Study on the in Vitro Antimicrobial Activity Screening for Different Extracts of Bateri Qiwei Pills and Acute Toxicity

OBJECTIVE To screening the antibacterial activity of different extracts of Mongolian medicine Bateri Qiwei pills against 7 common clinical pathogenic bacteria in vitro, and assessing the acute toxicity for the selected effective parts. METHODS The antimicrobial effect of the different extracts of the Bateri Qiwei pills was investigated according to the absorbance value and the minimum inhibitory concentration(MIC) measured by the methods of TTC and turbidimetric on micropore plate, and the effective parts of Bateri Qiwei pills were confirmed preliminarily by the above tests. Using the water extract of Bateri Qiwei pills as contrast, the acute toxicity of effective parts of Bateri Qiwei pills was evaluated by the experiment of half lethal dose(LD₅₀) and maximum tolerance in mice. RESULTS The six extracted parts of Bateri Qiwei pills, including petroleum ether, chloroform, ethyl acetate, n-butanol, ethyl acetate-n-butanol and water residue, had certain antibacterial activity. Among them, the parts of ethyl acetate-n-butanol had strong antimicrobial activity, especially to Staphylococcus aureus and Salmonella enteritidis, the value of MIC were 0.04 mg·mL^-1 and 0.08 mg·mL^-1, respectively. There were no LD₅₀ value for the water extract and the effective part of Bateri Qiwei pills appeared in the tests. And the maximum tolerance dosage in mice was 120 times of the clinical safe dosage in human(70 kg), and acute toxicity was not found. CONCLUSION The different extracts of Bateri Qiwei pills all have antibacterial activity, and the parts of ethyl acetate-n-butanol of Bateri Qiwei pills have strong antibacterial activity. Acute toxicity evaluation of the selected effective sites is relatively low, its mechanism of action needs to be further studied.