College of Traditional Chinese Medicine and College of Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210046, China; Key Laboratory of Integrative Biomedicine for Brain Diseases, College of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210046, China.
Nantong TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Nantong, Jiangsu, 226001, China.
J Ethnopharmacol. 2023 Oct 5;314:116604. doi: 10.1016/j.jep.2023.116604. Epub 2023 May 11.
Treating cognitive impairment is a challenging and necessary research topic. ZeXieYin Formula (ZXYF), is a traditional herbal formula documented in the book of HuangDiNeiJing. Our previous studies demonstrated the ameliorative effects of ZXYF on atherosclerosis by reducing the plasma trimethylamine oxide (TMAO) level. TMAO is a metabolite of gut microorganisms, our recent research found that the increasing level of TMAO may have adverse effects on cognitive functions.
Our study mainly focused on the therapeutic effects of ZXYF on TMAO-induced cognitive impairment in mice and explored its underlying mechanism.
After the TMAO-induced cognitive impairment mice models were established, we applied behavioral tests to estimate the learning and memory ability of the ZXYF intervention mice. Liquid chromatography-mass spectrometry (LC-MS) was used to quantify the TMAO levels in plasma and the brain. The effects of ZXYF on the hippocampal synaptic structure and the neurons were observed by transmission electron microscopy (TEM) and Nissl staining. In addition, western-blotting (WB) and immunohistochemical (IHC) staining were used to detect the level of related proteins in the synaptic structure and further verify the changes in synaptic plasticity and the mTOR pathway after ZXYF administration.
Behavioral tests showed that the learning and memory ability of mice impaired after a period of TMAO intervention and ZXYF could alleviate these changes. A series of results showed that ZXYF partly restored the damage of hippocampal synapse and neurons in TMAO-induced mice, at the same time, the expression of synapse-related proteins and mTOR pathway-related proteins were significantly regulated compared with the damage caused by TMAO.
ZXYF could alleviate TMAO-induced cognitive impairment by improving synaptic function, reducing neuronal damage, regulating synapse-associated proteins, and regulating the mTOR signaling pathway.
认知障碍的治疗是一个具有挑战性和必要性的研究课题。泽泻饮（ZXYF）是《黄帝内经》一书中记载的一种传统草药配方。我们之前的研究表明，ZXYF 通过降低血浆三甲胺氧化物（TMAO）水平对动脉粥样硬化有改善作用。TMAO 是肠道微生物的代谢物，我们最近的研究发现，TMAO 水平的升高可能对认知功能产生不良影响。
本研究主要关注 ZXYF 对 TMAO 诱导的小鼠认知障碍的治疗作用，并探讨其潜在机制。
在建立 TMAO 诱导的认知障碍小鼠模型后，我们应用行为测试来评估 ZXYF 干预小鼠的学习和记忆能力。液相色谱-质谱联用（LC-MS）用于定量血浆和大脑中的 TMAO 水平。透射电子显微镜（TEM）和尼氏染色观察 ZXYF 对海马突触结构和神经元的影响。此外，使用 Western-blotting（WB）和免疫组织化学（IHC）染色检测突触结构中相关蛋白的水平，进一步验证 ZXYF 给药后突触可塑性和 mTOR 通路的变化。
行为测试表明，TMAO 干预一段时间后，小鼠的学习和记忆能力受损，而 ZXYF 可减轻这些变化。一系列结果表明，ZXYF 部分恢复了 TMAO 诱导的小鼠海马突触和神经元的损伤，同时，与 TMAO 引起的损伤相比，突触相关蛋白和 mTOR 通路相关蛋白的表达也得到了显著调节。
ZXYF 可通过改善突触功能、减少神经元损伤、调节突触相关蛋白以及调节 mTOR 信号通路来缓解 TMAO 诱导的认知障碍。
