Angiotensin-conventing enzyme-inhibitory effect by Ruellia praetermissa

Abstract

In the search for lead drugs for hypertension from plant origin, Ruellia praetermissa was analyzed for its constituents and inhibitory effects on angiotensin-converting enzyme (ACE). The various fractions showed various inhibitory effects on ACE at a concentration of 0.33 mg/ml, e.g., n-hexane extract (13.15%), ethyl acetate extract (7.15%), methanol extract (38.35%), the aqueous extract (89.65%). TLC and HPLC fingerprint analyses of these extracts showed that lupeol is one of the constituents responsible for the effect in the n-hexane extract, and flavonoids (luteolin and apigenin) might be responsible for the activity in the methanol and aqueous extracts. The aqueous extract was found to be the most active, possibly due to saponigenins. This activity suggests a cardiovascular effect of the aqueous extract of Ruellia praetermissa.