Abstract: To study the antihypertensive effects and mechanisms of total flavonoids of Flos Chrysanthemi (TFFC) on spontaneous hypertension rats (SHR).The SHR were randomized into 5 groups:model group,high-dose,middle-dose,low-dose group of TFFC and enalapril group.Blood pressure and heart rate were measured by Non-Invasive Blood Pressure Analyzer,the contents of plasma endothelin (ET),angiotensinⅡ (AngⅡ),aldosterone (ALD) and plasma renin activity (PRA) were determined by radio-immunity method.The results showed that TFFC can decrease blood pressure (P<0.01) and heart rate (P<0.05),decrease the contents of plasma ET (P<0.05),AngⅡ (P<0.01),ALD (P<0.01) and PRA (P<0.01).The antihypertensive effect of TFFC was possibly caused by improving the endothelial function and inhibiting the activity of renin-angiotensin-aldosterone system (RAAS).

Key words: total flavonoids of Flos Chrysanthemi, SHR, blood pressure, ET, AngⅡ, ALD, PRA