Effects of luteolin on myocardial injury and underlying mechanisms in diabetic mice

AIM To explore the effects and mechanisms of luteolin on heart impairment in diabetic mice. METHODS Diabetes was induced by a single intraperitoneal of streptozotocin. Male C57/BL6J mice were randomly divided into three groups (n=16): control, diabetes, diabetes+luteolin. The diabetes+luteolin group were given a dose of 50 mg/(kg·d) of luteolin, while the control and diabetes groups received 50 g/L sodium carboxymethyl cellulose gavage. For 3 months, echocardiography was employed to evaluate cardiac function. Collagen volume fraction (CVF) was measured by masson staining and apoptotic index was examined by Tunel. Western blot was used to determine the expression of Rho and ROCK2. RESULTS Compared with the control group, cardiac function attenuated significantly (P<0.05), with increased CVF (P<0.05). There was enhanced apoptotic index (P<0.05) and expression of Rho and ROCK2 were upregulated (P<0.05) when compared to the control group. Compared with those in the diabetes group, the cardiac function was significantly improved (P<0.05) and CVF significantly diminished (P<0.05). There was a restored apoptotic index (P<0.05), and there was reduction of Rho and ROCK2 levels (P<0.05) by treatment with luteolin in the diabetes+luteolin group. CONCLUSION Luteolin significantly decreases the apoptotic index and protects against myocardial injury in diabetic mice, possibly by inhibiting activation of RhoA/ROCK2 signaling.