Inhibition of Angiotensin converting Enzyme in Sheep Tissues from Centellaasiatica: An in vitro Study

Angiotensin converting enzyme (EC: 3.4.15.1, ACE) catalyzes the hydrolysis of angiotensin I to angiotensin II. ACE and angiotensin II are biologically active components of renin-angiotensin-aldosterone system, which play central role in the maintenance of blood pressure, electrolyte and water homeostasis. ACE inhibitors are used in the treatment of congestive heart failure, coronary artery disease, diabetic nephropathy etc. Many medicinal plant active components are used as drugs for the treatment of high blood pressure. The present study was on inhibition of ACE activity in sheep (Ovisaries) tissues from extract of Centellaasiatica. Tissue ACE activity was measured with Hippuryl-Histidyl-leucine (HHL) as substrate and the hippuric acid released was measured at 228 nm. Methanol extract of Centellaasiaticawas used in the enzyme assay to determine its effect on kidney, lung and testis ACE activity. The linearity of ACE activity of kidney, lung and testis enzyme was established for the incubation period of 30 min at 37[degrees]C. ACE activity was confirmed by Captopril, a known inhibitor of ACE. ACE activity was determined in the presence of methanol extract of Centellaasiatica (10:1), it inhibited ACE activity significantly. 25 pls of C. asiatica leaves extract reduced sheep kidney, lung and testis ACE activity by 45%, 59% and 43% respectively. Use of medicinal plant is gaining considerable importance by reducing blood pressure. Significant inhibition of kidney, lung and testis ACE activity by Centellaasiatica extract indicates that, it may be beneficial in controlling blood pressure or in cardiovascular diseases.