Protective effects of total saponins of panax notoginseng on myocardial hypertrophy and fibrosis induced by isoproterenol in rats

AIM:To investigate the protective effects of total saponins of panax notoginseng (PNS) on myocardial hypertrophy and fibrosis induced by isoproterenol (ISO) in rats. METHODS: Myocardial hypertrophy and fibrosis model of rats were induced by injection of ISO (5 mg·kg-1·d-1, sc) for 7 days. From day 2, the rats were administered with PNS at dose of 25 and 50 mg·kg-1·d-1, ip for 14 days, the control and ISO model group were received saline injection. Then, the heart-weight (HW), left ventricular weight (LVW), the ratio of HW/BW and LVW/BW (LVI) were measured; the hydroxyproline and malondialdehyde (MDA) and angiotensin (AngII) content of left ventricle. The level of nitric oxide (NO), nitric oxide synthase (NOS), superoxide disrnutase (SOD) and glutathione peroxidase (GSH-Px) activities in left ventricle were determined by spectrophotemetry and radioimmunoassay, respectively. RESULTS: Compared with NS control group, the ratio of HW/BW, LVW/BW and the content of hydroxyproline, AngII, MDA and iNOS activity in the left ventricle were significantly increased. The cNOS, SOD, GSH-Px activities and NO content were obriously decreased in the ISO model group. After treatment with PNS, the left ventricular NO content, cNOS, SOD and GSH-Px activities were markedly higher than those in ISO model group. The content of MDA, AngII and iNOS activities and the ratio of HW/BW, LVI were significantly lower than those in ISO model group. CONCLUSION: PNS reverses the myocardial hypertrophy and fibrosis induced by isoproterenol in rats. This effect may be related to eliminating the oxygen free radicals and raising NO level.