Antinociceptive activity of aqueous extract of Bowdichia virgilioides in mice.

Bowdichia virgilioides Kunth (Family Fabaceae) is a plant that is distributed widely in the tropical and subtropical regions of the world. In the northeast region of Brazil, where B. virgilioides is called "sucupira-preta," the stem bark is used in folk medicine to treatment of inflammatory and painful diseases. This study aimed to evaluate the antinociceptive activity of the aqueous extract of the dried stem bark of B. virgilioides. The aqueous extract of B. virgilioides in doses of 50, 100, 200, and 400 mg/kg was administered orally 1 hour prior to pain induction. Only the doses of 200 and 400 mg/kg produced an inhibition by 61% and 74%, respectively, in the number of abdominal writhings induced by acetic acid. This antinociceptive effect was not reversed by pretreatment with naloxone, indicating that the effect is not associated with the activation of opioid receptors. In the formalin test, using the two highest doses, the extract had no effect in the first phase but produced an analgesic effect on the second phase with the inhibition of licking time (P < .001). In the hot plate test, no effect was seen at the dose of 400 mg/kg p.o. Our findings show that B. virgilioides contains pharmacologically active constituents that possess antinociceptive activity justifying its popular therapeutic use in treating conditions associated with the painful conditions.