5aminolevulinate

5-aminolevulinate, often abbreviated as 5-ALA, is a naturally occurring compound found in all living organisms. It is a key precursor in the biosynthesis of porphyrins, which are essential molecules involved in various biological processes, most notably in the formation of heme. Heme is a crucial component of hemoglobin, responsible for oxygen transport in the blood, and also of cytochromes, involved in cellular respiration.

In humans, 5-ALA is synthesized in the mitochondria and cytoplasm. The synthesis pathway is complex and regulated by feedback mechanisms. Exogenously administered 5-ALA can be taken up by cells and converted into protoporphyrin IX, a porphyrin that can accumulate in certain tissues. This accumulation property has led to its investigation and application in photodynamic therapy (PDT) and photodynamic diagnosis (PDD).

In PDT, 5-ALA is administered to a patient, and it preferentially accumulates in abnormal cells, such as cancer cells. When exposed to specific wavelengths of light, the accumulated protoporphyrin IX generates reactive oxygen species that can destroy these targeted cells. In PDD, the fluorescence of protoporphyrin IX under specific light conditions can help surgeons visualize and delineate tumor margins, aiding in more precise surgical resection. 5-ALA is also used as a dietary supplement in some contexts, though its precise role and efficacy in this application are still subjects of research.