Low-level laser irradiation attenuates production of reactive oxygen species by human neutrophils.
OBJECTIVE
The aim of this study was to examine the effects of low-level laser therapy (LLLT) on production of reactive oxygen (ROS) species by human neutrophils.


BACKGROUND
LLLT is an effective therapeutic modality for inflammatory conditions.


METHODS
The laser device used was the infrared diode laser (GaAlAs), 830-nm continuous wave (150 mW/cm(2)). After irradiation, ROS production by neutrophils was measured using luminol-dependent chemiluminescence (LmCL) and expression of CD11b and CD16 on neutrophil surface was measured by flow cytometry.


RESULTS
The LmCL response of neutrophils was reduced by laser irradiation at 60 min prior to the stimulation with opsonized zymosan and calcium ionophore. The attenuating effect of LLLT was larger in neutrophils of smokers than non-smokers, while the amount of produced ROS was larger in neutrophils of smokers. Expression of CD11b and CD16 on neutrophil surface was not affected by LLLT.


CONCLUSIONS
Attenuation of ROS production by neutrophils may play a role in the effects of LLLT in the treatment of inflammatory tissues. There is a possible usage of LLLT to improve wound healing in smokers.
Fujimaki
Yuji
Y
Department of Hygiene, Hirosaki University School of Medicine, Japan.
Shimoyama
Tadashi
T
Liu
Qiang
Q
Umeda
Takashi
T
Nakaji
Shigeyuki
S
Sugawara
Kazuo
K
D000328:Adult; D039481:CD11b Antigen / Q000096:biosynthesis; D006801:Humans; D028022:Low-Level Light Therapy; D008163:Luminescent Measurements; D008297:Male; D009504:Neutrophils / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D017452:Receptors, IgG / Q000096:biosynthesis; D012907:Smoking / Q000009:adverse effects*
D039481:CD11b Antigen; D017382:Reactive Oxygen Species; D017452:Receptors, IgG