Bothriurus bonariensis scorpion venom activates voltage-dependent sodium channels in insect and mammalian nervous systems

Abstract

Animal venoms have been widely recognized as a major source of biologically active molecules. Bothriurus bonariensis, popularly known as black scorpion, is the arthropod responsible for the highest number of accidents involving scorpion sting in Southern Brazil. Here we reported the first attempt to investigate the neurobiology of B. bonariensis venom (BBV) in the insect and mammalian nervous system. BBV (32 μg/g) induced a slow neuromuscular blockade in the in vivo cockroach nerve-muscle preparations (70 ± 4%, n = 6, p < 0.001), provoking repetitive twitches and significantly decreasing the frequency of spontaneous leg action potentials (SNCAPs) from 82 ± 3 min(-1) to 36 ± 1.3 min(-1) (n = 6, p < 0.05), without affecting the amplitude. When tested in primary cultures of rat hippocampal cells, BBV induced a massive increase of Ca(2+) influx (250 ± 1% peak increase, n = 3, p < 0.0001). The disturbance of calcium homeostasis induced by BBV on the mammalian central nervous system was not accompanied by cellular death and was prevented by the co-treatment of the hippocampal cells with tetrodotoxin, a selective sodium channel blocker. The results suggest that the biological activity of BBV is mostly related to a modulation of sodium channels function. Our biological activity survey suggests that BBV may have a promising insecticidal and therapeutic potential.

Comparison of biological activities of Tityus pachyurus venom from two Colombian regions

“…The neuromuscular facilitation produced by T. pachyurus venom at low concentrations and the rapid blockade of the twitch responses seen at high concentrations of this venom in PND preparations also were reported for the Brazilian species T. serrulatus [67] and T. bahiensis [70]. The neuromuscular action of scorpion venoms has been mostly associated with the presence of neurotoxins with high affinity for voltage-gated Na + channels [70][71].…”

“…The neuromuscular action of T. pachyurus venom demonstrated in this present study comprises the first report with Colombian scorpion species. The action of Tityus venoms on the somatic neurotransmission has been poorly demonstrated in the last decades, with only a few studies reporting their neurotoxic mechanisms in vertebrate nerve-muscle preparations [65][66][67][68][69][70][71]. The neuromuscular facilitation produced by T. pachyurus venom at low concentrations and the rapid blockade of the twitch responses seen at high concentrations of this venom in PND preparations also were reported for the Brazilian species T. serrulatus [67] and T. bahiensis [70].…”

“…The action of Tityus venoms on the somatic neurotransmission has been poorly demonstrated in the last decades, with only a few studies reporting their neurotoxic mechanisms in vertebrate nerve-muscle preparations [65][66][67][68][69][70][71]. The neuromuscular facilitation produced by T. pachyurus venom at low concentrations and the rapid blockade of the twitch responses seen at high concentrations of this venom in PND preparations also were reported for the Brazilian species T. serrulatus [67] and T. bahiensis [70]. The neuromuscular action of scorpion venoms has been mostly associated with the presence of neurotoxins with high affinity for voltage-gated Na + channels [70][71].…”

Jaburetox, a natural insecticide derived from Jack Bean Urease, activates voltage-gated sodium channels to modulate insect behavior

“…Our results also demonstrated that Jbtx caused a significant decrease in the amplitude of muscle and nerve action potentials in a L. migratoria leg preparation, to block muscle twitch. Alterations in the amplitude of a muscle or neuron action potential can be achieved not exclusively, but in part, by the interaction of neurotoxins with six different binding sites of sodium channels (Cestèle & Catterall, 2000;Dong, 2007;dos Santos et al, 2016;Wang & Wang, 2003). Blocking the sodium conductance, a negative shift in the voltage-dependence of activation, slowing down of inactivation or an alteration of ion selectivity are the most common results of the binding of neurotoxins to sodium channels (Stevens et al, 2011).…”

Efeitos das diferentes condições de processo na avaliação da hidrólise enzimática de barata cinérea (nauphoeta cinerea)

“…A barata cinérea pode estar entre as diversas espécies de baratas existentes. Ela também é popularmente conhecida como barata salpicada ou barata lagosta (Ordem: Blattodea, Família: Blaberidae), sendo originaria da África apresentando ampla distribuição geográfica devido a sua fácil associação com seres humanos (SANTOS et al, 2016). A composição química deste inseto varia de acordo com seu estágio de crescimento, apresentando aproximadamente 68,5% de proteína e 22,5% de lipídios em sua fase adulta (LUCAS; OLIVEIRA; PRENTICE, 2019).…”