title: A Scutellaria baicalensis radix water extract inhibits morphine-induced conditioned place preference.
abstract: BACKGROUND
  Scutellaria baicalensis Georgi (Lamiaceae) has been used as a traditional herbal preparation for the treatment of neuropsychiatric disorders in Asian countries for centuries.
  
  
  OBJECTIVE
  To evaluate the effects of S. baicalensis on morphine-induced drug dependence in rats.
  
  
  METHODS
  In order to evaluate the effect of S. baicalensis and baicalin on morphine-induced dependence-like behavior, a water extract of S. baicalensis [500 mg/kg, intraperitoneally (i.p.)] or baicalin (50 mg/kg, i.p., a flavonoid found in S. baicalensis) was administered prior to morphine injection [5 and 2.5 mg/kg, respectively, subcutaneously (s.c.)] to rats for 8 and 4 d, respectively. Morphine-induced conditioned place preference was assessed by measuring the time spent in a drug-paired chamber. The effect of S. baicalensis on dopamine receptor supersensitivity (locomotor activity) and dopamine agonist-induced climbing behavior due to a single apomorphine treatment (2 mg/kg, s.c.) was also measured.
  
  
  RESULTS
  At 50 mg/kg, a water extract of S. baicalensis decreased morphine (5 mg/kg)-induced conditioned place preference by 86% in rats. Apomorphine (2 mg/kg)-induced locomotor activity (dopamine receptor supersensitivity) in rats and climbing behavior in mice were attenuated after pretreatment with 500 mg/kg of S. baicalensis water extract by 41% and 56%, respectively. In addition, baicalin-reduced morphine-induced conditioned places preference by 86% in rats at 50 mg/kg.
  
  
  CONCLUSIONS
  These results suggest that S. baicalensis can ameliorate drug addiction-related behavior through functional regulation of dopamine receptors.
authors: Pharmaceutical Standardization Research and Testing Division, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety , Busan , Republic of Korea and.
authors: Jaesuk
authors: J
authors: Yun
authors: Young-Suk
authors: YS
authors: Jung
mesh_terms: D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009020:Morphine / Q000494:pharmacology*; D009021:Morphine Dependence / Q000378:metabolism / Q000517:prevention & control*; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D018517:Plant Roots; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000378:metabolism; D031364:Scutellaria baicalensis; D014867:Water / Q000494:pharmacology
chemical_list: D010936:Plant Extracts; D011954:Receptors, Dopamine; C499814:Scutellaria baicalensis extract; D014867:Water; D009020:Morphine
keywords: Abused drug; apomorphine; baicalin; climbing behavior; dopamine receptor supersensitivity; drug addiction