Isobolographic analysis reveals antinociceptive synergism between Phα1ß recombinant toxin and morphine in a model of cancer pain in C57BL/6J mice
Aoki, Caio Tavares; Moura, Rodrigo Andrade; Ferreira, Luana Assis; Mendes, Mariana Garcia; Santos, Duana Carvalho; Rezende, Marcio Junior; Gomez, Marcus Vinícius; Castro-Junior, Célio José.
J. venom. anim. toxins incl. trop. dis;
27: e20210027, 2021. ilus, graf, tab
Artigo
em Inglês
| VETINDEX
| ID: biblio-1395714
Resumo
Background: Phoneutria nigriventer venom contains Phα1ß. This toxin and its recombinant form have a remarkable analgesic potential that is associated with blockage of voltage-gated calcium channels and TRPA1 receptors. Although morphine is a mainstay drug to treat moderate and severe pain related to cancer, it has serious and dose-limiting side effects. Combining recombinant Phα1ß and morphine to treat pain is an interesting approach that has been gaining attention. Therefore, a quantitative and reliable method to establish the strength of the antinociceptive interaction between these two substances is necessary. The present study was designed to investigate the nature of the functional antinociceptive (analgesic) interaction between Phα1ß recombinant toxin and morphine in a model of cancer pain. Methods: Melanoma was produced by intraplantar inoculation of B16-F10 cells into the right paw of C57BL/6J mice. Von Frey filaments measured the paw-withdrawal threshold after intrathecal administration of morphine, recombinant Phα1ß, and their combination. Thermal hyperalgesia was assessed using Hargreaves apparatus. The degree of interaction was evaluated using isobolographic analysis. Spontaneous and forced motor performance was assessed with the open-field and rotarod tests, respectively. Results: Co-administration of recombinant Phα1ß and morphine synergistically reverses the melanoma-induced mechanical hyperalgesia. The potency of the mixture, measured as the effective dose to reach 50% of maximum possible effect (MPE) in ameliorating mechanical hyperalgesia, was about twice fold higher than expected if the interaction between morphine and recombinant Phα1ß was merely additive. Treatment with the combination at doses necessary to reach 50% of MPE caused no spontaneous nor forced motor alterations. Conclusion: The combinatorial use of recombinant Phα1ß and morphine allows significant and effective dose reduction of both agents, which has translational potential for opioid-sparing approaches in pain management related to cancer.(AU)
Biblioteca responsável:
BR68.1
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