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Low-Power Red and Infrared Laser Effects on Cells Deficient in DNA Repair

Lucas Kiyoshi da Fonseca Iwahara1, Flavia de Paoli2, Adenilson de Souza da Fonseca3,4,5

  • 1Instituto de Biociências, Universidade Federal do Estado do Rio de Janeiro, Avenida Pasteur, 296, Urca, Rio de Janeiro, 22290240, Brazil.

Journal of Lasers in Medical Sciences
|November 22, 2019
PubMed

Insights

Low-level laser therapy shows lethal effects on bacterial cells with DNA repair deficiencies. These findings address concerns about potential molecular side effects on DNA from laser treatments.

Area of Science:

  • Biomedical Engineering
  • Molecular Biology
  • Microbiology

Background:

  • Low-level lasers are used in oncology for treating oral and bone tissues affected by chemotherapy and radiotherapy.
  • Concerns exist regarding potential DNA damage induced by low-level laser therapy (LLLT).

Purpose of the Study:

  • To evaluate the effects of low-power lasers on DNA repair mechanisms in mutant *Escherichia coli* cells.
  • To assess laser-induced molecular side effects, specifically on DNA.

Main Methods:

  • Utilized *Escherichia coli* wild type, *recA*- (lacking recombination DNA repair), and *lexA*- (lacking SOS response) cultures.
  • Irradiated bacterial cells with lasers at varying energy densities, powers, and emission modes.
  • Assessed cell viability and morphology post-irradiation.

Main Results:

  • Laser irradiation decreased viability in *recA*- cultures but not in wild type or *lexA*- cells.
  • Morphological alterations were observed in wild type and *lexA*- cells, dependent on laser parameters.
  • Low-level lasers exhibited lethal effects on bacterial cells with compromised DNA repair and SOS response.

Conclusions:

  • Low-level lasers can have lethal effects on bacterial cells with impaired DNA repair and SOS response pathways.
  • The study indicates that LLLT does not induce significant morphological modifications in these bacterial cells.
  • Findings contribute to understanding the safety profile of LLLT concerning DNA integrity.
Keywords:
DNA repairEscherichia coliLaser therapy

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