齐墩果酸联合二甲亚砜对粪肠球菌的抑制作用

摘要

Objective To investigate the inhibiting effect of oleanolic acid ( OA) and dimethyl sulfoxide ( DMSO) on enterococcus faecalis ( E.faecalis) in drug sensitive test, and its antibacterial effect in E.faecalis infected root canals. Methods Measuring the minimal inhibitory concentrations ( MICs) of OA and DMSO respectively.The microdilution checkerboard technique was applied to evaluate the antibacterial effect of OA combined with DMSO and calculate the frac-tional inhibitory concentration index (FICI).E.faecalis infected root canal models in extracted single-canal permanent teeth were established.Samples were randomly divided into three groups:group A which was treated with 1 mg/ml OA+50%DMSO for intracranial medication, group B with 2% chlorhexidine (CHX), and group C with deionized water ( DIW) .Before intracranial medication or after treatment 1 h, 24 h and 7 d, the bacteria counting was recorded and the statistical analysis was conducted.Results The MIC of DMSO against E.faecalis was 20%, the MIC of OA against E. faecalis was 100μg/ml.The FICI of DMSO and OA against E.faecalis 0.5125.Statistical analysis found that the amount of bacteria in three groups after treatment was reduced, the decrement of groups A and B showed statistical difference ( all P<0.05).Group A needed a little longer action time than that of group B and significant difference was found in the a-mount of bacteria within 1 h (P<0.05), however, no viable E.faecalis was detected when the treatment time maintained for 24 h or 7 d in both groups (all P>0.05).Conclusion DMSO combined with OA have additive antibacterial effect a-gainst E.faecalis, and the combined application can effectively inhibit the bacteria growth in root canal.%目的：探讨齐墩果酸与二甲亚砜联合对粪肠球菌的抑制作用，以及在粪肠球菌感染根管模型中的抑菌效果。方法分别测定二甲亚砜、齐墩果酸的最小抑菌浓度值（ MIC），采用微量棋盘液体稀释法测定联合时对粪肠球菌的抑菌效果，计算抑菌浓度分数指数（ FICI）。建立离体牙粪肠球菌感染根管模型，随机分为3组，分别用1 mg／mL齐墩果酸＋50％二甲亚砜（ A组）、2％洗必泰（ B组）、去离子水（ C组）根管内封药，封药前及封药1 h、24 h、7 d分别取样进行细菌培养计数，并进行统计学分析。结果二甲亚砜对粪肠球菌的MIC为20％，齐墩果酸对粪肠球菌的MIC为100μg／mL。齐墩果酸联合二甲亚砜FICI为0．5125。3组处理后比处理前细菌数量均有减少， A、B组差异均具有统计学意义（P均＜0．05）；A组所需作用时间较B组稍长，1 h两者菌落数比较差异有统计学意义（P＜0．05），24 h、7 d均能完全抑制根管内粪肠球菌生长，比较差异无统计学意义（P均＞0．05）。结论齐墩果酸与二甲亚砜联合对体外粪肠球菌的抗菌作用表现为相加作用，二者联合应用可有效抑制根管内粪肠球菌生长。