Nephroprotective activities of quercetin with potential relevance to oxidative stress induced by valproic acid.

Valproic acid (VPA) is ubiquitously used as a major drug in the intervention of epilepsy and in the control of several kinds of seizures. Cellular toxicities are the serious dose-limiting side effects of VPA when applied in the treatment of diseases. Oxidative stress has been proven to be involved in VPA-induced toxicity. Accumulating evidence intimates that oxidative stress caused by free radicals and in kidney cells contributes to the pathogenesis of VPA-induced nephrotoxicity. The pathogenesis of these forms of VPA nephrotoxicity is still not clear. The aim of our investigation was to evaluate the nephrotoxic potential of VPA and protective effects of quercetin (QR) against VPA-induced nephrotoxicity by using rat kidney tissue preparation as an in vitro model. Oxidative stress indexes such as lipid peroxidation (LPO) and protein carbonyl (PC) content were appraised. The levels of oxidative stress markers, LPO, and PC were significantly elevated. Nonenzymatic antioxidants effect was also demonstrated as a significant increase in reduced glutathione (GSH) and nonprotein thiol level (NP-SH). VPA exposure altered the activities of glutathione metabolizing enzymes such as glutathione-S-transferase, glutathione peroxidase, and glutathione reductase. Pre-treatment with QR could reverse the VPA-induced effects in kidney tissue preparation of rat. Based on reno-protective and antioxidant action of QR, we suggest that this flavonoid compound could be considered as a potential safe and effective approach in attenuating the adverse effect of VPA-induced nephrotoxicity.