Antioxidant therapy prevents ethylene glycol-induced renal calcium oxalate crystal deposition in Wistar rats

Abstract

Renal epithelial cell injury by reactive oxygen species is a prerequisite step in the pathogenesis of urolithiasis, and there is increasing evidence that reactive oxygen species is produced and oxidative stress (OS) is developed during idiopathic calcium oxalate nephrolithiasis. It appears that the administration of natural antioxidants has been used to protect against nephrolithiasis in human and experimental animals. Calcium oxalate urolithiasis was induced experimentally by administration of 0.75 % v/v ethylene glycol in drinking water of male Wistar rats weighing 150-200 g. Study was conducted in 4- and 8-week periods. In the 4-week period, Group 1 (control) was fed a standard commercial diet. Group 2 received the same diet with the addition of 0.75 % of ethylene glycol (EG). Group 3 received EG plus the diet, and water with additional antioxidant nutrients, and lemon juice as the dietary source of citrate (EG + AX). Group 4 was the same as Group 3, but with no EG in water. In the 8-week study protocol, Group 5 was fed the standard diet with EG in water for the first 28 days, followed with no EG. Group 6 (curative group) received the diet with EG for the first 28 days, followed by discontinuation of EG plus the addition of antioxidant nutrients. Group 7 was provided the diet with antioxidant nutrients for 8 weeks. Group 8 (preventive group) received the diet with antioxidant nutrients for 4 weeks, followed by antioxidant nutrients with EG for the next 4 weeks. Lime juice was given along the antioxidants. After treatment period, kidneys were removed and used for histopathological examination. In the 4-week study, the mean number of crystal deposits in Group 2 was significantly higher than that of animals in Group 3. After 8 weeks, animals given curative antioxidant supplementation within the second 4-week period developed fewer deposits in Group 6 as compared to Group 5 animals. In the other preventive AX loading Group 8, the number of crystal deposits was substantially less than that of either Group 2 or Group 5 animals (EG-treated rats). Results showed a beneficial effect on treating and superior renal protection for preventing stone deposition in the rat kidney. These results provide a scientific rationale for preventive and treatment roles of antioxidant nutrient complex in human kidney stone disease.