Abstract: The aim of this study was to investigate the anti-bacterial and anthelminthic effects of different fractions of ethanol extract of Biebersteinia heterostemon Maxim. The B.heterostemon sample was firstly extracted by ethanol.The ethanol extract was then fractionated using petroleum ether,ethyl acetate and n-butanol sequentially. The anti-bacterial effects of different extracts of B.heterostemon were tested using the bacteriostatic cycle method.The minimal inhibitory concentrations (MICs) were determined by double dilution method.The modified Ren’s method was used to determine the active fraction with anthelminthic effect and its respective minimal effective concentration (MEC).The results showed that the ethyl acetate fraction of B.heterostemon ethanol extract had strong inhibitory effect on Staphylococcus aureus, Pseudomonas aeruginosa and Enterobacter cloacae, with MIC of 0.125 mg/mL.Its inhibitory effect on Bacillus proteus, Enterococcus faecalis and Blastomyces albicans were also strong with MIC of 0.25 mg/mL.Both petroleum ether fraction and ethyl acetate fraction had obviously inhibitory effect on Trichomonas vaginalis with MICs of 0.5 mg/mL and 0.25 mg/mL,respectively.Based on these experimental results,it was concluded that the ethyl acetate fraction of B.heterostemon ethanol extract had strong anti-bacterial and anthelminthic effects.

Key words: Biebersteinia heterostemon Maxim, active fraction, anti-bacterial and anthelminthic