Study On The Effect And Mechanism Of Water Extract Of Fructus Mume On Diarrhea Induced By Irinotecan

Objective: The aim of this study was to investigate the anti-diarrheal effect of water extract of Fructus Mume on irinotecan-induced diarrhea and explore possible mechanisms.To provide reference for development of Fructus Mume medicine,and the foundation for further research on antidiarrheal Chinese medicine.Methods: The content of citric acid was analyzed by high performance liquid chromatography in order to evaluate the quality of the water extract of Fructus Mume.Model animals were used for pharmacodynamic studies to investigate the therapeutic effect of Fructus Mume on irinotecan-induced diarrhea.70 male Sprague-Dawley rats were randomly divided into control group,model group,loperamide group,low,medium and high dose water extract of Fructus Mume,and Fructus Mume + Yihuo group.Rats were intragastrically administered for 12 days,and injected with saline or irinotecan through tail vein on day 6-9.The weight and diarrhea were recorded during the experiment.The HE pathological sections of colon was observed,and the relative expression of CD4 and CD8 in colon was determined by immunohistochemistry.The levels of TNF-α,IL-1β and IFN-γin plasma were measured by enzyme linked immunosorbent assay.The feces of the control group,model group and low dose water extract of Fructus Mume group were analyzed by16 S r RNA sequencing to investigate the changes in the intestinal microbiota.Results: The result of high performance liquid chromatography showed that the content of citric acid in the water extract of Fructus Mume was 19.43%,which complied with the Chinese Pharmacopoeia(greater than 12.0%).After the rats were injected with irinotecan,the weight of the rats in the model group decreased,each treatment group increased slowly.The diarrhea of the rats in the model group was severe,each treatment group showed significant antidiarrheal effects without dose dependence.The pathological results of the colon in the model group showed that the layers of the intestinal mucosa were damaged,the treatment groups showed excellent protective effect.The results of immunohistochemistry showed that compared with the control group,the average opticaldensity value of CD4 in the model group was significantly lower(P<0.05),the average optical density value of CD8 was not changed significantly,and the CD4/CD8 ratio was decreased,but the difference was not significant.Compared with the model group,the expression of CD4 was significantly increased in the treatment groups(P <0.05),there was no significant difference in the expression of CD8,and the CD4/CD8 ratio was increased significantly in loperamide,low dose of Fructus Mume and Fructus Mume + Yihuo groups(P<0.05).The results of pro-inflammatory factor levels showed that compared with the control group,the levels of TNF-α and IFN-γ in the model group were significantly higher(P<0.01),and the level of IL-1β was also significantly higher(P<0.05).Compared with the model group,the levels of TNF-α and IFN-γ in the treatment groups were significantly reduced(P<0.01),the level of IL-1β was reduced significantly by medium dose of Fructus Mume(P<0.05).The results of 16 S r RNA sequencing showed that the number of OTUs of the model group significantly changed during the experiment(P<0.05),and that of the Fructus Mume group recovered after the experiment.At different taxonomic levels,there were more differential species in the model group than the Fructus Mume group.The composition and structure of the intestinal microbiota in the model group were changed more obviously than that in the Fructus Mume group during the experiment.Conclusion: The water extract of Fructus Mume could treat diarrhea caused by irinotecan without dose dependence.The mechanisms may be to protect the structure of the intestinal mucosa,increase the CD4 and CD4/CD8 ratio in the colon to generate positive immune regulation,inhibit the expression of TNF-α,IFN-γ and IL-1β,and maintain the intestinal microbiota homeostasis.