Anti-nociceptive activity of aqueous fraction from the MeOH extracts of Paederia scandens in mice.

Aim of the Study: We examined the effects of the aqueous fraction (AF) on nociception models mice induced by the chemical and the thermal stimuli so as to elucidate the analgesic activity and provide scientific basis for the clinical use of Paederia scandens.
Materials and Methods: The AF of MeOH extract from P. scandens was evaluated on anti-nociceptive activity in mice using chemical and thermal models of nociception.
Results: Given orally, the aqueous fraction at doses of 200, 400 and 800 mg/kg produced significant inhibitions on chemical nociception induced by intraperitoneal acetic acid and subplantar formalin injections and on thermal nociception in the tail-flick test and in the hot plate test. More significant inhibition of nociception was observed at dose of 800 mg/kg of this fraction. In the pentobarbital sodium -induced sleeping time test and the open-field test, the aqueous fraction neither significantly enhanced the pentobarbital sodium -induced sleeping time nor impaired the motor performance, indicating that the observed anti-nociception was unlikely due to sedation or motor abnormality.
Conclusions: These results suggested that the aqueous fraction produced anti-nociception possibly related to the iridoid glycosides and polysaccharides in this fraction.