Novel formulation permits use of toxin from rattlesnake venom to treat chronic pain

Crotoxin, extracted from the venom of the South American rattlesnake Crotalus durissus terrificus, has been studied for almost a century for its analgesic, anti-inflammatory and antitumor activities and as an even more powerful muscle paralyzer than botulinum toxin. However, the toxicity of crotoxin limits its medicinal use.

A new study, published by Brazilian researchers in the journal Toxins, shows that crotoxin's therapeutic effects can be enhanced and its toxicity reduced when it is encapsulated in nanostructured SBA-15 silica, a material originally developed for use in vaccine formulations.

Osvaldo Sant'Anna is the principal investigator for a Thematic Project at Butantan Institute to study mesoporous silica as a vaccine adjuvant in collaboration with Márcia Fantini, a professor at the University of S?o Paulo's Physics Institute (IF-USP). An adjuvant is an agent used in conjunction with a vaccine antigen to augment the host's antigen-specific immune response.

When silica was tested with other toxins, a novel protective effect was discovered. "In tests conducted in horses to produce anti-diphtheria serum and with tetanus toxin, we found that silica makes antigens less potent and reduces the adverse effect of diphtheria toxin," Osvaldo Sant'Anna said.