Botulinum neurotoxin (BoNT) (BoNT)

Botulinum neurotoxins (BoNTs) are a family of extremely potent proteins produced by the bacterium Clostridium botulinum and related species, classified into seven primary serotypes (A-G) [4, 9, 15]. They function as zinc-dependent endopeptidases that specifically target and cleave SNARE proteins—such as SNAP-25, VAMP/synaptobrevin, and syntaxin—which are essential for the fusion of synaptic vesicles with the presynaptic membrane [1, 9, 16]. By disrupting this process, BoNTs inhibit the release of the neurotransmitter acetylcholine at the neuromuscular junction, resulting in flaccid paralysis [10, 12, 17]. While naturally occurring BoNTs are the causative agents of the life-threatening disease botulism, they have been successfully repurposed as therapeutic agents for treating conditions characterized by muscle hyperactivity, including dystonia, spasticity, and chronic migraine, as well as for cosmetic procedures [2, 7, 11, 15]. Pharmacologically, these toxins are administered via local injection, and their effects are temporary as the affected nerve terminals eventually regenerate or recover function [8, 17, 20]. However, therapeutic use carries significant safety warnings, most notably the risk of the toxin spreading beyond the injection site to cause systemic weakness or respiratory distress [14, 15].

Other names

Botulinum toxinBotoxDysportXeominMyoblocClostridial neurotoxinBoNT/ABoNT/BBoNT/CBoNT/DBoNT/EBoNT/FBoNT/G

Neutralization of toxin activity by antitoxins; cleavage of SNARE proteins (SNAP-25, VAMP, or syntaxin) by the toxin's light chain to inhibit acetylcholine release at the neuromuscular junction.