Dual Wavelength <scp>LEDs</scp> Induce Reactive Oxygen Species and Nitric Oxide That Inhibit the Production of Dihydrotestosterone by 5‐α Reductase

Androgenetic alopecia (AGA) causes balding in approximately 50% of adults. One primary cause of AGA is synthesis of dihydrotestosterone from testosterone by 5-α reductase. Systemic pharmaceutical interventions have potentially serious side effects, necessitating development of localized interventions. One such approach is administration of red light via low level light therapy (LLLT), which has promising clinical data. However, the LLLT mechanism of action remains unclear. We investigated the ability of LLLT to stimulate nitric oxide (NO) and the role of NO in inhibition of DHT synthesis. Our results show that red and red-orange light induce NO release in a cell-free platform. In A549 and HEK293T cells, we demonstrate 620 and 660 nm LED-emitted light stimulates the production of NO, reactive oxygen species (ROS), and decreases DHT synthesis. These results provide a plausible mechanism of action for LLLT employing LED-emitted red and red-orange wavelengths of light to treat AGA.