The analgesic properties of photobiomodulation therapy (PBMT) have been raising increasing interest in the clinical community due to the positive effects observed on patients, nevertheless the mechanistic basis of its action on peripheral sensory neurons remains still elusive. In this study, the effect of near‐infrared (NIR) PBMT at 800 and 970 nm of wavelength was investigated on the 50B11 immortalized nociceptive sensory neuronal cell line by evaluating capsaicin‐induced calcium flow and different markers correlated to mitochondria, that is, ATP, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP). Calcium peak stimulated by capsaicin, the ligand of TRPV1 channel, was decreased in neurons pre‐irradiated with the combination of the two wavelengths. Furthermore, delivering the 800 and 970 nm separately an increment of ATP, as well as MMP hyperpolarization were detected; notably, the 800 nm wavelength also increased ROS and O₂⁻ levels. Our findings, obtained on an in vitro model of nociception, show the positive effect of PBMT on two potential photo‐targets of NIR light, namely the TRPV1 channel and the mitochondria.

中文翻译：

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光生物调节疗法对50B11感觉神经元的体外影响：细胞代谢，氧化应激，线粒体膜电位（MMP）和辣椒素诱导的钙流的评估

由于对患者的积极作用，光生物调节疗法（PBMT）的止痛特性已引起临床界的越来越多的兴趣，尽管如此，其对周围感觉神经元作用的机理基础仍然难以捉摸。在这项研究中，通过评估辣椒素诱导的钙流和与线粒体相关的不同标志物，研究了波长为800和970 nm的近红外（PBN）PBMT对50B11永生伤害感受性感觉神经元细胞系的影响，活性氧（ROS）和线粒体膜电位（MMP）。辣椒素（TRPV1通道的配体）刺激的钙峰在用两种波长组合预辐照的神经元中降低。此外，分别提供800和970 nm的ATP增量，以及MMP超极化；值得注意的是，800 nm波长也增加了ROS和O₂ ^-水平。我们从伤害感受的体外模型中获得的发现表明，PBMT对NIR光的两个潜在光目标，即TRPV1通道和线粒体具有积极作用。