α-松油醇对大肠杆菌的抑菌作用及其机理研究

Bacteriostatic Action and Mechanism of α-terpineol on Escherichia coli

为探究α-松油醇的抑菌作用及其抑菌机理,采用肉汤培养基倍比稀释和沙氏琼脂平板稀释培养计数法测定α-松油醇对大肠杆菌标准菌的最小抑菌浓度(minimum inhibitory concentration,MIC)和最小杀菌浓度(mini-mum bactericidal concentration,MBC);通过细胞壁和细胞膜通透性变化试验、核酸合成抑制试验、SDS-聚丙烯酰胺凝胶电泳试验和内毒素活性抑制试验研究α-松油醇的抑菌机理。结果显示:α-松油醇对大肠杆菌有明显的抑制效果,MIC和MBC均为0.78μL.mL-1。α-松油醇可引起大肠杆菌胞外碱性磷酸酶和β-半乳糖苷酶活性明显增强;大肠杆菌DNA荧光强度明显减弱、可溶性蛋白谱带变浅。当α-松油醇浓度在2MIC以上时,内毒素分解率超过50%,家兔不呈现典型的热原反应。α-松油醇的抑菌机理是通过细菌细胞壁和细胞膜通透性的变化,抑制细菌核酸的合成和可溶性蛋白的表达以及药物与内毒素的拮抗作用实现的。

The present study was undertaken to study the inhibitory effect and mechanism of α-terpineol on Escherichia coli, to provide a theoretical basis for the development of new drugs. Minimal inhibitory concentration （MIC） were determined by the same ratio dilution method with broth medium and minimal bactericidal concentration （MBC） by SDA of α-terpineol on Escherichia coli. Permeability change experiment of cell wall and membrane, nucleic acid synthesis inhibitory experiment, SDS-polyacrylamide gel electrophoresis and endotoxin inhibitory experiment, were study in the study. Results were as follows： MIC and MBC of α-terpineol on Escherichia coli are all 0.78 μL·mL-1; Permeability of cell wall and membrane increasing; DNA fluorescence intensity is reduced and bacterial protein bands become light obviously; Endotoxin decomposed and show no typical pyrogen reaction in experimential group. It is suggested that the bacteriostatic mechanism of α-terpineol is based on its roles about changing the cell wall and membrance permeability, inhibite synthesis of nucleic acid and proteins and anti-endotoxin activity.