Study On The Mechanism Of Licorice Against Euphorbia Based On Intestinal Flor

Radix Glycyrrhizae and Radix Euphorbiae Pekinensis combination is one of the eighteen incompatible medicaments in traditional Chinese medicine(TCM);however,there are many applications in the clinical prescription.Their incompatible mechanism is still unclear,and the reason for incompatibility has not been recorded in historical literatures.On the basis of our previous study results that the combination of Radix Glycyrrhizae and Radix Euphorbiae Pekinensis resulted in increased toxicity,the potential harmful effects of Radix Glycyrrhizae and Radix Euphorbiae Pekinensis combination on human health were investigated via in vitro human microflora experiment and in vivo mouse colony experiment from the perspective of affecting the gut microbiota.Meanwhile,the influence of Radix Glycyrrhizae and Radix Euphorbiae Pekinensis combination on their individual therapeutical effects Radix Glycyrrhizae was also discussed.In in vitro experiments,a batch fermentation model and a semi-continuous fermentation model were established for the investigation of short-term and long-term effects of Radix Glycyrrhizae and Radix Euphorbiae Pekinensis combination on gut microbiota,respectively.Radix Glycyrrhizae and After Radix Euphorbiae Pekinensis were co-cultured individually and combinedly with human gut microbiota under in vitro anaerobic condition,the dynamic changes of short chain fatty acids(SCFAs)in culture supernatants were detected by gas chromatography(GC),and the dynamic changes of Bifidobacterium,Lactobacillus,butyrate-producing bacteria(BPB)and sulfate-reducing bacteria(SRB)were also determined by quantitative PCR(Q-PCR).The results showed that the combination of Radix Glycyrrhizae and Radix Euphorbiae Pekinensis boosted a part of harmful bacteria and inhibited a part of beneficial ones.The combination of both drugs significantly promoted the proliferation of SRB,which is an opportunistic pathogen,able to induce inflammation,and related to the occurrence and development of colon cancer,irritable bowel syndrome and other diseases.Radix Euphorbiae Pekinensis significantly increased BPB and the content of butyric acid,but this effect was inhibited by its combination with Radix Glycyrrhizae.In addition,Radix Euphorbiae Pekinensis counteracted the promoting effect of Radix Glycyrrhizae on probiotics Bifidobacterium and Lactobacillus.In in vivo experiments,the content of SCFAs in feces and composition and abundance of gut microbiota were determined by using GC and high-throughput sequencing of the 16S rRNA gene,respectively,after long-term oral administration in rats,and the incompatible machnism of both drugs was also discussed from the holistic view.The results showed that the combination of Radix Glycyrrhizae and Radix Euphorbiae Pekinensis significantly affected the composition and relative abundance of gut microbiota,and also counteracted the individual therapeutic effects of both drugs.The combination of both drugs accumulated opportunistic pathogens such as Streptococcus,Prevotella,Desulfovibrio,etc.,and inhibited mucosal colonization bacteria e.g.,Akkermansia,which resulted in inflammation,induced intestinal mucosal barrier system damage,and ultimately endangered human health.The combination also significantly inhibited the promoting effect of Radix Glycyrrhizae on immune regulation relevant probiotics Lactobacillus and Bifidobacterium and that of Radix Euphorbiae Pekinensis on butyric acid-producing bacteria Butyricimonas.Besides,the combination reduced the therapeutic effect of both individual drugs by influcing the bioactivities of rat hepatic enzymes,depressing bowel propulsion and decreasing the defecation function increased by Radix Glycyrrhizae.In summary,this study has demonstrated that the combination of Radix Glycyrrhizae and Radix Euphorbiae Pekinensis may result in potential damage to human health by affecting the structure and metabolites of gut microbiota,and may affect the therapeutic efficacy of both drugs as well.Therefore,the incompatibility between Radix Glycyrrhizae and Radix Euphorbiae Pekinensis in traditional Chinese medicine really has its rational basis.