title: Effect of standardized extract of Marsilea minuta on learning and memory performance in rat amnesic models.
abstract: BACKGROUND
  Marsilea minuta Linn (Marsileaceae) is a common Indian hydrophytic plant. Traditionally, the plant has been used as a sedative for the treatment of insomnia and other mental disorders. Background information of this plant has encouraged us to investigate its antiamnesic activity in rat.
  
  
  OBJECTIVE
  Standardized ethanol extract of M. minuta was investigated for their putative role in learning and memory performance in normal and amnesic rats.
  
  
  METHODS
  Ethanol extract of M. minuta (EMM) was standardized for marsiline using HPLC. The effect of standardized extract of M. minuta (1.15% w/w marsiline) was tested in amnesic rat using elevated plus maze (EPM) and passive avoidance (PA) test. Amnesia was induced after scopolamine (1 mg/kg, s.c.) and electroconvulsive shock (150 mA, 0.2 s) treatment. Behavioral studies were further substantiated with acetylcholinesterase (AChE) activity and radioligand muscarinic receptor binding studies in rat brain regions.
  
  
  RESULTS
  Oral administration of EMM at 200 and 400 mg/kg/day for 3 days significantly reversed the amnesia whereas, no per se effect was observed. In comparison to control, AChE activity in frontal cortex and hippocampus was found to be significantly (P < 0.05) inhibited by EMM. EMM at doses 200 and 400 mg/kg has significantly (P < 0.05) increased (+34 % and +40 % change in affinity, respectively) the binding of 3H-QNB in frontal cortex indicating the up regulation of the muscarinic receptors.
  
  
  CONCLUSIONS
  These findings suggest that standardized extract of M. minuta have excellent antiamnesic activity, probably mediating through central cholinergic system.
authors.affiliation: Neuropharmacology Laboratory, Department of Pharmaceutics, Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India. bhattamisra@yahoo.co.in
authors.forename: Subrat Kumar
authors.initials: SK
authors.lastname: Bhattamisra
authors.forename: Paras Nath
authors.initials: PN
authors.lastname: Singh
authors.forename: Sushil Kumar
authors.initials: SK
authors.lastname: Singh
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000647:Amnesia / Q000188:drug therapy* / Q000201:enzymology / Q000378:metabolism; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005625:Frontal Lobe / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D058851:GPI-Linked Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D007858:Learning / Q000187:drug effects*; D008297:Male; D043964:Marsileaceae / Q000737:chemistry*; D008515:Medicine, Ayurvedic; D008568:Memory / Q000187:drug effects*; D018721:Muscarinic Agonists / Q000627:therapeutic use; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D018697:Nootropic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000378:metabolism
chemical_list: D058851:GPI-Linked Proteins; D018721:Muscarinic Agonists; D009419:Nerve Tissue Proteins; D018697:Nootropic Agents; D010936:Plant Extracts; D011976:Receptors, Muscarinic; D000110:Acetylcholinesterase; C548246:Ache protein, rat