Protective Effects of Ginsenoside Rc Against Acute Cold Exposure Induced Myocardial Injury in Rats

Abstract Background: Ginsenoside Rc is one of the cardinal bioactive components of Panax ginseng that has been studied for various biological activities. This study aimed to investigate the protective effects of ginsenoside Rc against acute cold exposure induced myocardial injury in rats.Methods: The rats were intragastrically administrated with ginsenoside Rc (10, 20 mg/kg) or vehicle daily for 7 days. One hour after the seventh-day administration, 3% pentobarbital sodium was used to anesthetize the rats. Rats of the control group were kept in room temperature (22 ± 1 ℃) and the other groups of rats were exposed to low ambient temperature (-15 ± 1 ℃) in a cold chamber for 6 h. Cardiac function was monitored and recorded as well. To evaluate the protective effects of ginsenoside Rc, we also measured myocardial specific enzymes (lactate dehydrogenase, aspartate aminotransferase and creatine kinase-MB) in plasma, whole blood viscosity (WBV), plasma viscosity (PV), erythrocyte sedimentation rate (ESR) and hematocrit (HCT). The pathological changes of myocardium were observed through histopathological examination. The mRNA expression levels of TNF-α, IL-1β and IL-6 were by real-time quantitative PCR analysis. And the expressions of silent information regulator1 (SIRT1), B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (Bax) and Procaspase-3 in heart tissues were measured by Western blot method.Results: Ginsenoside Rc alone had no effect on cardiac function, myocardial enzyme activities and hemorheology in normal rats. Compared with the model group, pretreatment with ginsenoside Rc significantly improved cardiac function, diminished myocardial specific enzymes release and decreased erythrocyte aggregation index. As a result, the pretreatment regulated abnormal hemorheology, attenuated myocardial histological changes and structural abnormalities, reduced the mRNA expression levels of cardiac inflammatory markers. Ginsenoside Rc also resulted in up-regulating SIRT1, Bcl-2 and Procaspase-3 expressions and down-regulating Bax expression.Conclusion: The current study suggests that ginsenoside Rc alleviates acute cold exposure induced myocardial injury in rats by inhibiting cardiomyocyte apoptosis via SIRT1 and reducing inflammatory response.