Abstract:

Flavonols are a group of naturally occurring polyphenols in plants and exhibit a broad variety of biological effects that have potential applications in foods. With some biochemical assays, the cytoprotective effects of three flavonols (kaempferol, quercetin and myricetin) on human hepatocytes (HL-7702 cell line) oxidative injury induced by H2O2 or CCl4 were evaluated in vitro. The relationship between chemical structure of three flavonols and cytoprotective effect was investigated. Pretreatment of hepatocytes with three flavonols at concentrations of 20, 40, 60 μmol/L for 30 min could improve cell viability or the content of reduced glutathione (GSH) in cells, and reduce the lactate dehydrogenase (LDH) leakage into culture medium or the formation of malondialdehyde (MDA) in cells. Cytoprotective effect of three flavonols was in the order of quercetin> myricetin > kaempferol, which didn＇t show a clear structure-activity relationship between the numbers of hydroxyl group in ring B of flavonols and their cytoprotective effect.

Key words: flavonol, hepatocytes, oxidative injury, hydrogen peroxide, carbon tetrachloride