【作者】 左渝陵；

【导师】 周学东；

【作者基本信息】 四川大学 ， 口腔临床医学， 2005， 博士

【摘要】 一直以来,龋病的有效预防都是国内外的研究重点。近年来,国内外许多学者致力于天然药物的防治龋病研究,本课题组在国内外首次开展中药防龋的系列研究,通过对11味中药的防龋筛选实验发现蜂房(Nidus Vespae)具有良好的防龋效能。在体外抑龋实验中,即使在不影响各实验菌株生长的较低浓度下也可有效抑制致龋菌的产酸,合成胞外多糖及早期黏附等致龋毒力因子,在生物膜模型中随着蜂房提取物溶液的加入,显著减少了变形链球菌在羟磷灰石片上黏附的量以及胞外基质的量,提示蜂房溶液的加入可能对菌斑的致龋化转变有一定的抑制作用。本研究在前期研究的基础上,采用现代的分离手段对蜂房的化学成分进行提取、分离和鉴定,研究蜂房化学成分对口腔细菌的生长、代谢、黏附作用,以及蜂房化学成分对牙体硬组织的作用,并采用先进的口腔生物膜模型,研究蜂房药效成分对口腔细菌生物膜的作用,以此对蜂房的防龋物质基础进行系统研究。 方法:用现代的分离手段分离、提取和鉴定蜂房化学组分和化学单体,针对常见致龋菌的主要毒力因子进行系统的体外抑龋实验,评估蜂房化学成分对口腔常驻细菌生长、产酸、产糖及黏附的作用;利用pH循更多还原

【Abstract】 Dental caries is fundamentally a microbial disease, which involves the hard tissue of tooth. The prevention of dental caries have been extensively studied worldwide, however none of the existed preventive ways of dental caries is ideal. There are many theories and prescribes in ancient Chinese natural medicine deal with dental caries, which facilitate the study of preventing dental caries by herbal medicine. In our previous study, we find out the extract of Nidus Vespae has significant anticaries effects in vitro and in biofilm model. But no study tells us about the effective anticaries component of Nidus Vespae and how they affect the metabolism and growth of cariogenic bacteria and oral biofilm until now. The aim of this study is to investigate the chemical components of Nidus Vespae and their anticaries effect, to trace out and identify the most effective component and to evaluate the anticaries efficacy of the active component in biofilm model. Methods: Based on previous study, the five Nidus Vespae extracts （NVE） were isolated. Then four components were separated from five NVE and their chemical structure is identified using ¹H-NMR and ¹³C-NMR. A series of invitro anticarious experiments, inhibition of growth, acid production, glucan generation and initial adherence, have been carried out using the Galla Chinesis extract. A four-organism bacterial consortium was grown in a biofilm model on hydroxyapatite （HA） discs and bovine enamel blocks in a continuous culture system and exposed to repeated solution pulsing respectively. The negative control group was pulsed with 25mM sucrose solution, positve control group was pulsed with sucrose solution and 228ppm NaF. While 4.0 mg/ml NVE1 solution together with 25mmol/l sucrose was pulsed in the experiment group. During the experiment, the pH responses against the pulses are recorded. After 10 pulses, the biofilm surface structure was observed with the Fluorescence Microscope and the population of the biofilm was enumerated. And the affects of enamel structure was also check under a polarized microscope.Results: NVE1, NVE2, NVE3, NVE4 and NVE5 were extracted from Nidus Vespae. Four different compounds are further extracted from NVE and three of them were identified asP-sitosterol, P-daucosterol and one kind of saturated fatty acid which name by ZWC2. NVE and four different compounds were proved to be effective in in vitro anticaries experiments, and NVE1 can significantly inhibit the adherence of oral bacteria to HA discs compared with the control group of 25 mmol sucrose pulsed in, and can facilitate the remove of acid products. They are also found to reduce the extra-cellular polysaccharide production of biofim. The enamel lesion of NVE1 pulsed group is also shallower than the negative control.Conclusion: Five extracts of Nidus Vespae were successfully extracted and P-sitosterol, p-daucosterol and one kind of saturated fatty acid were fractioned and identified. Some NVE and compounds were proved to havesignificant anticaries effect in vitro and NVEl was proved to have significantanticaries effect in biofilm model, they appear to be a promising source ofnew agents that may prevent dental caries. The identification of the twocompound from Nidus Vespae will give us some light on the discovery ofnewly designed anticaries drugs.更多还原