title: Bioactive Flavonoids, Antioxidant Behaviour, and Cytoprotective Effects of Dried Grapefruit Peels (Citrus paradisi Macf.).
abstract: Grapefruit (Citrus paradisi Macf.) is an important cultivar of the Citrus genus which contains a number of nutrients beneficial to human health. The objective of the present study was to evaluate changes in bioactive flavonoids, antioxidant behaviour, and in vitro cytoprotective effect of processed white and pink peels after oven-drying (45°C-60°C) and freeze-drying treatments. Comparison with fresh grapefruit peels was also assessed. Significant increases in DPPH, FRAPS, and ABTS values were observed in dried grapefruit peel samples in comparison with fresh peels, indicating the suitability of the treatments for use as tools to greatly enhance the antioxidant potential of these natural byproducts. A total of thirteen flavonoids were quantified in grapefruit peel extracts by HPLC-MS/MS. It was found that naringin, followed by isonaringin, was the main flavonoid occurring in fresh, oven-dried, and freeze-dried grapefruit peels. In vivo assay revealed that fresh and oven-dried grapefruit peel extracts (45°C) exerted a strong cytoprotective effect on SH-SY5Y neuroblastoma cell lines at concentrations ranging within 0.1-0.25 mg/mL. Our data suggest that grapefruit (Citrus paradisi Macf.) peel has considerable potential as a source of natural bioactive flavonoids with outstanding antioxidant activity which can be used as agents in several therapeutic strategies.
authors.affiliation: Analytical Chemistry and Food Technology Area, Faculty of Pharmacy, University of Castilla-La Mancha, 02071 Albacete, Spain.
authors.forename: Lucia
authors.initials: L
authors.lastname: Castro-Vazquez
authors.affiliation: Food Technology Area, Faculty of Chemistry, University of Castilla-La Mancha, 02071 Ciudad Real, Spain.
authors.forename: María Elena
authors.initials: ME
authors.lastname: Alañón
authors.affiliation: Analytical Chemistry and Food Technology Area, Faculty of Pharmacy, University of Castilla-La Mancha, 02071 Albacete, Spain.
authors.forename: Virginia
authors.initials: V
authors.lastname: Rodríguez-Robledo
authors.affiliation: Analytical Chemistry and Food Technology Area, Faculty of Pharmacy, University of Castilla-La Mancha, 02071 Albacete, Spain; Food Technology Area, Faculty of Chemistry, University of Castilla-La Mancha, 02071 Ciudad Real, Spain.
authors.forename: María Soledad
authors.initials: MS
authors.lastname: Pérez-Coello
authors.affiliation: Food Technology Area, Faculty of Chemistry, University of Castilla-La Mancha, 02071 Ciudad Real, Spain.
authors.forename: Isidro
authors.initials: I
authors.lastname: Hermosín-Gutierrez
authors.affiliation: Analytical Chemistry and Food Technology Area, Faculty of Pharmacy, University of Castilla-La Mancha, 02071 Albacete, Spain; Food Technology Area, Faculty of Chemistry, University of Castilla-La Mancha, 02071 Ciudad Real, Spain.
authors.forename: María Consuelo
authors.initials: MC
authors.lastname: Díaz-Maroto
authors.affiliation: Medical Sciences Department, Faculty of Medicine, University of Castilla-La Mancha, 02071 Albacete, Spain.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Jordán
authors.affiliation: Analytical Chemistry and Food Technology Area, Faculty of Pharmacy, University of Castilla-La Mancha, 02071 Albacete, Spain.
authors.forename: María Francisca
authors.initials: MF
authors.lastname: Galindo
authors.affiliation: Analytical Chemistry and Food Technology Area, Faculty of Pharmacy, University of Castilla-La Mancha, 02071 Albacete, Spain.
authors.forename: María Del Mar
authors.initials: Mdel M
authors.lastname: Arroyo-Jiménez
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D052160:Benzothiazoles / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D032083:Citrus paradisi / Q000737:chemistry*; D019610:Cytoprotection / Q000187:drug effects*; D003890:Desiccation; D005419:Flavonoids / Q000494:pharmacology*; D005612:Freeze Drying; D006027:Glycosides / Q000032:analysis; D006801:Humans; D007501:Iron / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology*; D059808:Polyphenols / Q000494:pharmacology; D025341:Principal Component Analysis; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D005419:Flavonoids; D006027:Glycosides; D010851:Picrates; D010936:Plant Extracts; D059808:Polyphenols; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D007501:Iron