Received: November 3, 2004, Accepted: May 23, 2005, Published online: October 30, 2005.

NEUTRALIZATION OF THE NEUROMUSCULAR ACTIVITY OF BOTHROPSTOXIN-I, A MYOTOXIN FROM Bothrops jararacussu SNAKE VENOM, BY A HYDROALCOHOLIC EXTRACT OF Casearia sylvestris Sw. (GUAÇATONGA)

OSHIMA-FRANCO Y. (1,3), ALVES C. M. V. (1), ANDRÉO FILHO N. (1), GERENUTTI M. (1), CINTRA A. C. O. (2), LEITE G. B. (3), RODRIGUES-SIMIONI L. (3), SILVA M. G. (1)

(1) School of Pharmacy, University of Sorocaba, UNISO, Sorocaba, São Paulo, Brazil; (2) School of Pharmaceutical Sciences, University of São Paulo, USP, Ribeirão Preto, São Paulo, Brazil; (3) Department of Pharmacology, State University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.

ABSTRACT: Numerous plants are used as snakebite antidotes in Brazilian folk medicine, including Casearia sylvestris Swartz, popularly known as guaçatonga. In this study, we examined the action of a hydroalcoholic extract from C. sylvestris on the neuromuscular blockade caused by bothropstoxin-I (BthTX-I), a myotoxin from Bothrops jararacussu venom, in mouse isolated phrenic nerve-diaphragm (PND) preparations. Aqueous (8 and 12 mg/ml, n=4 and 5, respectively) and hydroalcoholic (12 mg/ml, n=12) extracts of the leaves of C. sylvestris caused facilitation in PND preparations followed by partial neuromuscular blockade. BthTX-I (20 mg/ml, n=4) caused 50% paralysis after 65±15 min (mean ± S.E.M). Preincubation (30 min at 37ºC) of BthTX-I (20 mg/ml, n=4) with a concentration of the hydroalcoholic extract (4 mg/ml) that had no neuromuscular activity, such as the control (n=5), prevented the neuromuscular blockade caused by the toxin. This protection may be mediated by compounds such as flavonoids and phenols identified by thin-layer chromatography and colorimetric assays.

KEY WORDS: alternative medicine, phytotherapy, plant extracts, snakebite.

CORRESPONDENCE TO:

YOKO OSHIMA-FRANCO, Rua das Garças, 80, 13405-132, Nova Piracicaba, Piracicaba, SP, Brasil, Email: yofranco@terra.com.br