Original Research Article

2015 - Volume 5 [Issue 1 ]

Pre-clinical Evaluation of the Hypotensive and Anti Atherogenic Activity of Hydroethanolic Extract of Eribroma oblongum (Malvaceae) Stem Bark on Wistar Rats Models

Published
November 21, 2014

Abstract

Aims: The stem bark of Eribroma oblongum (Malvaceae) is used in traditional Cameroonian medicine to treat various metabolic illnesses including the management of hypertension without scientific evidence to how relief is brought about. The present study was to evaluate the effect of the dried stem bark of hydroethanolic extract of E. oblongum on arterial blood pressure and heart rate in normotensive rat (NTR) and in atherogenic diet induced - hypertensive rats.
Study Design: This was a prospective cross-sectional analytical study.
Place and Duration of Study: Study was conducted in the Laboratories of Animal Physiology, Organic Chemistry and Natural Product of the Faculty of Sciences, and the Preclinical Animal Toxicology laboratory of the Faculty of Medicine and Biomedical Sciences of the University of Yaoundé 1-Cameroon, during the period August 2013 to April 2014. Fresh stem bark of Eribroma oblongum were collected at Eseka, Centre Region of Cameroon, in August 2013. The plant material was identified at the National Herbarium (HNC) of Yaoundé-Cameroon where a voucher specimen N°27489SRFCam has been deposited.
Methodology: The effects of a hydroethanolic extract of Eribroma oblongum (HEEO; 10, 20, 30 mg/kg; i.v) was tested on systolic blood pressure (SBP) and heart rate (HR) of normotensive rat. The mechanism of HEEO (10 mg/kg) was studied in the presence of atropine, yohimbine, propranolol, L-NAME or reserpine. Preventive effects were studied after feeding atherogenic diet (AD) with oral administration of HEEO (100 mg/kg/day) in rats for 45 days. Body weight and food intake were measured every five days during the 45 days of study At the end of the experiment, SBP and HR were recorded. Aorta, heart, liver and kidneys were weighted, and biochemical assays of superoxide dismutase (SOD), catalase, reduced glutathione (GSH), malondialdehyde (MDA), nitrites (NO2-) and lipid profile, transaminases and creatinine were done.
Results: HEEO (10-20 mg/kg) induced a significant hypotensive effect of SBP. The hypotensive effects of HEEO (10 mg/kg) were inhibited by pre-treatment of rats with atropine, reserpine, yohimbine and L-NAME. The AD significantly elevated SBP (P<0.01). Treatment with HEEO (100 mg/kg) reduced blood pressure and significantly decreased HR (P<0.01). HEEO significantly improved the plasma of triglycerides 35.08%, cholesterol total 33.71%, LDL-Cholesterol 73.73% with a significant low atherogenic index 1.73.HEEO significantly increased NO2-and SOD in aorta, CAT in heart P<0.01 and ASAT P<0.05.
Conclusion: This study demonstrates the hypotensive and antihypertensive potential of the crude hydroethanolic extract of the stem bark of Eribroma oblongum. Our data validate the use of the extract traditional medicine against hypertension in Cameroon. 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 now needed to identify the bioactive compounds responsible for the cardiovascular effects of Eribroma oblongum.