title: Beneficial effect of commercial Rhodiola extract in rats with scopolamine-induced memory impairment on active avoidance.
abstract: Rhodiola rosea L., family Crassulaceae also known as Golden Root or Arctic root is one of the most widely used medicinal plants with effect on cognitive dysfunction, psychological stress and depression. The aim of the study was to examine the effect of a standardized commercial Rhodiola extract on learning and memory processes in naive rats as well as its effects in rats with scopolamine-induced memory impairment.
  
  
  METHODS
  Sixty male Wistar rats were used in the study. The experiment was conducted in two series - on naive rats and on rats with scopolamine-induced model of impaired memory. The active avoidance test was performed in an automatic conventional shuttle box set-up. The criteria used were the number of conditional stimuli (avoidances), the number of unconditioned stimuli (escapes) as well as the number of intertrial crossings.
  
  
  RESULTS
  The chemical fingerprinting of the standardized commercial Rhodiola extract was performed by means of nuclear magnetic resonance (NMR). Naive rats treated with standardized Rhodiola extract increased the number of avoidances during the learning session and memory retention test compared to the controls. Rats with scopolamine-induced memory impairment treated with Rhodiola extract showed an increase in the number of avoidances during the learning session and on the memory tests compared to the scopolamine group. The other two parameters were not changed in rats treated with the extract of Rhodiola in the two series.
  
  
  CONCLUSIONS
  It was found that the studied Rhodiola extract exerts a beneficial effect on learning and memory processes in naive rats and rats with scopolamine-induced memory impairment. The observed effect is probably due to multiple underlying mechanisms including its modulating effect on acetylcholine levels in the brain and MAO-inhibitory activity leading to stimulation of the monoamines' neurotransmission. In addition the pronounced stress-protective properties of Rhodiola rosea L. could also play a role in the improvement of cognitive functions.
authors.affiliation: Department of Pharmacology and Clinical Pharmacology, Faculty of Medicine, Medical University, 15A Vassil Aprilov Blvd., Plovdiv 4000, Bulgaria; Department of Pharmacology and Medical Toxicology, Faculty of Pharmacy, Medical University, 15A Vassil Aprilov Blvd., Plovdiv 4000, Bulgaria; Laboratory of Experimental Neuropharmacology, Technological Center for Emergency Medicine (TCEMED), Plovdiv 4000, Bulgaria. Electronic address: vasileva.l.vl@gmail.com.
authors.forename: Liliya V
authors.initials: LV
authors.lastname: Vasileva
authors.affiliation: Laboratory of Experimental Neuropharmacology, Technological Center for Emergency Medicine (TCEMED), Plovdiv 4000, Bulgaria.
authors.forename: Damianka P
authors.initials: DP
authors.lastname: Getova
authors.affiliation: Department of Pharmacology and Medical Toxicology, Faculty of Pharmacy, Medical University, 15A Vassil Aprilov Blvd., Plovdiv 4000, Bulgaria.
authors.forename: Nina D
authors.initials: ND
authors.lastname: Doncheva
authors.affiliation: Laboratory of Applied Biotechnologies, The Stephan Angeloff Institute of Microbiology, Bulgaria Academy of Sciences, 139 Ruski Blvd., Plovdiv 4000, Bulgaria; Center of Plant System Biology and Biotechnology, Plovdiv 4000, Bulgaria.
authors.forename: Andrey S
authors.initials: AS
authors.lastname: Marchev
authors.affiliation: Laboratory of Applied Biotechnologies, The Stephan Angeloff Institute of Microbiology, Bulgaria Academy of Sciences, 139 Ruski Blvd., Plovdiv 4000, Bulgaria; Center of Plant System Biology and Biotechnology, Plovdiv 4000, Bulgaria.
authors.forename: Milen I
authors.initials: MI
authors.lastname: Georgiev
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001522:Behavior, Animal / Q000187:drug effects*; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced / Q000188:drug therapy* / Q000523:psychology; D010936:Plant Extracts / Q000302:isolation & purification / Q000627:therapeutic use*; D017208:Rats, Wistar; D029771:Rhodiola / Q000737:chemistry*; D012601:Scopolamine / Q000494:pharmacology
chemical_list: D010936:Plant Extracts; D012601:Scopolamine
keywords: Active avoidance test; Learning; Memory; Rats; Rhodiola; Salidroside (PubChem CID: 159278); Scopolamine (PubChem CID: 3000322); Scopolamine-induced memory impairment