The flavonoid quercetin ameliorates liver damage in rats with biliary obstruction

Background/Aims: Our aim was to investigate whether the antioxidant quercet in might protect against liver injury in chronically biliary obstructed rat s. Methods: Secondary biliary cirrhosis was induced by 28 days of bile duct ob struction. Animals received quercetin at 75, 150 and 300 mu mol . kg body w t(-1) . day(-1) i.p. through the experimental period or at 150 mu mol . kg body wt(-1) . day(-1) i.p. for the last 2 weeks. Results: Bile duct obstruction resulted in a decrease in the activities of antioxidant enzymes. Liver oxidised/reduced (GSSG/GSH) glutathione ratio, h epatic and mitochondrial thiobarbituric acid reactive substances (TBARS) an d collagen content were significantly increased and a marked fibrosis and b ile ductular proliferation was observed. Quercetin corrected the reduction in glutathione concentration and partially prevented the increase in collag en concentration, TEARS and GSSG/GSH ratio. Treatment resulted in a signifi cant preservation of the activities of antioxidant enzymes, a less pronounc ed fibrosis and a marked inhibition of bile ductular proliferation, Maximal effects were reached with the intermediate quercetin dose given for 2 or 4 weeks. Conclusions: Quercetin reduces liver oxidative damage, ductular proliferati on and fibrosis in biliary-obstructed rats. These effects suggest that it m ight be a useful agent to preserve liver function in patients with biliary obstruction.