Inhibiting effect of combination of oleanolic acid and dimethyl sulfoxide on enterococcus faecalis

WU You; HU Yan; WANG Yao

doi:10.3969/j.issn.1002-266X.2016.29.006

Abstract：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.