title: In vitro cholinesterase inhibitory and antioxidant effect of selected coniferous tree species.
abstract: OBJECTIVE
  To explore cholinesterase inhibitory and antioxidant effect of six coniferous trees (Abies bornmulleriana, Picea pungens, Juniperus communis, Cedrus libani, Taxus baccata, and Cupressus sempervirens var. horizantalis).
  
  
  METHODS
  Acetone (Ace), ethyl acetate (EtOAc), and ethanol (EtOH) extracts prepared from the needles and shoots of the six coniferous trees were screened for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity at 100 μg/mL. Antioxidant activity of the extracts was tested using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and N,N-dimethyl-p-phenylendiamine (DMPD) radical scavenging, metal-chelation capacity, ferric-(FRAP) and phosphomolibdenum-reducing antioxidant power (PRAP) assays. All of the assays were performed in ELISA microplate reader. Total phenol and flavonoid amounts in the extracts were determined spectrophotometrically.
  
  
  RESULTS
  Among thirty-six extracts in total, the shoot-Ace extract of Cupressus sempervirens var. horizantalis exerted the highest inhibition against AChE [(54.84±2.51)%], while the needle-Ace extract of Cedrus libani was the most effective in inhibiting BChE [(67.54±0.30)%]. The highest DPPH radical scavenging effect, FRAP and PRAP was observed in the shoot-Ace and EtOAc extracts from Taxus baccata, whereas all the extracts showed a variable degree of scavenging effect against DPMD radical. The shoot-EtOAc extract of Cedrus libani had the highest metal-chelation capacity [(58.04±0.70)%]. The shoot extracts of Taxus baccata were determined to have the richest total phenol content, which may contribute to its marked antioxidant activity.
  
  
  CONCLUSIONS
  The conifer species screened in this study may contain cholinesterase-inhibiting and antioxidant properties, which might be useful against Alzheimer's disease.
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey.
authors.forename: Fatma Sezer
authors.initials: FS
authors.lastname: Senol
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey. Electronic address: iorhan@gazi.edu.tr.
authors.forename: Ilkay Erdogan
authors.initials: IE
authors.lastname: Orhan
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey.
authors.forename: Osman
authors.initials: O
authors.lastname: Ustun
keywords: Alzheimer's disease; Antioxidant activity; Cholinesterase inhibition; Conifer; Total phenol and flavonoid