title: Anti-cholinesterase activity of the standardized extract of Syzygium aromaticum L.
abstract: BACKGROUND
  Clove (Syzygium aromaticum) is a well-known culinary spice with strong aroma; contains a high amount of oil known as clove oil. The major phyto-constituent of the clove oil is eugenol. Clove and its oil possess various medicinal uses in indigenous medicine as an antiseptic, anti-oxidant, analgesic and neuroprotective properties. Thus, it draws much attention among researchers from pharmaceutical, food and cosmetic industries.
  
  
  OBJECTIVE
  The aim of the present study was to determine the anti-cholinesterase activity of the methanol extract of clove, its oil and eugenol.
  
  
  METHODS
  In vitro anti-cholinesterase activity of S. aromaticum was performed by a thin layer chromatography bio autography, 96 well micro titer plate and kinetic methods. Reverse phase high performance liquid chromatography (RP-HPLC) analysis was carried out to identify the biomarker compound eugenol in clove oil.
  
  
  RESULTS
  Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition study revealed that eugenol possess better inhibition of the enzymes than extract and oil. Clove extract, its oil and eugenol showed better inhibition of AChE than BChE. Polyphenolic compound eugenol was detected through RP-HPLC analysis. The content of eugenol in essential oil was found to be 0.5 μg/ml. Kinetic analysis of the cholinesterase inhibition study of the extract; clove oil and eugenol have shown that they possess mixed type of inhibition for AChE and non-competitive type of inhibition for BChE.
  
  
  CONCLUSIONS
  These results might be useful in explaining the effect of clove as anti-cholinesterase agent for the management of cognitive ailments like Alzheimer's disease.
authors.affiliation: Department of Pharmaceutical Technology, School of Natural Product Studies, Jadavpur University, West Bengal, India.
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Dalai
authors.affiliation: Department of Pharmaceutical Technology, School of Natural Product Studies, Jadavpur University, West Bengal, India.
authors.forename: Santanu
authors.initials: S
authors.lastname: Bhadra
authors.affiliation: Department of Pharmaceutical Technology, School of Natural Product Studies, Jadavpur University, West Bengal, India.
authors.forename: Sushil K
authors.initials: SK
authors.lastname: Chaudhary
authors.affiliation: CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal, India.
authors.forename: Arun
authors.initials: A
authors.lastname: Bandyopadhyay
authors.affiliation: Department of Pharmaceutical Technology, School of Natural Product Studies, Jadavpur University, West Bengal, India.
authors.forename: Pulok K
authors.initials: PK
authors.lastname: Mukherjee
keywords: Acetylcholinesterase; Alzheimer's disease; Syzygium aromaticum; butyrylcholinesterase; eugenol