Background and purpose: Tretinoin is the most active metabolite of Retinoic acid (RA) in the body. It has a variety of biological activities, including antioxidant and immunomodulatory effects on a number of inflammatory and autoimmune conditions. The purpose of this study was to investigate the effects of tretinoin on plasma insulin and nitric oxide levels in streptozotocin-induced diabetes in mice.

Materials and methods: In this experimental study, 15 male C57BL/6 mice were divided into 3 groups (n= 5 per group) including a normal group, diabetic control group (streptozotocin: 40 mg/kg/day for 5 consecutive days) and treatment group (tretinoin: 20 mg/kg/day i.p. for 21 days after induction of diabetes).Then, the levels of nitric oxide in spleen cell culture supernatant and insulin level of plasma were evaluated. Data was analyzed by One-way analysis of variance (ANOVA) and Tukey’s test in Microsoft Excel.

Results: Tretinoin prevented the STZ-induced reduction in plasma insulin, indicating a possible protective effect of tretinoin against &beta;-cell damage. Also, nitric oxide production significantly reduced in treatment group (P<0.05).

Conclusion: These findings indicate that tretinoin may have a therapeutic effect against the autoimmune destruction of the pancreatic beta-cells during the development of STZ-induced type 1 diabetes in mice.