Polyphenol cytotoxicity

The study of the toxicity of several polyphenolic antioxidants, including alkyl gal-lates, toward human promyelocytic leukemia cells (HL-60) has shown that the polyphenol cytotoxicity may be related to their prooxidant properties since, as indicated above, the same polyphenol compounds could behave as both antioxidants and prooxidants, depending on concentration and free radical source [39]. Polyphenols may act as substrates for peroxidases and other metalloenzymes, yielding quinone- or quinomethide-type prooxidant and/or alkylating products. Another characteristic of the action of polyphenols is that their cytotoxicity increases upon an increase in their lipophilicity. Thus, the concentration of gallic acid, BG and OG for 50% survival of HL-60 cells (IC50) is 750, 110, and 30 pM, respectively. 

Manna, C. et al. (1997). The protective effect of the olive oil polyphenol (3,4-dihydroxyphenyl)-ethanol counteracts reactive oxygen metabolite-induced cytotoxicity in Caco-2 cells. J. Nutr. 127(2) 286-292. 

T. Nakatani, K. Ohtani, S. Sakanaka, CS059 M. Kim and I. Matsui-Yuasa. Protective effect of green tea extract and tea polyphenols against the cytotoxicity of 1,4-naphthoquinone in isolated rat hepatocytes. Biosci Biotech Biochem 1997 61(11) 1901-1905. 

Ito, H. et al., Polyphenols from Eriobotrya japonica and their cytotoxicity against human oral tumor cell lines, Chem. Pharm. Bull., 48, 687, 2000. 

Although many polyphenolic compounds can quench DPPH215 218 and scavenge radicals in competition with spin traps,225 232,278 consideration must also be given to the fate of the resultant phenoxyl radicals, which can include their direct reaction with important biomolecules, further oxidation to cytotoxic quinones and, in the case of semiquinones, their reduction of oxygen to superoxide. Thus,... 

Mantena SK, Meeran SM, Elmets CA, Katiyar SK. 2005. Orally administered green tea polyphenols prevent ultraviolet radiation-induced skin cancer in mice through activation of cytotoxic T cells and inhibition of angiogenesis in tumors. J Nutr 135 2871-2877. 

Peroxynitrite is a cytotoxic species generated by the reaction between superoxide and nitric oxide. Catechin polyphenols could also decrease the peroxynitrite-induced nitration of tyrosine and protect apolipoprotein B-lOO of LDL from peroxynihite-induced modification of critical amino acids, which contribute to its surface charge. ... 

Tacrolimus cytotoxicity seems to be mediated by a transient increase in intracellular calcium and by oxygen free radicals [740-742]. In fact, tea polyphenols, substances with anti-oxidant properties, protected LLC-PKl cells against TAC induced-apoptosis [743]. 

Kurarinone (13) of a lavandulyl flavanone was isolated from a polyphenolic extract of the roots of Sophora flavescens. First, kurarinone (13) had weak estrogenic activity both in the yeast screen and in the Ishikawa Var-I assay with EC50 values of 4.6 and 1.66 p,M, respectively. Second, kurarinone (13) had the potent cytotoxic activity (IC50) value = 22.2 jlM) against human MCF-7/6 breast cancer cells in the sulforhodamine-B assay (Fig. 19) [18]. 

FIGURE 11.2 The effect of the tea polyphenols on the viability of different cell lines. 1 X 10" cells were seeded in 96-well plates and treated with various doses of tea polyphenols. After 24 h incubation, cell viability was determined by ATPLite-M cytotoxicity assay. Results were obtained from three independent experiments as mean SD. 

Green tea polyphenol epigallocatechin-3-gallate protects cells against peroxynitrite-induced cytotoxicity modulatory effect of cellular G6PD status. 

An extract of mate was cytotoxic against human liver cancer HepG2 cells in vitro with an ICgj value of the total polyphenol content of 12.01 pg/ml (Gonzalez de Mejia et al. 2005). 

Liang J, Li F, Fang Y, Yang W, An X, Zhao L et al. Synthesis, characterization and cytotoxicity studies of chitosan-coated tea polyphenols nanoparticles. Colloids SurfB Biointerfaces. 2011 82(2) 297-301. 

Wang Y, Chan EL, Chen S, Leung LK (2005) The plant polyphenol butein inhibits testosterone-induced proliferation in breast cancer cells expressing aromatase. Life Sci 77 39 Yit CC, Das NP (1994) Cytotoxic effect of butein on human colon adenocarcinoma cell proliferation. Cancer Lett 82 65... 

Fig. 71.5 Potential pathways of apoptosis (extrinsic and intrinsic) and intracellular signaling elements modulated by polyphenols in chemoprevention and sensitizing cancw cells to cytotoxic chemotherapies...

Ono K, Condron MM, Ho L, Wang J, Zhao W, Pasinetti GM, Teplow DB (2008) Effects of grape seed-derived polyphenols on amyloid (3-protein self-assembly and cytotoxicity. J Biol Chem 283 32176-32187... 

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