Antinociceptive and anti-inflammatory properties of the hydroalcoholic extract of stems from Equisetum arvense L. in mice

In this study, antinociceptive and anti-inflammatory effects of hydroalcoholic extract of stem from Equisetum arvense in mice were evaluated. The extract (10, 25, 50 and 100 mg kg −1, i.p.), reduced the writhing induced by acetic acid in 49, 57, 93 and 98%, respectively. In the formalin test, 50 and 100 mg kg −1 (i.p.) extract, reduced in 80 and 95% the licking activity in the first phase, but in the second phase only the latter dose diminished the licking time (35%). In both phases, naloxone failed to revert the analgesic effect of the extract. In the hot-plate test, the extract at 100 and 200 mg kg −1 does not change the latency to licking or jumping. In the carrageenan-induced paw oedema, the extract at 50 mg kg −1, reduced the paw oedema 2 h (25%) and 4 h (30%) after carrageenan administration. The dose of 100 mg kg −1 caused reduction of the paw oedema (29%) only 4 h after carrageenan administration. These results indicate that this extract exhibits an antinociceptive effect in chemical models of nociception which is not related to the opioid system, as well as anti-inflammatory properties.