Lee Seung Won, Han Hee Chul
Good Doctor Research Institute, College of Medicine, Korea University, Seoul, South Korea.
Department of Physiology, College of Medicine and Neuroscience Research Institute, Korea University, Seoul, South Korea.
Front Neurosci. 2021 May 17;15:663650. doi: 10.3389/fnins.2021.663650. eCollection 2021.
Methylene blue (MB) is a cationic thiazine dye, widely used as a biological stain and chemical indicator. Growing evidence have revealed that MB functions to restore abnormal vasodilation and notably it is implicated even in pain relief. Physicians began to inject MB into degenerated disks to relieve pain in patients with chronic discogenic low back pain (CDLBP), and some of them achieved remarkable outcomes. For osteoarthritis and colitis, MB abates inflammation by suppressing nitric oxide production, and ultimately relieves pain. However, despite this clinical efficacy, MB has not attracted much public attention in terms of pain relief. Accordingly, this review focuses on how MB lessens pain, noting three major actions of this dye: anti-inflammation, sodium current reduction, and denervation. Moreover, we showed controversies over the efficacy of MB on CDLBP and raised also toxicity issues to look into the limitation of MB application. This analysis is the first attempt to illustrate its analgesic effects, which may offer a novel insight into MB as a pain-relief dye.
亚甲蓝（MB）是一种阳离子噻嗪染料，广泛用作生物染色剂和化学指示剂。越来越多的证据表明，MB具有恢复异常血管舒张的功能，尤其值得注意的是，它甚至与缓解疼痛有关。医生开始将MB注射到退变的椎间盘内，以缓解慢性盘源性下腰痛（CDLBP）患者的疼痛，其中一些患者取得了显著疗效。对于骨关节炎和结肠炎，MB通过抑制一氧化氮的产生减轻炎症，最终缓解疼痛。然而，尽管有这种临床疗效，但MB在缓解疼痛方面并未引起太多公众关注。因此，本综述重点关注MB如何减轻疼痛，指出这种染料的三个主要作用：抗炎、减少钠电流和去神经支配。此外，我们展示了关于MB对CDLBP疗效的争议，并提出了毒性问题，以探讨MB应用的局限性。这一分析是首次试图阐明其镇痛作用，这可能为将MB作为一种缓解疼痛的染料提供新的见解。
