Chimonanthus nitens Oliv leaves essential oil alleviates colitis induced by sodium dextran sulfate in BALB/C mice via MAPK/NF-κB/Nrf2 signaling pathway

In this study, the essential oil of Chimonanthus nitens Oliv leaves (EO) was extracted by steam distillation, and the protective effect on colitis induced by sodium dextran sulfate was investigated. The results showed that EO could significantly reduce colon injury in colitis mice. EO decreased the expression of inducible nitric oxide synthase (iNOS) and the levels of nitric oxide, tumor necrosis factor-α, interleukin-6, -1β (NO, TNF-α, IL-6, and -1β) and increased the levels of interleukin-10 (IL-10) via the MAPK/NF-κB/Nrf2 signaling pathway. Furthermore, EO reduced lipopolysaccharide (LPS) levels and increased the levels of the colonic tight junction proteins (zonula occludens1, Occludin1, and Claudin1) and mucin (MUC-2), protected the integrity of the colonic barrier. In addition, intestinal flora analysis showed that EO improved the diversity and richness of intestinal flora in colitis mice, restored the imbalance of intestinal flora, and improved the potential function of the flora. In summary, EO administration is a drug or dietary supplement strategy for the treatment of colitis.