influence of naringin on the oxidative state of rats with acute hyperglycaemia

ABSTRACT

To investigate the effect of naringin [a citrus flavonone] on streptozotocin [STZ]-induced hyperglycaemic rats to evaluate the possible hypoglycaemic and antioxidant activity of naringin in diabetes. Setting: Biochemistry Department, National Research Center, Cairo, Egypt. Design: Male diabetic Sprague-Dawley rats were treated with various doses [0, 10, 20, 40, or 80 mg/kg body weight] of naringin. The level of blood glucose, insulin, hydrogen peroxide [H2O2], and thiobarbituric acid reactive substances [TBARS] as well as erythrocytes total antioxidant, and antioxidative enzymes catalase [CAT], superoxide dismutase [SOD], glutathione peroxidase [GPx], paraoxonase [PON] were evaluated. In comparison to the normoglycaemic group, the treatment of rats with a single dose of STZ [65 mg/kg body weight] only revealed significant increase [P<0.05] in plasma H2O2 by 230%, TBARS as index of lipid peroxidation level by 69%, while total antioxidant was decreased by 36%, with consistent significant decrease [P<0.05] in the activity of erythrocytes antioxidative enzymes CAT, SOD, GPx, and PON. Exogenous administration of individual gradual doses of naringin to hyperglycaemic rats causes a dose dependent decrease of glucose level; increase of insulin concentration; decrease of H2O2 and TBARS levels, as well as increase of total antioxidant status with increase of antioxidant enzyme activities [CAT, SOD, GPx, and PON]. Our data suggest that naringin is able to reduce oxidative stress intensity in acute hyperglycaemia. The protective effects of naringin may be connected with the normalization of hyperglycaemia, the inhibition of glucose auto-oxidation and as a result, the reduction of free radical generation, however the greatest effect of naringin was observed at 80 mg/kg