Angiotensin Converting Enzyme (ACE): Inhibition of Sheep Kidney and Lung ACE In vitro by Rauwolfia serpentina and Allium sativum

Regulation of blood pressure is one of the important functions of Angiotensin I converting enzyme (ACE, EC. 3.4.15.1). ACE is widely distributed and appears to have several important physiological functions including its major role in blood pressure regulation. In the treatment of congestive heart failure, coronary artery disease, diabetic nephropathy etc.ACE inhibitors are used. The current study was aimed to find the effect of aqueous extracts of Rauwolfia serpentina leaves and Allium sativum cloves on sheep kidney and lung ACE. The method is Hippuryl-Histidyl-Leucine (HHL) as substrate, sheep kidney and lung ACE activity was measured and the hippuric acid released was measured spectrophotometrically at 228 nm. Aqueous extracts of Rauwolfia serpentina leaves and Allium sativum cloves were used in the enzyme assay to determine their effect on kidney and lung ACE. The results of linearity of ACE activity in kidney and lung was established with HHL as substrate for the incubation period of 30 min at 37°C. ACE activity was confirmed with specific ACE inhibitors like Captopril, Lisinopril, and Enalapril.25 μl of R. serpentina leaf extract reduced ACE activity by 68% and 57% in kidney and lung respectively. 25 μl of A. sativum cloves extract reduced ACE activity by 50% and 60% in kidney and lung respectively. In conclusion, use of medicinal plants is gaining considerable significance as a drug to treat hypertension. The significant inhibition of kidney and lung ACE activity by these two plant products suggests their possible role in controlling blood pressure as a mode of treatment for cardiovascular diseases, when used as supplement medicine.