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 100mgkg(-1), i.p.), reduced the writhing induced by acetic acid in 49, 57, 93 and 98%, respectively. In the formalin test, 50 and 100mgkg(-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 200mgkg(-1) does not change the latency to licking or jumping. In the carrageenan-induced paw oedema, the extract at 50mgkg(-1), reduced the paw oedema 2h (25%) and 4h (30%) after carrageenan administration. The dose of 100mgkg(-1) caused reduction of the paw oedema (29%) only 4h 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.