RESUMEN
【Objective】 To investigate the influence of matrine (MT) on the balance of T helper cell 17 (Th17)/regulatory T cells (Treg) in rats with inflammatory bowel disease by regulating interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3)/nuclear transcription factor-κB (NF-κB) pathway. 【Methods】 SD rats were grouped into control check group (CK group), model group, low-dose MT group (MT-L group, 50 mg/kg), medium-dose MT group (MT-M group, 100 mg/kg), high-dose MT group (MT-H group, 200 mg/kg), mesalazine group (MSLM group, 0.42 g/kg), and MT-H+rIL-6 (IL-6 activator) group (200 mg/kg+0.05 mg/kg) according to the random number table method, with 18 in each group. Except for the CK group, the rats in other groups all received with 5% trinitrobenzenesulfonic acid (20 mg/kg) buffer solution mixed with 50% ethanol at a ratio of 1∶1 and then enema to construct a rat model of inflammatory bowel disease. After the successful modeling, they were treated with drug administration once a day for 7 weeks. The body weight of rats was measured at 1, 3, 5, and 7 weeks of administration; the changes of colon length of rats in each group were compared; HE staining was used to detect the pathological damage of rat colon tissue; the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-17 and IL-10 in serum of rats were detected by ELISA; the proportions of Th17 and Treg cells in peripheral blood of rats were detected by flow cytometry; Western blottingt was performed to detect the protein expression of retinoic acid-related orphan receptor γt (RORγt), forkhead box protein P3 (Foxp3), IL-6, p-STAT3, and p-NF-κB p65 in rat colon tissue. 【Results】 Compared with the CK group, the colon tissue of the model group was severely damaged by pathology, and the body weight (at 3, 5, and 7 weeks), the level of IL-10, the proportion of Treg cell, and the expression of Foxp3 protein were decreased, the colon length shortened, the levels of TNF-α, IL-17, the proportions of Th17 cell, Th17/Treg ratio, and the protein expression of RORγt, IL-6, p-STAT3, and p-NF-κB p65 increased (P<0.05). Compared with the model group, the corresponding indicators of the MT-L group, MT-M group, MT-H group, and MSLM group had the opposite trends (P<0.05); rIL-6 attenuated the promoting effect of high-dose MT on Th17/Treg balance in inflammatory bowel disease rats. 【Conclusion】 MT may promote Th17/Treg balance in inflammatory bowel disease rats by inhibiting IL-6/STAT3/NF-κB signaling pathway.