Phytochemical screening and antibacterial activity of ethnomedicinal plants from Gayo Lues Highland, Indonesia

Abstract

Context: Investigations of phytochemical screening and antibacterial activity were carried out on traditional medicinal plants collected in the highlands of Gayo Lues, Aceh Province, at an elevation of 1,000 meters above sea level (m.a.s.l.). Aims: To evaluate the antibacterial activity of plants chosen based on the interview results with the traditional healers (n = 5) in Gayo Lues. Methods: Ethanolic maceration was performed on the 12 identified ethnomedicinal plants and qualitatively screened for the phytochemical contents. Antibacterial activities against Escherichia coli ATCC 25922 and Staphylococcus aureus were tested for each extract based on the disc diffusion method, and MIC was determined using cephazolin as a reference drug. Results: The phytochemical screening of twelve plant species showed secondary metabolites class steroids, terpenoids, flavonoids, phenols, alkaloids, and saponins. Evaluation of the antibacterial activity of the extract (10 mg/mL) yielded inhibition zone ranges of 9.8 ± 0.26 to 21.87 ± 0.47 mm for E. coli and 8.93 ± 0.9 to 23.97 ± 0.68 for S. aureus. The ethanolic extract of Garcinia macrophylla Mart stem barks showed the highest antibacterial activity, where at the lowest concentration (1.25 mg/mL), the inhibition zones were found to be 19.2 ± 0.61 and 20.72 ± 0.44 mm for E. coli and S. aureus, respectively. The MIC was found to be 1.25 mg/mL. Conclusions: This study concludes that the twelve plant species are worthy of further investigation for novel antibacterial agent exploration.