The beneficial effect of combined administration of vitamins C and E on renal function and selected parameters of antioxidant system in diabetic rats fed zinc-deficient diet
The aim of this study was to examine the progression of kidney damage induced by zinc deficiency in diabetic rats and to evaluate the effect of combined treatment of vitamin E and vitamin C in renal injury by providing protection against deleterious action of zinc deficiency. Female diabetic albino Wistar rats were randomly assigned into five groups. The first group received a diet containing a 54 mg zinc/kg diet (adequate zinc, AZ), the second group received a diet containing 1 mg zinc/kg diet (zinc deficient group, ZD), and the three other groups received ZD diet and treated orally with vitamin E (500 mg/kg body wt) (ZD + Vit E), vitamin C (500 mg/kg body wt) (ZD + Vit C), and combined vitamins C and E (250 + 250 mg/kg body wt) (ZD+VitC+VitE), respectively. Body weight was recorded regularly (twice weekly). After four weeks of dietary manipulation, kidney zinc level, serum albumin and total protein concentration of ZD group were significantly lower than those of AZ group. Dietary zinc deficiency also increased proteinuria excretion, serum and urinary urea and uric acid levels, serum creatinine and kidney malondialdehyde concentration. In contrast, the catalase activity and reduced glutathione level in the kidney were reduced. In conclusion, vitamins E and C act as beneficial antioxidants protect renal function against the noticed oxidative stress due to zinc deficiency and experimental diabetes.
Keywords: Experimental diabetes, zinc, vitamin E, vitamin C, oxidative stress, kidney damage.