Gomphrena celosioides Mart. (Amaranthaceae) is used in
folk medicine as a natural
analgesic, and in Brazil, the species of genus Gomphrena is used for
rheumatism. However, scientific evidence which supports its popular use as an
analgesic is scarce. This study assessed the antiarthritic and antihyperalgesic activities of the ethanolic extract obtained from G. celosioides aerial parts on Swiss or C57BL/6 mice. The antiarthritic and antihyperalgesic potential of Gomphrena celosioides was evaluated using paw
edema,
mechanical hyperalgesia, cold
allodynia,
carrageenan-induced
pleurisy, articular
inflammation zymosan-induced, Freund's complete adjuvant-induced
inflammation zymosan-induced
peritonitis, and
carrageenan-induced adhesion and rolling experiment models. All doses of G. celosioides (300, 700, and 1000 mg/kg) significantly reduced
edema formation in all the intervals evaluated, whereas the
mechanical hyperalgesia was reduced 3 hours after the
carrageenan injection. The cold
hyperalgesia was significantly decreased 3 (700 mg/kg) and 4 hours (700 and 1000 mg/kg) after the
carrageenan injection. Ethanolic extract of G. celosioides at 1000 mg/kg reduced the total leukocyte number, without interfering in the
protein extravasation in
carrageenan-induced
pleurisy model. Ethanolic extract of G. celosioides (300 mg/kg) was also able to reduce significantly the leukocyte migration in
zymosan-induced articular
edema, while a reduction of the adhesion and migration and leukocyte rolling was induced by the ethanolic extract of G. celosioides (300 mg/kg) in
zymosan-induced
peritonitis. In Freund's complete adjuvant-induced
inflammation model, an
edema formation and
mechanical hyperalgesia reduction were induced by the ethanolic extract of G. celosioides on day 22, whereas the cold
allodynia was reduced on day 6 of treatment with the extract. These results show that ethanolic extract of G. celosioides has antihyperalgesic and antiarthritic potential in different acute and persistent models, explaining, at least in part, the ethnopharmacological relevance of this plant as a natural
analgesic agent.