Department of Cell Biology, Physiology and Immunology, Faculty of Veterinary Medicine, University of Cordoba, Campus of Rabanales, Cordoba, 14071, Spain.
Maimonides Institute for Research in Biomedicine of Cordoba, (IMIBIC), Cordoba, 14004, Spain.
Arch Microbiol. 2024 Oct 9;206(11):427. doi: 10.1007/s00203-024-04151-9.
Melatonin (MLT) is a methoxyindole that has potent antioxidant actions, anti-inflammatory, and antiapoptotic capacity. However, its in vitro antibacterial capacity has been the least studied of its properties. Dimethylsulfoxide (DMSO) has been the most used solvent for these tests, but it shows an antimicrobial effect if it is not dissolved. Cyrene™ is a new solvent that has emerged as an alternative to DMSO. Therefore, this study aimed to determine the antimicrobial capacity of MLT by MIC assays, using Cyrene™ as a solvent. Likewise, the solubility of MLT in this solvent and whether it exerted any effect on bacterial growth at different percentages was also determined. Different dilutions of MLT in Cyrene™ with different concentrations, were prepared. No growth inhibition caused by MLT was observed. The growth inhibition observed was because of Cyrene™. The maximum amount of MLT that can be diluted in 100% Cyrene is 10 mg/mL, but this percentage of solvent shows a bactericidal effect. Therefore, it must be dissolved at 5% to avoid this effect, so only 4 mg/mL of MLT can be diluted in it. Therefore, if no other solvents are available, the in vitro antibacterial role of MLT cannot be adequately assessed.
褪黑素（MLT）是一种甲氧基吲哚，具有强大的抗氧化、抗炎和抗凋亡能力。然而，其体外抗菌能力是其性质中研究最少的。二甲亚砜（DMSO）是这些测试中最常用的溶剂，但如果不溶解，它就会显示出抗菌作用。Cyrene™是一种新兴的替代 DMSO 的溶剂。因此，本研究旨在通过 MIC 测定法，使用 Cyrene™作为溶剂来确定 MLT 的抗菌能力。同样，还确定了 MLT 在这种溶剂中的溶解度以及它在不同百分比下是否对细菌生长有任何影响。用不同浓度的 Cyrene™制备了 MLT 的不同稀释液。未观察到 MLT 引起的生长抑制。观察到的生长抑制是由于 Cyrene™引起的。在 100% Cyrene 中可以稀释的最大 MLT 量为 10mg/ml，但该溶剂百分比具有杀菌作用。因此，必须以 5%的比例溶解，以避免这种影响，因此只能在其中稀释 4mg/ml 的 MLT。因此，如果没有其他溶剂可用，则无法充分评估 MLT 的体外抗菌作用。
