β‐Cyclodextrin‐complexed carvacrol produces antinociceptive effect superior to that of carvacrol in orofacial pain models (657.15)

The aim of this study was to evaluate the antinociceptive effect of carvacrol/ β‐cyclodextrin complex (CARV/ β‐CD) and carvacrol (CARV) isolated, a monoterpene phenol, in formalin‐, capsaicin‐ and glutamate‐induced orofacial nociception on mice. Male mice were pretreated with CARV/ β‐CD (10 or 20 mg/kg, p.o.),CARV (10 or 20 mg/kg, p.o.), morphine (5 mg/kg, i.p.) or vehicle (distilled water), 1h before painful orofacial test (‐formalin (20 μl, 2%), ‐capsaicin (20 μl, 2.5 µg) or ‐glutamate (40 ìl, 25 ìM) induced by injection into the right upper lip). Experimental protocols were approved by the Animal Care and Use Committee at the Federal University of Sergipe (CEPA/UFS # 18/10). Our results demonstrated that acute treatment with complex CARV/ β‐CD was effective in reducing nociceptive face‐rubbing behavior in both phases on formalin test (p<0.01 and p<0.01or p<0.001) whereas isolated CARV produced similar effect did so only in higher dose (p<0.05) in second phase. Also produced an improvement significant antinociceptive effect at all doses in the capsaicin‐ (p<0.001or p<0.001) and glutamate‐ (p<0.01 or p<0.001) tests when compared with isolated monoterpene (CARV). Such results were unlikely to be provoked by motor abnormality. Our results provide evidence to propose that the complex with β‐CD improve analgesic profile of carvacrol. CARV/ β‐ CD might represent important tool for management of orofacial painful disorders. Grant Funding Source : FAPITEC/SE; CNPQ (Brazil).