Abstract
Bisphenol A is a chemical used in the production of the plastic lining of food and beverage containers. As plastics are used extensively in modern life, bisphenol A is liberated into the surrounding environment. The goal of this study was to illustrate the histopathological effects of bisphenol A on the renal cortex with referral to the possible ameliorative effect of green tea extract and to throw more light on some underlying mechanisms, for the first time up to our knowledge, by which green tea extract exerted its effects against bisphenol A-induced nephrotoxicity. Forty adult male Sprague-Dawley rats were classified into four groups: Group I (control group); Group II (bisphenol A-treated group), received bisphenol by gavage 125 mu g/kg once daily for 35 days; Group III (bisphenol A and green tea extract treated group), received bisphenol by gavage 125 mu g/kg simultaneously with 200 mg/kg/day green tea extract once daily for 35 days; and Group IV (green tea extract treated group), received 200 mg/kg/day green tea extract for 35 days by gavage. At the end of the study, rats were anesthetized and the kidney from all groups were extracted and examined histologically and immunohistochemically. Deterioration of kidney structure was greatest in group II as compared to control group. Some of the renal corpuscles showed widening of the Bowman's capsule, shrunken degenerated glomerular tuft and dilated congested glomerular capillaries. Interstitial and intratubular hemorrhage was also observed. Moreover, there was a significant increase in the collagen deposition in bisphenol A-treated group in addition to up-regulation of inducible nitric oxide synthase (iNOS), Fas Ligand (Fas L), alpha smooth muscle actin (alpha-SMA) and desmin immunoreaction. The co-administration of green tea extract greatly reduced these nephrotoxic effects of bisphenol A exposure through its antioxidant, antiapoptotic and antifibrotic effects.