The effects of Blumea megacephala extract on the blood pressure, heart rate and serum NO and ET-1 concen- trations of mice

WANG Cai-bing; ZHAO Shan-min; HE Xian-jiao; HUANG Li-juan; JIN Ling; HUANG Yan-feng; YANG Xiu-ying; LIANG Zuo-ren; HUANG Yong-yi

Abstract：Objective To investigate the effects of blumea megacephala extract on the blood pressure , heart rate and serum NO and ET-1 concentrations of mice , thus to preliminarily analyze the mechanism of Blumea megacephala ex-tract on the cardiovascular system .Methods Fifty mice were randomly divided into normal control group , metoprolol group, telmisartan group , Blumea megacephala low-concentration group and high -concentration group , in which differ-ent lavages were given to for 14 days.Blood pressure, heart rate and serum NO and ET -1 concentrations were were de-termined aftere that .Results There was no significant difference in the systolic blood pressure , diastolic blood pressure or serum NO and ET -1 concentrations between the Blumea megacephala low -concentration group and normal control group.Significantly lower systolic blood pressure and diastolic blood pressure were observed in Blumea megacephala high-concentration group than those in normal control group and Blumea megacephala low-concentration group ( P<0.05, P<0.01) , and with no significant difference comparing with telmisartan group .There was no significant difference in heart rate between normal control group and Blumea megacephala low-concentration group or telmisartan group , however , the heart rate in metoprolol group was significantly lower normal control group ( P<0.01 ) .The heart rate in Blumea megacephala high-concentration group was significantly lower than that in telmisartan group ( P<0.01) , with no signifi-cant difference comraring with normal control group .Serum NO concentration in Blumea megacephala high-concentration group was significantly higher than normal control group ( P<0.05 ) , while no significant difference revealed among the other 3 groups .Serum ET-1 concentrationsin Blumea megacephala high-concentration group and telmisartan group were significantly lower than normal control group (P<0.05, P<0.01), while there was no significant difference revealed a-mong the other groups .Conclusion Blumea megacephala in a certain dosage can reduce blood pressure , without appar-ent effect on heart rate , which probably via reduction in stroke volume and decreased peripheral vascular resistance .