Favorable Changes in Salivary Uric Acid and Acyl Peptide Enzyme Hydrolase Activity in a Photobiomodulation Pilot Study

Photobiomodulation (PBM) therapy has numerous documented health benefits, but the physiological mechanisms are still being elucidated. In this work, a pilot study of salivary biomarkers was investigated to potentially understand physiologic oxidative stress changes associated with PBM therapy. Eighteen participants completed six PBM sessions and provided saliva samples prior to session one and after each of the six sessions. Salivary uric acid, acyl peptide enzyme hydrolase (APEH) activity, and total protein were measured. While salivary uric acid and total protein have been measured before, APEH is a novel salivary marker. When grouped into ‘heightened risk’ categories, 67% of participants with high starting uric acid had a reduction in salivary uric acid and 57% of participants with low starting APEH activity had an increase in salivary APEH activity over the six PBM sessions. While a larger and more comprehensive study is required to make conclusions, this pilot study suggests that PBM therapy has beneficial outcomes to selected oxidative stress markers, thereby providing a physiological mechanism that may accompany reported positive biological outcomes.