Increased PpIX Production Following Infrared Photobiomodulation in Normal Skin

The exogenous administration of 5-aminolevulinic acid (ALA) has been widely studied, particularly for photodynamic therapy (PDT) in the treatment of skin cancer, as ALA is a natural precursor of protoporphyrin IX (PpIX) - an endogenous, fluorescent, and photosensitive molecule. One way to enhance PpIX production, and consequently achieve a better photodynamic response, is through photobiomodulation (PBM), which acts on the mitochondria where PpIX is produced. For this reason, a protocol was tested to determine whether PBM increases PpIX production in healthy skin. Topical application of methyl aminolevulinate (MAL) was performed, followed by PBM at 780 nm, and the cream was reapplied for 3 hours. Through fluorescence spectrum analysis, an increase in PpIX production was observed in the PBM group compared to the group without PBM, with a range of 20–60%. These results suggest that the photodynamic response in skin tumors can be enhanced.