title: Levo-tetrahydropalmatine attenuates oxycodone-induced conditioned place preference in rats.
abstract: Levo-tetrahydropalmatine (l-THP) is an alkaloid purified from the Chinese herb corydalis and stephania and is contained in many traditional Chinese herbal preparations. Our previous studies demonstrated the ability of l-THP to inhibit locomotor stimulation and physical dependence induced by oxycodone in mice and rats. The present study was designed to evaluate effects of l-THP on reward of oxycodone using conditioned place preference assay. Oxycodone (0.32-5.0 mg/kg) induced the development of conditioned place preference in rats. Furthermore, oxycodone (2.5 mg/kg) induced the increased phosphorylation of CREB and ERK in nucleus accumbens and hippocampus, but not in prefrontal cortex. l-THP (6.25-18.50 mg/kg) per se was not able to induce conditioned place preference or conditioned place aversion. l-THP co-administered with oxycodone during the conditioning sessions partly abolished the development of oxycodone-induced conditioned place preference in rats. Furthermore, l-THP inhibited the increased phosphorylation of ERK and CREB in nucleus accumbens and hippocampus of rats. All these results suggest that l-THP can inhibit oxycodone-induced psychological dependence by affecting phosphorylation of CREB and ERK in nucleus accumbens and hippocampus of rats. Together, the present data, combined with previous finding, support the potential use of l-THP for treatment of oxycodone addiction.
authors.affiliation: College of Pharmacy, Soochow University, Suzhou, China.
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Liu
authors.forename: Ling-Di
authors.initials: LD
authors.lastname: Yan
authors.forename: Pei-Lan
authors.initials: PL
authors.lastname: Zhou
authors.forename: Chun-Fu
authors.initials: CF
authors.lastname: Wu
authors.forename: Ze-Hui
authors.initials: ZH
authors.lastname: Gong
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001600:Berberine Alkaloids / Q000494:pharmacology*; D003213:Conditioning, Psychological / Q000187:drug effects*; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D010098:Oxycodone / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012201:Reward
chemical_list: D001600:Berberine Alkaloids; D017362:Cyclic AMP Response Element-Binding Protein; C014215:tetrahydropalmatine; D010098:Oxycodone; D048049:Extracellular Signal-Regulated MAP Kinases