Carvedilol Repurposing in Orofacial Pain: Preclinical Findings in Adult Zebrafish

Abstract

Carvedilol is a non‐selective β‐adrenergic antagonist that is used in the treatment of heart diseases. β‐blockers are known to have an anti‐inflammatory effect that contributes to its analgesic effect. Here we show the acute orofacial antinociceptive effect of carvedilol in adult zebrafish (Danio rerio). Acute nociception was induced by capsaicin (4.93 μM; TRPV1 agonist), formalin (0.1 %; TRPA1 agonist) or menthol (1.2 μM; TRPM8 agonist) into in the upper lip (5.0 μL) of adult wild (short‐fin phenotype) zebrafish. Corneal nociception was induced with hypertonic saline (TRPV1 agonist; 5.0 M NaCl; 5.0 μL) applied into the surface of the right or left eye of the fishes. Then, animals (n=6/group) were placed in a glass Petri dish (10 × 15 cm), divided into quadrants, and the nociceptive response was registered after capsaicin (10 – 20 min), formalin (0 – 5 and 15 – 30 min), menthol (0 – 10 min) or hypertonic saline (0 – 5 min) application. Zebrafish were pretreated by gavage (20 μL) with vehicle (Control; 3 % Tween 80) or carvedilol (0.03; 0.1 or 0.3 mg/mL) 60 min before induction. The effect of carvedilol on zebrafish locomotor behavior was evaluated with the open field test (0 – 5 min). Naive groups (n=6) were included. The interaction between carvedilol and TRPV1 was analyzed using molecular docking. The HEX software was used for molecular docking calculations and the direct action of carvedilol on TRPV1 was viewed using PyMOL v1.4.7. The experimental protocols followed the ethical guidelines of CONCEA (Brazilian Council for the Control of Animal Experimentation) and were approved by the UECE Animal Research Ethics Committee (#7210149/2016). Pre‐treatment with carvedilol (0.03 and 0.1 mg/mL) was associated with a reduction in nociceptive behavior induced by capsaicin and hypertonic saline (TRPV1 agonists; (*p<0.05 vs Control), but not by formalin, or menthol. Carvedilol per se promoted no alteration on the locomotor activity of zebrafish. In the docking experiments, the interaction between carvedilol and the TRPV1 channel showed high reproducibility. It was possible to observe a direct action of carvedilol on TRPV1 amino acids (Asn687, Asn687, Asn687, Asn687, Ala680 and Gly683). The results indicate the potential clinical application of carvedilol an inhibitor of orofacial nociception and that this effect may be due to the modulation of TRPV1 channel.Support or Funding InformationNational Council for Scientific and Technological Development ‐ CNPqCoordination for the Improvement of Higher Education Personnel ‐ CapesResearch Support Foundation of Ceará State ‐ FuncapEdson Queiroz Foundation ‐ FEQThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.