Table 1.

Snake-derived toxins able to inhibit pain.

Toxin/ Molecule	Species	Production	Administration	Mechanism of Analgesia	Model	Ref.
µ-EPTX-Na1	Naja atra	Purified from venom	Intraplantar (i.pl.) injection	Nav1.8 channel inhibitor	Acute inflammation models induced by formalin and acetic acid, chronic inflammation pain model induced by complete Freund’s adjuvant and partial nerve ligation-induced allodynia.	[69]
Mambalgin-1	Dendroaspis polylepis polylepis	Purified from venom	Intravenous (i.v.) and intratechal (i.t.) injection	Acid-sensing ion channel (ASIC) inhibitors	Motor behavior tests such as accelerated rotarod test and grip strength test. Pain and inflammation models induced by carrageenan, thermal and mechanical pain test by von Frey	[68]
Mambalgin-3	Dendroaspis polylepis polylepis	Purified from venom	Intravenous (i.v.), intrathecal (i.t.), and intraplantar (i.pl.) injection	Acid-sensing ion channel (ASIC) inhibitors	Motor behavior tests such as accelerated rotarod test and grip strength test. Pain and inflammation models induced by carrageenan, thermal and mechanical pain test by von Frey	[68]
Cobra neurotoxin	Naja naja atra	Purified from venom	Intraperitoneal (i.p.) injection	Adenosine receptor (A1 and A2A) pathway activation	Acute pain model induced by hot plate and spinal cord injury	[74]
Najanalgesin	Naja naja atra	Purified from venom	Intrathecal (i.t.) injection	c-Jun N-terminal kinase (JNK) inhibitor	Neuropathic pain induced by spinal nerve ligation	[75]
Crotoxin (CTX)	Crotalus durissus terrificus	Purified from venom	Subcutaneous injection (s.c.)	Formyl Peptide, α2-Adrenergic and Muscarinic Receptors	Acute and chronic phases of hypernociception induced by partial sciatic nerve ligation	[70]
Crotoxin (CTX)	Crotalus durissus terrificus	Purified from venom	Subcutaneous injection (s.c.)	Analgesia dependent on formyl peptide, lipoxygenase and muscarinic receptors	Pain on the MOG 35-55-induced experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis	[71]
Crotalphine	Crotalus durissus terrificus	Chemical synthesis	Oral administration (p.o.)	TRPA1	The ciguatoxin-induced cold hypersensitivity, and the bradykinin-induced and zymosan-induced mechanical hypersensitivity	[73]
Cobratoxin (CbTX)	Naja naja kaouthia	Purified from venom	Intrathecal (i.t.) injection	α7 nicotinic acetylcholine receptor (nAChRs)	Acute pain model induced by hot plate and tail-flick	[76]