目的 探讨小檗碱（berberine, BBR）对新生儿坏死性小肠结肠炎（necrotizing enterocolitis, NEC）相关脑损伤的保护作用及其机制。 方法 构建NEC小鼠模型，将小鼠分为对照组、模型组、BBR低剂量组（2.5 mg/kg）、BBR高剂量组（5 mg/kg），每组24只。记录小鼠体重变化及生存情况；采用苏木精-伊红染色观察肠道、脑组织病理损伤程度，尼氏染色评估海马神经元损伤情况，免疫组化法检测海马小胶质细胞活化水平，酶联免疫吸附试验检测肠、脑脂多糖（lipopolysaccharide, LPS）含量，蛋白质印迹法（Western blot, WB）与荧光定量聚合酶链式反应法检测脑组织肿瘤坏死因子‑α、白细胞介素（interleukin, IL）‑6、IL‑1β mRNA及蛋白表达水平；WB法检测Toll样受体4 （Toll‑like receptor 4, TLR4）/髓系分化初级反应蛋白质88（myeloid differentiation primary response 88, MyD88）/核因子κB（nuclear factor‑κB, NF‑κB）信号通路及核苷酸结合结构域富含亮氨酸重复序列和含热蛋白结构域受体3（nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3, NLRP3）炎症小体相关蛋白、血脑屏障紧密连接相关蛋白表达水平；采用旷场实验、新物体识别实验、Y迷宫实验及Morris水迷宫实验评估小鼠远期神经行为功能。将BV2小胶质细胞随机分为空白组、LPS组、LPS+BBR组、LPS+瑞沙托维（Resatorvid, TAK‑242）组（n=3）。采用CCK‑8法检测细胞活力，WB法检测各组细胞炎症通路蛋白表达水平。 结果 与模型组比较，BBR低剂量组、BBR高剂量组肠道与脑组织病理改变较模型组减轻，肠道病理评分、第3~5天逃避潜伏期、活化表型的离子钙接头蛋白分子1阳性小胶质细胞数量及肿瘤坏死因子‑α、IL‑6、IL‑1β mRNA和蛋白表达水平降低（P<0.05），自发交替率升高（P<0.05）；BBR高剂量组肠、脑LPS水平及脑组织TLR4/MyD88/NF‑κB信号通路、NLRP3炎症小体相关蛋白表达水平降低（P<0.05），造模后第1~3天体重、中央区行进距离、中央区停留时间、测试期识别指数、平台穿越次数、目标象限停留时间百分比、脑组织紧密连接相关蛋白表达升高（P<0.05）。与LPS组比较，LPS+BBR组、LPS+TAK‑242组TLR4/MyD88/NF‑κB信号通路及NLRP3炎症小体相关蛋白表达水平降低（P<0.05）。 结论 BBR可减轻NEC模型小鼠脑损伤并改善远期神经功能，高剂量作用更显著；其机制可能与维持血脑屏障完整性、抑制TLR4/MyD88/NF‑κB信号通路及NLRP3炎症小体活化有关。

Objective To investigate the protective effects and underlying mechanisms of berberine (BBR) on brain injury related to neonatal necrotizing enterocolitis (NEC). Methods An NEC mouse model was established and mice were assigned to control, model, low-dose BBR (2.5 mg/kg), and high-dose BBR (5 mg/kg) groups (n=24 per group). Body weight and survival were recorded. Hematoxylin-eosin staining was performed to assess pathological damage in intestinal and brain tissues; Nissl staining was performed to evaluate neuronal injury in the hippocampus; immunohistochemistry was conducted to detect microglial activation in the hippocampus. Lipopolysaccharide (LPS) levels in the intestine and brain were measured by ELISA. Western blot and quantitative PCR were used to quantify the protein and mRNA expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in brain tissue. Western blot was further used to examine the protein expression related to the TLR4/MyD88/NF-κB signaling pathway, NLRP3 inflammasome, and blood-brain barrier (BBB) tight junction proteins (ZO-1, Occludin, Claudin-5). Neurobehavioral functions were evaluated by the open field, novel object recognition, Y-maze, and Morris water maze tests. In vitro, BV2 microglial cells were divided into control, LPS, LPS+BBR, or LPS+TAK-242 (TLR4 inhibitor) groups (n=3 per group). Cell viability was assessed by CCK-8 assay and inflammatory signaling proteins were measured by Western blot. Results Compared with the model group, both BBR doses alleviated intestinal and brain pathology; the intestinal pathology score, escape latency on days 3 to 5, number of activated microglia (immunoreactive for ionized calcium-binding adaptor molecule 1), and TNF-α, IL-6, IL-1β mRNA/protein levels decreased significantly (P<0.05), while the spontaneous alternation rate increased (P<0.05). High-dose BBR reduced intestinal and brain LPS levels and downregulated the TLR4/MyD88/NF-κB pathway and NLRP3 inflammasome-related protein expression in the brain (P<0.05). During days 1 to 3 after NEC induction, body weight, central zone movement distance, central zone residence time, recognition index in the testing phase, platform crossings, percentage of time spent in the target quadrant, and expression of BBB tight junction proteins increased significantly in the high-dose group (P<0.05). In vitro, LPS+BBR and LPS+TAK-242 treatments reduced the protein expression related to the TLR4/MyD88/NF-κB pathway and NLRP3 inflammasome compared with LPS alone (P<0.05). Conclusions BBR can alleviate brain injury in NEC model mice and improve long-term neurological outcomes dose-dependently. These effects likely involve preservation of BBB integrity and suppression of microglial activation via inhibition of the TLR4/MyD88/NF-κB/NLRP3 signaling pathway.