PLANT BASED DRUG DEVELOPMENT IN NIGERIA: OUR EXPERIENCE WITH SALT AND HYPERTENSION
Peter Olatunde Ajagbonna
Department of Pharmacology/ Toxicology, University of Abuja, Nigeria.
Excess dietary salt ingestion is known to cause hypertension in humans and in several apecies of experimental animals, In the present study, Salt loading for six weeks was used to induced hypertension on Sprague dawley rats and treatment with Rhaptopetalum coriaceum oliv (R C O) extract reduced significantly (p<0.05) the blood pressure, it however induced natriuresis and dieresis. Hypokalemia induced following salt loading of rats was prevented by RCO administration. Similarly, treatment with RCO extract decreased the sensitivity of the aortic rings to noradrenaline (NA) and potassium Chloride (KCL) in salt loaded rats, resulting in decreased contractile responses of the rings to both of these agents. Acetylcholine (Ach) also caused relaxation of the NA induced precaution and relaxation response to Ach was higher with salt-RCO treated rings compared to the control. While salt loaded rings attenuated the relaxation response to Ach. The results suggest that salt induced hypertension is associated with impairment of vascular response to vasoactive agents and endothelium dependent relaxation to Ach and these were corrected by treatment with RCO extract.