In vivo measurement of nitric oxide release from intact human skin post photobiomodulation using visible and near-infrared light: A chemiluminescence detection study

Significance : This study investigates the therapeutic potential of photobiomodulation (PBM) using visible and near-infrared (NIR) light on nitric oxide (NO) release from intact human skin. Given NO's critical role in physiological processes such as wound healing, inflammation control, and vasodilation, this research could lead to innovative non-invasive treatments. Aim: The primary aim was to explore how PBM at different wavelengths affects NO release from human skin. Custom-built airtight sleeves equipped with gas ports were used to measure NO levels, assessing the impact of three specific wavelengths of light (455 nm, 660 nm, and 850 nm). Approach: Eighteen healthy participants had their forearms enclosed in airtight sleeves. The skin was irradiated with the specified wavelengths at a fluence of 45 J/cm² and an irradiance of 50 mW/cm² for 15 min. NO levels were quantified after irradiation using chemiluminescence detection (CLD), which measures the chemiluminescent reaction of NO with ozone (O3) for real-time analysis. Results: Significant differences in NO release were observed among the wavelengths tested, indicating that PBM stimulates NO release from intact human skin. Conclusions: The study provides strong evidence that PBM using visible and NIR light can enhance NO release from human skin, suggesting potential therapeutic applications for conditions involving NO. Further research is needed to understand the mechanisms behind PBM-induced NO release and its clinical implications.