Abstract
Shenmai formula (SM) has been a traditional medicinal remedy for treating cardiovascular diseases in China for 800 years; however, its mechanism of action remains unclear. To explore the mechanism underlying cardioprotective effects of SM, iTRAQ-based proteomic approach was applied to analyze protein of myocardium in rats with myocardial ischemic injury. Upon treatment with SM and its two major components Red ginseng (RG) and Radix Ophiopogonis (OP), 101 differentially expressed proteins were filtered from a total of 712 detected and annotated proteins. They can be classified according to their locations and functions, while most of them are located in intracellular organelle, participating in cellular metabolic process. The functions of them are mostly associated with mitochondrial oxidative phosphorylation/respiration. The differentially expressed proteins were validated by liquid chromatography-tandem mass spectrometry and Western blotting (ATP5D, NDUFB10, TNNC1). Further in vitro experiments found that SM could attenuate hypoxia induced impairment of mitochondrial membrane potential and cellular ATP concentration in neonatal rat ventricular myocytes. Interestingly, the result of quantitative mitochondrial biogenesis assays revealed that SM had dominant positive effects on the maximum respiration, ATP-coupled respiration, and spare capacity of mitochondria in response to hypoxia. Hence, our findings suggest that SM promotes mitochondrial function to protect cardiomyocytes against hypoxia, which provides a possible illustration for conventional botanical therapy on a molecular level.