柠檬提取物对口腔致龋菌生长影响的研究

目的:检测柠檬提取物的生物安全性,研究柠檬提取物对主要致龋菌生长的影响,为进一步机制研究提供依据。方法:柠檬提取物ICR小鼠急性毒性试验(LD50试验):实验分两组,实验组柠檬水提浓缩液按0.05ml/10g.bw灌胃,空白对照组室温、阳光等饲养条件与实验组相同。饲养14d观察动物反应,第15天处死,解剖检查脏器情况;采用琼脂稀释法研究柠檬提取物对5种主要致龋菌(变异链球菌、血链球菌、内氏放线菌、远缘链球菌、嗜酸乳杆菌)生长的抑制作用,并采用菌落计数法检测柠檬提取物对5种细菌生长的影响。结果:ICR小鼠在14d观察期中未发现死亡现象,处死后检查各脏器无异常现象。柠檬提取物对变异链球菌、血链球菌、远缘链球菌的最小抑菌浓度MIC(minimum inhibitory concentration)为4.5g/L,对嗜酸乳杆菌和内氏放线菌的MIC为2.25g/L。5种致龋菌在柠檬提取物作用下,其生长曲线均在第6小时左右出现明显的转折点,实验组与阴性组的细菌菌量均有显著性差异(P<0.05)。结论:柠檬提取物样品LD50大于5000mg/kg.bw,属于实际无毒物质;柠檬提取物对口腔致龋菌的生长有抑制作用。

Effect of Lemon Peel Extracts on the Growth of Cariogenic Bacteria

Objective: To test the biological safety of lemon peel extract,find effect of lemon peel extracts on the growth of cariogenic bacteria and provide a basis for further study of mechanism.Methods: Acute toxicity test of lemon peel extracts on ICR mice(LD50 test): This experiment was divided into two groups.The experimental group was fed by lemonade concentrate with concentration of 0.05ml/10g·bw.The room temperature,sunlight and other breeding conditions of control group were same with experimental group.14-day’s observation of animal response to feeding was conducted.These mice were killed and dissected to check the organs on the 15th day.The effect of lemon peel extracts on the growth of L.acidophilus,A.naeslundii,S.sangius,S.mutans and S.sobrinus was studied by the agar dilution diffusion test.And the effects on the growth curve of these cariogenic bacteria were also investigated.Results: ICR mice have no abnormal phenomena fed by LPE during the 14-day observation period.Also,we found that the organs were normal by macrography after mice dissected.The MIC(minimum inhibitory concentration)value of the lemon peel extracts against S.mutans,S.sangius,S.sobrinus is 4.5mg/ml,and the MIC value against L.acidophilus,A.naeslundii is 2.25mg/ml.All the growth curves of cariogenic bacteria have a turning point at the sixth hour,which is affected by the LPE.And there are significant difference between the control groups and the experimental groups.Conclusion: Lemon peel extracts samples,whose LD50 are bigger than 5000mg/kg·bw,are nontoxic.The growth of cariogenic bacteria can be significantly inhibited by the lemon peel extracts(LPE).