DNA damage in blood cells exposed to low-level lasers.
OBJECTIVE
In regenerative medicine, there are increasing applications of low-level lasers in therapeutic protocols for treatment of diseases in soft and in bone tissues. However, there are doubts about effects on DNA, and an adequate dosimetry could improve the safety of clinical applications of these lasers. This work aimed to evaluate DNA damage in peripheral blood cells of Wistar rats induced by low-level red and infrared lasers at different fluences, powers, and emission modes according to therapeutic protocols.


METHODS
Peripheral blood samples were exposed to lasers and DNA damage was accessed by comet assay. In other experiments, DNA damage was accessed in blood cells by modified comet assay using formamidopyrimidine DNA glycosylase (Fpg) and endonuclease III enzymes.


RESULTS
Data show that exposure to low-level red and infrared lasers induce DNA damage depending on fluence, power and emission mode, which are targeted by Fpg and endonuclease III.


CONCLUSIONS
Oxidative DNA damage should be considered for therapeutic efficacy and patient safety in clinical applications based on low-level red and infrared lasers.
Laboratório, de Ciências, Radiológicas, Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, Maracanã, Rio de Janeiro, 20550900, Brazil.
Luiz Philippe da Silva
LP
Sergio
Ana Paula Almeida da
AP
Silva
Philipi Freitas
PF
Amorim
Vera Maria Araújo
VM
Campos
Luis Alexandre Gonçalves
LA
Magalhães
Flavia
F
de Paoli
Adenilson
A
de Souza da Fonseca
D000818:Animals; D001773:Blood Cells / Q000528:radiation effects*; D020552:Comet Assay; D004249:DNA Damage / Q000528:radiation effects*; D043382:DNA-Formamidopyrimidine Glycosylase / Q000494:pharmacology; D004706:Endodeoxyribonucleases / Q000494:pharmacology; D007834:Lasers; D017208:Rats, Wistar
D004706:Endodeoxyribonucleases; C552940:Nthl1 protein, rat; D043382:DNA-Formamidopyrimidine Glycosylase
Wistar rats; comet assay; oxidative lesion