Antibacterial and antioxidant activities of Eleutherine americana (Aubl.) Merr. leaves extract growing in different cultivation sites

Eleutherine americana (Aubl.) Merr. is used as a traditional remedy in Indonesia. Based on its chemical compounds, the leaves were expected to exhibit antibacterial and antioxidant activities. The aim of the study was to assess the antibacterial capacity, antioxidant capacity, total phenolic content, total flavonoid content, and phytochemical compounds in ethanolic extract of E. americana leaves collected from various cultivation sites, namely West Kotawaringin, Central Kalimantan (EW); Malang, East Java (EM); and Probolinggo, East Java (EP). The antibacterial activity assay was conducted utilizing the diffusion method, whereas the determination of antioxidant capacity was performed utilizing the DPPH method. The total phenolic content and total flavonoid content were determined using UV-Vis spectrophotometry. The phytochemical screening was conducted utilizing a tube test and thin layer chromatography (TLC) method. The growth of E. coli and S. aureus was found to be inhibited by EW, EM, and EP. Furthermore, the antibacterial activity of all samples against S. aureus was higher than that against E. coli. EP had the highest antioxidant activity (IC₅₀ = 32.83±3.51 µg/mL), total phenolic content of 129.40±0.19 mg GAE/g extract, and total flavonoid content of 0.61±0.01 mg QE/g extract. Phytochemical screening revealed that the leaves of E. americana contained alkaloids, terpenoids, flavonoids, polyphenols, and tannins. According to the findings of this study, E. americana leaves could potentially be developed as a new natural antibacterial and antioxidant agent.