Suppression of active oxygen-induced cytotoxicity by flavonoids.
The flavonoids quercetin, kaempferol, catechin and taxifolin suppressed cytotoxicity of active oxygen species (O2- and H2O2) on Chinese hamster V79 cells. Cytotoxicity of active oxygen species was assessed with a colony formation assay. The flavonoids prevented the decrease in the number of colonies caused by H2O2 or O2- at concentrations which were not themselves cytotoxic. There was a very substantial difference in the dose-dependency of the protective effects brought about by quercetin and kaempferol in contrast to catechin and taxifolin. The structure-activity relationship revealed that either the o-dihydroxy structure in the B ring or certain structures in the A and C rings of the flavonoids are necessary for the protective activities.
Nakayama
T
T
Department of Food Science and Technology, Nagoya University, Japan.
Yamada
M
M
Osawa
T
T
Kawakishi
S
S
D000818:Animals; D002392:Catechin / Q000494:pharmacology; D002460:Cell Line; D003114:Colony-Forming Units Assay; D006224:Cricetinae; D003412:Cricetulus; D005419:Flavonoids / Q000494:pharmacology*; D044948:Flavonols; D006861:Hydrogen Peroxide / Q000037:antagonists & inhibitors*; D044949:Kaempferols; D011794:Quercetin / Q000031:analogs & derivatives / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013481:Superoxides / Q000037:antagonists & inhibitors*
D005419:Flavonoids; D044948:Flavonols; D044949:Kaempferols; D013481:Superoxides; C006552:kaempferol; D002392:Catechin; D011794:Quercetin; C003377:taxifolin; D006861:Hydrogen Peroxide