[Study of antibacterial effects of different fractions of leaves extract of Ajuga chamaecistus Ging. Subsp. Scoparia [Bioss] rech. f. and bioautography of effective fraction]

ABSTRACT

Today, the emergence of antimicrobial resistance against conventional antibiotics is increasing. Many researchers consider plants with antimicrobial properties as a good alternative. In this study, the antimicrobial activity of Ajuga chamaecistus Ging. Subsp. Scoparia [Bioss] Rech. f. on 8 bacterial strains was investigated. The leaf extract was prepared by methanolic maceration. The concentrated, dried extract was fractionated by different solvents including petroleum ether, dichloro methane, and ethyl acetate. Determination of minimum inhibitory concentration [MIC] of crude extract was performed using agar dilution method. Disk diffusion method was used for antimicrobial assay of different fractions. Then, the chemical constituents of the most effective fraction were separated on thin-layer chromatography [TLC] plates. Then, the prepared chromatograms were analyzed using immersion bioautography. According to disk diffusion method, ethyl acetate fraction had stronger antibacterial activity against all tested bacteria. Bioautography of this fraction showed antibacterial activity against Staphylococcus aureus in R[f] = 0.9. However, all tested bacteria had inhibition spots in the site of fraction loading. Antibacterial activity of ethyl acetate fraction will appear if all components are used together