Efficacy of Wumei Baijiang prescription(乌梅败酱方) on regulatory T cells/helper T cells Immune balance in mice with ulcerative colitis

OBJECTIVE: To observe the therapeutic effect of Wumei Baijiang prescription(乌梅败酱方), empirical prescription of Lu Zhizheng, on experimental ulcerative colitis(UC) mice, and to investigate the mechanism of the prescription in UC from the perspective of the immune balance of regulatory T cells(Treg) and helper T cells(Th17). METHODS: Sixty C57 BL/6 mice were randomly divided into 6 groups: normal group, model group, Chinese medicine group(high, medium and low dose group of Wumei Baijiang prescription) and control group(mesalazine sustained-release granules). Except for the normal group, the other groups used 2.5% dextran sulfate sodium to induce UC mice model. At the end of the model, the Chinese medicine group was given high, medium and low dose administration of Wumei Baijiang prescription, the control group was given slow-release granules of mesalazine, and the model group was given equal volume saline for 10 d. The changes of food intake, body weight, disease activity index(DAI) score, length of large intestine and histopathology were observed. The number of Treg, Th17, CD4+, CD8+ cells in spleen was detected by flow cytometry. The expression of tumor necrosis factor-α(TNF-α), interleukin-10(IL-10) and C-reactive protein(CRP) in serum was detected by enzyme-linked immunosorbent assay.RESULTS: The middle and high-dose groups of Wumei Baijiang prescription were superior to the model group in terms of increasing food intake and body weight of colitis mice, restoring colon morphology, improving pathological damage, and reducing DAI(P < 0.05). There was no statistical difference with the mesalazine group(P > 0.05). Compared with the model group, the spleen Treg and CD4+ of the mice in the high and middle dose groups of Wumei Baijiang prescription were higher, while Th17 and CD8+ were lower(P < 0.05), and there was no statistical difference compared with the mesalazine group(P > 0.05). In addition, compared with the model group, the serum levels of TNF-α and CRP in mice with high and middle doses of Wumei Baijiang prescription and mesalazine group were lower(P < 0.05), and IL-10 content was higher( P < 0.05). CONCLUSIONS: Wumei Baijiang prescription can improve the general conditions of colitis mice, such as diarrhea, hematochezia, weight loss, and mucosal damage. The mechanism may be related to the regulation of Treg/Th17 immune balance.