Promotive effect of salvia extract on angiogenesis of myocardium in rats with myocardial infarction

Objective: This study is to determine the effect and mechanism of salvia extract on angiogenesis of the myocardium in rats with myocardial infarction (MI). Methods: Left coronary artery of Sprague-Dawley rats was ligated to establish MI model. Forty rats were randomly divided into five groups: sham operation group, MI model group, and three salvia extract groups (10, 20, 40 mg/kg/day), with each group consisted of 8 rats. The salvia extract groups were orally administered with salvia extract while the MI group and sham operation group were fed with the same volume of saline. The rats were sacrificed 4 weeks later, and segmental heart samples were used for hematoxylin and eosin staining, masson staining, or electron microscopy. The expression of vascular endothelial growth factors (VEGF) and cluster of differentiation 34 (CD34) were analyzed using immunohistochemistry. Results: Compared with sham operation group, morphology of myocardium in MI group was disordered. Part of myocardial cell outline disappeared, showing obvious fibrosis in necrotic myocardial tissues, along with fuzzy or disappeared vascular ultrastructure. Compared with MI group, the number of new vessels in all salvia extract groups was increased, and the endothelial cell morphology was relatively complete according to the electron microscopy. The protein expression levels of VEGF and CD34 in the cytoplasm of myocardial tissues showed a trend that all salvia extract groups > MI group > sham operation group (P < 0.01). Conclusions: The present study demonstrates that salvia extract promotes angiogenesis in myocardial tissues of rats with MI.