Assessing the impact of low level laser therapy (LLLT) on biological systems: a review

Abstract

Purpose: Low level laser therapy (LLLT) in the visible to near infrared spectral band (390–1100 nm) is absorption of laser light at the electronic level, without generation of heat. It may be applied in a wide range of treatments including wound healing, inflammation and pain reduction. Despite its potential beneficial impacts, the use of lasers for therapeutic purposes still remains controversial in mainstream medicine. Whilst taking into account the physical characteristics of different qualities of lasers, this review aims to provide a comprehensive account of the current literature available in the field pertaining to their potential impact at cellular and molecular levels elucidating mechanistic interactions in different mammalian models. The review also aims to focus on the integral approach of the optimal characteristics of LLLT that suit a biological system target to produce the beneficial effect at the cellular and molecular levels.

Methods: Recent research articles were reviewed that explored the interaction of lasers (coherent sources) and LEDs (incoherent sources) at the molecular and cellular levels.

Results: It is envisaged that underlying mechanisms of beneficial impact of lasers to patients involves biological processes at the cellular and molecular levels. The biological impact or effects of LLLT at the cellular and molecular level could include cellular viability, proliferation rate, as well as DNA integrity and the repair of damaged DNA. This review summarizes the available information in the literature pertaining to cellular and molecular effects of lasers.

Conclusions: It is suggested that a change in approach is required to understand how to exploit the potential therapeutic modality of lasers whilst minimizing its possible detrimental effects.

Keywords:

• Low level laser therapy (LLLT)
• cell proliferation
• DNA damage
• DNA repair
• light emitting diodes (LEDs)

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Dr Ruwaidah A. Mussttaf, is a Lecturer of Medical Physics at Al-Nahrain University in Iraq. She recently completed her PhD in the School of Computing, Electronics and Mathematics at University of Plymouth. Her thesis was titled Laser light interaction and their influence on DNA and cell under in vitro conditions.

Dr David F. L. Jenkins, is a Lecturer in School of Computing, Electronics and Mathematics at University of Plymouth. His research interests are micro sensor and actuator systems, nanomaterials and devices which are focused on applications in clean water, health and energy in developing countries.

Awadhesh N. Jha, is a Professor of Genetic Toxicology and Ecotoxicoloy in the School of Biological and Marine Sciences, University of Plymouth, UK. His research interest involves elucidation of interactions of environmental agents including radiations with the genomes and its potential impact on the health of humans and wild species.

Additional information

Funding

We acknowledge the financial support from the Ministry of Higher Education and Scientific Research, Republic of Iraq (PhD Studentship for RAM).