Phoneutria nigriventer Venom and Toxins: A Review

Abstract

The venom of Phoneutria nigriventer spider has been extensively studied. It is highly neurotoxic, with clinical manifestations occurring a few minutes after the bite, mainly in children. Among the intoxication signs that may lead to neurogenic shock are agitation, somnolence, sweating, nausea, profuse vomiting, lacrimation, excessive salivation, hypertension, tachycardia, tachypnea, tremors, muscle spasms, and priapism. Many toxins from this venom have been purified and characterized for their structure and/or function. The most studied Phoneutria nigriventer toxins are PnTx1, PnTx2-5, and PnTx2-6, which show complex effects on sodium channel kinetics. PnTx2-5 and PnTx2-6 are both described as responsible for priapism; PnTx4(6-1) and PnTx4(5-5) show insecticidal activities and act on insect sodium channels; PnTkPs are muscle-active peptides; and nigriventrine is a piperidine derivative that has neuroactive properties and causes convulsive spells. PnTx3-3 and PnTx3-4 toxins were demonstrated to be effective on preventing cell death after ischemia injury. On the other hand, PnTx3-6 was shown to be efficient in the treatment of persistent pathological pain. The present chapter compiles biochemical, physiological, and pharmacological studies of fractions and purified toxins from Phoneutria nigriventer venom, showing their great potential as new tools for pharmacological studies and drug development.