Inductive effect of copper 8-quinolinolate on oxidative DNA damage in HepG2 cells / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVETo assess the DNA damage of copper 8-quinolinolate (CuQ) and to elucidate the plausible mechanisms.METHODSHepG2 cells were treated with CuQ0-4 μmol·L-1 for different time,DNA damage was measured by Comet assay.Catalase (CAT) activity,glutathione(GSH) level and thiobarbituric acid reactive substances (TBARS) were measured.NF-κB was examined using Western blotting.8-Hydroxydeoxyguanosine (8-OHdG) was measured by immunoperoxidase staining analysis.RESULTSCuQ 0.5 -4 μmol·L-1 caused significant increase of DNA migration in HepG2 cells.CuQ significantly decreased levels of GSH and activity of CAT in HepG2 cells (P ＜0.05).Moreover,CuQ significantly increased accumulation of the p65 subunit of NF-κB into nucleus,levels of lipid peroxidation product TBARS and the formation of 8-OHdG (P ＜0.05).The intracellular GSH level was modulated by pre-treatment with buthionine-(S,R)-sulfoximine (BSO),depletion of GSH in HepG2 cells pre-treated with BSO dramatically increased susceptibility of HepG2 cells to CuQ-induced DNA damage.CONCLUSIONCuQ exerts DNA damage by oxidative stress and increases accumulation of p65 subunit of NF-κB into nucleus in HepG2 cells.