Background and Aim: The most common disease of abnormal carbohydrate metabolism, diabetes mellitus is due to defects in insulin secretion or failure in performance or both will develop. It is known that melatonin may be involved in sugar metabolism .Therefore in this study meet the compounds of indole ring (melatonin precursor) on non-diabetic and diabetic rats were studied.

Material and Methods: Diabetic and non diabetic rats were divided into 4groups. Control group: diabetic and non diabetic rats that received daily water and normal food. Sham group: diabetic and non diabetic rats that received daily water and normal food with 0.5 ml grape seed oil. Exp1&2 groups: diabetic and non diabetic rats that received daily 4 mg/kg indole, 4mg/kg5-hydroxy indole 2- carboxylic acid in 0.5ml oil respectively. Diabetizing with alloxan was performed using 150 mg/kg dose with single IP injection. In this study, blood sugar, average urine and water consumption, blood insulin levels were measured, and pancreas as well as histological studies were performed.

Results: After treatment for 30 days in the exp1D showed a blood sugar levels, water consumption and urine significantly at p <0.001 decreased While insulin levels also increased in this group (p <0.001). While the exp 2D have less effect on insulin levels, blood sugar and the water consumption and urine. Histology also showed that the indole in the exp1D repair pancreatic tissue.

Conclusion: this study it was found indole may have beneficial effects in decrease blood sugar and increase insulin synthesis and repair of the pancreas.