CAS Key Laboratory of Chemistry of Northwestern Plant Resources, Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences (CAS), Lanzhou, 730000, People's Republic of China.
University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
Anal Sci. 2024 Nov;40(11):2063-2073. doi: 10.1007/s44211-024-00644-1. Epub 2024 Aug 13.
Emodin is an important anthraquinone compound with good anti-inflammatory activity in Chinese traditional medicine rhubarb. Detailed spatial distribution information in bio-tissues plays an important role in revealing the pharmacodynamics, toxicology and chemical mechanism of emodin. Herein, the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry imaging (MALDI-TOF-MSI) analytical method was established to obtain information on the spatial and temporal changes of emodin in multiple mouse tissue sections (heart, liver, spleen, lung, kidney, and brain) after intraperitoneal injection of emodin in mice. The measurements were accomplished in the negative ion mode in the range of m/z 250-285 Da with a spatial resolution on 40 µm. It was found that emodin was predominantly distributed in the arteriolar vascular region of the heart, the capsule region of the spleen, and the cortex of the kidney. Moreover, the MALDI-TOF-MSI result implied that emodin might be distributed in the brain. These more detailed spatial distribution information provides the significant reference for investigating the action mechanism of emodin, which cannot be obtained from conventional LC-MS analysis. The distribution trend of emodin in the results of MALDI-TOF-MSI analysis agreed with the ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) results well, demonstrating the complementarity and reliability of the established MALDI-TOF-MSI method. Our work provided a label-free molecular imaging method to investigate the precise spatial distribution of emodin in various organs, which prove great potential in studying the effective substances and mechanism of rhubarb.
大黄素是一种重要的蒽醌类化合物，具有良好的抗炎活性，是中国传统医学大黄中的一种成分。生物组织中详细的空间分布信息对于揭示大黄素的药效学、毒理学和化学机制起着重要作用。在此，建立了基质辅助激光解吸/电离飞行时间质谱成像（MALDI-TOF-MSI）分析方法，以获得大黄素在小鼠腹腔注射后多个小鼠组织切片（心、肝、脾、肺、肾和脑）中时空变化的信息。测量在负离子模式下，在 m/z 250-285 Da 的范围内进行，空间分辨率为 40 µm。结果发现，大黄素主要分布在心脏的小动脉血管区域、脾脏的包膜区域和肾脏的皮质。此外，MALDI-TOF-MSI 结果表明，大黄素可能分布在大脑中。这些更详细的空间分布信息为研究大黄素的作用机制提供了重要的参考，而这些信息是从常规 LC-MS 分析中无法获得的。MALDI-TOF-MSI 分析结果中大黄素的分布趋势与超高效液相色谱/串联质谱（UPLC-MS/MS）结果吻合较好，表明所建立的 MALDI-TOF-MSI 方法具有互补性和可靠性。我们的工作提供了一种无标记的分子成像方法，用于研究大黄素在各种器官中的精确空间分布，这证明了其在研究大黄有效物质和机制方面具有很大的潜力。
