Phytochemical Screening and In Vitro Angiotensin-Converting Enzyme (ACE) Inhibitory Activity of Selected Indonesian Medicinal Plants

Abstract

Hypertension remains a major global health challenge, and angiotensin-converting enzyme (ACE) is an important therapeutic target for blood pressure control. Indonesian medicinal plants have long been used traditionally to manage hypertension; however, comparative evaluations of their ACE inhibitory activity remain limited. This study investigated the extraction yield, phytochemical composition, and in vitro ACE inhibitory activity of ten medicinal plant parts traditionally used for hypertension treatment. Plant materials were extracted by maceration with 96% ethanol, followed by phytochemical screening and ACE inhibition testing using the ACE Kit-WST assay at 100 µg/mL. Extraction yields ranged from 9.82% to 45.30%, with Averrhoa bilimbi fruit producing the highest yield. Phytochemical screening revealed the presence of alkaloids and flavonoids in all extracts, whereas saponins, quinones, tannins, and steroids/triterpenoids showed variable distributions. ACE inhibitory activity ranged from 62.61 ± 1.21% to 96.92 ± 3.05%. The highest activities were observed for Morinda citrifolia fruit (96.92 ± 3.05%), Piper betle leaf (96.87 ± 2.05%), and Dracaena angustifolia leaf (95.09 ± 1.27%), with no significant difference from captopril (99.09 ± 0.07%; p > 0.05). These findings support the traditional use of selected Indonesian medicinal plants for hypertension management and identify M. citrifolia, P. betle, and D. angustifolia as promising sources of natural ACE inhibitors for further investigation. The scientific validation of these medicinal plant resources may also support the sustainable utilization of biodiversity and the preservation of traditional ethnomedicinal knowledge.