Atractylenolide III Ameliorates TNBS-Induced Intestinal Inflammation in Mice by Reducing Oxidative Stress and Regulating Intestinal Flora.

The present study aimed to explore the therapeutic effects of the main active ingredients of Atractylodes macrocephala on the 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced mouse colitis model. TNBS-induced colitis was established in mice, which were treated with 8-β-Hydroxyasterolide (Atractylenolide III) for 14 days. The body weight of the mice in the middle and high dose groups of Atractylenolide III was increased compared with that of the model group. The disease activity index score was significantly reduced. The activity levels of myeloperoxidase were significantly decreased following increase in the dosage of Atractylenolide III, as determined by histological analysis. Moreover, Atractylenolide III downregulated the expression levels of the inflammatory factors interleukin-1β and tumor necrosis factor-α, and greatly suppressed the levels of the pro-oxidant markers, reactive oxygen species and malondialdehyde, while enhancing the expression levels of the antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase. The protein expression levels of formyl peptide receptor 1 (FPR1) and nuclear respiratory factor 2 (Nrf2) were upregulated in the colonic tissues of TNBS-treated mice. This effect was effectively reversed by Atractylenolide III treatment. In vivo studies indicated that TNBS alone induced a decrease in the abundance of lactobacilli and in the biodiversity of the colon. In conclusion, the present study suggested that Atractylenolide III attenuated TNBS-induced acute colitis by regulating oxidative stress via the FPR1 and Nrf2 pathways and by affecting the development of intestinal flora.