, Dannenberg AJ. (2000). Ursolic Acid Inhibits Cyclooxygenase-2 Transcription in Human Mammary Epithelial Cells. Cancer Res, 60:2399

 

Qian J, Li X, Guo GY, et al. (2011). Potent anti-tumor activity of emodin on CNE cells in vitro through apoptosis. J Zhejiang Sci-Tech Univ (Chin), 42:756-759

 

Wang X, Zhang F, Yang L, et al. (2011). Ursolic Acid Inhibits Proliferation and Induces Apoptosis of Cancer Cells In Vitro and In Vivo. J Biomed Biotechnol, 2011:419343. doi: 10.1155/2011/419343.

 

Yamai H, et al. (2009). Triterpenes augment the inhibitory effects of anti-cancer drugs on growth of human esophageal carcinoma cells in vitro and suppress experimental metastasis in vivo. Int J Cancer, 125(4):952-60. doi: 10.1002/ijc.24433.

 

Yeh CT, Wu CH, Yen GC. (2010). Ursolic acid, a naturally occurring triterpenoid, suppresses migration and invasion of human breast cancer cells by modulating c-Jun N-terminal kinase, Akt and mammalian target of rapamycin signaling. Mol Nutr Food Res, 54:1285–1295. doi: 10.1002/mnfr.200900414.

 

Zhang Y, Kong C, Zeng Y, et al. (2010). Ursolic acid induces PC-3 cell apoptosis via activation of JNK and inhibition of Akt pathways in vitro. Mol Carcinog, 49:374–385.

 

Zhang LL, Wu BN, Lin Y et al. (2014) Research Progress of Ursolic Acid’s Anti-Tumor Actions. Chin J Integr Med 2014 Jan;20(1):72-79

 

Reference

 

Huang HC, Huang CY, Lin-Shiau SY, Lin JK. Ursolic acid inhibits IL-1beta or TNF-alpha-induced C6 glioma invasion through suppressing the association ZIP/p62 with PKC-zeta and downregulating the MMP-9 expression. Mol Carcinog 2009;48:517-531

 

Huang CY, Lin CY, Tsai CW, Yin MC. Inhibition of cell proliferation, invasion and migration by ursolic acid in human lung cancer cell lines. Toxicol In Vitro 2011;25:1274-1280.

 

Park KS, Kim NG, Kim JJ, Kim H, Ahn YH, Choi KY. Differential regulation of MAP kinase cascade in human colorectal tumorigenesis. Br J Cancer 1999;81:1116-1121.

 

 

Pathak AK, Bhutani M, Nair AS, Ahn KS, Chakraborty A, Kadara H, et al. Ursolic acid inhibits STAT3 activation pathway leading to suppression of proliferation and chemosensitization of human multiple myeloma cells. Mol Cancer Res 2007;5:943-595

 

 

Koo HJ, Gang DR. (2012) Suites of terpene synthases explain differential terpenoid production in ginger and turmeric tissues. PLoS One. 2012;7(12):e51481. doi: 10.1371/journal.pone.0051481.

 

 

Wang W, Zhao C, Jou D, Lü J, Zhang C, Lin L, Lin J. (2013) Ursolic acid inhibits the growth of colon cancer-initiating cells by targeting STAT3. Anticancer Res. 2013 Oct;33(10):4279-84.

 
Lu C-C, Huang B-R, Liao P-J, Yen G-C. Ursolic acid triggers a non-programmed death (necrosis) in human glioblastoma multiforme DBTRG-05MG cells through MPT pore opening and ATP decline. Molecular Nutrition & Food Research. 2014 DOI: 10.1002/mnfr.201400051

 

 

 

Piceatannol

Cancer: Esophageal, colorectal, breast

Action: Anti-inflammatory, anti-oxidative

Piceatannol, a naturally occurring analogue of resveratrol found in certain plants and berries of the Vaccinium genus, including Picea abies [(L.) H.Karst.], Aiphanes horrida [(Jacq.) Burret], Gnetum cleistostachyum (C. Y. Cheng), Vaccinium arboretum (Marshall), Vaccinium angustifolium (Aiton) and Vaccinium corymbosum (L.). It was previously identified as the active ingredient in herbal preparations in folk medicine. Piceatannol is an anti-inflammatory, immunomodulatory, and anti-proliferative stilbene that has been shown to interfere with the cytokine signaling pathway. It is isolated from various types of berries, grapes, rhubarb and sugar cane.

It has been shown that a diet containing freeze-dried black raspberries (BRB) inhibits the development of chemically-induced cancer in the rat esophagus. To provide insights into possible mechanisms by which BRB inhibit esophageal carcinogenesis, an ethanol (EtOH) extract of BRB was evaluated, and two component anthocyanins (cyanidin-3-O-glucoside and cyanidin-3-O−rutinoside) in BRB, for their effects on growth, apoptosis, and gene expression in rat esophageal epithelial cell lines. The EtOH extract and both anthocyanins selectively caused significant growth inhibition and induction of apoptosis in a highly tumorigenic cell line (RE-149 DHD) but not in a weakly tumorigenic line (RE-149).

The growth-inhibitory and pro-apoptotic effects were enhanced by the daily addition of the EtOH extract and the anthocyanins to the medium.

Esophageal Cancer

This differential effect may have been related to the relative amounts of anthocyanins in the extract vs.when they were added individually to the medium. It was hence concluded that the selective effects of the EtOH extract on the growth and apoptosis of highly tumorigenic rat esophageal epithelial cells in vitro may be due to preferential uptake and retention of its component anthocyanins, and this may also be responsible for the greater inhibitory effects of freeze-dried whole berries on tumor cells in vivo (Schwartz et al., 2009).

Colorectal

The effects of piceatannol on growth, proliferation, differentiation and cell-cycle distribution profile of the human colon carcinoma cell line Caco-2 were investigated. Growth of Caco-2 and HCT-116 cells was analyzed by crystal violet assay, which demonstrated dose- and time-dependent decreases in cell numbers. Treatment of Caco-2 cells with piceatannol reduced proliferation rate. No effect on differentiation was observed.

Determination of cell-cycle distribution by flow cytometry revealed an accumulation of cells in the S phase. Immunoblotting demonstrated that cyclin-dependent kinases (cdk) 2 and 6, as well as cdc2 were expressed at steady-state levels, whereas cyclin D1, cyclin B1 and cdk 4 were down-regulated. The abundance of p27Kip1 was also reduced, whereas the protein level of cyclin E was enhanced. Cyclin A levels were enhanced only at concentrations up to 100 µmol/L. These changes also were observed in studies with HCT-116 cells. On the basis of our findings, piceatannol can be considered to be a promising chemo-preventive or anti-cancer agent (Wolter et al., 2002).

Anti-inflammatory

Treatment of human myeloid cells with piceatannol suppressed TNF-induced DNA binding activity of NF-κB. In contrast, stilbene or rhaponticin (another analog of piceatannol) had no effect, suggesting the critical role of hydroxyl groups. The effect of piceatannol was not restricted to myeloid cells, as TNF-induced NF- κB activation was also suppressed in lymphocyte and epithelial cells. Piceatannol also inhibited NF-κB activated by H2O2, PMA, LPS, okadaic acid, and ceramide.

Piceatannol abrogated the expression of TNF-induced NF-κB-dependent reporter gene and of matrix metalloprotease-9, cyclooxygenase-2, and cyclin D1. When examined for the mechanism, it was found that piceatannol inhibited TNF-induced IκBα phosphorylation, p65 phosphorylation, p65 nuclear translocation, and IκBα kinase activation, but had no significant effect on IκBα degradation. Piceatannol inhibited NF-κB in cells with deleted Syk, indicating the lack of involvement of this kinase.

Overall, these results clearly demonstrate that hydroxyl groups of stilbenes are critical and that piceatannol, a tetrahydroxystilbene, suppresses NF- κB activation induced by various inflammatory agents through inhibition of IκBα kinase and p65 phosphorylation (Ashikawa et al., 2002).

There are multiple lines of evidence supporting that inflammation is causally linked to carcinogenesis. Abnormal up-regulation of cyclooxygenase-2 (COX-2), a rate-limiting enzyme in the prostaglandin biosynthesis, has been implicated in carcinogenesis. Trans-3,4,3',5'-tetrahydroxystilbene (piceatannol), a naturally occurring hydroxylated stilbene with potent anti-inflammatory and anti-oxidative activities, has been shown to inhibit the proliferation of several cancer cells by inducing apoptosis or blocking cell-cycle progression. The effect of piceatannol was examined on the activation of the nuclear transcription factor NF-κB, one of the major transcription factors that regulate pro-inflammatory COX- 2 gene transcription, in human mammary epithelial (MCF-10A) cells treated with the tumor promoter 12-O-tetradecanoylphorbol- 13-acetate (TPA).

When pre-treated to MCF-10A cells, piceatannol markedly inhibited TPA-induced NF-κB DNA binding to a greater extent than resveratrol and oxyresveratrol, stilbene analogs structurally related to piceatannol. Piceatannol also inhibited TPAinduced phosphorylation and degradation of IκBα as well as nuclear translocation of the phosphorylated form of p65, the functionally active subunit of NF-κB. Likewise, TPA-induced expression of COX-2 was abrogated by piceatannol pre-treatment. The thiol reducing agent dithiothreitol abolished the inhibitory effects of piceatannol on NF-κB DNA binding activity, suggesting that piceatannol may directly modify NF-kB (Liu et al., 2009).

Breast Cancer

Piceatannol (trans-3,4,3′,5′-tetrahydroxystilbene; PIC) exhibits immunosuppressive and anti-tumorigenic activities in several cell lines, and it was found that PIC inhibited migration and anchorage-independent growth of human mammary epithelial cells (MCF-10A) treated with the prototypic tumor promoter, 12-O-tetradecanoylphorbol-13-aceate (TPA). PIC treatment suppressed the TPA-induced activation of NF-κB and expression of cyclooxygenase-2 (COX-2) in MCF-10A cells. It was speculated that an electrophilic quinone formed as a consequence of oxidation of PIC bearing the catechol moiety may directly interact with critical cysteine thiols of IKKβ, thereby inhibiting its catalytic activity.

Results show that direct modification of IKKβ by PIC, presumably at the cysteine 179 residue, blocks NF-κB activation signaling and COX-2 induction in TPA-treated MCF-10A cells and also migration and transformation of these cells (Son et al., 2010).

References

Ashikawa K, Majumdar S, Banerjee S, et al. (2002). Piceatannol inhibits TNF-induced NF- κB activation and NF- κ B-mediated gene expression through suppression of IκBα kinase and p65 phosphorylation. The Journal of Immunology, 169(11):6490-7.


Liu D, Kim DH, Park JM. (2009). Piceatannol Inhibits Phorbol Ester-Induced NF- κ B Activation and COX-2 Expression in Cultured Human Mammary Epithelial Cells. Nutrition and Cancer, 61(6):855–63. doi: 10.1080/01635580903285080.


Schwartz SJ and Stoner GD. (2009). Black Raspberry Components Inhibit Proliferation, Induce Apoptosis, and Modulate Gene Expression in Rat Esophageal Epithelial Cells. Nutrition and Cancer, 61(6):816–26. doi: 10.1080/01635580903285148


Son PS, Park SA, Na HK, et al. (2010). Piceatannol, a catechol-type polyphenol, inhibits phorbol ester-induced NF- κ B activation and cyclooxygenase-2 expression in human breast epithelial cells: cysteine 179 of IKK β as a potential target. Carcinogenesis, 31(8):1442-1449. doi: 10.1093/carcin/bgq099.


Wolter F, Clausnitzer A, Akoglu B and Stein J. (2001). Down-regulation of the cyclin D1/Cdk4 complex occurs during resveratrol-induced cell-cycle arrest in colon cancer cell lines. J. Nutr, 132(2):298-302.

Lunasin

Cancer: Colon, breast, liver metastasis

Action: Induces apoptosis, MDR

Lunasin is a peptide found in soy, barley, wheat, and rye, including Glycine max [(L.) Merr.], Hordeum vulgare L., Triticum (L.) genus and Secale cereale L.

Colon Cancer; Metastasis

Lunasin bound with α(5)β(1) integrin and internalized into the nucleus of KM12L4 human colon cancer cells. Lunasin (10µM) inhibited the activation of focal adhesion kinase (FAK) by 28%, 39% and 60% in RKO, HCT-116 and KM12L4 human colon cancer cells, respectively. Lunasin caused an increase in the expression of the inhibitor of kappa B alpha (IκB-α), a decrease in nuclear p50 NF-κB and a reduction in the migration of cancer cells. Lunasin (4mg/kg bw) inhibited metastasis and potentiated the effect of oxaliplatin by reducing the expression of proliferating cell nuclear antigen.

Liver metastatic nodules were reduced from 28 (PBS) to 14 (lunasin, P=0.047) while combination of lunasin and oxaliplatin to 5 (P=0.004). The tumor burden was reduced from 0.13 (PBS) to 0.10 (lunasin, P=0.039) to 0.04 (lunasin+oxaliplatin, P<0.0001). Moreover, lunasin potentiated the effect of oxaliplatin in modifying expression of proteins involved in apoptosis and metastasis including Bax, Bcl-2, IKK-α and p-p65. Lunasin inhibited metastasis of human colon cancer cells by direct binding with α(5)β(1) integrin suppressing FAK/ERK/NF-κB signaling, and potentiated the effect of oxaliplatin in preventing the outgrowth of metastasis (Dia et al., 2011).

Induces Apoptosis

Galvez et al. (2001) demonstrated previously that transfection of mammalian cells with the lunasin gene arrests mitosis, leading to cell death. Here they show that exogenous application of the lunasin peptide inhibits chemical carcinogen-induced transformation of murine fibroblast cells to cancerous foci. The results suggest a mechanism whereby lunasin selectively induces apoptosis, mostly in cells undergoing transformation, by preventing histone acetylation. In support of this, lunasin selectively induces apoptosis in E1A-transfected cells but not in nontransformed cells. Finally, in the SENCAR mouse skin cancer model, dermal application of lunasin (250 microg/week) reduces skin tumor incidence by approximately 70%, decreases tumor yield/mouse, and delays the appearance of tumors by 2 weeks relative to the positive control. These results point to the role of lunasin as a new chemo-preventive agent that functions possibly via a chromatin modification mechanism.

Breast Cancer

Combinations of two or more chemo-preventive agents are currently being used to achieve greater inhibitory effects on breast cancer cells. This study reveals that both aspirin and lunasin inhibit, in a dose-dependent manner, human estrogen-independent breast cancer MDA-MB-231 cell proliferation.

These compounds arrest the cell-cycle in the S- and G1-phases, respectively, acting synergistically to induce apoptosis. The cell growth-inhibitory effect of a lunasin/aspirin combination is achieved, at least partially, by modulating the expression of genes encoding G1 and S-phase regulatory proteins. Lunasin/aspirin therapy exerts its potent pro-apoptotic effect, at least partially achieved through modulating the extrinsic-apoptosis dependent pathway.

Therefore, our results suggest that a combination of these two compounds is a promising strategy to prevent/treat breast cancer (Hsieh et al., 2010).

Colon Cancer; MDR

Various human colon cancer cell lines which underwent metastasis were evaluated in vitro using cell flow cytometry and fluorescence microscopy. Lunasin cytotoxicity to different colon cancer cells correlated with the expression of α5b1 integrin was investigated, being most potent to KM12L4 cells (IC50 = 13 µM). Lunasin arrested cell-cycle at G2/M phase with concomitant increase in the expression of cyclin-dependent kinase inhibitors p21 and p27. Lunasin (5–25 µM) activated the apoptotic mitochondrial pathway as evidenced by changes in the expressions of Bcl-2, Bax, nuclear clusterin, cytochrome c and caspase-3 in KM12L4 and KM12L4-OxR.

Lunasin increased the activity of initiator caspase-9 leading to the activation of caspase-3 and also modified the expression of human extracellular matrix and adhesion genes, down-regulating integrin α5, SELE, MMP10, integrin β2 and COL6A1 by 5.01-, 6.53-, 7.71-, 8.19- and 10.10-fold, respectively, while up-regulating COL12A1 by 11.61-fold. Lunasin can be used in cases where resistance to chemotherapy developed (Dia et al., 2011).

References

Dia VP, Gonzalez de Mejia E. (2011). Lunasin potentiates the effect of oxaliplatin preventing outgrowth of colon cancer metastasis, binds to α5β1 integrin and suppresses FAK/ERK/NF-κ B signaling, Cancer Lett, 313(2):167-80.


Dia VP, Gonzalez de Mejia E. (2011). Lunasin induces apoptosis and modifies the expression of genes associated with extracellular matrix and cell adhesion in human metastatic colon cancer cells. Mol Nutr Food Res, 55(4):623-34. doi: 10.1002/mnfr.201000419.


Galvez AF, Chen N, Macasieb J, de Lumen BO. (2001). Chemo-preventive property of a soybean peptide (lunasin) that binds to deacetylated histones and inhibits acetylation. Cancer Res, 61(20):7473-8.


Hsieh CC, Hern‡ndez-Ledesma B, de Lumen BO. (2010). Lunasin, a novel seed peptide, sensitizes human breast cancer MDA-MB-231 cells to aspirin-arrested cell-cycle and induced apoptosis. Chem Biol Interact, 186(2):127-34. doi: 10.1016/j.cbi.2010.04.027.

Dietary Flavones

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

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

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

Anti-inflammatory

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

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

Colorectal Cancer

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

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

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

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

Anti-angiogenic, Prostate Cancer

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

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

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

Pancreatic Cancer; Chemo-sensitizer

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

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

Breast Cancer; Chemo-sensitizer, Tamoxifen

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

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

Breast Cancer

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

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

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

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

CSCs

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

Anti-inflammatory

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

Bladder Cancer

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

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

Ovarian Cancer

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

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

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

Leukemia Stem Cells

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

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

DCIS Stem Cells

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

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

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

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

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

Breast Cancer Metastasis

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

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

Osteosarcoma, Melanoma

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

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

Prostate Cancer

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

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

Bladder Cancer; Adramycin (ADM) Resistance

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

Breast Cancer; Chemo-enhancing

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

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

References

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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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

Caffeic acid phenethyl ester (CAPE)

Cancer:
Breast, prostate, leukemia, cervical., oral., melanoma

Action: EMT, anti-mitogenic, anti-carcinogenic, anti-inflammatory, immunomodulatory

Anti-mitogenic, Anti-carcinogenic, Anti-inflammatory, Immunomodulatory Properties

Caffeic acid phenethyl ester (CAPE), an active component of propolis from honeybee hives, is known to have anti-mitogenic, anti-carcinogenic, anti-inflammatory, and immunomodulatory properties. A variety of in vitro pharmacology for CAPE has been reported. A study using CAPE showed a positive effect on reducing carcinogenic incidence. It is known to have anti-mitogenic, anti-carcinogenic, anti-inflammatory, and immunomodulatory properties in vitro (Orban et al., 2000) Another study also showed that CAPE suppresses acute immune and inflammatory responses and holds promise for therapeutic uses to reduce inflammation (Huang et al., 1996).

Caffeic acid phenethyl ester (CAPE) specifically inhibits NF-κB at µM concentrations and shows ability to stop 5-lipoxygenase-catalyzed oxygenation of linoleic acid and arachidonic acid. Previous studies have demonstrated that CAPE exhibits anti-oxidant, anti-inflammatory, anti-proliferative, cytostatic, anti-viral., anti-bacterial., anti-fungal., and, most importantly, anti-neoplastic properties (Akyol et al., 2013).

Multiple Immunomodulatory and Anti-inflammatory Activities

The results show that the activation of NF-kappa B by tumor necrosis factor (TNF) is completely blocked by CAPE in a dose- and time-dependent manner. Besides TNF, CAPE also inhibited NF-kappa B activation induced by other inflammatory agents including phorbol ester, ceramide, hydrogen peroxide, and okadaic acid. Since the reducing agents reversed the inhibitory effect of CAPE, it suggests the role of critical sulfhydryl groups in NF-kappa B activation. CAPE prevented the translocation of the p65 subunit of NF-kappa B to the nucleus and had no significant effect on TNF-induced I kappa B alpha degradation, but did delay I kappa B alpha resynthesis. When various synthetic structural analogues of CAPE were examined, it was found that a bicyclic, rotationally constrained, 5,6-dihydroxy form was superactive, whereas 6,7-dihydroxy variant was least active.

Thus, overall our results demonstrate that CAPE is a potent and a specific inhibitor of NF-kappa B activation and this may provide the molecular basis for its multiple immunomodulatory and anti-inflammatory activities (Natarajan et al., 1996).

Breast Cancer

Aqueous extracts from Thymus serpyllum (ExTs), Thymus vulgaris (ExTv), Majorana hortensis (ExMh), and Mentha piperita (ExMp), and the phenolic compounds caffeic acid (CA), rosmarinic acid (RA), lithospermic acid (LA), luteolin-7-O-glucuronide (Lgr), luteolin-7-O-rutinoside (Lr), eriodictiol-7-O-rutinoside (Er), and arbutin (Ab), were tested on two human breast cancer cell lines: Adriamycin-resistant MCF-7/Adr and wild-type MCF-7/wt.

ExMh showed the highest cytotoxicity, especially against MCF-7/Adr, whereas ExMp was the least toxic; particularly against MCF-7/wt cells. RA and LA exhibited the strongest cytotoxicity against both MCF-7 cell lines, over 2-fold greater than CA and Lgr, around 3-fold greater than Er, and around 4- to 7-fold in comparison with Lr and Ab. Except for Lr and Ab, all other phytochemicals were more toxic against MCF-7/wt, and all extracts exhibited higher toxicity against MCF-7/Adr. It might be concluded that the tested phenolics exhibited more beneficial properties when they were applied in the form of extracts comprising their mixtures (Berdowska et al., 2013).

Prostate Cancer

Evidence is growing for the beneficial role of selective estrogen receptor modulators (SERM) in prostate diseases. Caffeic acid phenethyl ester (CAPE) is a promising component of propolis that possesses SERM activity. CAPE-induced inhibition of AKT phosphorylation was more prominent (1.7-folds higher) in cells expressing ER-α such as PC-3 compared to LNCaP. In conclusion, CAPE enhances the anti-proliferative and cytotoxic effects of DOC and PTX in prostate cancer cells (Tolba et al., 2013).

EMT, Prostate Cancer

CAPE suppressed the expression of Twist 2 and growth of PANC-1 xenografts without significant toxicity. CAPE could inhibit the orthotopic growth and EMT of pancreatic cancer PANC-1 cells accompanied by down-regulation of vimentin and Twist 2 expression (Chen et al., 2013).

CAPE is a well-known NF-κB inhibitor. CAPE has been used in folk medicine as a potent anti-inflammatory agent. Recent studies indicate that CAPE treatment suppresses tumor growth and Akt signaling in human prostate cancer cells (Lin et al., 2013). Combined treatments of CAPE with chemotherapeutic drugs exhibit synergistic suppression effects. Pharmacokinetic studies suggest that intraperitoneal injection of CAPE at concentration of 10mg/kg is not toxic. CAPE treatment sensitizes cancer cells to chemotherapy and radiation treatments. In addition, CAPE treatment protects therapy-associated toxicities (Liu et al., 2013).

Cervical Cancer

CAPE preferentially induced S- and G2 /M-phase cell-cycle arrests and initiated apoptosis in human cervical cancer lines. The effect was found to be associated with increased expression of E2F-1, as there is no CAPE-mediated induction of E2F-1 in the pre-cancerous cervical Z172 cells. CAPE also up-regulated the E2F-1 target genes cyclin A, cyclin E and apoptotic protease activating of factor 1 (Apaf-1) but down-regulated cyclin B and induced myeloid leukemia cell differentiation protein (Mcl-1) (Hsu et al., 2013).

Oral Cancer

CAPE attenuated SCC-9 oral cancer cells migration and invasion at noncytotoxic concentrations (0  µM to 40 µM). CAPE exerted its inhibitory effects on MMP-2 expression and activity by upregulating tissue inhibitor of metalloproteinase-2 (TIMP-2) and potently decreased migration by reducing focal adhesion kinase (FAK) phosphorylation and the activation of its downstream signaling molecules p38/MAPK and JNK (Peng et al., 2012).

Melanoma

CAPE is suggested to suppress reactive-oxygen species (ROS)-induced DNA strand breakage in human melanoma A2058 cells when compared to other potential protective agents. CAPE can be applied not only as a chemo-preventive agent but also as an anti-metastatic therapeutic agent in lung cancer and because CAPE is a nuclear factor-κB (NF-κB) inhibitor and 5α reductase inhibitor, it has potential for the treatment of prostate cancer (Ozturk et al., 2012).

References

Akyol S, Ozturk G, Ginis Z, et al. (2013). In vivo and in vitro antõneoplastic actions of caffeic acid phenethyl ester (CAPE): therapeutic perspectives. Nutr Cancer, 65(4):515-26. doi: 10.1080/01635581.2013.776693.


Berdowska I, Ziel iński B, Fecka I, et al. (2013). Cytotoxic impact of phenolics from Lamiaceae species on human breast cancer cells. Food Chem, 15;141(2):1313-21. doi: 10.1016/j.foodchem.2013.03.090.


Chen MJ, Shih SC, Wang HY, et al. (2013). Caffeic Acid phenethyl ester inhibits epithelial-mesenchymal transition of human pancreatic cancer cells. Evid Based Complement Alternat Med, 2013:270906. doi: 10.1155/2013/270906.


Hsu TH, Chu CC, Hung MW, et al. (2013). Caffeic acid phenethyl ester induces E2F-1-mediated growth inhibition and cell-cycle arrest in human cervical cancer cells. FEBS J, 280(11):2581-93. doi: 10.1111/febs.12242.


Huang MT, Ma W, Yen P, et al. (1996). Inhibitory effects of caffeic acid phenethyl ester (CAPE) on 12-O-tetradecanoylphorbol-13-acetate-induced tumor promotion in mouse skin and the synthesis of DNA, RNA and protein in HeLa cells. Carcinogenesis, 17(4):761–5. doi:10.1093/carcin/17.4.761.


Lin HP, Lin CY, Liu CC, et al. (2013). Caffeic Acid phenethyl ester as a potential treatment for advanced prostate cancer targeting akt signaling. Int J Mol Sci, 14(3):5264-83. doi: 10.3390/ijms14035264.


Liu CC, Hsu JM, Kuo LK, et al. (2013). Caffeic acid phenethyl ester as an adjuvant therapy for advanced prostate cancer. Med Hypotheses, 80(5):617-9. doi: 10.1016/j.mehy.2013.02.003.


Natarajan K, Singh S, Burke TR Jr, Grunberger D, Aggarwal BB. (1996). Caffeic acid phenethyl ester is a potent and specific inhibitor of activation of nuclear transcription factor NF-kappa B. Proc Natl Acad Sci USA, 93(17):9090-5.


Orban Z, Mitsiades N, Burke TR, Tsokos M, Chrousos GP. (2000). Caffeic acid phenethyl ester induces leukocyte apoptosis, modulates nuclear factor-kappa B and suppresses acute inflammation. Neuroimmunomodulation, 7(2): 99–105. doi:10.1159/000026427.


Ozturk G, Ginis Z, Akyol S, et al. (2012). The anti-cancer mechanism of caffeic acid phenethyl ester (CAPE): review of melanomas, lung and prostate cancers. Eur Rev Med Pharmacol Sci, 16(15):2064-8.


Peng CY, Yang HW, Chu YH, et al. (2012). Caffeic Acid phenethyl ester inhibits oral cancer cell metastasis by regulating matrix metalloproteinase-2 and the mitogen-activated protein kinase pathway. Evid Based Complement Alternat Med, 2012:732578. doi: 10.1155/2012/732578.


Tolba MF, Esmat A, Al-Abd AM, et al. (2013). Caffeic acid phenethyl ester synergistically enhances docetaxel and paclitaxel cytotoxicity in prostate cancer cells. IUBMB Life, 65(8):716-29. doi: 10.1002/iub.1188.

Berbamine

Cancer: Breast, leukemia, liver, neutropenia

Action: Anti-metastatic, chemo-sensitizer

Breast Cancer, Leukemia

Berbamine (BER), isolated from the Chinese herb Berberis amurensis and Berberis vulgaris (L.), selectively induces apoptosis in certain breast cancer and leukemia cell lines.

Studies have shown that berbamine suppresses the growth, migration and invasion in highly-metastatic human breast cancer cells by possibly inhibiting Akt and NF-kappaB signaling with their upstream target c-Met and downstream targets Bcl-2/Bax, osteopontin, VEGF, MMP-9 and MMP-2.

BER has synergistic effects with anti-cancer agents trichostatin A, celecoxib and carmofur on inhibiting the growth of MDA-MB-231 cells and reducing the ratio of Bcl-2/Bax and/or VEGF expressions in the cancer cells. These findings suggest that berbamine may have wide therapeutic and/or adjuvant therapeutic application in the treatment of human breast cancer and other cancers (Wang, 2009).

MDR, Leukemia stem cells

Previous studies have shown that berbamine selectively induces apoptosis of imatinib (IM)-resistant-Bcr/Abl-expressing leukemia cells from the K562 cell line and CML patients. Berbamine derivatives obtained by synthesis were found to have very high activity in vitro. Six of these exhibited consistent high anti-tumor activity for imatinib-resistant K562 leukemia cells. Their IC(50) values at 48h were 0.36-0.55 microM, whereas berbamine IC(50) value was 8.9 microM. Cell cycle analysis results showed that compound 3h could reduce G0/G1 cells. In particular, these compounds displayed potent inhibition of the cytoplasm-to-nucleus translocation of NF-kappaB p65 which plays a critical role in the survival of leukemia stem cells (Xie, 2009).

Liver Cancer, Leukemia

Meng et al. (2013) reported that berbamine and one of its derivatives, bbd24, potently suppressed liver cancer cell proliferation and induced cancer cell death by targeting Ca2+/calmodulin-dependent protein kinase II (CAMKII). Furthermore, berbamine inhibited the in vivo tumorigenicity of liver cancer cells in NOD/SCID mice and downregulated the self-renewal abilities of liver cancer-initiating cells. Berbamine inhibits proliferation and induces apoptosis of KU812 leukaemia cells by increasing Smad3 activity (Kapoor, 2012).

Chronic Myeloid Leukemia, Leukopenia

During imatinib therapy, many patients with chronic myeloid leukemia (CML) develop severe neutropenia, leading to treatment interruptions, and potentially compromising response to imatinib. Berbamine (a bisbenzylisoquinoline alkaloid) has been widely used in Asian countries for managing leukopenia associated with chemotherapy. With berbamine support, the time to achieve complete cytogenetic response was significantly shorter (median, 6.5 vs. 10 months, p = 0.007). There were no severe adverse events associated with berbamine treatment. In conclusion, the present study reveals the potential clinical value of berbamine in the treatment of CML with imatinib-induced neutropenia (Zhao et al., 2011).

References

Kapoor S. (2012). Emerging role of berbamine as an anti-cancer agent in systemic malignancies besides chronic myeloid leukemia. Zhejiang Univ Sci B, 13(9):761-2.


Meng Z, Li T, Ma X, et al. (2013). Berbamine Inhibits the Growth of Liver Cancer Cells and Cancer-Initiating Cells by Targeting Ca2+/Calmodulin-Dependent Protein Kinase II. Mol Cancer Ther.


Wang S, Liu Q, Zhang Y, et al. (2009). Suppression of growth, migration and invasion of highly-metastatic human breast cancer cells by berbamine and its molecular mechanisms of action. Mol Cancer, 8:81.


Xie J, Ma T, Gu Y, et al. (2009). Berbamine derivatives: A novel class of compounds for anti-leukemia activity. Eur J Med Chem, 44(8):3293-8. doi: 10.1016/j.ejmech.2009.02.018


Zhao Y, Tan Y, Wu G, et al. (2011). Berbamine overcomes imatinib-induced neutropenia and permits cytogenetic responses in Chinese patients with chronic-phase chronic myeloid leukemia. Int J Hematol, 94(2):156-62. doi: 10.1007/s12185-011-0887-7.

Luteolin

Cancer: Colorectal., pancreatic, ovarian, breast

Action: Anti-inflammatory, radio-protective, TAM chemo-sensitizer

Luteolin is a flavonoid found in many plants and foods, including Terminalia chebula (Retz.), Prunella vulgaris (L.) and Perilla frutescens [(L.) Britton].

Luteolin is contained in Ocimum sanctum L. or Ocimum tenuiflorum L, commonly known as Holy Basil in English or Tulsi in various Indian languages; it is an important medicinal plant in the various traditional and folk systems of medicine in Southeast Asia. Scientific studies have shown it to possess anti-inflammatory, anti-analgesic, anti-pyretic, anti-diabetic, hepato-protective, hypolipidemic, anti-stress, and immunomodulatory activities. It has been found to prevent chemical-induced skin, liver, oral., and lung cancers and mediates these effects by increasing the anti-oxidant activity, altering the gene expressions, inducing apoptosis, and inhibiting angiogenesis and metastasis.

Radio-protective

The aqueous extract of Tulsi has been shown to protect mice against γ-radiation-induced sickness and mortality and to selectively protect the normal tissues against the tumoricidal effects of radiation. The chemo-preventive and radio-protective properties of Tulsi emphasize aspects that warrant future research to establish its activity and utility in cancer prevention and treatment (Baliga et al., 2013).

Anti-inflammatory

Pre-treatment of RAW 264.7 with luteolin, luteolin-7-glucoside, quercetin, and the isoflavonoid genistein inhibited both the LPS-stimulated TNF-αand interleukin-6 release, whereas eriodictyol and hesperetin only inhibited TNF-αrelease. From the compounds tested luteolin and quercetin were the most potent in inhibiting cytokine production with an IC50 of less than 1 and 5 µM for TNF-αrelease, respectively. Pre-treatment of the cells with luteolin attenuated LPS-induced tyrosine phosphorylation of many discrete proteins. Luteolin inhibited LPS-induced phosphorylation of Akt. Treatment of macrophages with LPS resulted in increased IκB-αphosphorylation and reduced the levels of IκB-α. It was concluded that luteolin inhibits protein tyrosine phosphorylation, nuclear factor-κB-mediated gene expression and pro-inflammatory cytokine production in murine macrophages (Xagorari et al., 2001).

Luteolin (Lut) possesses significant anti-inflammatory activity in well established models of acute and chronic inflammation, such as xylene-induced ear edema in mice (ED50= 107 mg/ kg), carrageenin-induced swellingof the ankle, acetic acid-induced pleurisy and croton oil-induced gaseous pouch granuloma in rats. Its combined immunostimulatory and anti-inflammatory activity, and inhibitory effect upon immediate hypersensitive response provide the pharmacologic bases for the beneficial effects of Lut in the treatment of chronic bronchitis (Chen et al., 1986).

Anti-inflammatory; Lung

Luteolin dose-dependently inhibited the expression and production of nitric oxide (NO) and prostaglandin E2 (PGE2), as well as the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). Luteolin also reduced the DNA binding activity of nuclear factor-kappa B (NF-κB) in LPS-activated macrophages. Moreover, luteolin blocked the degradation of IκB-α and nuclear translocation of NF-κB p65 subunit.

In sum, these data suggest that, by blocking NF-κ>B and AP-1 activation, luteolin acts to suppress the LPS-elicited inflammatory events in mouse alveolar macrophages, and this effect was mediated, at least in part, by inhibiting the generation of reactive oxygen species. These observations suggest a possible therapeutic application of this agent for treating inflammatory disorders in the lung (Chen et al., 2007).

Anti-inflammatory; Neuroinflammation

Pre-treatment of primary murine microglia and BV-2 microglial cells with luteolin inhibited LPS-stimulated IL-6 production at both the mRNA and protein levels. Whereas luteolin had no effect on the LPS-induced increase in NF-κB DNA binding activity, it markedly reduced AP-1 transcription factor binding activity. To determine whether luteolin might have similar effects in vivo, mice were provided drinking water supplemented with luteolin for 21 days and then they were injected i.p. with LPS. Luteolin consumption reduced LPS-induced IL-6 in plasma 4 hours after injection. Taken together, these data suggest luteolin inhibits LPS-induced IL-6 production in the brain by inhibiting the JNK signaling pathway and activation of AP-1 in microglia. Thus, luteolin may be useful for mitigating neuroinflammation (Jang et al., 2008).

Colon Cancer

Activities of CDK4 and CDK2 decreased within 2 hours after luteolin treatment, with a 38% decrease in CDK2 activity (P < 0.05) observed in cells treated with 40 µmol/l luteolin. Luteolin inhibited CDK2 activity in a cell-free system, suggesting that it directly inhibits CDK2.

tLuteolin promoted G2/M arrest at 24 hours post-treatment  by down-regulating cyclin B1 expression and inhibiting cell division cycle (CDC)2 activity. Luteolin promoted apoptosis with increased activation of caspases 3, 7, and 9 and enhanced poly(ADP-ribose) polymerase cleavage and decreased expression of p21CIP1/WAF1, survivin, Mcl-1, Bcl-xL, and Mdm-2. Decreased expression of these key antiapoptotic proteins could contribute to the increase in p53-independent apoptosis that was observed in HT-29 cells. Lim et al., (2007) demonstrated that luteolin promotes both cell-cycle arrest and apoptosis in the HT-29 colon cancer cell line, providing insight about the mechanisms underlying its anti-tumorigenic activities.

Pancreatic Cancer; Chemotherapy

Simultaneous treatment or pre-treatment (0, 6, 24 and 42 hours) of flavonoids and chemotherapeutic drugs and various concentrations (0-50µM) were assessed using the MTS cell proliferation assay. Simultaneous treatment with either flavonoid (0,13, 25 or 50µM) and chemotherapeutic drugs 5-fluorouracil (5-FU, 50µM) or gemcitabine (Gem, 10µM) for 60h resulted in less-than-additive effect (p<0.05). Pre-treatment for 24 hours with 13µM of either Api or Lut, followed by Gem for 36 hours was optimal to inhibit cell proliferation.

Pre-treatment of cells with 11-19µM of either flavonoid for 24 hours resulted in 59-73% growth inhibition when followed by Gem (10µM, 36h). Lut (15µM, 24h) Pre-treatment followed by Gem (10µM, 36h), significantly decreased protein expression of nuclear GSK-3βand NF-κB p65 and increased pro-apoptotic cytosolic cytochrome c. Pre-treatment of human pancreatic cancer cells BxPC-3 with low concentrations of Lut effectively aid in the anti-proliferative activity of chemotherapeutic drugs (Johnson et al., 2013).

Ovarian Cancer

Luteolin has been found to repress NF-kappaB (NF-κ>B, a pro-inflammatory transcription factor) and inhibit pro-inflammatory cytokines such as TNF-αand IL-6. Additionally, it has been shown to stabilize p53 protein, sensitize TRAIL (TNF receptor apoptosis-inducing ligand) induced apoptosis, and prevent or delay chemotherapy-resistance.

Recent studies further indicate that luteolin potently inhibits VEGF production and suppresses ovarian cancer cell metastasis in vitro. Lastly, oridonin and wogonin were 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 compounds in the treatment of ovarian cancer, strategically designed, large scale studies are warranted (Chen et al., 2012).

Chemo-sensitizer

The sensitization effect of luteolin on cisplatin-induced apoptosis is p53 dependent, as such effect is only found in p53 wild-type cancer cells but not in p53 mutant cancer cells. Moreover, knockdown of p53 by small interfering RNA made p53 wild-type cancer cells resistant to luteolin and cisplatin. Second, Shi et al., (2007) observed a significant increase of p53 protein level in luteolin-treated cancer cells without increase of p53 mRNA level, indicating the possible effect of luteolin on p53 posttranscriptional regulation.

In summary, data from this study reveal a novel molecular mechanism involved in the anti-cancer effect of luteolin and support its potential clinical application as a chemo-sensitizer in cancer therapy.

Breast Cancer; TAM Chemo-sensitizer

This study found that the level of cyclin E2 (CCNE2) mRNA was higher in tumor cells (4.89-fold, (∗)P=0.005) than in normal paired tissue samples as assessed using real-time reverse-transcriptase polymerase chain reaction (RT-PCR) analysis (n=257). Further, relatively high levels of CCNE2 protein expression were detected in tamoxifen-resistant (TAM-R) MCF-7 cells.

These results showed that the level of CCNE2 protein expression was specifically inhibited in luteolin-treated (5µM) TAM-R cells, either in the presence or absence of 4-OH-TAM (100nM). Combined treatment with 4-OH-TAM and luteolin synergistically sensitized the TAM-R cells to 4-OH-TAM. The results of this study suggest that luteolin can be used as a chemo-sensitizer to target the expression level of CCNE2 and that it could be a novel strategy to overcome TAM resistance in breast cancer patients (Tu et al., 2013).

References

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


Chen CY, Peng WH, Tsai KD and Hsu SL. (2007). Luteolin suppresses inflammation-associated gene expression by blocking NF-κB and AP-1 activation pathway in mouse alveolar macrophages. Life Sciences, 81(23-24):1602-1614. doi:10.1016/j.lfs.2007.09.028


Chen MZ, Jin WZ, Dai LM, Xu SY. (1986). Effect of luteolin on inflammation and immune function. Chinese Journal of Pharmacology and Toxicology, 1986-01.


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.


Jang S, Kelley KW, Johnson RW. (2008). Luteolin reduces IL-6 production in microglia by inhibiting JNK phosphorylation and activation of AP-1. PNAS, 105(21):7534-7539


Johnson JL, Gonzalez de Mejia E. (2013). Interactions between dietary flavonoids apigenin or luteolin and chemotherapeutic drugs to potentiate anti-proliferative effect on human pancreatic cancer cells, in vitro. Food Chem Toxicol, S0278-6915(13)00491-2. doi: 10.1016/j.fct.2013.07.036.


Lim DY, Jeong Y, Tyner Al., Park JHY. (2007). Induction of cell-cycle arrest and apoptosis in HT-29 human colon cancer cells by the dietary compound luteolin. Am J Physiol Gastrointest Liver Physiol, 292: G66-G75. doi:10.1152/ajpgi.00248.2006.


Shi R, Huang Q, Zhu X, et al. (2007). Luteolin sensitizes the anti-cancer effect of cisplatin via c-Jun NH2-terminal kinase-mediated p53 phosphorylation and stabilization. Molecular Cancer Therapeutics, 6(4):1338-1347. doi: 10.1158/1535-7163.MCT-06-0638.


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


Xagorari A, Papapetropoulos A, Mauromatis A, et al. (2001). Luteolin inhibits an endotoxin-stimulated phosphorylation cascade and pro-inflammatory cytokine production in macrophages. JPET, 296(1):181-187.

Luteolin

Cancer: Colorectal., ovarian, pancreatic

Action: Anti-inflammatory, immunomodulatory, radio-sensitizer, chemo-sensitizer

Luteolin is a flavonoid found in many plants and foods, including Terminalia chebula (Retz.), Prunella vulgaris (L.) and Perilla frutescens [(L.) Britton].

Luteolin is contained in Ocimum sanctum L . or Ocimum tenuiflorum L , commonly known as Holy Basil in English or Tulsi in various Indian languages, which is an important medicinal plant in the various traditional and folk systems of medicine in Southeast Asia. Scientific studies have shown it to possess anti-inflammatory, analgesic, anti-pyretic, anti-diabetic, hepato-protective, hypolipidemic, anti-stress, and immunomodulatory activities. It has been found to prevent chemical-induced skin, liver, oral., and lung cancers and mediates these effects by increasing the anti-oxidant activity, altering the gene expressions, inducing apoptosis, and inhibiting angiogenesis and metastasis.

Colon Cancer

Luteolin inhibited cyclin-dependent kinase (CDK)4 and CDK2 activity, resulting in G1 arrest with a concomitant decrease of phosphorylation of retinoblastoma protein. Activities of CDK4 and CDK2 decreased within 2 hours after luteolin treatment, with a 38% decrease in CDK2 activity (P < 0.05) observed in cells treated with 40 µmol/l luteolin. Luteolin also promoted G2/M arrest at 24 hours post-treatment by down-regulating cyclin B1 expression and inhibiting cell division cycle (CDC)2 activity. Luteolin promoted apoptosis with increased activation of caspases 3, 7, and 9 and enhanced poly(ADP-ribose) polymerase cleavage and decreased expression of p21CIP1/WAF1, survivin, Mcl-1, Bcl-xL, and Mdm-2. Lim et al. (2007) demonstrated that luteolin promotes both cell-cycle arrest and apoptosis in the HT-29 colon cancer cell line, providing insight about the mechanisms underlying its anti-tumorigenic activities.

Radio-protective

The aqueous extract of Perilla frutescens has been shown to protect mice against γ-radiation-induced sickness and mortality and to selectively protect the normal tissues against the tumoricidal effects of radiation. The chemo-preventive and radio-protective properties of Perilla emphasize aspects that warrant future research to establish its activity and utility in cancer prevention and treatment (Baliga et al., 2013).

Anti-inflammatory

Pre-treatment of RAW 264.7 macrophages with luteolin, luteolin-7-glucoside, quercetin, and the isoflavonoid genistein inhibited both the LPS-stimulated TNF-α and interleukin-6 release, whereas eriodictyol and hesperetin only inhibited TNF-α release. From the compounds tested, luteolin and quercetin were the most potent in inhibiting cytokine production with an IC50 of less than 1 and 5 µM for TNF-α release, respectively. Moreover, luteolin inhibited LPS-induced phosphorylation of Akt. Treatment of macrophages with LPS resulted in increased IκB-α phosphorylation and reduced the levels of IκB-α. Pre-treatment of cells with luteolin abolished the effects of LPS on IκB-α.

Xagorari et al. (2001) concluded that luteolin inhibits protein tyrosine phosphorylation, nuclear factor-κB-mediated gene expression and pro-inflammatory cytokine production in murine macrophages.

Anti-inflammatory; Neuroinflammation

Pre-treatment of primary murine microglia and BV-2 microglial cells with luteolin inhibited LPS-stimulated IL-6 production at both the mRNA and protein levels. Whereas luteolin had no effect on the LPS-induced increase in NF-κB DNA binding activity, it markedly reduced AP-1 transcription factor binding activity. Consistent with this finding, luteolin did not inhibit LPS-induced degradation of IκB-α but inhibited JNK phosphorylation.

Luteolin consumption reduced LPS-induced IL-6 in plasma 4 hours after injection. Furthermore, luteolin decreased the induction of IL-6 mRNA by LPS in the hippocampus but not in the cortex or cerebellum. Taken together, these data suggest luteolin inhibits LPS-induced IL-6 production in the brain by inhibiting the JNK signaling pathway and activation of AP-1 in microglia. Thus, luteolin may be useful for mitigating neuroinflammation (Jang et al., 2008).

Immunostimulatory and Anti-inflammatory

Luteolin (Lut) possesses significant anti-inflammatory activity in well-established models of acute and chronic inflammation, such as xylene-induced ear edema in mice (ED50= 107 mg/ kg), carrageenin-induced swellingof the ankle, acetic acid-induced pleurisy and croton oil-induced gaseous pouch granuloma in rats. Lut had a marked inhibitory effect on the inflammatory exudation, but did not affect the number of leucocytes. Its combined immunostimulatory and anti-inflammatory activity, and inhibitory effect upon immediate hypersensitive response, provide the pharmacologic bases for the beneficial effects of Lut in the treatment of chronic bronchitis (Chen et al., 1986).

Anti-inflammatory

Luteolin dose-dependently inhibited the expression and production of those inflammatory genes and mediators in macrophages stimulated with lipopolysaccharide (LPS). Semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR) assay further confirmed the suppression of LPS-induced TNF- α, IL-6, iNOS and COX-2 gene expression by luteolin at a transcriptional level. Luteolin also reduced the DNA binding activity of nuclear factor-kappa B (NF-κB) in LPS-activated macrophages.

In addition, luteolin significantly inhibited the LPS-induced DNA binding activity of activating protein-1 (AP-1). It was also found that luteolin attenuated the LPS-mediated protein kinase B (Akt) and IKK phosphorylation, as well as reactive oxygen species (ROS) production. In sum, these data suggest that, by blocking NF-κB and AP-1 activation, luteolin acts to suppress the LPS-elicited inflammatory events in mouse alveolar macrophages, and this effect was mediated, at least in part, by inhibiting the generation of reactive oxygen species. These observations suggest a possible therapeutic application of this agent for treating inflammatory disorders in the lung (Chen et al., 2007).

Pancreatic Cancer; Chemo-enhancing

Simultaneous treatment or pre-treatment (0, 6, 24 and 42h) of flavonoids and chemotherapeutic drugs and various concentrations (0-50µM) were assessed using the MTS cell proliferation assay. Pre-treatment for 24 hours with 13µM of either Apigenin or Luteolin, followed by Gem for 36 h was optimal to inhibit cell proliferation.

Pre-treatment of cells with 11-19µM of either flavonoid for 24 hours resulted in 59%–73% growth inhibition when followed by Gem (10µM, 36 hours). Lut (15µM, 24 hours) pre-treatment followed by Gem (10µM, 36h), significantly decreased protein expression of nuclear GSK-3β and NF-κB p65 and increased pro-apoptotic cytosolic cytochrome c. Pre-treatment of human pancreatic cancer cells BxPC-3 with low concentrations of Lut effectively aid in the anti-proliferative activity of chemotherapeutic drugs (Johnson et al., 2013).

Ovarian Cancer

Recent studies further indicate that luteolin potently inhibits VEGF production and suppresses ovarian cancer cell metastasis in vitro. Lastly, oridonin and wogonin were 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 compounds in the treatment of ovarian cancer, strategically designed, large scale studies are warranted (Chen et al., 2012).

Chemo-sensitizer

The sensitization effect of luteolin on cisplatin-induced apoptosis is p53 dependent, as such effect is only found in p53 wild-type cancer cells but not in p53 mutant cancer cells. Moreover, knockdown of p53 by small interfering RNA made p53 wild-type cancer cells resistant to luteolin and cisplatin. The critical role of c-Jun NH(2)-terminal kinase (JNK) was identified in regulation of p53 protein stability: luteolin activates JNK, and JNK then stabilizes p53 via phosphorylation, leading to reduced ubiquitination and proteasomal degradation.

An in vivo nude mice xenograft model confirmed that luteolin enhanced the cancer therapeutic activity of cisplatin via p53 stabilization and accumulation. In summary, data from this study reveal a novel molecular mechanism involved in the anti-cancer effects of luteolin and support its potential clinical application as a chemo-sensitizer in cancer therapy (Shi et al., 2007).

Breast Cancer; Chemo-sensitzer

Luteolin is a flavonoid that has been identified in many plant tissues and exhibits chemo-preventive or chemo-sensitizing properties against human breast cancer. However, the oncogenic molecules in human breast cancer cells that are inhibited by luteolin treatment have not been identified.

Relatively high levels of cyclin E2 (CCNE2) protein expression were detected in tamoxifen-resistant (TAM-R) MCF-7 cells. These results showed that the level of CCNE2 protein expression was specifically inhibited in luteolin-treated (5µM) TAM-R cells, either in the presence or absence of 4-OH-TAM (100nM). Combined treatment with 4-OH-TAM and luteolin synergistically sensitized the TAM-R cells to 4-OH-TAM. The results of this study suggest that luteolin can be used as a chemo-sensitizer to target the expression level of CCNE2 and that it could be a novel strategy to overcome TAM resistance in breast cancer patients (Tu et al., 2013).

References

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

Chen CY, Peng WH, Tsai KD and Hsu SL. (2007). Luteolin suppresses inflammation-associated gene expression by blocking NF- κ B and AP-1 activation pathway in mouse alveolar macrophages. Life Sciences, 81(23-24):1602-1614. doi:10.1016/j.lfs.2007.09.028

Chen MZ, Jin WZ, Dai LM, Xu SY. (1986). Effect of luteolin on inflammation and immune function. Chinese Journal of Pharmacology and Toxicology, 1986-01.

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.

Jang S, Kelley KW, Johnson RW. (2008). Luteolin reduces IL-6 production in microglia by inhibiting JNK phosphorylation and activation of AP-1. PNAS, 105(21):7534-7539

Johnson JL, Gonzalez de Mejia E. (2013). Interactions between dietary flavonoids apigenin or luteolin and chemotherapeutic drugs to potentiate anti-proliferative effect on human pancreatic cancer cells, in vitro. Food Chem Toxicol, S0278-6915(13)00491-2. doi: 10.1016/j.fct.2013.07.036.

Lim DY, Jeong Y, Tyner Al., Park JHY. (2007). Induction of cell-cycle arrest and apoptosis in HT-29 human colon cancer cells by the dietary compound luteolin. Am J Physiol Gastrointest Liver Physiol, 292: G66-G75. doi:10.1152/ajpgi.00248.2006.

Shi R, Huang Q, Zhu X, et al. (2007). Luteolin sensitizes the anti-cancer effect of cisplatin via c-Jun NH2-terminal kinase-mediated p53 phosphorylation and stabilization. Molecular Cancer Therapeutics, 6(4):1338-1347. doi: 10.1158/1535-7163.MCT-06-0638.

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

Xagorari A, Papapetropoulos A, Mauromatis A, et al. (2001). Luteolin inhibits an endotoxin-stimulated phosphorylation cascade and pro-inflammatory cytokine production in macrophages. JPET, 296(1):181-187.

Parthenolide

Cancer:
Myeloma, ovarian adenocarcinoma, breast, acute myelogenous leukemia, epithelial-to-mesenchymal transition (EMT)

Action: Anti-cancer, anti-inflammatory, inhibits NF-κB, promotes apoptosis

Inhibits NF-κB & Promotes Apoptosis

Parthenolide, a sesquiterpene lactone derived from the leaves of feverfew (Tanacetum parthenium (L.)), is considered a main bioactive component of this herb. Feverfew has been used orally or as an infusion for the treatment of migraine, arthritis, fever, and stomachache. Besides its anti-inflammatory and anti-migraine properties, parthenolide also shows anti-cancer activities in a variety of cell lines. It contains an alpha-methylene-gamma-lactone ring and an epoxide moiety which are able to interact with nucleophilic sites of biologically important molecules.

Parthenolide modulates multiple targets, thereby contributing to its various in vitro and in vivo effects. Inhibition of NF-kappaB activity, constitutive in many types of cancers via either interaction with IKK or more directly with the p65 subunit of NF-kappaB, is considered one of the main mechanisms of its action. In addition, inhibition of STAT and MAP kinase activities and the induction of sustained JNK activity as well as p53 activity via influencing MDM2 and HDAC1 levels lead to an increased susceptibility of cancer cells to chemo- and radio- therapy. At the epigenetic level, parthenolide reduces HDAC1 level and, by inhibiting DNMT2 activity, induces global hypomethylation of DNA, which can restore the expressions of some suppressor genes.

Moreover, this compound reduces the cellular level of GSH in cancer cells, followed by ROS accumulation and apoptosis. A unique property of parthenolide is its ability to induce cell death mainly in cancer cells, while sparing healthy ones and it also protects normal cells from UVB and oxidative stress. More remarkably, it seems to have the potential to target some cancer stem cells. Its wide array of biological activity and low toxicity make parthenolide a very promising drug with multi-pharmacological potential, largely dependent on the cellular context (Koprowska et al., 2010).

Multiple Myeloma

It has been shown that parthenolide is a potent anti-MM-CSC agent. Multiple myeloma (MM) is an incurable plasma cell malignancy where nearly all patients succumb to a relapse. The current preclinical models of MM target the plasma cells, constituting the bulk of the tumor, leaving the cancer stem cells to trigger a relapse. It demonstrated preferential toxicity toward MM-CSCs over non-tumorigenic MM cells. Addition of the bone marrow stromal compartment abrogated andrographolide activity while having no effect on parthenolide cytoxicity. It hence has anti-CSC activity in myeloma, suggesting that it has the potential to improve the survival of patients with MM by eliminating the relapse-causing MM-CSCs (Gunn et al., 2011).

Acute Myelogenous Leukemia

Parthenolide (PTL), a naturally occurring small molecule, induces robust apoptosis in primary human acute myelogenous leukemia (AML) cells and blast crisis CML (bcCML) cells while sparing normal hematopoietic cells. Furthermore, analysis of progenitor cells using in vitro colony assays, as well as stem cells using the non-obese diabetic/severe combined immunodeficient (NOD/SCID) xenograft model, show that PTL also preferentially targets AML progenitor and stem cell populations.

Notably, in comparison to the standard chemotherapy drug cytosine arabinoside (Ara-C), PTL is much more specific to leukemia cells. The molecular mechanism of PTL-mediated apoptosis is strongly associated with inhibition of nuclear factor κB (NF-κB), pro-apoptotic activation of p53, and increased reactive oxygen species (ROS) (Guzman, et al., 2005).

PTL is known to be a potent inhibitor of NF-κB (Bork et al., 1997). The mechanism of NF-κB down-regulation appears to occur via inhibition of the IKK complex. Guzman et al. (2005) observed strong inhibition of NF-κB in primary AML cells and speculate that this activity contributes to the efficacy of PTL. However, previous genetic studies using a dominant-negative repressor of NF-κB activity have shown that inhibition of NF-κB alone is not sufficient to mediate the robust cell death observed with PTL. Rather, blockade of the NF-κB pathway appears to sensitize primary AML cells to death and induces a relatively slow spontaneous apoptosis (~50% cell death in 36 h) (Guzman et al., 2002). Similarly, studies by Romano et al. (2000) showed that treatment of primary AML blasts with NF-κB decoy oligonucleotides was not sufficient to induce a strong apoptotic response.

Consequently, PTL must be affecting other pathways relevant to AML-specific survival. One such pathway appears to be mediated by the activity of p53. PTL induced rapid up-regulation of p53 protein with concomitant phosphorylation on serine (Woynarowski & Konopa, 1981).

Ovarian Carcinoma

Results suggest that parthenolide may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of parthenolide appears to be mediated by the formation of reactive oxygen species and the depletion of GSH. Parthenolide might be beneficial in the treatment of epithelial ovarian adenocarcinoma and combination therapy (Kwak et al., 2013).

Epithelial-to-Mesenchymal Transition (EMT)

Detyrosinated tubulin, a post-translational modification of α-tubulin and a hallmark of stable microtubules, has gained recent attention given its association with tumor progression, invasiveness, and chemoresistance. Also, epithelial-to-mesenchymal transition (EMT) promotes tubulin detyrosination through tubulin tyrosine ligase (TTL) suppression. Given the induction of EMT associated with inflammation and cancer progression, Whipple et al. (2013) tested anti-inflammatory nuclear factor-kappaB (NF-κB) inhibitors on a panel of human breast carcinoma cells to examine their effects on detyrosinated tubulin to identify more specific tubulin-directed anti-cancer treatments.

Breast Cancer

Sesquiterpene lactones, parthenolide and costunolide, selectively decrease detyrosinated tubulin independent of their inhibition of NF-κB. Live-cell scoring of suspended cells treated with parthenolide and costunolide show reduction in the frequency of microtentacles and inhibition of reattachment. Selective targeting of detyrosinated tubulin with parthenolide and costunolide can reduce McTN frequency and inhibit tumor cell reattachment. These actions are independent of their effects on NF-κB inhibition, presenting a novel anti-cancer property and therapeutic opportunity to selectively target a stable subset of microtubules in circulating tumor cells to reduce metastatic potential with less toxicity in breast cancer patients (Whipple et al., 2013).

References

Bork PM, Schmitz ML, Kuhnt M, Escher C, Heinrich M. (1997). Sesquiterpene lactone containing Mexican Indian medicinal plants and pure sesquiterpene lactones as potent inhibitors of transcription factor NF-kappaB. FEBS Lett, 402:85-90.


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