title: Evaluation of Citrus aurantifolia peel and leaves extracts for their chemical composition, antioxidant and anti-cholinesterase activities.
abstract: BACKGROUND
  The replacement of synthetic antioxidants by safe natural antioxidants fosters research on the screening of vegetables and food as sources of new antioxidants. Moreover, oxidative degeneration of cells is associated with neurodegenerative diseases such as Alzheimer's disease. On the basis of these considerations this work aimed to investigate the antioxidant properties [by using the diphenyl picryl hydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric reducing ability of plasma assays, and the β-carotene bleaching test] and the anti-cholinesterase activity of Citrus aurantifolia peel and leaves from different areas of growth.
  
  
  RESULTS
  Methanol extracts of the peel and leaves demonstrated the strongest radical scavenging activity. A similar trend was observed with the reducing ability, with values from 112.1 to 146.0 µmol L(-1) Fe(II) g(-1). The relationship between phenol and flavonoid contents and antioxidant activity was statistically investigated. Based on analysis by high-performance liquid chromatography, the most abundant flavonoids found in C. aurantifolia extracts were apigenin, rutin, quercetin, kaempferol and nobiletin. n-Hexane fractions of both peel and leaves showed a good acetylcholinesterase inhibitory activity with IC(50) values in the range 91.4-107.4 µg mL(-1). Gas chromatography-mass spectrometry analysis revealed the presence of monoterpenes and sesquiterpenes as most common components.
  
  
  CONCLUSIONS
  The findings of this study suggest a potential use of C. aurantifolia peel and leaves for supplements for human health.
authors.affiliation: Department of Pharmaceutical Sciences, Faculty of Pharmacy, Nutrition and Health Sciences, University of Calabria, I-87036 Rende (CS), Italy.
authors.forename: Monica Rosa
authors.initials: MR
authors.lastname: Loizzo
authors.forename: Rosa
authors.initials: R
authors.lastname: Tundis
authors.forename: Marco
authors.initials: M
authors.lastname: Bonesi
authors.forename: Federica
authors.initials: F
authors.lastname: Menichini
authors.forename: Damiano
authors.initials: D
authors.lastname: De Luca
authors.forename: Carmela
authors.initials: C
authors.lastname: Colica
authors.forename: Francesco
authors.initials: F
authors.lastname: Menichini
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D032082:Citrus aurantiifolia / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis; D005638:Fruit / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D039821:Monoterpenes / Q000032:analysis; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D012717:Sesquiterpenes / Q000032:analysis
chemical_list: D000975:Antioxidants; D002800:Cholinesterase Inhibitors; D005419:Flavonoids; D039821:Monoterpenes; D010636:Phenols; D010936:Plant Extracts; D012717:Sesquiterpenes