<i>Artemisia argyi</i> extracts alleviated colitis in mice <i>via</i> modulating gut microbiota and bile acid metabolism

<em>Artemisia argyi</em> (<em>A. argyi</em>) is a Chinese herbal medicine with reported anti-inflammatory effects. In this study, the <em>A. argyi</em> was extracted with water and ethanol, and the concentrations of 35 flavonoids in <em>A. argyi</em> water extract (WE) and ethanol extract (EE) were measured via targeted metabolomics. The antioxidant and anti-inflammatory activities of both WE and EE were firstly explored <em>in vitro</em> via chemical assays and cellular experiment, respectively. Both WE and EE showed significant DPPH, ABTS, OH^-, and O₂^-radical scavenging ability in a dose-dependent manner, and reduced the levels of IL-1β, TNF-α and IL-22 in LPS induced RAW264.7 cell model. In addition, the <em>in vivo </em>anti-colitis activity of both extracts was performed in dextran sulfate sodium (DSS)-induced colitis mouse, and the mechanisms were elucidated by 16S rDNA sequencing and targeted metabolomics. We found that both WE and EE relieved colitis in mice, characterized by decreased disease activity index, increased colon length, improved pathological changes in colon tissue, while EE showed better anti-colitis activity. In addition, both 16S rDNA sequencing and targeted bile acids metabolomics indicated EE modulated gut microbiota and specifically increased the abundance of lithocholic acid, which might contribute to intestinal barrier function improvement via up-regulating the expression of colonic FXR. In summary, this study identified the anti-colitis mechanism of <em>A. argyi</em> ethanol extract by modulating gut microbiota, facilitating the production of lithocholic acid, activating FXR and improving intestinal barrier function.