Antihypertensive Potential of Aqueous Extract of Nephrolepis biserrata Leaves on Toad Aorta

Abstract

Of our ethnobotanic investigations in the district of Franceville, on 30 requested people, 20 answered the survey questionnaire. The present study aims at evaluating the hypotensive activity of Nephrolepis biserrata (NB) used by Ndoumou in the province of Haut-Ogooué in Gabon to treat or prevent against arterial hypertension. The Phytochemical studies show that the aqueous foliar extract of Nephrolepis biserrata consists of phenolic constituents, terpeniques and nitrogenous. This extract was used to realize all the tests of our study. The contraction is recorded by a system of isolated organ. NB (5-200 mg/ml) provoke the decrease of the contraction of the aorta of the toad induced by the norepinephrine (10-6 M) in presence and in absence of the endothelium. The threshold of the effect is 5 mg/ml in the presence and 50 mg/ml in absence of endothelium; a maximal decrease is observed in 200 mg/ml. The acetylcholine (10-11-10-7 M) decreases the contraction of the aorta caused by the norepinephrine (10-6 M) in the presence of the endothelium; 3.10-11 M is the threshold of the effect and 10-7 M the maximum, whereas in the absence of endothelium, we observe an increase of the contraction. Nephrolepis biserrata (5-200 mg/ml) cause the reduction of the contraction induced by the norepinephrine (10-6 M) of the aorta pretreated with a solution of L-NAME (10-5 M), in the presence of endothelium; the threshold of the effect is 5 mg/ml and maximum to 200 mg/ml, so highlighting the antihypertensive potential of Nephrolepis biserrata, and those this in presence and in absence of endothelium.