Abstract: Objective: To investigate the protective effect of Rosa roxburghii Tratt. juice (RRTJ) fermented by Lactobacillus paracasei SR10-1 against ulcerative colitis (UC) in mice. Methods: SR10-1 fermented Rosa roxburghii Tratt. juice was prepared in the laboratory. A mouse model of UC induced by dextran sulfate sodium (DSS) was created. The experiments were designed using five groups, i.e., blank control, DSS-induced model, positive control (mesalazine), lactic acid bacteria fermented RRTJ (LAB-RRTJ) and RRTJ. Disease activity index (DAI) score, visceral organ indices, colon length, colon pathological changes, the levels of inflammatory factors including interleukin (IL)-1β, IL-6, IL-10, IL-17A, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), the levels of oxidative stress indicators including malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH), the activity of myeloperoxidase (MPO), and the expression levels of gut barrier-related genes (claudin-3, ZO-1 and MUC2) were analyzed in UC mice. Results: Compared with the DSS-induced model group, LAB-RRTJ significantly reduced the DAI score (P < 0.05), and relieved diarrhea, bloody stools, colonic atrophy and pathological changes of mice. In addition, the colon length was significantly increased (P < 0.001), and the spleen and liver indices were significantly decreased (P < 0.001 and P < 0.05, respectively). The levels of IL-1β, IL-6, IL-17A, TNF-α, and IFN-γ were significantly decreased (P < 0.05), while the level of IL-10 was significantly increased (P < 0.05). The levels of MDA and MPO were significantly decreased (P < 0.05), the activities of SOD and GSH were significantly increased (P < 0.001 and P < 0.05), and the expression levels of claudin-3, ZO-1 and MUC2 were significantly increased (P < 0.01). Conclusion: Fermented Rosa roxburghii Tratt. juice with Lactobacillus paracasei SR10-1 could reduce intestinal damage in UC mice by improving inflammatory responses and regulating the level of oxidative stress and intestinal barrier function.

Key words: lactic acid bacteria; Rosa roxburghii Tratt.; fermentation; ulcerative colitis; relieving effect