Photobiology| Volume 139, ISSUE 5, SUPPLEMENT , S128, May 2019

745 Low-level red and infrared lights provide anti-aging skin benefits

      Photobiomodulation (PBM), also known as low-level light therapy, uses photons at a non-thermal irradiance to alter biological activities, such as reducing pain and inflammation, augmenting tissue repair and promoting regeneration, and skin rejuvenation. PBM can have either inhibitory or stimulatory effects on various biological activities at the same wavelength with either higher or lower energy densities. This study's objective is to evaluate the anti-aging benefits provided by non-coherent light-emitting diodes (LEDs). Human dermal fibroblasts or human skin explant tissues were treated by red (640 nm) and/or infrared (IR, 830 nm) LED lights at 0.3 J/cm2 (0.5 mW/cm2 for 10 minutes) to examine the antiaging benefits of PBM by light. Reactive oxygen species (ROS) were measured using a fluorescent reactive dye, real time qPCR was used to investigate gene expression, and ELISA/histology/non-invasive fluorescent measurement were used to assess protein production. Red and IR lights at 0.3 J/cm2 didn’t induce ROS formation in human fibroblasts. Red and/or IR LED lights could enhance elastin (ELN) gene expression and elastin production in human fibroblasts as well as induce COL1A1, COL3A1, and ELN genes expression and increase procollagen and elastin fibers formation in human skin explants. Furthermore, red and IR Iights could significantly induce hyaluronic acid (HA) production in human fibroblasts obtained from both Caucasian and African American donors. In conclusion, low-level red and/or IR LED lights stimulated the production of multiple biomarkers with proven anti-aging skin benefits. Taken together, low-level red and/or infrared LED lights provide a convenient, safe and effective mode of anti-aging treatment for photo-damaged skin.