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Melatonin generates singlet oxygen on laser irradiation but acts as a quencher when irradiated by lamp photolysis
Author(s) -
Maharaj D. S.,
Molell H.,
Antunes E. M.,
Maharaj H.,
Maree D. M.,
Nyokong T.,
Glass B. D.,
Daya S.
Publication year - 2005
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/j.1600-079x.2004.00185.x
Subject(s) - singlet oxygen , melatonin , photochemistry , radical , photodissociation , irradiation , chemistry , scavenger , free radical scavenger , singlet state , oxygen , triplet state , organic chemistry , molecule , biology , antioxidant , physics , nuclear physics , excited state , neuroscience
Melatonin, a naturally occurring chemical mediator, although assigned a diverse range of functions, has attracted interest in recent years because of its ability to function as a free radical scavenger. Because of the implications of singlet oxygen in neurotoxicity, the objective of the study was to investigate the ability of melatonin to quench singlet oxygen generated using laser irradiation or lamp photolysis. The results show that melatonin produces radicals upon laser irradation while the lamp photolysis studies show that melatonin is able to scavenge singlet oxygen produced by naphthalene. While melatonin is a free radical scavenger under biological conditions, it acts as a generator of singlet oxygen and or radicals (as Φ Δ is 1.41) when irradiated with laser light, implying that it has the potential to be used in photodynamic therapy in the destruction of tumors.