RESUMEN
Echium amoenum and Citrus aurantifolia are used in traditional medicine for the treatment of cardiac arrhythmia and regulation of blood pressure. In this study the effects of co-administration of these herbs on heart rate and blood pressure of rats before and after phynelephrine injection were investigated. Ten groups of rats respectively received 100, 200, 400 and 600 mg/kg Echium Amoenum, 250 mg/kg Citrus Aurantiflia and combination of 250 mg/kg Citrus Aurantiflia with 100, 200, 400 and 600 mg/kg Echium Amoenum for 6 days. Control group received water. Blood pressure and heart rate before and after phynelephrine injection were measured and compared among groups. Echium amotnum at 400 and 600 mg/kg dozes significantly increased blood pressure of rats in comparison to the control group [P<0.05] and this effect was more significant after phynelephrine injection [P<0.05]. Echium amoenum in combination whit citrus aurantiflia decreased heart rate after phynelephrine injection and also in comparison to the control group. This decreasing effect was more than the effect of 6.688 mg/kg phynelephrine [P<0.05]. Since Echium amoentum has an increasing effect on blood pressure especially in higher blood pressures, it is not suggested for those with hypertension. Co-administration of Echium amoentum and Citrus aurantiflia is recommended for decreasing heart rate