Abstract: AIM : To investigate the effect of sequoyitol on the expression of NADPH oxidase p22phox, p47phox and iNOS protein in myocardium of type 2 diabetic rats.METHODS: Diabetic rats were induced by high-fat diet and low dose streptozotocin (30 mg/kg) and were administered with sequoyitol (12.5, 25 and 50 mg/kg) for 6 weeks. The changes in blood glucose (BG) and left ventricular mass index were calculated. Morphological change was observed by HE staining. We also measured nitric oxide (NO), hydrogen peroxide (H₂O₂), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC) in myocardial tissue. In addition, the expression of NADPH oxidase p22phox, p47phox, and inducible nitric oxide synthase (iNOS) protein in myocardium were determined by Western Blot.RESULTS:Compared with the normal control group, the BG and left ventricular mass index were significantly increased. The levels of NO and H₂O₂ were significantly increased and the vitalities of SOD and T-AOC were obviously decreased. The expression of p22phox, p47phox, and iNOS were also significantly increased (P<0.01).Compared with the diabetic group, all above indexes of sequoyitol or acarbose treatment groups had been improved by gavage 6 weeks (P<0.05, P<0.01).CONCLUSION: These results showed that sequoyitol may be lessen the myocardial damage of diabetes by decreasing the expression of NADPH oxidase p22phox, p47phox and iNOS and reducing the sources of oxidative stress.

Key words: sequoyitol, diabetic rat, iNOS, NADPH oxidase, oxidative stress