The stem bark of Eribroma oblongum (malvaceae) is used in traditional Cameroonian medicine to treat various metabolic illnesses including the management of hypertension but there is no scientific evidence to how relief is brought about. The present study was to evaluate the effect of the ethyl acetate extract of the dried stem bark of E. oblongum on arterial blood pressure and heart rate in normotensive rat (NTR) and their mechanisms of EAEO. The effects of ethyl acetate extract of Eribroma oblongum (EAEO; 10, 20, 30 mg/kg; i.v) was tested on systolic blood pressure (SBP) and heart rate (HR) of normotensive rat. The mechanism of EAEO (20mg/kg) was studied in the presence of atropine, yohimbine, propranolol, L-NAME or reserpine. At the end of the experiment, SBP and HR were recorded. EAEO (10-20 mg/kg) induced a significant hypotensive effect of SBP. The hypotensive effects of EAEO (20 mg/kg) were inhibited by pre-treatment of rats with atropine, reserpine, yohimbine and L-NAME. At the end of this study the result demonstrates that the hypotensive as well as the antihypertensive effects of the ethyl acetate extract of the stem bark of Eribroma oblongum. Our data validate the use of the extract in traditional medicine against hypertension. The effect on blood pressure is, at least in part, due to a modulation of the orthosympathetic nervous system and to the improvement of the antioxidant status. Further studies are from now needed to study the toxicity of Eribroma oblongum.
