Oridonin ameliorates ulcerative colitis by regulating the PI3K/AKT/mTOR signaling pathway to activate autophagy

The present study aimed to investigate the therapeutic effects and underlying mechanism of oridonin (ORI) in ulcerative colitis (UC) using the lipopolysaccharide (LPS)‑induced macrophage inflammatory model in vitro and the dextran sulfate sodium (DSS)‑induced mouse UC model in vivo. Cell Counting Kit‑8 assay was used to determine the appropriate drug concentrations for the in vitro experiments. Western blotting and reverse transcription‑quantitative polymerase chain reaction were performed to evaluate the expression levels of proteins and mRNAs related to signaling pathways, autophagy and inflammatory cytokines. The autophagy inhibitor 3‑methyladenine was applied to verify the role of the PI3K/AKT/mTOR pathway. In vivo, the disease activity index (DAI) was recorded and colon tissue damage was assessed by hematoxylin and eosin staining. Serum inflammatory cytokines were measured using an enzyme‑linked immunosorbent assay. Network pharmacology based on GeneCards and Traditional Chinese Medicine Systems Pharmacology databases, along with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, predicted involvement of the PI3K/AKT/mTOR pathway in the pathogenesis of UC, which was further validated by the immunohistochemistry, immunofluorescence and western blotting of colon tissues. The results indicated that ORI significantly reduced the expression of pro‑inflammatory cytokines and increased the anti‑inflammatory cytokine interleukin‑10 in LPS‑stimulated macrophages. In DSS‑induced colitis mice, ORI treatment alleviated body weight loss, decreased DAI scores, improved colon shortening and upregulated the expression of intestinal tight junction proteins. Mechanistically, ORI inhibited the PI3K/AKT/mTOR pathway and altered autophagy‑related molecular markers, as evidenced by increased levels of autophagy‑related (ATG)13, beclin‑1, ATG12, ATG7 and ATG5 as well as decreased expression of p62. In conclusion, ORI alleviates inflammatory responses in vitro and mitigates UC‑related pathological changes in vivo, which may be associated with suppression of the PI3K/AKT/mTOR pathway and modulation of autophagy‑associated protein markers.