Effect of taurine on toxicity of vitamin A in rats

A study was undertaken to investigate the effect of taurine on the toxicity of vitamin A in male wistar rats. The rats were divided into six groups and fed different diets with or without supplements of 5% taurine and 25,000–50,000 (IU) vitamin A for 2 months. It was found that the body weight of rats, the ratios of liver and kidney weight to body weight, and the level of glutathione in the liver were decreased with increasing the dose of vitamin A. The levels of vitamin A in the liver and kidney, the levels of thiobarbituric acid-reactive substances (TBARS) in the plasma and liver, the activities of aspartate transaminase (AST) and alanine transaminase (ALT) in the plasma, and the levels of blood urea nitrogen (BUN) and creatinine in the plasma of rats were increased with the increasing dose of vitamin A. Hence, symptoms of vitamin A toxicity in rats included loss of body weight, hepatotoxicity and nephrotoxicity. However, these toxic effects of vitamin A were significantly reduced when the rats were fed the diet with the supplement of taurine. Furthermore, the level of vitamin A in the serum of rats treated with taurine and vitamin A was higher than that of rats treated with vitamin A alone. This indicated that taurine might play a role in reducing the toxic effect of vitamin A in rats.