Overview of Applications to Flavonoids to Cancer

Flavonoids and its effect on the proliferation of the cells:

Published date suggested that flavonoids have capability to inhibit phosphate protein kinases on their specific sites. Flavonoids interact with Akt/PKB (protein-kinase B), tyrosine kinase P1KC (protein-1 kinase C), PI3-kinase (phosphoinositide 3-kinase), and MAP (mitogen-activated protein) kinase signaling pathways. Flavonoids have been reported to activate and inhibit the effects on these signaling pathways by modulating of their gene expressions (Williams et al., 2004). Flavonoids inhibitory mechanism has been proved by altering their receptor phosphorylations or blocking growth factor receptor binding. Flavonoids also inhibit Fyn and Lck protein kinases, involved in T cell signaling transport (Calic et al., 2005).

PI3K catalyze productions of PIP1 and PIP2. PIP3 may activate the PDK1 which stimulates the Akt/PKB. Of these effects PDK1 is essential for regulator of cell growth, proliferation, differentiation, migration and apoptosis. Bad, Bcl-2, and caspases proteins are responsible for apoptosis, these can be inhbitied by Akt pathway.

Several data have been suggested that flavonoids directly inhibit the PI3K pathway by their interacting their ATP binding sites. MAPK pathway ((ERK2, JNK1 and p38) are responsible for releasing of many survival genes (c-Fos, c-Jun) and those genes which are involved in the antioxidant activity (detoxification enzymes, glutathione S-transferase, glutathione-reductase) have also been activated by low level of quercetin.

Anti-cancerous properties of the flavonoids:

Flavonoids also have anticancer activities by blocking their cellular mechanism. Flavonoids targets the cell cycle regulator proteins (cycline-dependent kinases and their inhibitors, protein p53 and Rb, E2Fs, ATM/ATR and surviving transition-controlling points G1/S and G2/M) (Sing et al., 2006).

Flavopiridol properly inhibits the CDK1-and CDK2 cell regulating pathways (Vermeulen et al., 2003). Cell proliferation and cell viability ratio of the prostate cancer decreased with treatment of quercetin. Quercetin induced apoptosis with down-regulating mechanism of Hsp90 expression of proteins, resulting in the death of cancer cells by inhibiting the cellular growth. (Aalinkeel et al., 2008). Inhibiting cellular growth and DNA synthesis and blockage of cell cycle at S-phase in squamta cells have been reported with quercetin (Haghiac et al., 2005). Querecetin also prevents growth of nasopharyngeal cancer cells via arrest of cell cycle at G1/S phase (Ong et al., 2004). ERK (extracellular signal-regulated kinase) pathway stimulates the lung cancer which is derived from the A549 cell proliferation have been reported combine inhibitory effects of querecetin and kaempferol (Hung et al., 2007). Quercetin stimulates the protein expressions of p21 and p22 which inhibited the cell cycle in HepG2 cells (Mu C et al., 2007).

Quercetin at the concentration of (248uM) down-regulates the mutantp53 expressions which is almost untraceable in the cell lines of the breast cancer. Negative control was too lower as compare to normal gene p53. Quercetin at the dose of 70 uM, having inhibiting activity on cell division, and trysine kinase activity, is an enzyme placed on the cell membrane and is involved in growth factors and signaling transduction in nucleus (Lamson et al., 2000).

Scientific data have been reported that flavonoids especially the quercetin having oral anticancer properties. Quercetin inhibits the cellular growth and DNA synthesis depending the dose and timing of the administration. Quercetin induced apoptosis with treatment of caspase-3 proteins after 72 hours, and cell necrosis after 24-48 hours in SCC-9 cells. Flow cytometer studies confirmed cell cycle blockage at S-phase with the treatment of quercetin (Haghiac et al., 2005). Quercetin induced cell proliferation of B16-BL6 after 72 hours and also caused apoptosis in B16-BL6 cells and reduced the expressions of Bcl-2 and anti-apoptotic proteins (Zhang et al., 2000).

Anti-apoptotic properties of the flavonoids:

Flavonoids have been reported to induce apoptosis process by activating and modulating cellular signaling pathways resulting in death of pre-cancerous and maligne cells, which terminates cancer development or progression. Human prostate cancer cell line LNCaP, treated with different concentrations of quercetin shown to inhibited cell death after 24 hours. Inhibition of Akt survival signals have been activated in the treated cells. Rapid decrease in Ser 136 phosphorylation in Bad that is a Akt target have been reported with treatment of LNCaP and 100 uM of quercetin. Quercetin have been shown to reduce the Bcl-XL, Bx ratio and enhances translocation and multimeriation of Bax in the mitochondrial membrane; cytochrome-c released by translocation, and the caspase 3, 5, 9 proteins and PARB (poli(ADP-ribose)polymerase). Remarkably, quercetin does not induce cellular viability or apoptosis at same concentrations in normal prostatic epithelial cells (Zhanget al., 2000). Exposure of cells for longer time on quercetin induced apoptosis intervened by reduction of thymidylate synthase (Ong et al., 2004). Quercetin induced apoptosis in CNE2 and HK1 cells after 24 hours of treatment and treatment was continued when necrosis was observed.

HeLa cells have been exposed on non-toxic flavonoid concentrations which slightly susceptible to TRAIL induced cell death. TRAIL mediated cytotoxicity in HeLa cells was increased by apigenin and ginstein but no effect have been documented with kaempfeol and quercetin (Leeet al., 2008). Luteoline induced cell cytotoxicity by suppressing PI3K/Akt (phosphattidylinositol 3?-kinase), NF-kB (nuclear factor kappa B) and XIAP (X-linked inhibitor of apoptosis protein) and activates of apoptotic pathways, such as p53 protein (Lin et al., 2008 and Lopez-Lazaro., 2009). At high doses majority of the flavonoids suppressors AP-1 activity (activator protein 1) by MAPK (mitogen – activated protein kinase) pathway (Gopalakrishnan et al., 2006).

Activation of cellular signaling pathways in cancer and flavonoids:

Figures-9. Sources of inflammatory mediators and their origin

Figure-7. Some diseases and cancers associated with reactive oxygen species (ROS)

S.N0

Inflammatory diseases

References

Cancers

References

1

Acute respiratory distress syndrome

Wilson et al., 2001

Bladder

Miyajima, et al., 1997

2

Aging

Dugan et al., 2005

Brain tumor

Salganik et al., 2000

Alzheimer

Hensley et al., 1996 and Multhaup et al., 1997

Breast

Brown et al., 2001

3

Atherosclerosis

Halliwell B., 1989

Cervical

Sharma et al., 2010

Cardiovascular disease

Touyz RM., 2004 and Yoshizumi et al., 2001

Gastric (Gastric)

Oliveira et al., 2003

4

Diabetes

Muhammad et al., 2009

Liver

Calvisi, et al., 2004

5

Inflammation

Di Virgilio, F., 2004

Lung

Azad et al., 2008

6

Inflammatory joint disease

Mouton PJ., 1996

Melanoma

Fruehauf et al., 2008

Neurological disease

Bolanos et al., 2009

Multiple myeloma

Kuku et al., 2005

7

Obesity

Atabek et al., 2004 and Furukawa et al., 2004

Leukemia

Sumi et al., 2010

8

Parkinson

Tabner, et al., 2001 and Tieu, et al., 2003

Lymphoma

van de Wetering et al., 2010

9

Pulmonary fibrosis

Kamp et al., 1992 and Kinnula, et al., 2005

Oral

Bahar et al., 2007

10

Rheumatoid arthritis

Gelderman, et al., 2007

Ovarian

Chan et al., 2008

11

Vascular diseases

Haurani, et al., 2007 and Jeremy et al., 2004

Pancreatic

Edderkaoui et al., 2005

12

–

–

Prostate

Khandrika, et al., 2009

13

–

–

Sarcoma

Ma Q et al. 2009

Conclusion:

Oxidative stress brings the changes into the cells resulting in gene mutation which leads to the carcinogenesis. It brings direct or indirect intra and inter-cellular and intercellular transduction and transcription changes by antioxidants. The role of oxidative stress in carcinogenesis and tumor bearing conditions is complex and various mechanisms and substances are involved.

Clinical evidence suggests that oxidative stress and inflammation linked to free radicles over generation may be the key factor in development of chronic diseases, insulin resistance, diabetes, cardiovascular and other diseases. Excessive nutrition, stress in combination with sedentary lifestyle, can independently result in overburden of glucose and fatty acid accumulation with musle, adipose tissue and pancreatic cells. All these factors lead to chronic inflammation resulting in chronic diseases. Published data suggested that the key role of polyphenolic compounds such as flavonoids as therapeutics agents in the inflammatory diseases including obesity, T2DM, cardiovascular diseases, neurodegenerative diseases cancer and aging. Flavonoids are the key modulators of inflammatory molecules.

Flavonoids inhibits the AMPK one of the major pathway of inflammation and cancer. Activation of AMPK by flavonoids causes to increase the cancer cell apoptosis, inhibit cell proliferation and some studies suggested that it a neoplastic agent

Furthermore, inflammation stimulates various inflammatory mediators, chemokine’s, cytokines, signaling transductions and transcriptional factors; overproduction for long periods may lead to chronic inflammation which in turn to chronic diseases such as neurological diseases and cancer. Better clarification of these mechanisms will be beneficial to the development of efficacious prevention and therapies of inflammation associated cancers. Moreover, effects of flavonoids at molecular mechanism and study also should be carried out on modulatory action; effects on transcription levels of the flavonoids should be studied.

Fig-4. Anti-inflammatory activities of the flavonoids

Target Activities

Effects

Flavonoids

Mechanism

References

Antioxidants and radical

Scavenging activities

Enhancing antioxidant activity

Quercetin, resveratoral, curcumin, hydroxytyrosol, catechin, luteolin

Increase the activity of SOD, CAT, GPx, GR, GST, ?GCS, NADPH, NQO1 and HSP70.

Alia et al., 2006 and Shen et al., 2007

Inhibiting pro-oxidant enzymatic activity

Epigallocarechin, ECG, EGCG

Inhibiting lipoxypenase and cycloxygnase

Hong et al., 2001

Typheramide alfrutamide, (-)-epicatechin, procyanidin,

Inhibiting the activities of 5-liopooxygenase, 12-lipoxygenase and 15- lipooxygenase

Park J.B., 2011 and Schewe et al., 2001

Curcumin, resveratrol, lupeol

Reducing the acitivity of iNOSand MPO level.

Gulcin I., 2010; Shen et al., 2007; and Fernandez et al., 2001

Ellagic acid gallic, acid corilagin, luteolin

Inhibiting tyrosinase and xanthine oxidase

Rangkadilok et al., 2007 and Leopoldini et al., 2011

Resveratrol

Inhibiting O-acetyltransferase and sulfotransferase activities

Cadenas et al., 1999

inhibits of free radical attacks

Epicatechin, rutin, mannitol

Scavenging hydroxyl radical (OH+)

Hanaski et al., 1994

Ellagic acid gallic, acid corilagin, luteolin, ?-carotene, tetrandrine

Scavenging superoxide radical (O2.)

Rangkadilok et al., 2007; Leopoldini et al., 2011 and Chen et al., 2011

Quercetin,curcumin, lycopene

Decreasing MDA and lipoperoxidation

Pendey et al., 2010 Shen et al., 2007 and Srinivasan et al., 2007

Enhancing endogenous antioxidant molecules

Quercetin, resveratrol, catechin, proanthocyanidin B4, ?-carotene

Elevating cellular GSH conten

Alia et al., 2006, Gulcin et al., 2010; Du Y. et al., 2007 and Yang et al., 2004

Modulation of

cellular activities

of inflammation related

cells

Inhibition of enzymes

involved in signaling

transduction and cell

activation processes

(T cell, B lymphocyte) or

cytokine production

Genistein

Inhibition of tyrosine protein kinase inducing anti-proliferative effects on T cell, reducing IL-2 secretion and IL-2R expression

Manna S.K., 2012 and Trevillyan et al., 1990

Quercetin, kaempferol, apigenin, chrysin, luteolin

Inhibition of tyrosine protein kinase inducing anti-proliferative effects on M-CSF-activated macrophages

Comalada et al., 2006

Modulation of cellular activities of inflammation related cells

Inhibition of arachidonic acid release from membranes

(degranulation)

Quercetin

Inhibiting lysosomal enzyme release from stimulated neutrophil (elastase,

?-glucuronidase)

Pecivova et al., 2012 and Tordera et al., 1994

Rutin

Reducing the polymorphonuclear neutrophils chemotaxis to FMLP

Selloum et al., 2003

Modulation of

arachidonic acid

(AA) related

Enzymes

Inhibition of arachidonic acid

metabolism

Quercetin, kaempferol, myricetin, hesperetin, naringenin, quercetagetin, kaempferol-3-galactoside, scutellarein, ochnaflavone, amentoflavone, ginkgetin, morelloflavone, bilobetin, triptolide, papyriflavonol A

Inhibition of PLA2 activity

Lee et al., 1982 and Kwak et al., 2003

Inhibition of proinflammatory

enzymes (COX, LOX and NOS) from different sources

Luteolin, 3?,4?-dihydroxyflavone, galangin, morin, apigenein, chrysin, quercetin, myricetin, morusin, kuwanon C, sanggenon D, broussoaurone A, cycloheterophyllin, broussochalcone A broussoflavonol F, catechin, EGCG, resveratrol, xanthomicrol, cirsiliol, hypolaetin, diosmetin, tectorigenin, kuraridin, kurarinone, sophoraflavanone G, morusin, sanggenon B, kazinol B, rutaecarpine, 1,2-di-O-?-linolenoyl-3-O-?- galactopyranosyl-sn-glycerol (dlGG), curcumin, 4?-Me-gallocatechin, lonchocarpol A, tomentosanol D, catechins, catechins gallate

Inhibited COX activity

Kim et al., 2009 ,Hong et al., 2004; Bauman et al., 1980 and Moon et al., 1999

Sophoraflavanone G, kenusanone A, kuraridin, papyriflavonol A, sanggenon B, sanggenon D, boswellic acid, diphyllin acetylapioside

Inhibited 5-LOX activity

Chi et al., 2001; Sailor et al., 1996 and Prieto et al., 2002

Quercetin, kaempferol, fisetin, quercetagetin-7-O-glucoside, hibifolin,

hypolaetin, sideritoflavone, 5,6,7-trihydroxyflavone (baicalein)

Inhibited 12-LOX activity

Kim et al., 2009 and Nakadate et al., 1984

Kaempferol, quercetin, myricetin, morin, cirsiliol, artonins

Inhibited 5-LOX and 12-LOX activity

Laughton et al., 1991 and Reddy et al., 1991

Quercetin

Inhibited iNOS activity

Kinaci et al., 2012

Modulation of the production of other

proinflammatory

molecules

Inhibition of

proinflammatory

cytokines from different

sources

Formononetin

Inhibited iNOS activity

Wang et al., 2012

Genistein, apigenin, quercetin, morin, wogonin, soyisoflavones, daidzein, glycitein, dlGG, paeonol

Inhibited NO production

Hou et al., 2007; Soliman et al., 1998 and Fu, P.K et al., 2012

Genistein, quercetin, wogonin, baicalein, luteolin, nobiletin, paeonol, chlorogenic acid, hematein, aucubin, catalposide, tetrandrine,

fangchinoline, colchicines, piperlactam S

Inhibited cytokine production : IL-1?, IL-6, TNF-?

Fu, P.K et al., 2012 and Chiou et al., 2003

Curcumin, amoradicin, genistein, silybin, quercetin, wogonin, rutin, luteolin, eriodictyol, hesperitin, EGCG, geraniin, corilagin, pinoresinol, woorenoside, lariciresinol glycoside, terpinen-4-ol, physalin B, triptolide, lupeol, [6]-shogaol, vitamin D, cepharanthine, fangchinoline,

adenosine

Inhibited TNF-? production

Fernendez et al., 2001; Choi et al., 2000; Sun et al., 2012 and Parmely et al., 1993

Apigenin, wogonin, bacalein

Inhibited IL-6 and IL-8 production

Gerritsen et al. 1995 and Nakamura et al., 2003

Genistein, ilicic acid, inuviscolide acid, tryptanthrin

Inhibited LTB4 production

Atluru et al., 1991 and Danz et al., 2002

Saikosaponins, masticaienonic acid, masticadienolic acid, morolic acid

Reducing LTC4 production

Danz et al., 2002 and Giner-larza et al. 2002

Chrysin, flavone, galangin, kaempferol, quercetin, salidroside, syringin, phillyrin, coniferin, tryptanthrin

Inhibited TXB2 production

Laughton et al., 1991 Danz et al., 2002 and Diaz-Lanza et al., 2001

Lupeol, paeonol, quercetin, salidroside, syringin, phillyrin, tectorigenin,

tectoridin, platycodin D, ?-turmerone, ar-turmerone, rutaecarpine

Inhibited PGE2 production

Fernendez et al., 2001; Fu, P.K et al., 2012; Morikawan et al., 2003; Diaz-Lanza et al., 2001 and Woo et al., 2001

Modulation of

proinflammatory

gene expression

Inhibition of the

expression of various

inflammation-related

proteins/enzymes, by

suppressing activation of

transcription factors such

as NF-?B and AP-1

Baicalein,oroxylinA, baicalin, skullcapflavone II

Rutin, bilobetin, ginkgetin, isoginkgetin, ochnaflavone, morusin, kuwanon C, kazinol B, sanggenon B and D, echinoisoflavanone,

wogonin, apigenin, kaempferol, genistein, chrysin, luteolin, quercetin, myricetin, flavone, tectorigenin, nobiletin, oroxylin A, galangin,

EGCG, isoliquiritigenin, silymarin, curcumin, flavones, daidzein, glycitein, isorhamnetin, naringenin, pelargonidin, soyisoflavones,

wogonin, resveratrol, triptolide, lupeol, butyrate, zeaxanthin, ?-carotene

Inhibited eotaxin production

Inhibited iNOS expression

Nakajima et al., 2001

Gil B. et al., 1997, Wang et al., 2012, Kim et al., 2001, Chi et al., 2001 and Kang et al., 2011

Bilobetin, ginkgetin, paeonol, tectorigenin, tectoridin, platycodin D, apigenin, genistein, kaempferol, quercetin, myricetin, nobiletin,

rhamnetin, eriodictyol, luteolin, fisetin, phloretin, wogonin, galangin, oroxylin A, lupeol, isoliquiritigenin, amentoflavone, butyrate, ursolic acid, iridoid, pendunculariside, agnuside, ferulic acid, [6]-Gingerol,

resveratrol, EGCG

Inhibited COX-2 expression

Gil B et al., 1997; Fu. P.K, et al., 2012, Kim et al., 1999; 2001; Liang et al., 1999; Raso et al., 2001; Takahashi et al., 2004; Suh N, et al., 1998; Hooshmand et al., 2007 and Peng et al., 2006

Lycopene, dlGG, wogonin, genistein, apigenin, kaempferol, myricetin, oroxylin, silymarin, ?-carotene, resveratrol, quercetin, avicins, parthenolide, chlorogenic acid, triptolide, capsaicin, butyrate, luteolin, curcumin

Inhibition of NF-?B activation

Murakami et al.,

2000; Hou et al., 2007; Kim et al., 2001; Geng et al., 1993; Liang et al., 1999; Chen et al., 2000; Singh et al., 2002; Kang et al., 2002; kang et al., 2011; Kundu et al., 2006; Donnelly et al., 2004 and Jobin et al., 1999

Hematein, casearinols A and B, casearinones A and B, colchicine

Inhibited the expression of ICAM-1 and VCAM-1 on the surface of different cells

Hong et al., 2001; Hunter et al., 1997 and Asahina et al., 2001

SOD- Superoxide dismutase 2- CAT- Catalase 3- GPx- Glutathione peroxidase 4- GR- Glutathione reductase 5- GST- Glutathione S-transferase. 6- ?GCS- ?-glutamylcysteine synthetase 7- NADPH:NQO1- quinone oxidoreductase-1. 8- HSP70- heat shock proteins. 9- MPO- myeloperoxidase 10- iNOS- inducible nitric oxidase synthase. 11- OH^– Hydroxyl radical. 12- O2^– -superoxide radical. 12- MDA- Malondialdehyde 13- IL-2 interlukins-2 14- FMLP- Formyl-Methionyl-Leucyl-Phenylalanine. 15- TNF-?- Tumor necrosis factor ?. 16- LTB4- Leukotriene B4. 17- LTC4- Leukotriene C4. 18- TXB2- Thomboxane B2 19. PGE2- Prostaglandins e2. 20- NF-?B- Nuclear Factor Kappa Beta 21- ICAM-1- Intercellular Adhesion Molecule 22- VCAM-1- vascular cell adhesion molecule-1