title: Effects of Papaver rhoeas extract on the acquisition and expression of morphine-induced behavioral sensitization in mice.
abstract: In the present study, the effects of a water-alcohol extract of Papaver rhoeas on the acquisition and expression of morphine-induced behavioral sensitization in mice were investigated. The subcutaneous (s.c.) administration of morphine (50 mg/kg) induced locomotor activity in animals, whereas the drug did not show an effect at a dose of 5 mg/kg. On the other hand, intraperitoneal (i.p.) administration of the plant extract (25, 50 and 100 mg/kg) did not show any effect. The locomotor behavioral response was enhanced in mice pretreated with morphine (5 mg/kg, daily x 3 days) alone, indicating that sensitization had developed. Extract (25, 50 and 100 mg/kg, i.p.) administration, 30 min before each of the three daily doses of morphine decreased the development of sensitization. Moreover, intraperitoneal administration of the plant extract (25, 50 and 100 mg/kg) 30 min before the test reduced the expression of morphine-induced behavioral sensitization. The results indicate that administration of the extract of Papaver rhoeas reduced the acquisition and expression of morphine-induced behavioral sensitization in mice.
authors.affiliation: Department of Physiology and Biophysics, and Behavioral Sciences Research Center (BSRC), School of Medicine, Baqiyatallah, University of Medical Sciences, Tehran, Iran. h.sahraei@bmsu.ac.ir
authors.forename: Hedayat
authors.initials: H
authors.lastname: Sahraei
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Faghih-Monzavi
authors.forename: Sayedeh Maedeh
authors.initials: SM
authors.lastname: Fatemi
authors.forename: Shahrokh
authors.initials: S
authors.lastname: Pashaei-Rad
authors.forename: Seyed Hossein
authors.initials: SH
authors.lastname: Salimi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Kamalinejad
mesh_terms: D000818:Animals; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects*; D010207:Papaver; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts; D009020:Morphine