Paeoniflorin alleviates DSS-induced ulcerative colitis by suppressing inflammation, oxidative stress, and apoptosis via regulating serum metabolites and inhibiting CDC42/JNK signaling pathway.

Ulcerative colitis (UC) poses a threat to human health. The present study attempts to unravel the efficacy and potential mechanisms of paeoniflorin (PF), a naturally sourced active ingredient, for the management of UC. By establishing a DSS (dextran sulphate sodium)-induced experimental rat model of UC, this study found that PF was effective in ameliorating UC symptoms, inhibiting oxidative stress, inflammation and apoptosis, and repairing colonic epithelial damage. In addition, metabolomics revealed that PF may alleviate UC by primarily improving linoleic acid metabolism. Mechanistically, PF inhibited the CDC42/JNK signaling pathway by targeting CDC42. In particular, HuProtTM20K proteomics, molecular docking and MST revealed that PF is a novel CDC42 inhibitor. In LPS-treated Caco-2 cells, PF similarly inhibited oxidative stress, inflammation, and apoptosis and down-regulated the CDC42/JNK signaling pathway. Overall, PF inhibits oxidative stress, inflammation and apoptosis and repairs colonic epithelial damage through modulation of serum metabolites and inhibition of the CDC42/JNK signaling pathway, leading to alleviation of UC.