Crocin Attenuates Oxidative Stress and Myocardial Infarction Injury in Rats.

Oxidative stress and excessive nitric oxide (NO) production play considerable roles in infarction-induced injury impairing cardiac functions. Crocin is the active constituent of Crocus sativus (saffron) with antioxidant properties and has protective effects against disturbances induced by ischemia in many organs. The present study aimed to investigate the protective effects and the underlying mechanisms of crocin on myocardial infarction (MI)-induced injury in rats in vivo. MI rats were intraperitoneally injected with crocin at different doses for seven successive days after coronary ligation. Infarct size, hemodynamic studies, and capillary density were evaluated. Levels of oxidative stress, inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and their corresponding phosphorylation expressions were then measured. Crocin decreased infarct size, left ventricular (LV) end-diastolic pressure, and LV minimum dP/dt while increased LV maximum dP/dt and percentage of LV fractional shortening dose dependently. Capillary density was markedly increased after crocin treatment. Crocin enhanced superoxide dismutase activity and reduced malondialdehyde levels as well as inhibited excessive production of NO through downregulating iNOS as well as upregulating eNOS during MI-induced injury. This study reveals that crocin improves MI-induced impairments in cardiac function, which is associated with its antioxidant properties.