厚朴酚及和厚朴酚对变异链球菌形态及细胞膜通透性的影响

摘要

目的:研究厚朴酚及和厚朴酚对变异链球菌形态、细胞膜通透性的影响.方法:以变异链球菌(S.mutans)ATCC 25175为实验菌株,测定厚朴酚及和厚朴酚的最低抑菌浓度(MIC)及最低杀菌浓度(MBC).以MIC、10×MIC的厚朴酚及和厚朴酚为实验组,青霉素G为阳性对照组,生理盐水为阴性对照组,然后加入液体培养基培养实验菌株.用扫描电镜观察细菌表面形态,原子吸收分光光度计测定培养基中的钙离子浓度.结果:厚朴酚及和厚朴酚MIC(μg/mL)分别为15.7、7.8,MBC(μg/mL)分别为125、62.5;作用于S.mutans 后,细菌结构及形态与阴性对照组相似,表面光滑、饱满;阳性对照组细菌表面呈"桑椹状",可见部分菌体破裂.实验组细菌的培养液中钙离子浓度高于阴性对照组(P<0.05),低于阳性对照组(P<0.05).同种药物作用下,10×MIC浓度组较MIC浓度组培养液中钙离子浓度增加(P<0.05);相同药物浓度下,和厚朴酚组培养液中钙离子浓度高于厚朴酚组(P<0.05).结论:厚朴酚及和厚朴酚对S.mutans形态无明显影响,但可导致细胞内钙离子的流失,具有浓度依赖性,且和厚朴酚的作用强于厚朴酚.%AIM:To investigate the effects of magnolol and honokiol on the morphology and cellular membrane permeability of Streptococcus mutans (S.mutans).METHODS:The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of magnolol and honokiol on S.mutans ATCC 25175 were measured.S.mutans were treated by magnolol and honokiol at of MIC and 10×MIC respectively.Penicillin G was used as the positive control and saline as the negative control.Morphology of the bacteria were observed by a scanning electron microscope.The concentration of calcium ions in culture medium was measured by an atomic absorption spectrophotometer.RESULTS:After treatment with magnolol and honokiol,the morphology and structure of S.mutans showed no obvious changes.The bacteria arranged in a chain with a smooth surface.While in positive control group,S.mutans showed damaged structure with a "mulberry-like" surface.Calcium concentration of the experimental groups was higher than that of the negative control group(P<0.05),but lower than positive control(P<0.05).With both treatment,calcium concentrations in 10×MIC groups were higher than that of MIC groups (P<0.05).In the same concentration groups,calcium concentrations in honokiol groups were higher than that of magnolol groups (P<0.05).CONULUSION:Magnolol and honokiol do not induce obvious morphological changes of S.mutans.Both magnolol and honokiol may increase the cellular membrane permeability of S.mutans.