Modified Pulsatilla decoction alleviates 5-fluorouracil-induced intestinal mucositis by modulating the TLR4/MyD88/NF-κB pathway and gut microbiota

Modified Pulsatilla decoction (PD), a PD with licorice and ejiao, is a classic Traditional Chinese Medicine formula with significant efficacy in treating intestinal mucositis (IM) induced by tumor therapy. However, its specific molecular and biological mechanisms remain unclear. To investigate the therapeutic effect and mechanism of modified PD in IM. This study used an IM mouse model established using 5-fluorouracil injections to investigate the effects of the modified PD (3, 6, and 12 g/kg) in IM. The primary chemical components of the modified PD were identified using liquid chromatography-mass spectrometry. Body weight loss, diarrhea scores, intestinal length, histopathological scores, and inflammatory cytokine levels were measured to evaluate the effects of the modified PD in IM. Effects on the TLR4/MyD88/NF-κB pathway were evaluated using western blot analysis. The intestinal microbiota was characterized using Illumina NovaSeq sequencing. The results showed that modified PD significantly improved weight loss and diarrhea and shortened the intestines in IM mice. Mechanistically, modified PD suppressed the TLR4/MyD88/NF-κB pathway and downregulated the expression of reactive oxygen species, lipopolysaccharides, and pro-inflammatory cytokines (IL-1β, TNF-α, IFN-γ, IL-6, IL-8, and IL-17), while increasing the expression of the anti-inflammatory cytokine IL-10. Furthermore, modified PD protected the intestinal mucosal barrier by increasing the expression of tight junction proteins (occludin-1, claudin-1, and ZO-1) and mucin-2. Finally, 16S rDNA sequencing revealed that modified PD improved intestinal dysbiosis. Our research offers new insights into the potential mechanism of modified PD in alleviating IM and provides experimental evidence supporting its pharmaceutical application in clinical IM treatment.