Preventive effect of Atractylodis Rhizoma extract on DSS-induced acute ulcerative colitis through the regulation of the MAPK/NF-κB signals in vivo and in vitro

Atractylodes lancea (Thunb.) DC. is traditionally used as a folk medicine for treating gastrointestinal diseases in China. Nevertheless, the effect and mechanisms of its anti-inflammatory activity on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) have not yet been fully investigated.This study aimed to explore the therapeutic effect and underlying molecular mechanisms of Ethanolic Extract of Atractylodis Rhizoma (EEAR) on DSS-induced UC mice and LPS-induced RAW264.7 cells.The EEAR was obtained and then analyzed by HPLC analysis. The protective effect of EEAR on DSS-induced UC was evaluated by weight loss, disease activity index (DAI) score, spleen index, goblet cell loss, colon length shortening, myeloperoxidase (MPO) activity and pathological changes. The level of inflammatory cytokines were detected by immunohistochemistry (IHC) and RT-PCR analysis. The expressions of the tight junction (TJ, such as ZO-1, Occludin) proteins and the target proteins in mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) were determined by western blotting analysis.EEAR significantly attenuated the symptoms of UC, suppressed the colon MPO activity, and increased the goblet cell loss. In addition, EEAR could significantly increase the expression of TJs in UC mice. Meanwhile, EEAR treatment could reduce the levels of inflammatory cytokines and inhibit the phosphorylation of MAPK and NF-κB signaling pathways in UC mice and in LPS-induced RAW264.7 cells.Our results indicated that EEAR ameliorated DSS-induced UC by inhibiting the inflammatory response and maintaining the intestinal barrier function via modulation of MAPK/NF-κB pathways, thus, EEAR might be a promising therapeutic candidate for UC therapy.