青钱柳多糖抑菌活性及作用机制研究

Study on the antibacterial activity and mechanism of polysaccharides from Cyclocarya paliurus

目的研究青钱柳多糖(Cyclocarya paliurus polysaccharides,CPP)抑菌活性及作用机制。方法用不同质量浓度CPP处理细菌后,通过最小抑菌浓度(minimum inhibitory concentration,MIC)、抑菌生长曲线分析CPP对细菌的抑菌效果,并从抑制效果最佳的受试菌菌体电导率、细胞蛋白和核酸含量、还原糖的释放、呼吸链脱氢酶活性、脂质过氧化程度、细胞内三磷酸腺苷(adenosine triphosphate,ATP)含量、细胞外碱性磷酸酶(alkaline phosphatase,AKP)活力的角度来揭示其抑菌机制。结果CPP对金黄色葡萄球菌(Staphylococcus aureus)、大肠杆菌(Escherichia coil)、单增李斯特氏菌(Listeria monocytogenes)和鼠伤寒沙门氏菌(Salmonella typhimurium)有明显的抑制作用,MICs分别为2、4、6、6 mg/mL,对枯草芽孢杆菌(Bacillus subtilis)的抑菌性不明显;对指示菌的电导率、蛋白质和核酸渗漏、还原糖释放、呼吸链脱氢酶活性、细菌脂质过氧化程度、菌体胞内ATP和胞外碱性磷酸酶含量均有影响。结论CPP具有抑菌活性,其抑菌性主要是破坏菌体细胞壁和细胞膜完整性,改变其通透性,使得胞内大小分子物质外泄,抑制细胞的呼吸代谢和引起氧化损失,进而影响细胞的生长代谢或造成细胞死亡,达到抑菌效果。本研究结果为CPP的抑菌机制探究提供一定的基础数据。

Objective To investigate the antibacterial activity and mechanism of Cyclocarya paliurus polysaccharides(CPP)against common bacteria.Methods After treating the bacteria with different mass concentrations of CPP,the inhibitory effect of CPP on bacteria was analyzed by minimum inhibitory concentration(MIC)and growth curve.The best inhibitory effect of the tested bacteria was from the aspects of conductivity,cellular protein and nucleic acid content,reducing sugar release,respiratory chain dehydrogenase activity,lipid peroxidation degree,intracellular adenosine triphosphate(ATP)content,extracellular alkaline phosphatase(AKP)activity to reveal the antibacterial mechanism.Results CPP showed significant inhibitory effects on Staphylococcus aureus,Escherichia coil,Listeria monocytogenes and Salmonella typhimurium,with MICs of 2,4,6 and 6 mg/mL,respectively.CPP showed no significant inhibitory effects on Bacillus subtilis.It also affected the conductivity,protein and nucleic acid leakage,reducing sugar release,respiratory chain dehydrogenase activity,bacterial lipid peroxidation,intracellular adenosine triphosphate and extracellular alkaline phosphatase content of the indicator bacteria.Conclusion CPP has bacteriostatic activity.The antibacterial effect of CPP may mainly by destroying the integrity of the cell wall and cell membrane,changing its permeability,resulting in the release of intracellular large and small molecular substances,inhibiting the respiration and metabolism of cells and causing oxidative loss,thereby affecting the growth and metabolism of cells or causing cell death and achieving the antibacterial effect.The results of this study provide some basic data for the exploration of the antibacterial mechanism of CPP.