Phytochemical screening and antimicrobial activities of the Heamatostaphis barteri stem bark

Abstract

Medicinal plants serve as reservoirs of bioactive compounds with therapeutic potential. Stem bark of Heamatostaphis barteri, though traditionally utilized in various communities for treating infections, remains underexplored scientifically. This study aimed to evaluate the phytochemical composition, antimicrobial activity, antioxidant potential, functional group characterization, and cytotoxic properties of the ethanolic extract of stem bark of Heamatostaphis barteri. Ethanolic extraction was carried out on powdered H. barteri stem bark. Qualitative and quantitative phytochemical analyses were performed using standard procedures. Antimicrobial activity was evaluated against five pathogens; E. coliS. aureus, P. aeruginosa, B. subtilis and C. albicans sing agar well diffusion. Antioxidant assay 2-di-phenyl-1-picryhydrazyl and hydrogen peroxide scavenging were conducted, and Fourier Transform Infrared spectroscopy (FTIRS) was used for functional group analysis. Cytotoxicity was preliminarily assessed via brine shrimp lethality assay. Phytochemical screening revealed the presence of alkaloids, flavonoids, tannins, phenols, and terpenoids. Quantitative analysis indicated phenols (5.23 ± 0.15 mg/100g) and flavonoids (4.67 ± 0.12 mg/100g) as the most abundant. Antimicrobial results showed concentration-dependent inhibition, with highest zones against Staphylococcus aureus (16.1 ± 0.6 mm) and Bacillus subtilis (15.7 ± 0.8 mm) at 200 mg/mL. Antioxidant activity was significant with IC₅₀ values of 0.44 µg/mL 2-di-phenyl-1-picryhydrazyl (DPPH) and 0.42 µg/mL (H₂O₂), surpassing ascorbic acid. FTIR analysis confirmed the presence of O–H, C=O, and C–O groups. The brine shrimp assay showed moderate cytotoxicity (LC₅₀ = 23.31 ppm). Results obtained in this study have indicated that Heamatostaphis barteri stem bark ethanolic extract contained potent bioactive compounds with significant antimicrobial and antioxidant properties, validating its ethnomedicinal use and potential for drug development.