Protective Effects Of Veratrum Nigrum L.Var.ussurience Nakaialkaloids On Myocardial Hypertrophy Induced By Isoproterenol In Mice

Objectives : Myocardial hypertrophy is one kind of pathological changes of many cardiovascular diseases. It is mainly expressed as myocardial remodeling with cells hypertrophy and mesenchymal components change. Myocardial remodeling and ventricular hypertrophy increase the risk of arrhythmia and lead to heart failure finally. So prevention and inhibition of myocardial hypertrophy is very significant for the prevention and treatment of heart failure.Veratrum nigrum L.Var. ussurience Nakai alkaloids (VnA) is extracted from the root of Veratrum nigrum L.var.ussuriense Nakai from qianshan, Liaoning province. VnA has been shown to decrease blood pressure, blood viscosity and thrombosis,and inhibit central nervous system. However, the protection effect of VnA on cardiac hypertrophy hasn't been reported. The purpose of the present study is to investigate protective effects and mechanism of VnA on myocardial hypertrophy induced by isoproterenol (ISO) in mice.Methods:1. Establishing model: Myocardial hypertrophy models of mice were established by subcutaneous injection of ISO (3mgï¹’kg^-1) for 5d.2. Treatments: Six groups were divided according to different treatments:â‘ Control group (Sodium Chloride group);â‘¡Isoproterenol group (ISO, 3mgï¹’kg^-1);â‘¢VnA at high dosage group (45ugï¹’kg^-1);â‘£VnA at middle dosage group (30ugï¹’kg^-1);⑤VnA at low dosage group (15ugï¹’kg^-1);â‘¥Captopril group (Cap, 100mgï¹’kg^-1). VnA groups were given via tail vein 6h before ISO treatment (3mgï¹’kg^-1, sc, 5d ).3. Measurements: The cardiac weight index, the content of malonydialdehyde (MDA) and superoxide dismutase (SOD), the activity of Ca²⁺-ATPase and the level of nitric oxide (NO) in myocardium were measured, and myocardiac morphological alterations were observed with HE staining and transmission electron microscope(TEM).Results:VnA at high and middle dosage significantly decreased the cardiac weight index and the content of MDA, and increased the content of SOD and the activity of Ca²⁺-ATPase in myocardium (p<0.05, compared with the NS control group). Moreover, the impaired left ventricular tissue was improved obviously in both groups. VnA at the low dosage did not show significant improvents. There was no significant changes on NO content at all three dosages.Conclusions : VnA showed protective effects on myocardial hypertrophy induced by ISO in mice, which might be related to reducing the oxidative stress and activating the activity of Ca²⁺-ATPase of myocardial cells.