目的 基于核因子 E2 相关因子 2（Nrf2）/溶质载体家族 7 成员 11（SLC7A11）/谷胱甘肽过氧化物酶 4 （GPX4）信号通路介导的铁死亡探讨白头翁汤对溃疡性结肠炎（UC）小鼠的作用及机制。方法 将 C57BL/6J 小 鼠随机分为正常组、模型组、白头翁汤低剂量组（8 g·kg-1 ）、白头翁汤高剂量组（16 g·kg-1 ）、美沙拉嗪组 （500 mg·kg-1 ）及铁死亡抑制剂组（Ferrostatin-1，1 mg·kg-1 ），每组各 8 只。采用连续 7 d 自由饮用 3% 葡聚糖硫 酸钠（DSS）溶液复制 UC 小鼠模型，各给药组同时每天给予对应药物干预。白头翁汤低、高剂量组及美沙拉嗪 组灌胃给药（灌胃体积均为 20 mL·kg-1 ），铁死亡抑制剂组腹腔注射给药，每天 1 次，连续给药 7 d。观察记录 小鼠一般状态，并进行疾病活动指数（DAI）评分、结肠黏膜损伤指数（CMDI）评分；采用 HE 染色法及阿利新 蓝-过碘酸-雪夫（AB-PAS）染色法观察结肠组织病理变化；免疫组化法检测结肠组织中 Occludin、Claudin-1 的 表达水平；ELISA 法检测血清炎症因子肿瘤坏死因子 α（TNF-α）、白细胞介素 6（IL-6）及白细胞介素 10 （IL-10）水平；微量法检测结肠组织超氧化物歧化酶（SOD）、丙二醛（MDA）、谷胱甘肽（GSH）及亚铁离子（Fe2+ ） 水平；透射电镜观察结肠组织超微结构变化；qPCR 法及 Western Blot 法检测结肠组织 Nrf2、SLC7A11、GPX4 mRNA 及蛋白表达水平。结果 与正常组比较，模型组小鼠 DAI 评分显著升高（P＜0.01）；结肠黏膜出现明显 充血、水肿，伴有糜烂及溃疡形成，CMDI 评分显著升高（P＜0.01）；结肠组织结构严重破坏，腺体数量减少且 排列紊乱，隐窝结构丧失，伴有明显的水肿、炎性细胞浸润及溃疡形成；杯状细胞数量显著减少，染色变浅， 腺体腔内几乎无明显黏液；结肠组织中 Claudin-1、Occludin 阳性表达水平显著降低（P＜0.01）；血清促炎因子 TNF-α 、IL-6 水平显著升高（P＜0.01），抗炎因子 IL-10 水平显著降低（P＜0.01）；结肠组织中 MDA、Fe2+ 水 平显著升高（P＜0.01），而 SOD、GSH 水平显著降低（P＜0.01）；结肠上皮细胞微绒毛数量明显减少、排列紊 乱，细胞间连接破坏，线粒体明显肿胀、变形，嵴结构断裂或缺失；结肠组织 Nrf2、GPX4、SLC7A11 mRNA 及蛋白表达均显著下调（P＜0.01）。与模型组比较，各给药组小鼠的 DAI 评分均显著下降（P＜0.05，P＜0.01）； 结肠黏膜充血及水肿程度明显减轻，糜烂范围缩小，CMDI 评分显著降低（P＜0.05，P＜0.01）；结肠黏膜结构 有所恢复，腺体排列较之前整齐，炎性细胞浸润及水肿程度减轻；杯状细胞数量明显增多，染色加深，腺体腔 内可见较多黏液分泌；结肠组织中 Claudin-1、Occludin 阳性表达水平显著升高（P＜0.05，P＜0.01）；血清 TNF-α 、IL-6 水平显著降低（P＜0.05，P＜0.01），IL-10 水平显著升高（P＜0.05，P＜0.01）。与模型组比较， 白头翁汤低、高剂量组及铁死亡抑制剂组小鼠结肠组织中 MDA、Fe2+ 水平显著降低（P＜0.05，P＜0.01），SOD、 GSH 水平显著升高（P＜0.05，P＜0.01）；结肠上皮细胞微绒毛明显恢复，线粒体轻度肿胀，但嵴结构仍清晰可 见；结肠组织 Nrf2、GPX4、SLC7A11 mRNA 及蛋白表达均显著上调（P＜0.05，P＜0.01）。结论 白头翁汤对 UC 小鼠具有明显改善作用，其机制可能与激活 Nrf2/SLC7A11/GPX4 信号通路，抑制铁死亡，从而减轻结肠组织损伤有关。

Objective To investigate the mechanism of Baitouweng Decoction （mainly consist of Pulsatillae Radix 15 g， Phellodendri Chinensis Cortex 12 g，Coptidis Rhizoma 6 g，Fraxini Cortex 12 g） in treating ulcerative colitis （UC） mice， based on ferroptosis mediated by the nuclear factor erythroid 2-related factor 2（Nrf2）/solute carrier family 7 member 11（SLC7A11）/glutathione peroxidase 4（GPX4） signaling pathway. Methods C57BL/6J mice were randomly divided into a normal group， a model group， a Baitouweng Decoction low-dose group （8 g·kg-1 ）， a Baitouweng Decoction high-dose group （16 g·kg-1 ），a mesalazine group （500 mg·kg-1 ），and a ferroptosis inhibitor group （Ferrostatin-1， 1 mg·kg-1 ），with 8 mice in each group. A UC mouse model was established by allowing mice free access to 3% dextran sulfate sodium （DSS） solution for 7 consecutive days. Concurrently，each treatment group received the corresponding drug intervention daily. The Baitouwen Decoction low-dose，high-dose groups and the mesalazine group received oral gavage （all at a volume of 20 mL·kg-1 ），while the ferroptosis inhibitor group received intraperitoneal injection，once daily for 7 consecutive days. The general condition of the mice was observed and recorded，and the disease activity index （DAI） and colonic mucosal damage index （CMDI） were scored. Histopathological changes in colon tissue were observed using hematoxylin and eosin （HE） staining and Alcian blue-periodic acid-Schiff （AB-PAS） staining. The expression levels of Occludin and Claudin-1 in colon tissue were detected by immunohistochemistry. Serum levels of the inflammatory cytokines tumor necrosis factor-α （TNF-α），interleukin-6（IL-6），and interleukin-10（IL-10） were measured by ELISA. Levels of superoxide dismutase （SOD）， malondialdehyde （MDA）， glutathione （GSH）， and ferrous ion （Fe²⁺） in colon tissue were detected by micro-methods. Ultrastructural changes in colon tissue were observed by transmission electron microscopy （TEM）. The mRNA and protein expression levels of Nrf2，SLC7A11，and GPX4 in colon tissue were detected by qPCR and Western Blot，respectively. Results Compared with the normal group，the model group showed a significant increase in DAI score （P＜0.01）； obvious congestion and edema in the colonic mucosa，accompanied by erosion and ulcer formation，and a significant increase in CMDI score （P＜0.01）；severely damaged colon tissue structure， with reduced and disordered glands， loss of crypt architecture， accompanied by significant edema，inflammatory cell infiltration，and ulcer formation；a significant decrease in the number of goblet cells with lighter staining，and almost no obvious mucus in gland lumens；significantly decreased positive expression levels of Claudin-1 and Occludin in colon tissue （P＜0.01）；significantly elevated serum levels of pro-inflammatory factors TNF- α and IL-6（P＜0.01），and significantly decreased levels of the anti-inflammatory factor IL-10（P＜ 0.01）；significantly increased levels of MDA and Fe2+ in colon tissue （P＜0.01），while SOD and GSH levels were significantly decreased （P＜0.01）；a marked reduction and disarray in the number of microvilli of colonic epithelial cells， disrupted intercellular junctions， significantly swollen and deformed mitochondria with broken or missing cristae；mRNA and protein expression of Nrf2，GPX4，and SLC7A11 in colon tissue were significantly downregulated （P＜0.01）. Compared with the model group，all treatment groups showed a significant decrease in DAI scores （P＜0.05，P＜0.01）；the degree of colonic mucosal congestion and edema was significantly alleviated，the scope of erosion was reduced， and CMDI scores were significantly decreased （P＜0.05， P＜0.01）； the colonic mucosal structure showed some recovery，with more orderly gland arrangement and reduced degrees of inflammatory cell infiltration and edema；the number of goblet cells significantly increased with deeper staining，and more mucus secretion was visible in gland lumens；positive expression levels of Claudin-1 and Occludin in colon tissue were significantly increased （P＜ 0.05，P＜0.01）；serum levels of TNF-α and IL-6 were significantly decreased （P＜0.05，P＜0.01），while IL-10 levels were significantly increased （P＜0.05，P＜0.01）. Compared with the model group，the Baitouwen Decoction low-dose，high-dose groups and the ferroptosis inhibitor group showed significantly decreased levels of MDA and Fe2+ in colon tissue （P＜0.05， P＜0.01）， and significantly increased levels of SOD and GSH （P＜0.05， P＜0.01）； microvilli of colonic epithelial cells were markedly restored，mitochondria showed mild swelling but cristae structures remained clearly visible； mRNA and protein expression of Nrf2， GPX4， and SLC7A11 in colon tissue were significantly upregulated （P＜0.05，P＜0.01）. Conclusion Baitouwen Decoction has a significant ameliorative effect on UC mice. Its mechanism may be related to activating the Nrf2/SLC7A11/GPX4 signaling pathway，inhibiting ferroptosis， and thereby alleviating colonic tissue damage.

R285.5

国家自然科学基金面上项目（82374426）；湖南中医药大学平台开放基金项目（2022FTKFJJ07）；湖南中医药大学中医学国内一流 学科建设项目（2018-2020）。