title: Botulinum toxin type-A effect as a preemptive treatment in a model of acute trigeminal pain: a pre-clinical double-blind and placebo-controlled study.
abstract: The purpose of this study was to investigate if botulinum neurotoxin type-A (BoNT/A) had a preemptive antinociceptive effect in a formalin-induced orofacial pain model (FT). To test this hypothesis, male Rattus norvegicus were injected with isotonic saline solution 0.9% or BoNT/A administered as a 40 μl bolus, lateral to their nose, at 24 hours, 8, 15, 22, 29 or 36 days pre-FT. The procedures were repeated 42 days later. Influence on motor activity was assessed through the open-field test. Pain scores corresponded to the time spent rubbing and flicking the injected area. Animals pre-treated with BoNT/A at the first protocol (8 days subgroup) showed reduced inflammatory scores (p=0.011). For the other groups no significant results were observed at any phase. Motor activity was similar in both groups. BoNT/A showed to be effective preventing inflammatory pain up to eight days after the first treatment, an effect not reproduced on the second dose administration.
authors.affiliation: Unit of Headache, Neurology Division, Internal Medicine Department, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba PR, Brazil. piovesan1@hotmail.com
authors.forename: Elcio Juliato
authors.initials: EJ
authors.lastname: Piovesan
authors.forename: Lucas da Silva
authors.initials: Lda S
authors.lastname: Leite
authors.forename: Helio Ghizoni
authors.initials: HG
authors.lastname: Teive
authors.forename: Pedro André
authors.initials: PA
authors.lastname: Kowacs
authors.forename: Rogério Andrade
authors.initials: RA
authors.lastname: Mulinari
authors.forename: Victor
authors.initials: V
authors.lastname: Radunz
authors.forename: Marco
authors.initials: M
authors.lastname: Utiumi
authors.forename: Helder Groenwold
authors.initials: HG
authors.lastname: Campos
authors.forename: Lineu Cesar
authors.initials: LC
authors.lastname: Werneck
mesh_terms: D000208:Acute Disease; D000818:Animals; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D004311:Double-Blind Method; D005157:Facial Pain / Q000517:prevention & control; D007552:Isotonic Solutions / Q000008:administration & dosage; D008297:Male; D010147:Pain Measurement / Q000379:methods; D010919:Placebos; D011897:Random Allocation; D051381:Rats; D012965:Sodium Chloride / Q000008:administration & dosage; D014277:Trigeminal Neuralgia / Q000517:prevention & control*
chemical_list: D007552:Isotonic Solutions; D010919:Placebos; D012965:Sodium Chloride; D019274:Botulinum Toxins, Type A