Ergothioneine is associated with the severity of cognitive impairment in Alzheimer's patients, and it has neuroprotective effects. However, whether it can improve cognitive dysfunction in rats with vascular dementia (VD) is indistinct, and the specific mechanism is still unclear.

To investigate the effect of ergothioneine on cognitive dysfunction in VD rats by activating NRF2/HO-1 signaling pathway.

From August 2021 to September 2023, 48 adult male SD rats were selected and randomly assigned to four groups (n=12/pergroup) : control, model, ergothioneine and ergothioneine + NRF2 inhibitor (ML385). The VD rat model was replicated by permanent ligation of bilateral common carotid arteries. Two weeks before VD replicated, ergothioneine rats was intraperitoneally injected with 2 mg/kg of ergothioneine daily for 4 weeks. And ergothioneine + ML385 group receiving ergothioneine 2 mg/kg and ML385 30 mg/kg daily for 4 weeks before VD operation. The effects of ergothioneine on cognitive dysfunction in VD rats were detected by Morris water maze test, HE staining and TUNEL staining. The level of various proteins was measured utilizing Western blotting. Oxidative stress factors level and inflammatory factors level were tested with ELISA.

The model was successfully established. VD model group had longer escape latency and less residence time than control group (P<0.05). The number of neurons in rat hippocampal tissue decreased, the cells atrophied, the morphology was abnormal, and the nuclei were deeply stained. VD model group had more neurons apoptosis rate in brain tissue than control group (P<0.05). Decreased NRF2, HO-1, NQO1, SOD and GSH-Px levels were observed in VD model group (P<0.05). Increased MDA, IL-1β, IL-6 and TNF-α were also observed in VD model group (P<0.05). Ergothioneine group had shorter escape latency and more residence time than VD model group (P<0.05). The pathological degree hippocampal tissue reduced, and ergothioneine group had more neurons apoptosis rate in brain tissue than VD model group (P<0.05). Increased NRF2, HO-1, NQO1, SOD and GSH-Px levels were observed in ergothioneine group (P<0.05). Decreased MDA, IL-1β, IL-6 and TNF-α were also observed in ergothioneine group (P<0.05). Compared with ergothioneine group, the escape latency of rats in the ergothioneine + ML385 group was prolonged, the percentage of residence time in the target quadrant was decreased (P<0.05). The hippocampus was seriously damaged, and the apoptosis rate of brain neurons was increased (P<0.05). NRF2, HO-1, NQO1, SOD and GSH-Px levels were decreased (P<0.05). MDA, IL-1β, TNF-α and IL-6 levels were increased (P<0.05) .

Ergothioneine can improve cognitive dysfunction in VD rats by activating NRF2/HO-1 signaling pathway.

麦角硫因与阿尔茨海默病患者认知功能障碍的严重程度有关，并具有神经保护的作用。但其是否能改善血管性痴呆（VD）大鼠认知功能障碍暂不明晰，且其具体作用机制尚不清楚。

探讨麦角硫因通过激活核因子E2相关因子2/血红素加氧酶1（NRF2/HO-1）信号通路改善VD大鼠认知功能障碍的作用机制。

于2021年8月—2023年9月，选取成年雄性SD大鼠48只，随机分为对照组、模型组、麦角硫因组、麦角硫因+NRF2抑制剂（ML385）组，每组12只。除对照组外，其他各组采用双侧颈总动脉永久性结扎法建立VD大鼠模型，麦角硫因组于造模前2周开始每天腹腔注射麦角硫因2 mg/kg，持续4周；麦角硫因+ ML385组在造模前2周开始每天腹腔注射麦角硫因2 mg/kg和ML385 30 mg/kg，持续4周。通过Morris水迷宫测试、HE染色以及TUNEL染色检测麦角硫因对VD大鼠认知功能障碍的影响；Western blotting法检测各蛋白质表达水平，ELISA法检测氧化应激因子及炎症因子水平。

本研究成功建立了VD大鼠模型。与对照组比较，模型组大鼠的逃避潜伏期延长，目标象限停留时间百分比降低（P<0.05），大鼠海马组织中神经元数量减少，细胞萎缩，形态异常，细胞核深度染色，脑组织神经元凋亡率增加（P<0.05），海马组织中NRF2、HO-1和醌氧化还原酶1（NQO1）蛋白表达水平降低（P<0.05），超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）水平降低，丙二醛（MDA）水平增加（P<0.05），白介素（IL）-1β、IL-6和肿瘤坏死因子（TNF）-α水平增加（P<0.05）；与模型组比较，麦角硫因组大鼠逃避潜伏期缩短，目标象限停留时间百分比升高（P<0.05），海马组织病理程度减轻，脑组织神经元凋亡率降低（P<0.05），海马组织NRF2、HO-1和NQO1蛋白表达水平升高（P<0.05），SOD、GSH-Px水平升高，MDA水平降低（P<0.05），IL-1β、TNF-α和IL-6水平降低（P<0.05）；与麦角硫因组比较，麦角硫因+ML385组大鼠逃避潜伏期延长，目标象限停留时间百分比降低（P<0.05），海马组织损伤严重，脑组织神经元凋亡率增加（P<0.05），海马组织NRF2、HO-1和NQO1蛋白表达水平降低（P<0.05），SOD、GSH-Px水平降低，MDA水平升高（P<0.05），IL-1β、TNF-α和IL-6水平升高（P<0.05）。

麦角硫因通过激活NRF2/HO-1信号通路改善VD大鼠认知功能障碍。