Suppressive effect of accumulated aluminum trichloride on the hepatic microsomal cytochrome P450 enzyme system in rats

Aluminum (Al) is a low toxicological metal and can accumulate in the liver. The hepatic microsomal cytochrome P450 enzyme system (CYPS) plays important role in the transformation of the toxic materials. It is not clear if the CYPS is affected by Al exposure. Thus, the aim of this study is to investigate the effects of aluminum trichloride (AlCl3) on CYPS in rats. Forty male Wistar rats (5 weeks old) weighing 110–120 g were randomly allocated and orally exposed to 0, 64.18, 128.36 and 256.72 mg/kg body weight (BW) AlCl3 in drinking water for 120 days. The body weight (BW) of rats, hepatosomatic index (HSI), hepatic Al content, the concentrations of cytochrome P450 (CYP450), cytochrome B5 (B5), microsomal protein and the activities of NADPH-cytochrome c reductase (CR), aminopyrin N-demethylase (AND), erythromycin N-demethylase (ERND) and aniline-4-hydeoxylase (AH) were assessed at the end of the experiment. The results showed that the increase in Al concentration decreased BW, HIS, concentrations of CYP450, B5, microsomal protein and the activity of CR, AND, ERND and AH in hepatic microsomes. The results revealed that exposure to AlCl3 inhibited the microsomal CYP450 dependent enzyme system of liver. Our findings suggest that long term daily exposure of AlCl3 exerts the suppressive effects and thus may cause dysfunction of hepatic CYP450 dependent enzyme system of rat.