中药小分子探针导向突变结肠癌肠道微生物P450酶定向调节肠道微生物的探究

It is reported that the occurrence and development of colorectal cancer (CRC) are closely related to the intestinal microorganisms. Adjusting or improvement the intestinal flora are very helpful for prevention and treatment of colon cancer. However, the current method are mainly focused on improving diet and adding exogenous probiotics. There are few people using the strategy that mutating enzyme especially the P450 enzymes adjusted or improved the intestinal flora. The pre-experimental results showed that the intestinal flora of CRC could digest the anti-CRC macromolecule compounds isolated from the traditional Chinese medicine (TCM), while the metabolic mechanism need to be further studied. Therefore, we hypothesized that TCM can be used as a small molecule or probe to directed mutagens the intestinal microbial P450 enzymes. In order to verify this hypothesis, we firstly intend to screened the intestinal strains that closely related to colon cancer by using small molecular probe obtained from the traditional medicinal plant. Secondly, we will guided mutating these P450 enzymes in vivo by means of the small molecule probes. We hope we could keep the activity of the drug without breaking the intestinal flora. This project will use small molecule medicine as probes guiding mutilation of the intestinal microbial P450 enzymes and regulating intestinal microbial balance for the first time. In addition, this project will also lay the foundation for revealing the intestinal microbial metabolism and provide new ideas for colon cancer prevention and control.

近来研究发现结肠癌的发生、发展与肠道菌群有着密切的联系，调节或者改善肠道菌群将对于预防和治疗结肠癌有着十分重要的意义。然而当下思路多集中在改善饮食以及添加外源性益生菌，鲜有从突变肠道微生物代谢酶，尤其是其主要的代谢酶--P450酶出发对肠道微生物进行定向调节。预实验结果提示，结肠癌肠道微生物能显著代谢消化抗结肠癌中药小分子。但是其具体的代谢机制有待进一步探究。为此我们提出假说，中药小分子或可成为定向突变肠道微生物P450酶的探针。为了验证这一假说，我们拟以传统药用植物活性分子作为小分子探针筛选出与结肠癌有密切关系的肠道菌株，并利用小分子定向引导突变这些菌株体内的P450代谢酶，使得在不伤害某些有益菌株的前提下，又突出表现药物活性。本研究将以中药小分子导向突变肠道微生物P450酶，调节肠道微生物平衡这个新视点，为揭示肠道微生物的代谢机制奠定基础，为结肠癌的预防和控制提供新的思路。

结肠癌的发生、发展与肠道菌群有着密切的联系，调节或者改善肠道菌群将对于预防和治疗结肠癌有着十分重要的意义。本研究以中药小分子导向突变肠道微生物P450酶，调节肠道微生物平衡这个视点，对云南产的 4种山蚂蝗属民族药用植物中的C-烷基化黄酮类化合物的分离、鉴定，共得到C-烷基化黄酮化合物38个，其中新化合物20余个；体外抗结肠癌细胞毒活性筛选得到3个化合物作为合适的小分子探针评价化合物对AOM/DSS诱导的结肠癌小鼠肠道微生态改善的效果。从结肠癌小鼠粪便及肠道内容物中分离纯化出可培养的肠道细菌100余种，通过16srDNA测序鉴定得到7种可培养细菌，并完成了山蚂蝗属中的抗结肠癌烷基化黄酮类化合物与结肠癌肠道菌株的共培养代谢物的分析、结构鉴定，对Candidatus SP.1121 菌株中能够代谢黄酮类化合物的 P450 酶进行了体内和体外的突变和验证，观察到小分子探针对植入改造后菌株的结肠癌小鼠的肠道微生态以及肿瘤发生情况有一定的改善。共发表论文8篇，其中SCI 5篇，学科前 15%文章 1 篇，申请获受理专利 2 项。本项目的实施既对开发和挖掘传统药用植物起到一定的借鉴意义，同时又可以为改善和调节肠道菌群平衡，从而预防和治疗结肠癌的发生提供新的思路。