Dihydrotanshinone attenuates chemotherapy-induced intestinal mucositis and alters fecal microbiota in mice.

Chemotherapy-induced intestinal mucositis (CIM) is a principal reason for reduced living quality of patients undergoing chemotherapy. Growing evidence showed gut microbiota played an important role in the development of intestinal mucositis. Dihydrotanshinone I (DHTS) is a liposoluble extract of Salvia miltiorrhiza Bunge with many bioactivities. Here we investigated the effect of DHTS on intestinal mucositis induced by 5-fluorouracil and irinotecan in mice. We detected the degree of intestinal mucosal damage and inflammatory response in CIM mice with or without DHTS administration. The body weight and disease activity index (DAI) of mice were monitored each day. H&E staining was used to evaluate pathological damage. The contents of interleukin 6 (IL-6), tumor necrosis factor (TNFα), diacylglycerol (DAO) and triglyceride (TG) in serum were determined by commercial kits. We also investigated the changes of fecal microbiota by 16S rRNA high-throughput sequencing. Spearman correlation analysis was used to evaluate the correlation between fecal microbiota and inflammatory factors. Tax4Funwas performed to infer the potential function of the microbial community. Results showed DHTS significantly reduced DAI, intestinal mucosal damage and inflammatory response in CIM mice by decreasing serum IL-6 and TNFα. In addition, there is an intense correlation between fecal microbiota and inflammatory factors. DHTS efficiently reversed disordered fecal microflora close to normal and increased the abundance of g__Akkermansia. DHTS also enriched bacterial species which promote butyric acid metabolism or negatively correlated with inflammatory factors. Besides, species enriched by DHTS in fecal microbiota were probably involved in glutamine production and ammonia oxidation. In conclusion, our study provides evidence that DHTS effectively attenuates CIM induced by 5-fluorouracil and irinotecan in mice. Regulation of the composition and function of fecal microbiota probably plays a critical role in the therapeutic effect of DHTS in CIM mice.