Avaliação do potencial antinociceptivo de novos 3-Metil-1H-1-pirazol metil esteres 5-substituídos em Camundongos

Abstract

In the present study the antinociceptive activity of six 1-H-1-pyrazol methyl ester derivatives in the hot-plate test and Complete Freund s Adjuvant (CFA)-induced inflammation in mice was investigated. The administration of 3,5-dimethyl-1H-1-pyrazole methyl ester (1), 3-methyl-5-trichloromethyl-1H-1-pyrazole methyl ester (2), 5-dichloromethyl-5-hydroxy-3-methyl-4,5-dihydro-1H-1-pyrazole methyl ester (4), 5-(chloro-difluoro-methyl)-5-hydroxy-3-methyl-4,5-dihydro-1H-1-pyrazole methyl ester (5) (20 1000 μmol/kg, i.p.) produced antinociception in the hot plate test. All compounds, except compound 4, did not cause motor alterations in the rotarod and open field tests. The compounds 3 and 6 did not produce antinocicpetive effects. Since compound 2 presented good antinociceptive activity in the hot plate test and was devoid of motor effects, we tested whether it caused antinociception in an animal model of chronic pain. Compound 2 (0.6 20 μmol/kg, i.p.) effectively reduced CFA-induced mechanical allodynia (83 ± 8%) and paw edema. The results of the present study suggest that novel 1-H-1-pyrazol methyl ester derivatives, particularly compound 2, have a good analgesic potential against acute and chronic pain.