title: Evaluation of anti-amnesic effect of extracts of selected Ocimum species using in-vitro and in-vivo models.
abstract: BACKGROUND
  Ocimum species are traditionally used for the treatment of anxiety, nerve pain, convulsions and a variety of neurodegenerative disorders. The present study was undertaken to evaluate the anti-amnesic effect of O. basilicum L., O. sanctum L. and O. gratissimum L. extracts using in-vitro and in-vivo models.
  
  
  METHODS
  In-vitro acetylcholinesterase (AChE) inhibitory and antioxidant activities of hydro-methanol extracts of plants were evaluated using Ellman and DPPH and FRAP assays, respectively. The most active extract i.e. O. basilicum extract (OBE) was further explored for the possible anti-amnesic activity in mouse model of scopolamine induced amnesia using behavioral models (elevated plus maze and passive shock avoidance task). Brain AChE activity, oxidative profile and histopathological studies were assessed to outline the anti-amnesic mechanism of the extract.
  
  
  RESULTS
  Significant antioxidant and AChE inhibition activity was observed with all prepared extracts and however, OBE showed most marked free radical scavenging, reducing power and AChE inhibition (IC500.65±0.15mg/ml) activity. Basil leaves were standardized with respect to content of 7 phenolic acids using a HPLC-PDA method. A TLC densitometric method was employed to determine the quercetin content in the leaves. The in-vivo studies showed that OBE pre-treatment (200 and 400mg/kg, p.o.) reversed the memory deficit induced by scopolamine in mice, evident by significant (p<0.05) decrease in the transfer latency time and increase in step down latency in elevated plus maze and passive shock avoidance task, respectively. Moreover, OBE significantly reduced the brain AChE activity and oxidative stress. Further, histopathological examination of brain tissues displayed decrease in vacuolated cytoplasm and increase in pyramidal cells in hippocampal and cortical regions with OBE pre-treatment.
  
  
  CONCLUSIONS
  OBE possesses antioxidant and AChE inhibitory activity. These biochemical changes are responsible for the anti-amnesic and neuroprotective activities of O. basilicum which may be attributed to the presence of phenolic and flavonoid compounds. This can be developed as an effective anti-amnesic drug.
authors.affiliation: Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, Punjab, India.
authors.forename: Varinder
authors.initials: V
authors.lastname: Singh
authors.affiliation: Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, Punjab, India.
authors.forename: Aditi
authors.initials: A
authors.lastname: Kahol
authors.affiliation: Natural Products Research Laboratory, Department of Natural products, NIPER, Mohali, Punjab, India.
authors.forename: Inder Pal
authors.initials: IP
authors.lastname: Singh
authors.affiliation: Natural Products Research Laboratory, Department of Natural products, NIPER, Mohali, Punjab, India.
authors.forename: Isha
authors.initials: I
authors.lastname: Saraf
authors.affiliation: Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, Punjab, India. Electronic address: rshri587@hotmail.com.
authors.forename: Richa
authors.initials: R
authors.lastname: Shri
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000647:Amnesia / Q000139:chemically induced / Q000188:drug therapy* / Q000201:enzymology / Q000523:psychology; D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects*; D001713:Biphenyl Compounds / Q000737:chemistry; D002540:Cerebral Cortex / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology; D002800:Cholinesterase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D003071:Cognition / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D058851:GPI-Linked Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects*; D000432:Methanol / Q000737:chemistry; D008807:Mice, Inbred BALB C; D018696:Neuroprotective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D031339:Ocimum / Q000737:chemistry; D018649:Ocimum basilicum / Q000737:chemistry*; D000070004:Ocimum sanctum / Q000737:chemistry; D010636:Phenols / Q000302:isolation & purification / Q000494:pharmacology; D008517:Phytotherapy; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal; D011930:Reaction Time; D012601:Scopolamine; D012997:Solvents / Q000737:chemistry; D013997:Time Factors
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002800:Cholinesterase Inhibitors; D058851:GPI-Linked Proteins; D018696:Neuroprotective Agents; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D012997:Solvents; C004931:1,1-diphenyl-2-picrylhydrazyl; D012601:Scopolamine; D000110:Acetylcholinesterase; C548245:Ache protein, mouse; D000432:Methanol
keywords: Acetylcholinesterase inhibition; Amnesia; Antioxidant; Neuroprotection; Ocimum basilicum