藠头总皂苷抗菌活性及其作用机理

Antimicrobial Activity and Mechanism of Total Saponins from Allium chinense

藠头总皂苷、30%和60%乙醇藠头粗提物分别作用于酵母菌、白色念球菌、金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、绿脓杆菌等,采用滤纸片法测定藠头总皂苷抗菌活性,并从生理代谢方面研究其抗菌作用机理,结合DNS法测定葡萄糖含量,直接紫外分光光度法测定过氧化氢酶活性,Brandford法测定菌体总蛋白含量并进行SDS-PAGE检测。结果表明:藠头总皂苷对酵母菌、白色念球菌及金黄色葡萄球菌等都具有抑制作用,但对大肠杆菌、枯草芽孢杆菌、绿脓杆菌等抗菌活性很弱或无抗菌活性,同时经藠头总皂苷、30%和60%乙醇藠头粗提物处理后的酵母菌、白色念球菌及金黄色葡萄球菌对葡萄糖的利用率降低,过氧化氢酶活性受到抑制,菌体总蛋白质含量下降,一些蛋白谱带明显减弱甚至消失。藠头总皂苷是通过降低菌对葡萄糖的利用率,从而影响菌的生长与繁殖,降低一些生理代谢所需关键酶的活性,进而抑制相关蛋白质的合成,并最终达到抑菌效果。

Total saponins, 30% and 60% ethanol crude extracts from Allium chinense were tested on different microorganisms. The antimicrobial activity of total saponins was determined using filter slice method. In order to explore their antimicrobial mechanisms from physiological metabolic aspects, glucose content was determined through DNS test, catalase activity was tested by direct ultraviolet spectrophotometric method, and total protein of bacteria was measured by Bradford method. The results showed that total saponins had excellent antimicrobial activity against Saccharomycete, Tritirachium album and Staphylococcus aureus, but very weak or without inhibitory effect against others test microorganisms. At the same time, glucose utilization rate, catalase activity, and protein content in these microorganisms were reduced and some protein spectra were weakened obviously even disappeared in the presence of Allium chinense saponins. Based on our current knowledge, the possible antimicrobial mechanism of total saponins was due to the reduced glucose utilization efficiency in microorganisms, then affecting their growth and proliferation, reducing the activity of key enzymes in physiological metabolism and suppressing the synthesis of relevant proteins, and finally executing the antibacterial effect. This study will provide theoretical and practical application value to reduce the utilization of currently available antibiotics and develop natural antimicrobial drugs.