染料木素的抑菌活性及其机制的研究

STUDY ON ANTI-MICROBIAL ACTIVITY OF GENISTEIN AND ITS MECHANISM

目的研究染料木素(genistein)的抑菌活性以及抑菌机制。方法利用杯碟法、扫描电镜与透射电镜、呼吸代谢抑制实验和SDS-PAGE蛋白谱带变化对染料木素的抑菌活性及其作用机制进行研究。结果染料木素具有明显的抑菌活性;扫描电镜观察,染料木素作用金黄色葡萄球菌24h后,表面出现皱缩、囊泡状或不规则突起结构;透射电镜观察,染料木素处理4h后,金黄色葡萄球菌的细胞质开始固缩,14h后有明显的质壁分离现象,并出现空腔,24h后细胞壁和细胞膜破裂,破裂处有胞浆内容物溢出;染料木素主要是抑制金黄色葡萄球菌的三羧酸循环途径;SDS-PAGE蛋白谱带分析结果显示,染料木素可抑制金黄色葡萄球菌的蛋白合成,使其蛋白总量呈下降趋势,尤其是较大分子量的蛋白含量下降显著,其蛋白量减少了90.1%。结论染料木素对金黄色葡萄球菌有较强的抑菌活性,其抑菌机制是通过破坏细菌细胞壁及细胞膜的完整性、抑制细菌的呼吸代谢和抑制蛋白质的合成等多种作用的结果。

Objective To investigate the anti-microbial activity of genistein and its mechanism. Method The anti-microbial experiment was carried out by utilizing scanning and transmission electron microscope（SEM and TEM）, and further analyzing the respiratory metabolism and change of SDS-PAGE protein spectra. Results Genistein could inhibit several kinds of bacteria obviously.The erose structures such as rugae and bubbles were observed on the surface of cells by SEM after 24h. Moreover, with TEM, we detected the shrinkage of cytoplasm, the plasmolyses, and then the breach of wall and membrane along with the outflow of protoplasm in Staphylococcus aureus treated with genistein for 4h, 14h and 24h respectively. Notablely the respiratory inhibition experiment revealed that the genistein mainly inhibits the TCA cycle of bacteria. Besides, the SDS-PAGE elucidated that the total expression of proteins was decreased in the cell treated with genistein, and especially the larger proteins were reduced with 90.1%. Conclusion Genistein showed obvious anti-microbial activity to Staphylococcus aureus. It could destroy the integrity of cell wall and membrane, prevent the respiratory metabolism and orotein synthesis of the bacteria.