Metformin improves liver antioxidant potential in rats fed a high-fructose diet.

Increased lipid peroxidation plays a role in the pathology associated with fructose feeding. The present study reports the effects of metformin on the liver lipid peroxidation and antioxidant defence system of rats fed a high-fructose diet. The experimental animals were divided into two batches of 12 animals each. The control batch received a control diet containing 60% starch; the second batch was given a high-fructose diet containing 60% fructose as the sole source of carbohydrate. At the end of second week these were each subdivided into two groups. One was given metformin (50 mg/kg body weight/day in water) by intragastric intubation and the other group was left untreated. The rats were continued on the same dietary regimen for the next two weeks. After the experimental period of four weeks, liver lipid peroxidation and antioxidant status were quantified. Enhanced thiobarbituric acid-reactive substance reactivity and lipid hydroperoxides were observed in high-fructose-fed rats. However, the activities of enzymic antioxidants were lower in this group. Administration of metformin attenuated the rise in lipid peroxidation and improved the antioxidant potential in high-fructose-fed rats. Metformin did not have any effect on the antioxidant status of control rats. Attenuation of lipid peroxidation by metformin could be related to its insulin sensitising action.