Background

Ellagitannins (ETs) are a major classification of natural tannins, with relatively large and complex structures. ETs from medicinal plants are focused increasingly due to urolithins, a kind of intestinal metabolite of ETs, which showed promising anti-Alzheimer's disease (AD) effects. Melastoma dodecandrum (MD), a widely used traditional Chinese medicine is rich in ETs, but their chemistry and potential neuroprotective effects have not been investigated.

Purpose

This study aimed to identify the chemical composition of ETs in the crude extract of MD and to investigate their neuroprotective effects in vivo.

Methods

UPLC-QTOF-MS-based molecular networking (MN) and structural characterization were applied to targeted profiling of the MD-ETs. Animal behavior experiments, including the novel object recognition test (NOR), open field test (OFT), and Morris water maze test (MWM), were conducted to assess the memory improvement effects of MD-ETs in AD model mice.

Results

A total of 70 ETs, ranging from monomers to tetramers, were tracked and characterized in the MD extract using MN-guided targeted profiling, with 59 of them reported for the first time in this species. MD-ETs significantly improved memory impairment in AD mice, as indicated by decreased escape latency, increased number of crossings and target quadrant distance in MWM, increased rearing number in OFT, and increased preference index in NOR.

Conclusion

This study systematically characterized the composition and structural features of ETs in MD using targeted LC-MS profiling, expanding the chemical information of ETs in MD. Furthermore, the results demonstrate that MD-ETs have significant effects on improving impaired memory in AD mice, suggesting their potential as alternative natural medicines for the treatment of neurodegenerative diseases.

中文翻译：

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分子网络辅助的系统分析和来自野牡丹的鞣花单宁的体内神经保护作用

背景

鞣花单宁 (ETs) 是天然单宁的主要分类，具有相对较大且复杂的结构。由于尿石素是一种 ET 的肠道代谢产物，药用植物中的 ET 越来越受到关注，它显示出有希望的抗阿尔茨海默病 (AD) 作用。野牡丹(MD) 是一种广泛使用的中药，富含 ET，但尚未研究其化学成分和潜在的神经保护作用。

目的

本研究旨在鉴定 MD 粗提物中 ET 的化学成分，并研究其在体内的神经保护作用。

方法

基于 UPLC-QTOF-MS 的分子网络 (MN) 和结构表征应用于 MD-ET 的靶向分析。进行动物行为实验，包括新物体识别试验（NOR）、旷场试验（OFT）和莫里斯水迷宫试验（MWM），以评估 MD-ET 对 AD 模型小鼠的记忆改善作用。

结果

使用 MN 引导的靶向分析在 MD 提取物中跟踪和表征了从单体到四聚体的总共 70 个 ET，其中 59 个在该物种中首次报道。MD-ET 显着改善了 AD 小鼠的记忆障碍，表现为逃避潜伏期减少、MWM 中交叉次数和目标象限距离增加、OFT 中饲养次数增加以及 NOR 中偏好指数增加。

结论

本研究使用靶向 LC-MS 分析系统地表征了 MD 中 ET 的组成和结构特征，扩展了 MD 中 ET 的化学信息。此外，结果表明，MD-ET 对改善 AD 小鼠的记忆力受损具有显着影响，表明它们具有作为治疗神经退行性疾病的替代天然药物的潜力。