An 808-nm Diode Laser with a Flat-Top Handpiece Positively Photobiomodulates Mitochondria Activities.
OBJECTIVE
Photobiomodulation is proposed as a non-linear process. Only the action of light at a low intensity and fluence is assumed to have stimulation on cells; whereas a higher light intensity and fluence generates negative effects, exhausting the cell's energy reserve as a consequence of a too strong stimulation. In our work, we detected the photobiomodulatory effect of an 808-nm higher-fluence diode laser [64 J/cm2-1 W, continuous wave (CW)] irradiated by a flat-top handpiece on mitochondria activities, such as oxygen consumption, activity of mitochondria complexes I, II, III, and IV, and cytochrome c as well as ATP synthesis.


METHODS
The experiments are performed by standard procedure on mitochondria purified from bovine liver.


RESULTS
Our higher-fluence diode laser positively photobiomodulates the mitochondria oxygen consumption, the activity of the complexes III and IV, and the ATP production, with a P/O = 2.6. The other activities are not influenced.


CONCLUSIONS
Our data show for the first time that even the higher fluences (64 J/cm2-1 W), similar to the low fluences, can photobiostimulate the mitochondria respiratory chain without uncoupling them and can induce an increment in the ATP production. These results suggest that the negative effects of higher fluences observed to date are not unequivocally due to higher fluence per se but might be a consequence of the irradiation carried by handpieces with a Gaussian profile.
1 Protistology Laboratory, Department of Earth, Environmental and Life Sciences, University of Genoa , Genoa, Italy .|2 Department of Surgical Sciences and Integrated Diagnostic, University of Genoa , Genoa, Italy .
Andrea
A
Amaroli
3 Biochemistry Laboratory, Department of Pharmacy, University of Genoa , Genoa, Italy .
Silvia
S
Ravera
2 Department of Surgical Sciences and Integrated Diagnostic, University of Genoa , Genoa, Italy .
Steven
S
Parker
3 Biochemistry Laboratory, Department of Pharmacy, University of Genoa , Genoa, Italy .
Isabella
I
Panfoli
2 Department of Surgical Sciences and Integrated Diagnostic, University of Genoa , Genoa, Italy .
Alberico
A
Benedicenti
2 Department of Surgical Sciences and Integrated Diagnostic, University of Genoa , Genoa, Italy .
Stefano
S
Benedicenti
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004867:Equipment Design; D054023:Lasers, Semiconductor; D008099:Liver / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D028022:Low-Level Light Therapy / Q000379:methods*; D008928:Mitochondria / Q000528:radiation effects*; D010101:Oxygen Consumption / Q000502:physiology / Q000528:radiation effects; D010247:Paramecium / Q000378:metabolism / Q000528:radiation effects; D012680:Sensitivity and Specificity
D000255:Adenosine Triphosphate
diode laser; paramecium; photobiomodulation