茎直黄芪提取物的体外抑菌作用

Experimental Study on Antimicrobial Effects of Extracts from Astragalus strictus in Vitro

为研究茎直黄芪提取物的体外抑菌作用,采用琼脂扩散和试管稀释法对其抑菌效果进行了研究。结果显示茎直黄芪石油醚部分、氯仿部分、乙酸乙酯部分和正丁醇部分提取物对金黄色葡萄球菌、大肠埃希菌、无乳链球菌、沙门氏菌和多杀性巴氏杆菌等5种细菌有不同程度的抑菌作用,其中正丁醇部分抑菌作用较强。通过进一步试验表明正丁醇部分主要抑菌活性成分集中在20%乙醇和40%乙醇部分,尤其以后者抑菌活性最佳。40%乙醇部分对5种细菌的MIC均为6.25 mg/mL,对大肠埃希菌的MBC为6.25 mg/mL。对金黄色葡萄球菌、沙门氏菌和多杀性巴氏杆菌的MBC均为12.25 mg/mL,对无乳链球菌的MBC为25.00mg/mL。通过研究发现茎直黄芪提取物在体外具有明显的抑菌作用。

In order to st ud：y the bacteriostatic action of extractives from Astragalus strictus in vitro, agar diffusion and tube dilution method were used to observe experimentally its bacteriostatic efficacy. The results showed that the four kinds of extractives which were extracted by petroleum ether, CHCl3, EtOAc and nBuOH, successively have different bacteriostatic action to five kinds of bacteria, such as ： Staphylococcus aureus , Escherichia c oli, Streptococcus agalactia , Salmonella and Pasteurel- la multocida. The extractum from nBuOH has significant in vitro effect of growth inhibition on bacteria, advanced test indicated the major active components of nBuOH fraction exist in 20% and 40% EtOH, especially in the latter. The minimum inhibition concentration （MIC） of 40% EtOH extracturn for five bacteria was 6.25 mg/mL. The minimal bactericidal concentration （MBC） of 40% EtOH extractum for Escherichia coli was 6.25 mg/mL, for Staphylococcus aureus ,Salmonella and Pasteurella multocida was 12.25 mg/mL ,for Streptococcus agatactia was 25.00 mg/mL. Through this experiment indicated that the extractives from Astragalus strictus have obvious in vitro bacteriostatic effect.