Ursolic acid increases SIRT1 protein level and β-cells number in diabetic rats

Ursolic acid (UA) is a triterpenoid compound which widely found in the apple’s peel. It has wide health-promoting properties; as previous studies properly indicated to its abilities. In this scenario our attention has been paid to the application of UA as an anti-diabetic compound. Based on our recent studies in relating to SIRT1 protein/gene and UA, the aim of this research was to evaluate UA effects on the SIRT1 expression in diabetic rat’s pancreas. In this study we used 20 male diabetic wistar rats. To develop diabetic rats, they received 30mg/kg of streptozotocin for 2 days sequentially. Then, they classified to 2 groups, the ones received UA + corn oil twice daily for two weeks and others (the control group) just received corn oil. Our findings obviously showed that UA enhanced SIRT1 (4±0.2 folds) proteins levels in pancreas (P<0.001), in comparison with control rats. In addition, the findings showed that UA significantly decreased fasting blood glucose from 416.17±12 mg/dl to 149.75±11 mg/dl. Moreover, we found that UA increased β-cell numbers and islet Langerhans diameters (~2 folds). Our results provide valuable information not only into the mechanisms underlying β-cells protection but also into the regulation of SIRT1 as a main target to attenuate β-cells damage. Therefore, UA is a promising pharmacological therapeutic target for β-cell regeneration through enhancing of SIRT1 over-expression.