Low-level laser therapy decreases local effects induced by myotoxins isolated from  Bothrops jararacussu  snake venom

Barbosa AM (1), Villaverde AB (2), Guimarães-Sousa L (1), Soares AM (3), Zamuner SF (4), Cogo JC (1), Zamuner SR (5)

(1) Institute of Research and Development, University of Vale do Paraíba, UNIVAP, São José dos Campos, São Paulo State, Brazil; (2) Institute of Biomedical Engineering, Camilo Castelo Branco University, UNICASTELO, São José dos Campos, São Paulo State, Brazil; (3) Department of Clinical, Toxicological and Bromatological Analysis, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, USP, Ribeirão Preto, São Paulo State, Brazil; (4) Laboratory of Pharmacology, Butantan Institute, São Paulo, São Paulo State, Brazil; (5) School of Applied Sciences, State University of Campinas, UNICAMP, Limeira, São Paulo State, Brazil.

ABSTRACT: The prominent myotoxic effect induced by Bothrops jararacussu crude venom is due, in part, to its polycationic myotoxins, BthTX-I and BthTX-II. Both myotoxins have a phospholipase A₂ structure: BthTX-II is an active enzyme Asp-49 PLA₂, while BthTX-I is a Lys-49 PLA₂ devoid of enzymatic activity. In this study, the effect of low-level laser therapy (LLLT), in 685 nm and 4.2 J/cm² laser dose, on edema formation, leukocyte influx and myonecrosis caused by BthTX-I and BthTX-II, isolated from Bothrops jararacussu snake venom, was analyzed. BthTX-I and BthTX-II caused a significant edema formation, a prominent leukocyte infiltrate composed predominantly by neutrophils and myonecrosis in envenomed gastrocnemius muscle. LLLT significantly reduced the edema formation, neutrophil accumulation and myonecrosis induced by the BthTX-I and BthTX-II 24 hours after the myotoxin injection. LLLT induces a reduction of 41.02% and 60.74% on the edema formation, 57.5% and 51.6% of the leukocyte influx and, 60% and 43% on the myonecrosis caused by BthTX-I and BthTX-II, respectively. In conclusion, LLLT significantly reduced the effect of BthTX-I and BthTX-II on the inflammatory response and myonecrosis. These results suggest that LLLT should be considered as a potentially therapeutic approach for treatment of local effects of Bothrops species venom.

KEY WORDS: Bothrops jararacussu, myotoxins, inflammation, myonecrosis, low-level laser therapy. 

CORRESPONDENCE TO:

ANTONIO BALBIN VILLAVERDE, Instituto de Engenharia Biomédica, Universidade Camilo Castelo Branco, UNICASTELO, Parque Tecnológico de São José dos Campos, Rod. Presidente Dutra, km 138, Distrito de Eugênio de Melo, São José dos Campos, SP, 12.247-004, Brasil. Phone: +55 12 3905 4401. Email: abvillaverde@gmail.com