Anti-nociceptive Activity of Aqueous-methanolic Extract of Phytolacca americana Growing in Iran

Abstract anti-nociceptive activity of aerial parts of phytolacca americana were investigated, using the hot plate method in mice. results of the present study showed that the aqueous methanolic extract of aerial parts of p. americana produced a statistically significant increase in pain threshold after 30 min, in comparison with the control, at adose of 190 mg kg^-1 (p<0.001). the activity was comparable to that of morphine (30 mg kg^-1 i.p., p> 0.05). the anti-nociceptive activity of p. americana increased until the 60th min (p<0.05 compared to morphine). the results of this study support the extensive use of p. americana in western asia and america. the ld50 of extract following a 14 days acute toxicity study was calculated to be 208 mg kg^-1 i.p.