Kaempferol Ameliorates Functional Constipation in Mice by Regulating Autophagy of Interstitial Cells of Cajal via the p53/AMPK/mTOR Axis.

BACKGROUND

Functional constipation (FC) is a prevalent gastrointestinal disorder, and abnormal autophagy in interstitial cells of Cajal (ICCs) has been implicated in its pathogenesis. Kaempferol, a natural flavonoid, shows therapeutic potential for constipation, though its precise mechanism remains unclear.

AIM: This study aimed to investigate whether kaempferol alleviates FC by modulating autophagy in ICCs through the p53/AMPK/mTOR signaling pathway.

METHODS

A mouse model of FC was established using loperamide (10 mg/kg/day) for 14 d. Animals received kaempferol (15, 30, or 60 mg/kg) or mosapride for 7 d. Constipation symptoms were evaluated by measuring fecal water content and intestinal propulsion rate. Colon tissue damage was assessed histologically, and c-Kit expression was analyzed via qRT-PCR and immunohistochemistry. Autophagy activity and pathway protein expression were examined using transmission electron microscopy and Western blot. In vitro experiments utilized L-glutamate-stimulated ICCs with the mTOR agonist MHY1485 for mechanistic validation.

RESULTS

Kaempferol significantly improved constipation symptoms, increased c-Kit expression, and alleviated colon tissue damage in FC mice. It effectively suppressed excessive autophagy in ICCs, demonstrated by reduced autophagosome formation, decreased LC3-II/LC3-I ratio and Beclin1, and increased p62. Mechanistically, kaempferol activated the p53/AMPK/mTOR pathway both in vivo and in vitro, elevating p53 and p-mTOR while reducing p-AMPK expression. The anti-autophagic effect was enhanced by MHY1485.

CONCLUSION

Kaempferol ameliorates functional constipation by inhibiting excessive autophagy in ICCs via activation of the p53/AMPK/mTOR pathway, providing new insights into its mechanism and supporting its potential as a therapeutic agent for FC.