绿茶粗提物对耻垢分枝杆菌的生长抑制研究

Inhibitory Effect of Crude Extract from Green Tea on Mycobacterium smegmatis mc2155

采用乙酸乙酯在中性条件下萃取绿茶,得到含有表没食子儿茶素没食子酸酯(Epigallocatechin gallate,EGCG)的粗提物。通过纸片琼脂扩散法和细菌生长曲线来评价绿茶粗提物对耻垢分枝杆菌的抑菌效果,利用透射电子显微镜(Transmission electron microscopy,TEM)观察其对耻垢分枝杆菌细胞壁结构的影响。结果显示,绿茶粗提物对耻垢分枝杆菌生长产生明显抑制作用,且抑菌作用随着浓度的升高逐渐加强;经绿茶粗提物处理的耻垢分枝杆菌细胞壁呈现膨出、变形等形态学变化。因此,绿茶粗提物具有抑制耻垢分枝杆菌生长的功能,其作用机制可能与其主要成分EGCG影响细胞壁肽聚糖的生物合成有关。

Crude green tea extract containing epigallocatechin gallate（EGCG） was prepared by ethyl acetate extraction under neutral condition.Inhibitory effect from crude extract against Mycobacterium smegmatis mc2155 was determined by both disk agar diffusion method and growth curve.The changes of structure of cell wall were observed by transmission electron microscopy（TEM）.Crude extract showed significant growth inhibition of M.smegmatis mc2155 from both approaches,and the inhibitions were dose-dependent.The changes of cell wall structure were confirmed by TEM.The inhibitory effect of crude tea extract against M.smegmatis mc2155 was detected in this study,and it was postulated that EGCG,a known biologically active compound in green tea,might played a major role against Mycobacterium causing inhibition of biosynthesis of peptidoglycan in the cell wall.