Oleanolic acid protects against diabetic cardiomyopathy via modulation of the nuclear factor erythroid 2 and insulin signaling pathways.

Oleanolic acid (OL) is a pentacyclic triterpene compound used for the treatment of hepatitis, liver fibrosis and liver cirrhosis. In China, there is no published research on the effect or biological utilization of OL on liver diseases. The aim of the present study was to investigate the protective effects of OL against diabetic cardiomyopathy and its possible mechanism. A rat model of diabetes was established using streptozotocin and the effect of OL on diabetic cardiomyopathy (DCM) was evaluated. The results demonstrated that OL significantly reversed the DCM-induced changes to body weight, heart rate, echocardiography and hemodynamics, phosphorylated-glycogen synthase (GS) and glycogen phosphorylase (GP) activity in diabetic rats (all P<0.01). Treatment of diabetic rats with OL significantly inhibited oxidative stress and activated heme oxygenase (HO)-1/nuclear factor erythroid 2 (Nrf2) signaling in a rat model of diabetes (both P<0.01). The results of the present study indicate that OL protects against DCM through the HO-1/Nrf2 and insulin modulating GS/GP signaling pathways.