Mechanisms of podophyllotoxin-induced enterotoxicity: A multi-omics integration of gut microbiota, short-chain fatty acids, and inflammatory mediators.

Podophyllotoxin (PPT), a lignan extracted from the roots and stems of Podophyllum species, exhibits significant enterotoxicity that limits its clinical application. However, its underlying mechanisms remain unclear. This study aimed to elucidate the mechanisms underlying PPT-induced enterotoxicity. Changes in body weight, fecal morphology, toxic phenotypes, and histopathological features were evaluated. 3D reconstruction, 16S rRNA sequencing, targeted short-chain fatty acids (SCFAs) analysis, and inflammatory cytokine assays were performed. The findings demonstrated that PPT induced pathological changes in rats, including weight loss, diarrhea, and colonic damage. PPT administration significantly reduced beneficial bacteria such as Lactobacillus, while increasing harmful bacteria such as Escherichia-Shigella. The predicted pathways of bacterial invasion of epithelial cells and lipopolysaccharide biosynthesis were significantly upregulated. Levels of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), were also increased. Additionally, the expression of undecaprenyl-diphosphate synthase (UPPS) and SCFAs production was reduced. These findings indicate that PPT may alter gut microbial composition, increase Escherichia-Shigella invasion in the intestinal epithelial cells, promote lipopolysaccharide production, enhance the release of pro-inflammatory cytokines, including TNF-α and IL-6, and inhibit UPPS expression and SCFAs generation, collectively contributing to enterotoxicity. This study provides novel insights into the mechanisms behind PPT-induced enterotoxicity, which is essential for preventing and treating PPT toxicity.