title: 808-nm laser therapy with a flat-top handpiece photobiomodulates mitochondria activities of Paramecium primaurelia (Protozoa).
abstract: Photobiomodulation is proposed as a non-linear process, and only low-level laser therapy (LLLT) is assumed to stimulate exposed cells, whereas high powered laser and fluences can cause negative effects, exhausting the cell's energy reserve as a consequence of excessive photon-based stimulation. In our work, we investigated and compared the effects of 808-nm diode laser (CW) with a new flat-top handpiece. To this purpose, we tested the photobiomodulation effects of 1 and 3 J/cm(2) fluence, both generated by 100 mW or 1 W of laser power and of 64 J/cm(2) of fluence generated by 100 mW, 1 W, 1.5 W or 2 W, as expressed through oxygen consumption and ATP synthesis of Paramecium. Data collected indicates the incremental consumption of oxygen through irradiation with 3 J/cm(2)-100 mW or 64 J/cm(2)-1 W correlates with an increase in Paramecium ATP synthesis. The Paramecium respiration was inhibited by fluences 64 J/cm(2)-100 mW or 64 J/cm(2)-2 W and was followed by a decrease in the endogenous ATP concentration. The 1 J/cm(2)-100 mW or 1 W and 3 J/cm(2)-1 W did not affect mitochondrial activity. The results show that the fluence of 64 J/cm(2)-1 W more than the 3 J/cm(2)-100 mW causes greater efficiency in Paramecium mitochondria respiratory chain activity. Our results suggest that thanks to flat-top handpiece we used, high fluences by high-powered laser have to be reconsidered as an effective and non-invasive therapy. Possible associated benefits of deeper tissue penetration would increase treatment effectiveness and reduced irradiation time.
authors.affiliation: Department of Earth, Environmental and Life Sciences, Protistology Laboratory, University of Genoa, Corso Europa, 26, 16132, Genoa, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Amaroli
authors.affiliation: Department of Pharmacy, Biochemistry Laboratory, University of Genoa, Viale Benedetto XV, 3, 16132, Genoa, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Ravera
authors.affiliation: Department of Surgical Sciences and Integrated Diagnostic, University of Genoa, Largo R. Benzi, 10, 16132, Genoa, Italy.
authors.forename: Steven
authors.initials: S
authors.lastname: Parker
authors.affiliation: Department of Pharmacy, Biochemistry Laboratory, University of Genoa, Viale Benedetto XV, 3, 16132, Genoa, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Panfoli
authors.affiliation: Department of Surgical Sciences and Integrated Diagnostic, University of Genoa, Largo R. Benzi, 10, 16132, Genoa, Italy.
authors.forename: Alberico
authors.initials: A
authors.lastname: Benedicenti
authors.affiliation: Department of Surgical Sciences and Integrated Diagnostic, University of Genoa, Largo R. Benzi, 10, 16132, Genoa, Italy. stefano.benedicenti@tiscali.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Benedicenti
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D006801:Humans; D054023:Lasers, Semiconductor; D008928:Mitochondria / Q000378:metabolism / Q000528:radiation effects*; D010101:Oxygen Consumption; D010247:Paramecium / Q000378:metabolism / Q000528:radiation effects*
chemical_list: D000255:Adenosine Triphosphate
keywords: High fluence; Laser irradiation; Laser phototherapy; Low-level laser therapy; Mitochondria; Photobiostimulation