In Vitro Angiotensin-Converting Enzyme (ACE) Inhibition Test on Extract Dayak Onion Herb (Eleutherine americana (Aubl.) Merr. ex K. Heyne)

Abstract

One of the world's silent killer diseases is hypertension. Hypertension occurs when angiotensin I is converted to angiotensin II, causing vasoconstriction, which decreases sodium and water excretion. The mechanism of angiotensin I conversion to angiotensin II appears in the presence of the Angiotensin-Converting Enzyme (ACE). Flavonoids have the potential as ACE inhibitors due to their structure. Dayak onion is widely used as an antihypertensive in traditional medicine. This study aims to identify secondary metabolites, determine total flavonoid content, determine extract quality parameters, and ACE inhibitory activity of the Dayak onion herb. Dayak onion herb was extracted with 70% ethanol by kinetic maceration, and then phytochemical screening was carried out, extract quality parameters tested, and ACE inhibitory activity. The results of the examination of the quality parameters, total ash content of 4.49%, water-soluble ash content of 4.00%, acid-insoluble ash content of 0.41%, drying shrinkage of 9.70%, the water content of 5.72%, solvent residue of 0.67%, Pb heavy metal content of 0.2908 mg/kg, Cd heavy metal content of 0.0880 mg/kg, Total plate number ≤103 colonies/g, and yeast mold numbers ≤103 colonies/g. Dayak onions herbs extract contains flavonoid, alkaloid, saponin, tannin, triterpenoid, quinone, steroid and essential oil compounds. The total flavonoid content was 2.24%. The IC50 of ACE inhibitory activity was 98.5 ± 0.77 ppm. The result of this study indicates that the Dayak onion herb can be used as an alternative for antihypertensive treatment.