Background: Azathioprine (AZA) is the most widely used immunosuppressive drug for preventing graft rejection and autoimmune disease. However, the therapeutic treatment induces several side effects such as toxicity to bone marrow, pancrease, liver and gastrointestinal tract. One of the major functions of Vitamin A is to act as a natural antioxidant by scavenging free radicals. Considering the kind of Azathioprine-induced damage in Liver tissue, we decided to study the protective effect of Vitamin A against Azathiprine-induced toxicity.

 Materials and Methods: Forty Male Wistar rats were divided into 4 groups (each group contains 10 rats). Group 1 was control group and only took normal saline. Groups 2 & 3 were administrated daily use of Vitamin A for 7 days I.M. and Group 4 was administrated with normal saline instead of Vitamin A in same condition as groups 2&3. In the last day groups 3 & 4 were administrated with single dose of AZA, 15 mg/kg (IP). After 24 hours, we took the animals blood and tissue samples and studied them for biochemical and pathological examinations.

Results: This study showed that Azathioprine-induced damage on liver in group 3 is less than that in group 4 while the function of organ in group 3 is nearly the same as control group. Also vitamin A decreases Azathioprine-induced hepatotoxicity in rats.

Conclusion: Regarding importance of Azathioprine-induced damage, the usage rate of this drug in medicine, and the results of this study, we suggest that co-administration of Azathioprine and vitamin E decreases the toxicity of this drug.