Antibacterial Sensitivity of Crude Extracts and Various Fractions of Berberis vulgaris L. Roots

Abstract

The problem of antibiotic resistance is an increasing health challenge in the world and is requiring the search of natural sources of new antimicrobial agents. Plant-based phytochemicals have also been of much interest as alternative therapeutic agents. Berberis vulgaris L., also known as barberry, is a typical medicinal plant which has a broad range of secondary metabolites that have been reported to have antimicrobial ability. This study investigates the antibacterial activity of crude methanolic extract and solvent-partitioned fractions (n-hexane, chloroform, ethyl acetate, methanol and butanol) of B. vulgaris roots. Antibacterial activity was evaluated against five clinically significant bacterial strains (E. coli, K. pneumoniae, S. epidermidis, S. aureus and B. subtilis) using the disc diffusion assay. Streptomycin served as a standard reference drug. The results showed that antibacterial activity varied considerably among fractions, with methanol, butanol and ethyl acetate displaying the strongest inhibitory effects. The methanol fraction demonstrated the highest activity against B. subtilis (28.44 ± 1.60 mm), while chloroform fraction exhibited notable activity against S. epidermidis (22.76 ± 1.05 mm). Comparatively, non-polar fractions such as n-hexane showed limited antibacterial effects. The findings suggest that B. vulgaris root extracts, particularly polar fractions, contain potent antibacterial constituents that warrant further purification and pharmacological validation.