Inhibition of the Toxic Effects of Lachesis muta, Crotalus durissus cumanensis and Micrurus mipartitus Snake Venoms by Plant Extracts

Abstract

The ethanol extracts of eight plants utilized against snakebites by traditional healers in Colombia (Pleopeltis percussa, Trichomanes elegans, Brownea rosademonte, Tabebuia rosea, Heliconia curtispatha, Bixa orellana, Renealmia alpinia and Citrus limon) were examined for their possible inhibitory ability against the venoms of Lachesis muta, Crotalus durissus cumanensis, and Micrurus mipartitus. Extracts were preincubated with 1.5 LD₅₀ of each venom, and injected by the intraperitoneal route, in mice. Under these conditions, the lethal effect of L. muta venom was neutralized by all of the extracts, whereas C. d. cumanensis and M. mipartitus venoms were inhibited by six extracts, exceptions being P. percussa and C. limon. In addition, the myotoxic activity of C. d. cumanensis venom was neutralized by the extracts of H. curtispatha, B. rosademonte, P. percussa, and T. elegans. The neutralizing ability of the plant extracts was also evaluated by independent administration experiments. Extracts were injected by intravenous or i.m. (in situ) routes, immediately after the i.p or i.m. injection of 1.5 LD₅₀ of venom, respectively. Under such conditions, their neutralizing efficacy was significantly reduced, and in some cases disappeared. Nevertheless, in situ administration of B. rosademonte, H. curthispatha, P. percussa, and T. elegans extracts still caused a partial but significant inhibition of the lethal effect of C. d. cumanensis venom, and the first three extracts reduced significantly the development of myonecrosis. These results identify useful plant species for future purification of venom-neutralizing components that might become helpful in the development of supplementary therapies against snakebites.

Keywords::

• Medicinal plants
• extracts
• neutralization
• snake venoms
• lethality
• myotoxicity