Antihypertensive Potency of Wild Cosmos (Cosmos caudatus Kunth, Asteraceae) Leaf Extract

摘要

The wild cosmos {Cosmos caudatus Kunth, Asteraceae) is one of the vegetables mostly consumed by rural people of Central and East Java Provinces of Indonesia and those of the Malay Peninsula. Yet, it has not been widely used medicinally. The leaf has distinctive taste as well as odor and contains high level of flavonoid, especially flavonol and flavon glycosides which have potent antioxidant activity. In this study, in an attempt to explore the antihypertensive effect, wild cosmos leaf aqueous extract was tested in rats treated with adrenaline and sodium chloride. The frequency of heart rate and amplitude of stroke volume were measured using the non-invasive tail cuff method. The extract at doses of 500 and 1000 mg kg-1 showed similar potency to that of 9 mg kg-1 atenonol, in lowering both parameters, induced by adrenaline. However, after sodium chloride, the extract only suppressed the amplitude and this effect was comparable to that of 0.45 mg kg-1 hydrochlorothiazide and 13.5 mg kg-1 captopril. Besides cardiac effects, the extract also demonstrated diuretic activity which was comparable to that of 1.8 mg kg"1 furosemide. Taken together, results of present study suggest that wild cosmos leaf extract have antihypertensive effect which may be related, at least in part, to the decreased cardiac output and induction of diuresis. The results may further indicate that consumption of wild cosmos leaf in diet is beneficial for hypertensive patients.