Biological characterization of a myotoxin phosphoplipase A2 homologue purified from the venom of the snake Bothrops moojeni

Queiroz MR (1, 2), Mamede CC (1), Fonseca KC (1), Canabrava LCMN (1), França LV (3), Silva MC (1), Stanziola L (1, 2), Beletti ME (1), Canabrava HAN (1, 2), Oliveira F (1, 2)

(1) Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Minas Gerais State, Brazil; (2) National Institute of Science and Technology on Nano-Biopharmaceuticals (N-Biofar); (3) Department of Biochemistry and Immunology, Medical School of Ribeirão Preto, University of São Paulo, USP, Ribeirão Preto, São Paulo State, Brazil.

Abstract: A myotoxin phospholipase A2 homologue, BmooMtx, was isolated from the venom of Bothrops moojeni by a combination of ion-exchange chromatography on DEAE-Sephacel column and gel filtration on Sephadex G-75. SDS-PAGE showed the enzyme to be a monomer with a molecular weight of 16,500. BmooMtx induced release of creatine kinase and morphological analyses indicated that it provoked an intense myonecrosis, with visible leukocyte infiltrate and damaged muscle cells 24 hours after injection. Anti-BmooMTx antibodies partially neutralized the myotoxic activity of BmooMtx and crude B. moojeni venom, as judged by determination of plasma creatine kinase levels and histological evaluation of skeletal muscle in mice. Anti-BmooMTx antibodies were effective in reducing the plasma creatine kinase levels of crude B. alternatus and B. leucurus venoms, evidencing immunological cross-reactivity between BmooMTx and other bothropic venoms. Intraplantar (i.pl.) injection of BmooMtx (1 to 15 μg/animal) caused a dose- and time-dependent hyperalgesia and edematogenic responses. Dexamethasone (0.4 mg/kg), meloxicam (2 mg/kg) and promethazine (5 mg/kg) markedly reduced the hyperalgesia. Our data suggest that these drugs may likely serve as complementary therapies in cases of accidents with Bothrops moojeni, provided that such pharmacological treatments are administered immediately after the incident.

Key words: Bothrops moojeni, hyperalgesia, myotoxin, edema.

COPYRIGHT

© CEVAP 2011

SUBMISSION STATUS

Received: July 30, 2010.

Accepted: December 21, 2010.

Abstract published online: January 25, 2011.

Full paper published online: February 28, 2011.

CONFLICTS OF INTEREST

There is no conflict.

FINANCIAL SOURCE

The State of Minas Gerais Research Foundation (FAPEMIG), the National Council for Scientific and Technological Development (CNPq) and the Ministry of Science and Technology (MCT) of Brazil.

ETHICS COMMITTEE APPROVAL

The present study was approved by the Ethics Committee on Animal Research of the Federal University of Uberlândia (CEUA/UFU) under the protocol n. 028/09, and followed the protocols of the International Society of Toxinology and the Brazilian Society of Science in Laboratory Animals.

CORRESPONDENCE TO

FÁBIO DE OLIVEIRA, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Av. Pará, 1720, Uberlandia, MG, Brasil. Phone: +55 34 32182200. Fax: +55 34 32182200. Email: foliveira@umuarama.ufu.br