Isolation and antimicrobial efficacy tests of Bergenia ciliate using in vitro models

Antimicrobial activities of five compounds isolated from ethyl acetate fractions of Bergenia ciliate were investigated. All compounds exhibited antimicrobial efficacy on the tested microorganisms, that included two human Gram-positive bacteria (Staphylococcus aureus and Micrococcus luteus) and four Gram-negative ones (Escherichia coli, Pseudomonas aeruginosa, Enterobacter cloacae, and Klebsiella Pneumonia). Compound 1 exhibited the highest antimicrobial activity compared to the other compounds. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of compound 1 was carried out by agar dilution method and viable cell count method, respectively. These constituents were isolated first time from B. ciliate which is credible as standard antimicrobial drugs. MICs ranged from 0.156 to >10 µg/ml and MBCs from 1.26 to 15 µg/ml. Compound 1 showed antifungal activity 7 (±0.3) mm while compounds 2 to 5 have moderate activity 5 (±0.12) ~ 2 (±0.1) mm. Key words: Bergenia ciliate, isolation, antimicrobial activity, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC).