Central antinociceptive effects of Cissus sicyoides on mice

Abstract The acute and chronic treatment of mice with a hydroalcohol extract from the leaves of Cissus sicyoides. L. (Vitaceae) (CS) at doses of 300, 600, and 1000 mg/kg, by intraperitoneal administration, produced a significant central antinociceptive effect on the hot plate, tail immersion, and acetic acid-induced writhing, tests, and the effect was inhibited by naloxone. CS was given to mice daily for 30 days at a dose of 600 mg/kg, causing an effect similar to that of drugs with typical action on opioid receptors. The effective dose (ED50) was approximately 600 mg/kg in mice.