蜂胶与柠檬提取物混合液对变形链球菌作用的体外研究

目的：探讨蜂胶与柠檬提取物混合液对变形链球菌（Streptococcus mutans．S．m）生长、产酸的抑制作用，以及对主要致龋毒力因子乳酸脱氢酶（Lactate dehydrogenase，LDH）活性的影响。方法：分别测定蜂胶、柠檬以及两者混合液的最小抑菌浓度（MIC）值，通过分级抑制浓度（FIC）指数来判断两者联合使用对S．m（ATCC25175）生长作用的影响，并在低于混合液最小抑菌浓度的混合液中培养S．m，用pH计测其培养前后的ApH（酸碱度的变化），同时采用还原性辅酶I氧化法测定混合液对S．m乳酸脱氢酶活性的影响。结果：蜂胶与柠檬提取物混合液对变形链球菌的体外抗菌活性具有相加作用，随着菌混合液浓度的升高，△pH和乳酸脱氢酶活性逐渐降低。结论：蜂胶与柠檬提取物混合液能有效的抑制变形链球菌的生长，对其产酸及乳酸脱氢酶有较强的抑制作用。

Experimental study of inhibitory effect of Propolis and Lemon peel extract compounds on streptococcus mutans in vitro

Objective： To investigate the effects of Propolis and Lemon peel extraet（LPE） compounds on the growth and acid production of S. m; and the effect of compounds on lactate dehydrogenase（LDH） which is the main virulence factor that leads to caries. Methods： Minimal inhibitory concentration（MIC） of alone and combined applications of Propolis with LPE on growth of S. m were measured. Fractional inhibitory concentra- tion （FIC） was calculated accordingly to evaluate the combined effect of Propolis with LPE. The ApH values were measured after combined application of Propolis with LPE in the low concentrations of MIC. Lactate de- hydrogenase＇s activity was assayed by pyruvate -- dependent oxidation of NADH. Results. Combined applica- tion of Propolis and LPE has additive antibacterial effect on S.m. ApH and lactate dehydrogenase of s. m de- creased gradually with the increase of each combined concentration at low concentrations. Conclusion. Combined application of Propolis and LPE can inhibit the growth and acid production of S. m as well as lactate dehydrogenase.