紫穗槐种子提取物的抑菌活性研究

目的研究紫穗槐种子提取物的抑菌活性。方法将紫穗槐种子乙醇提取物分别通过石油醚、乙酸乙酯和正丁醇萃取，选择金黄色葡萄球菌和肺炎克雷伯杆菌为供试菌，采用试管二倍稀释法测定紫穗槐种子提取物的最小抑菌浓度（MIC）和最小杀菌浓度（MBC），涂布平板法绘制杀菌曲线，电镜下观察药物对细菌超微结构的影响。结果紫穗槐种子提取物经乙酸乙酯萃取后对供试菌抑制作用较强，其中对金黄色葡萄球菌的MIC和MBC分别为2．5、5．0mg／mL；对肺炎克雷伯杆菌的MIC和MBC分别为5．0、10．0mg／mL；杀菌曲线结果表明，药物对供试菌的抑制作用存在浓度和时间依赖性；电镜结果说明，药物的作用可能与破坏菌体细胞壁、改变细胞膜通透性有关。结论紫穗槐种子提取物具有显著的抗菌活性。

Antibacterial activity of the extracts of Amorpha fruticosa seeds

Objective To measure the antibacterial activity of extracts of Amorpha frutieosa seeds. Methods The ethanol extracts of Amorpha fruticosa seeds were extracted with petroleum ether, ethyl acetate and n-butanol, re- spectively. Staphylococcus aureus and Klebsiella pneumoniae were selected as the tested bacteria. The minimum in- hibitory concentration （MIC） and the minimum bactericidal concentration （MBC） were determined by tube double dilution method; time-kill curve was determined by spread plate method; bacterial ultrastructure was observed by u- sing electron microscopy. Results The antibacterial activity of the ethanol extract of Amorpha fruticosa seeds trea- ted with ethyl acetate was stronger against the tested bacteria, with the MIC and MBC against Staphylococcus aureus were respectively 2.5 mg/mL and 5.0 mg,/mL, while the MIC and MBC to KlebsieUa pneumoniae were 5.0 mg/mL and 10.0 mg/mL respectively. Time kill curves showed that the inhibiton of the extracts against bacteria was con- centration- and time-dependent. Electron microscope results suggested that the drug effect may be related to the de- struction of bacterial cell wall and changes of cell membrane permeability. Conclusion The extracts of Amorpha fruticosa seeds have obvious antibacterial effects.