RESUMEN
Leonurus cardiaca, commonly known as motherwort, is a member of the Lamiaceae family. It has a number of interesting biological activities, for example, sedative and hypotensive, antioxidant, anti-inflammatory, and antimicrobial activities. The aim of the present study was to investigate the effect of alcoholic extract of aerial part of Leonurus cardiaca on nociceptive response using formalin, tail flick, and hot plate tests in mice. The acute treatment of mice with an ethanolic extract at doses of 500 and 250 mg/kg by intraperitoneal administration produced a significant antinociceptive in the first and second phases of formalin test, respectively. The hot plate and tail flick tests showed an increase in the antinociceptive effect at dose 500 mg/kg. These results suggest that Leonurus cardiaca possesses central and peripheral antinociceptive actions.