Effect of 808nm Diode Laser on Swimming Behavior, Food Vacuole Formation and Endogenous ATP Production of Paramecium primaurelia (Protozoa)

Photobiomodulation (PBM) has been used in clinical practice for more than 40years. To clarify the mechanisms of action of PBM at cellular and organism levels, we investigated its effect on Paramecium primaurelia (Protozoa) irradiated by an 808nm infrared diode laser with a flat-top handpiece (1W in CW). Our results led to the conclusion that: (1) the 808nm laser stimulates the P.primaurelia without a thermal effect, (2) the laser effect is demonstrated by an increase in swimming speed and in food vacuole formation, (3) the laser treatment affects endogenous adenosine triphosphate (ATP) production in a positive way, (4) the effects of irradiation dose suggest an optimum exposure time of 50s (64Jcm(-2) of fluence) to stimulate the Paramecium cells; irradiation of 25s shows no effect or only mild effects and irradiation up to 100s does not increase the effect observed with 50s of treatment, (5) the increment of endogenous ATP concentration highlights the positive photobiomodulating effect of the 808nm laser and the optimal irradiation conditions by the flat-top handpiece.