基于肠道菌-SCFAs/GPCRs免疫通路研究甘草蜜炙增强补脾益气的效应机制

中医临床有“补脾宜炙用”之说，甘草作为代表，蜜炙后增强补脾益气功效确切。文献及前期研究表明，甘草蜜炙后黄酮、多糖及单糖等成分存在增减转化，免疫活性提升，但炮制增效机制尚未阐明。现代研究显示，肠道菌及其SCFAs/GPCRs通路在肠道及机体免疫稳态中起着关键作用；而多糖、单糖是SCFAs代谢的前体物质，且各组分具有肠道菌群调节作用。据此提出：甘草蜜炙增强补脾益气功效是炙甘草多组分调节肠道菌群及其介导的SCFAs/GPCRs免疫信号通路的结果。项目拟在生、炙甘草组分制备、分析与结构表征基础上，采用16S rRNA基因测序、靶向代谢组学结合免疫活性评价方法，研究生、炙甘草及不同组分对脾虚模型动物肠道菌群调节—宿主SCFAs代谢/GPCRs免疫通路的对应关系及作用差异，进一步通过体外共培养/共孵育实验进行验证，以期揭示炙甘草增强补脾益气功效的物质基础及作用机制，为饮片炮制及临床应用提供科学依据。

Traditional Chinese medicine (TCM) has the theory of "Enhance the efficacy of the spleen should use TCM roasted with honey". Licorice is one of the typical representatives whose efficacy of strengthening spleen and benefiting Qi could be promoted significantly after roasted with honey. Previous reports and our preliminary studies confirmed that honey-roasted licorice had higher efficacy of reinforcing spleen and Qi than crude licorice. The content of flavonoids and carbohydrates were changed during the roasting process. However, the action mechanism has not been properly elucidated. Modern researches showed that intestinal flora balance and SCFAs/GPCRs immune pathway play a key role in host intestinal function and immune regulation. Polysaccharides and monosaccharides are precursor substances for the metabolism of SCFAs. Multi-components in licorice has the regulatory effect of intestinal flora. According to the above, we propose a hypothesis: the effective mechanism of honey-roasted licorice strengthening spleen and benefiting qi is closely related with the synergistic effects of the multiple components from honey-roasted licorice on regulation of the balance of intestinal flora and the immune signaling pathway of SCFAs/GPCRs. The following studies will be carried out: Based on the preparation, analysis and structural characterization of raw and processing licorice, it would be expected to establish the relationship between intestinal bacteria regulation and SCFAs/GPCRs immune pathway in spleen deficiency model mouse using 16s rRNA gene sequencing, targeted metabonomics and immunological activity evaluation. Then regulation effect of raw, roasted licorice and different components will be discussed. Finally, the results will be verified with co-culture and co-incubation experiments in vitro. The objects of studies are to systematically clarify the bioactive components and molecular mechanisms of honey-roasted licorice for reinforcing spleen and benefiting Qi, and to provide scientific basis for the quality control, clinical application of honey-roasted licorice.