Cardiovascular Actions of Daucus carota

Ethanolic extract of Daucus carota (DC) at the dose of 10-100 mg/kg caused a dose-dependent fall in systolic and diastolic arterial blood pressure in nomotensive anesthetized rats. These effects were not blocked by atropine (1 mg/kg) and pretratment with DC did not alter the pressor response to norepinephrine indicating that cardiovascular effects of DC are independent of cholinergic or adrenergic recptors involvement. In spontaneously beating guinea-pig paired atria, DC induced a concentration-dependent (03-5 mg/ml) decrease in force and rate of atrial contractions. In rabbit thoracic aorta, DC caused inhibition of $K^+$-induced contractions at similar concentrations. These results suggest that the extract may exhibit $Ca^{2+}$ channel blocking-like direct relaxant action on cardiac and smooth muscle preperations and this action may be responsible for its hypotensive effect observed in the in vivo studies.