title: Piper betle leaves: profiling phenolic compounds by HPLC/DAD-ESI/MS(n) and anti-cholinesterase activity.
abstract: BACKGROUND
  Piper betle L. is a widely distributed plant in the tropical and subtropical regions, its leaves being largely consumed as a masticator and mouth freshener.
  
  
  OBJECTIVE
  The purposes of this work were to characterise the phenolic profile of this species and to improve knowledge of its anti-cholinesterase properties.
  
  
  METHODS
  The phenolic composition of P. betle leaf aqueous and ethanol extracts was characterised by HPLC coupled with a diode-array detector and combined with electrospray ionisation tandem MS, and in vitro cholinesterase inhibitory capacity of both extracts was assessed by spectrophotometric microassays. The effect on neuronal cells (SH-SY5Y) viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction and lactate dehydrogenase leakage.
  
  
  RESULTS
  Twelve phenolic compounds, comprising a phenylpropanoid, five cinnamoyl and six flavonoids derivatives were identified in P. betle leaves. Hydroxychavicol was the major compound in both extracts; however, the aqueous extract presented a greater diversity of compounds. Both extracts showed strong activity against both acetyl- and butyrylcholinesterase, which can be due, at least partially, to the phenolic composition. Furthermore, the aqueous extract proved to be cytotoxic to human neuroblastoma cells at concentrations higher than 500 µg/mL.
  
  
  CONCLUSIONS
  The results suggest that the consumption of P. betle leaves as an infusion can have a positive impact in the prevention and treatment of neurodegenerative diseases. Apigenin and luteolin derivatives are reported for the first time in this species.
authors.affiliation: Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS (CSIC), P.O. Box 164, 30100 Campus University Espinardo, Murcia, Spain.
authors.forename: Federico
authors.initials: F
authors.lastname: Ferreres
authors.forename: Andreia P
authors.initials: AP
authors.lastname: Oliveira
authors.forename: Angel
authors.initials: A
authors.lastname: Gil-Izquierdo
authors.forename: Patrícia
authors.initials: P
authors.lastname: Valentão
authors.forename: Paula B
authors.initials: PB
authors.lastname: Andrade
mesh_terms: D002460:Cell Line; D002470:Cell Survival; D002800:Cholinesterase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D015394:Molecular Structure; D009474:Neurons / Q000187:drug effects; D010636:Phenols / Q000737:chemistry*; D031721:Piper betle / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D002800:Cholinesterase Inhibitors; D005419:Flavonoids; D010636:Phenols
keywords: HPLC/DAD-ESI/MSn; Piper betle Linn; anti-cholinesterases; human neuroblastoma cells; phenolic compounds