RESUMEN
AIM OF THE STUDY: To investigate the cardioprotective potential of Syringa pinnatifolia Hems1. var. alashanensis essential oil (SPEO) against experimental acute myocardial ischemia (AMI), hydrogen peroxide (H(2)O(2))-induced myocyte injury and activities against hypoxia and platelet aggregation. MATERIALS AND METHODS: Wistar rats, Kunming mice and primary cultured rat neonatal myocytes were used in this study. AMI in rats was induced by ligation of the left anterior descending (LAD) coronary artery, and deviation of ST-segment, as well as changes of myocardial enzyme activities were observed. Hypoxia test in Kunming mice was performed to evaluate the effect of SPEO against hypoxia. The protective effect of SPEO on H(2)O(2)-induced cell injury was evaluated in terms of cell viability assay. The in vitro effect of SPEO against platelet aggregation was studied using adenosine 5'-diphosphate (ADP) as agonist. RESULTS: Administration of SPEO reduced deviation of ST-segment, decreased the levels of lactate dehydrogenase (LDH), creatine kinase (CK) and Troponin T (TnT) while increased the activities of superoxide dismutase (SOD). The protective role of SPEO was further confirmed by histopathological examination. In the hypoxia test, both 8 and 32 mg/kg of SPEO could prolong survival time of mice under hypoxia condition. At the meantime SPEO showed remarkable protective effect on cultured rat myocyte death induced by H(2)O(2). SPEO also inhibited ADP-induced rat platelet aggregation by 47.4%, 37.0% and 32.9% at the dose of 5, 2.5 and 1.25 microg/mL, respectively. CONCLUSIONS: These results suggest that SPEO possessing activities against hypoxia, oxidative stress and platelet aggregation has a significant protective effect against experimental myocardial ischemia.