PHYSICOCHEMICAL, PHYTOCHEMICAL, AND EVALUATION ANGIOTENSIN-CONVERTING ENZYME INHIBITORY ACTIVITY OF TAMOENJU (Hibiscus surattensis L.) LEAVES EXTRACT

Abstract

Tamoenju (Hibiscus surattensis L.) is one of the ethnomedicinal plants used in treating hypertension. One of the potential antihypertensive mechanisms includes angiotensin-converting enzyme ACE inhibitors, considered the firstchoice treatment for hypertension. This research presents a physicochemical, phytochemical, and ACE inhibitory activity test of tamoenju leaf extract (TLE). The leaf extract was evaluated to determine the physicochemical and phytochemical profiles using standard methods. The physicochemical evaluation indicated 20.66 ± 3.51% water content, 26.67±5.77% drying shrinkage, 2.0 ± 1.0% total ash value, 0.30 ± 0.13% acid insoluble ash value, 20.00 ± 4.00% water soluble extractive value, 57.00 ± 4.61% alcohol soluble extractive value, and 0.89±0.01 g/ml specific gravity extract. The total plate and yeast mold numbers were 15x103 CFU/g and 92 x 10 CFU/g, respectively. The results of metal contamination showed Pb 1.05 ± 0.15 mg/kg and Cd 0.14 mg/kg. The phytochemical evaluation revealed the presence of tannins (69.02%), flavonoids (27.63%), alkaloids (14.18%), saponins (2.12%), and steroids (1.06%). ACE inhibitory activity was tested and obtained at 38.50±1.41 µg/mL for TLE and 9.44±0.58 µg/mL for captopril. Based on the research results, TLE qualifies as a standardized extract and can be used as a reference for developing herbal medicines. Tamoenju leaves extract is quite high as a natural ACE inhibitor and has the potential as an antihypertensive.