Chemical Composition and Antibacterial, Antioxidant, and Cytotoxic Activities of Essential Oils from Leaves and Stems of Aeschynomene indica L

The objective of this study was to analyze the chemical composition and evaluate the biological capabilities of the essential oils (EOs) extracted from leaves and stems of wild Aeschynomene indica L. plants by the hydrodistillation method. By using GC-FID/MS, fifty-six and fifty-five compounds, representing 95.1 and 97.6% of the essential oils in the leaves and stems, respectively, were characterized. The predominant constituents of A. indica EOs were (E)-caryophyllene, linalool, viridiflorol, phytol, hexadecanoic acid, trans-verbenol, and α-guaiene. The antibacterial and synergistic activities of the EOs were assessed by microdilution and checkerboard assays. The results revealed a potent inhibition and bactericidal activity against Staphylococcus aureus and Bacillus subtilis with MICs of 0.312–0.625 mg/mL. When combined with traditional antibiotics, the essential oils of A. indica possessed excellent synergistic effects against all tested bacteria. Additionally, the EOs of A. indica leaves showed higher antioxidant activity (IC₅₀ = 0.11 ± 0.01 µg/mL) compared to the stem oil (IC₅₀ = 0.19 ± 0.01 µg/mL) using the ABTS radical scavenging assay. The in vitro cytotoxicity of EOs against human cancer cell lines HepG2, MCF-7, A-549, and HCT-116 was examined, and MTT assays showed that the EOs possessed a significant cytotoxic potential against MCF-7 breast cancer cells, with IC₅₀ values of 10.04 ± 1.82 and 15.89 ± 1.66 μg/mL, and a moderate cytotoxic activity against other tested cells. In conclusion, the A. indica EOs could be considered a potential source of pharmacologically active compounds.