EFFECTS OF LOW-LEVEL LASER THERAPY ON LIVER REGENERATION AND THE LASER PARAMETERS EMPLOYED

Fernando De Santana Belli Rodrigues,Gisele Lopes Bertolini

doi:10.25110/arqsaude.v25i3.2021.8373

Fernando De Santana Belli Rodrigues, Gisele Lopes Bertolini

Open Access

https://doi.org/10.25110/arqsaude.v25i3.2021.8373

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Abstract

Low-level laser therapy has various biological effects; one of them is tissue regeneration. Its application in the liver of rats after partial hepatectomy to promote liver regeneration has recently been studied. The aim of this article was to review the recent studies on the effects of low-level laser therapy on rat liver regeneration after partial hepatectomy and the laser parameters used. A review of recent relevant literature was performed in Pubmed, Scielo, Medline and Bireme databases. Articles about the application of low-level laser therapy on hepatic regeneration were included. Articles with hepatic regeneration in the presence of pathologies were not included. Nine studies were found matching the study criteria. In most studies, low-level laser therapy promoted liver regeneration after partial hepatectomy, without further damage to the remaining liver. Not all laser parameters necessary for the reproducibility of the study were described by all authors. The therapeutic use of low-level laser therapy in liver regeneration can be promising, however, as liver is a vital organ and the laser application is intraoperative, future studies are needed. The parameters used must be properly described and standardized to allow the reproducibility of the study, so that a therapeutic window can be defined and its clinical use can be considered. It is also essential to clarify the mechanisms by which the laser promotes liver regeneration, to guarantee its safety and therapeutic efficacy.

Highlights

Low level laser therapy (LLLT) has been studied for over 50 years
Phototherapy is the application of light amplification by stimulated emission of radiation (LASER) or light emitting diodes (LED), for therapeutic endings, which has several biological effects, as increase in ATP production (PASSARELLA et al, 1983; PASSARELLA et al, 1988), DNA and RNA synthesis (ENDRE; MESTER; MESTER, 1985; KARU et al, 1983; NAGINO et al, 1989), cellular proliferation (ENWEMEKA et al, 2004; HU et al, 2007; PASSARELLA et al, 1988), collagen synthesis (GODOY et al, 2017), and wound healing (ENDRE; MESTER; MESTER, 1985; HAMERSKI, STEFANELLO, 2006; GODOY et al, 2017), in addition to anti-inflammatory effect (BJORDAL et al, 2003; KITCHEN; PARTRIDGE, 1991)
A review of recent relevant literature was performed in PubMed, Scielo, Medline and Bireme, published in a period between 2001 and 2018, using the keywords hepatectomy, laser therapy, liver regeneration, low-level laser therapy, partial hepatectomy and phototherapy

Summary

Introduction

Low level laser therapy (LLLT) has been studied for over 50 years. Its first applications occurred in Hungary, when Professor Endre Mester reported the first application of LLLT in medicine (ENDRE; MESTER; MESTER, 1985). In 1983, Tiina Karu, a russian researcher, published her first article about LLLT, when she started explaining light’s mechanisms on biological tissue (KARU et al, 1983). Phototherapy is the application of light amplification by stimulated emission of radiation (LASER) or light emitting diodes (LED), for therapeutic endings, which has several biological effects, as increase in ATP production (PASSARELLA et al, 1983; PASSARELLA et al, 1988), DNA and RNA synthesis (ENDRE; MESTER; MESTER, 1985; KARU et al, 1983; NAGINO et al, 1989), cellular proliferation (ENWEMEKA et al, 2004; HU et al, 2007; PASSARELLA et al, 1988), collagen synthesis (GODOY et al, 2017), and wound healing (ENDRE; MESTER; MESTER, 1985; HAMERSKI, STEFANELLO, 2006; GODOY et al, 2017), in addition to anti-inflammatory effect (BJORDAL et al, 2003; KITCHEN; PARTRIDGE, 1991). LLLT has been studied on promoting liver regeneration after partial hepatectomy (PH). Considering the therapeutic potential of LLLT, the aim of this article was to review the recent studies on the effects of LLLT on rat healthy liver regeneration after PH and the laser parameters employed

Methods

Literature Review

Conclusion