Phytochemical analysis, evaluation of the antioxidant and antibacterial activities of the leaf extracts of Premna schimperi

Premna schimperi, commonly known as chocho, is a medicinal plant in the Lamiaceae family, with its leaves traditionally used to treat external injuries, wounds, and common eye infections in cattle. The study focused on phytochemical analysis and evaluation of the antioxidant and antibacterial properties of the solvent extracts of the leaves. The leaves of P. schimperi (0.5 kg) were macerated successively with 1250 mL n-hexane, ethyl acetate (EtOAc), and methanol (MeOH), resulting in 1.1 % n-hexane, 2.6% ethyl acetate, and 5.02% methanol crude extracts. Phytochemical screening showed the presence of alkaloids, saponins, flavonoids, phenols, steroids, terpenoids, tannins, anthraquinones, and glycosides in the MeOH extract. The solvent extracts were tested against four bacteria using the disc diffusion method. Results showed greater inhibition at 200 mg/mL than at lower concentrations. The antioxidant activities of the crude extracts were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and H2O2 assays. Among the tested extracts, the MeOH extract demonstrated the most potent antioxidant activity in both assays, with the lowest IC50 values (35.35 µg/mL for DPPH and 51.4 µg/mL for H2O2 scavenging), performing closest to the ascorbic acid standard. Therefore, it is strongly recommended to isolate antioxidant components from the MeOH extract. KEY WORDS: Maceration, Phytochemicals, Antibacterial, Antioxidant, Premna schimperi Bull. Chem. Soc. Ethiop. 2027, 41(1), 43-53. DOI: https://dx.doi.org/10.4314/bcse.v41i1.4