小乌桂汤治疗小鼠胶原诱导性关节炎的作用机制

目的 以胶原诱导性关节炎（CIA）小鼠为模型，探讨小乌桂汤治疗类风湿关节炎的免疫学机制。方法 构建DBA/1小鼠CIA模型，将关节炎指数（AI）评分相近的30只CIA小鼠随机分为正常对照组、模型组（CIA）、甲氨蝶呤组、小乌桂汤低剂量组（0.975 g/mL）、小乌桂汤中剂量组（1.95 g/mL）、小乌桂汤高剂量组（3.9 g/mL），5只/组。其中，正常对照组和CIA组给予生理盐水，甲氨蝶呤组给予0.1 mg/mL甲氨蝶呤溶液，3个小乌桂汤处理组按照规定剂量分别给予小乌桂汤药液（0.2 mL/10 g体质量）连续灌胃28 d处理。使用AI评分和HE染色评价小乌桂汤对CIA模型小鼠关节的影响。利用流式细胞术观察小乌桂汤对CIA小鼠脾脏Th1、Th17、MDSC、G-MDSC、M-MDSC细胞亚群的影响。结果 甲氨蝶呤和不同剂量组小乌桂汤治疗后小鼠AI评分降低，炎症程度比其他组明显缓解，踝关节损伤得到有效修复，且随着小乌桂汤剂量增高，其治疗效果呈现出逐渐增强的趋势（P<0.05）。与模型组相比，甲氨蝶呤组和不同剂量组小乌桂汤组脾脏中Th1、Th17和M-MDSC细胞比例降低（P<0.05），GMDSC细胞比例显著增加，且随着小乌桂汤剂量增高，细胞比例变化呈现逐渐明显的趋势（P<0.01）。相关分析结果显示，Th1、Th17细胞比例与M-MDSC细胞比例呈正相关，而与G-MDSC细胞比例呈负相关（P<0.01）。结论 小乌桂汤可通过调节MDSC细胞亚群水平，升高G-MDSC细胞比例和降低M-MDSC、Th1、Th17细胞比例改善CIA小鼠关节损伤，高剂量小乌桂汤其作用与甲氨蝶呤等效，且安全性更高。

Mechanism of Xiaowugui decoction for treating collagen-induced arthritis in mice

Objective To explore the mechanism of Xiaowugui decoction (XWGD) decoction in treating rheumatoid arthritis (RA) in mice. Methods Healthy male DBA/1 mice were used for CIA modeling. Twenty-five CIA mice with successful modeling and similar arthritis index (AI) scores were randomized equally into model group (CIA), methotrexate (MTX) group, and low- , medium-, and high-dose XWGD groups (0.975, 1.95, and 3.9 g/mL, respectively), with another 5 normal mice as the normal control group. The mice in normal control and CIA groups were given saline once a day, those in MTX group were given 0.1 mg/mL MTX once a week, and those in XWGD groups were treated daily via garage of XWGD containing crude drugs of different doses for 28 consecutive days. The AI score and HE staining were used to evaluate the changes in the joints of the CIA mice. The effect of XWGD on Th1, Th17, MDSC, G-MDSC and M-MDSC cells were evaluated with flow cytometry. Results Treatment with MTX and different doses of XWGD significantly decreased the AI score of the mice and relieved joint inflammation as compared with the model group (P<0.05), and a higher dose of XWGD decoction produced a stronger therapeutic effect. Compared with those in CIA model group, the mice in MTX and XWGD treatment groups showed significantly decreased percentages of Th1, Th17 and M-MDSC cells in the spleen and increased percentages of G-MDSC cells (P<0.01), and these changes were more conspicuous with a higher dose of XWGD. Correlation analysis showed that Th1 and Th17 cells were positively correlated with M-MDSC and negatively correlated with G-MDSC cells (P<0.01). Conclusion XWGD can improve joint inflammation in CIA mice by increasing the percentages of G-MDSC cells and decreasing the percentages of M-MDSC, Th1 and Th17 cells, and a high dose of XWGD can produce an equivalent therapeutic effect to methotrexate but with better safety.