Preventive effects of taurine and vitamin C on renal DNA damage of mice exposed to arsenic.

Arsenic (As), as a pollutant, ubiquitously exists in well water and contaminated soil. There is also exposure to arsenic in some industries, such as non-ferrous smelting, wood preservation, and electronics. The risk of Asinduced human diseases is high in some developing countries such as Bangladesh, India, and China . Epidemiologic investigations and animal experiments have demonstrated that acute and chronic exposure to As can cause injury to the kidney and increase the risk of renal cancer, so the kidney may be a major target of toxicities induced by As. It was reported that As depresses the functions of the antioxidant defense system and led to oxidative damage to cellular macromolecules . The above results show that increase of oxidative stress and subsequent oxidative DNA damage of cells may be involved in the renal disorders induced by As. Taurine, an end product of l-cysteine metabolism, is the most abundant free amino acid in many tissues and protects against the adverse effects of reactive oxygen species (ROS) caused by various toxic substances. Vitamin C (Vit C), as a kind of water-soluble antioxidant, also prevents oxidative damage to many important macromolecules. 8-OHdG is formed from deoxyguanosine (dG) in DNA by hydroxy free radicals. Because of its stability, 8-OHdG is known as one of the most reliable markers of oxidative DNA damage. In the present study, in order to investigate the protective effects of taurine and Vit C against As-induced nephrotoxicity, we examined the expression of 8-OHdG and the histopathological changes in the renal tissues of mice administered As or both As and taurine or Vit C.