Role of flavonoids in suppressing the enhancement of phospholipid metabolism by tumor promoters.
Quercetin, a ubiquitous flavonoid in plants, inhibited the incorporation of [32P]inorganic phosphate (32Pi) into phospholipid of HeLa cells enhanced by 12-O-tetradecanoylphorbol-13-acetate (TPA), a potent tumor promoter. Among the flavonoids tested, luteolin was the most effective in inhibiting the action of TPA. Studies on structure-activity relationships demonstrated that more hydroxylated flavones and flavonols had stronger inhibitory effects. Quercetin and luteolin also inhibited enhancement of 32Pi-incorporation into phospholipid by dihydroteleocidin B, another potent tumor promoter. The inhibitory effect of quercetin on the biological action of tumor promoters is interesting in relation to the non-carcinogenicity of this flavonoid in animals, in spite of its mutagenicity.
D004347:Drug Interactions; D005419:Flavonoids / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D044949:Kaempferols; D047311:Luteolin; D010704:Phorbols / Q000494:pharmacology*; D010743:Phospholipids / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000378:metabolism / Q000494:pharmacology*
D005419:Flavonoids; D044949:Kaempferols; D010704:Phorbols; D010743:Phospholipids; C006552:kaempferol; D047311:Luteolin; D013755:Tetradecanoylphorbol Acetate