In vivo effect of quercetin flavonoid on hepatic gene expression and enzyme activity levels in old rats

Abstract

Quercetin, one of the major flavonoids present in the human diet, has been associated with a wide range of biological properties, including antioxidant, anti-inflammatory and anticarcinogenic actions. The antioxidant action is considered as the most likely mechanism for the beneficial effects of quercetin. Therefore, the present study aimed to investigate the in vivo effects of quercetin on mRNA and activity levels of hepatic glutathione-S Transferase (GSTa2) and glutathione peroxidase (GPx) in aged rats. Quercetin treatment resulted in significant increase in relative hepatic mRNA levels for glutathione peroxidase, liver GPx enzyme activity and hepatic glutathione concentrations. On the other hand, it significantly decreased relative hepatic mRNA levels for Gsta2 and hepatic GST enzyme activity. No significant difference was found in BMI or in plasma concentration of ox-LDL between the two groups of aged rats. The present study may elucidate the molecular basis of the actions played by quercetin in vivo by increasing gene expression and enzymatic activities of the antioxidant GPx and by decreasing gene expression and enzymatic activities of GSTa2 in aged rats.

Key words: Quercetin, glutathione, GPx, GST, aging, oxidized LDL.