Abstract:Objective: To study the effects of total saponins of Panax notoginseng(PNS)on the overall model and vitro model of cardiac hypertrophy, and investigate the mechanism of its action. Method: Cardiac hypertrophy of rats due to pressure overload was induced by constricting of abdominal aorta. The rats were given ip PNS for three weeks after operation. Three weeks later , the systolic blood pressure (SBP), heart weight(HW), left ventricular weight(LVW), the ratio of HW/BW, LVW/BW (LVI) and the myofibril diameters(MD) in left ventricles were measured. Cardiac hypertrophy was induced by norepinephrine (NE) in cultured neonatal rat myocardial cells. PNS were given to the cultured myocardial cells,72 hours later, the cell surface area and protein content (used as the index of cardiac hypertrophy) were determined. Result: PNS inhibited the markers of cardiac hypertrophy in rats (HW/BW, LVI, MD) in a dose dependent manner, but SBP of rats wasn‘t obviously influenced ;0.1-0.5 g·L-1 PNS significantly inhibited the NE induced increase of surface area and protein content in the cultured myocardial cells, P<0.01. Conclusion: PNS can prevent the overall model and vitro model of cardiac hypertrophy in rats, and this action may be related to its inhibitory action on neurohormonal factor NE,but not on pressure overload.