title: Fractionation, enzyme inhibitory and cellular antioxidant activity of bioactives from purple sweet potato (Ipomoea batatas).
abstract: Sweet potato (Ipomoea batatas L.) is mainly cultivated in Asia. The deep purple color of purple sweet potato (PSP) is due to the high content of acylated anthocyanins. In the present study, PSP-derived polyphenols were identified using HPLC-PDA and HPLC-ESI-MSnanalyses. After concentration of the polyphenols from PSP, preparative separation into two fractions, designated anthocyanins (AF) and copigments (CF), was carried out using adsorptive membrane chromatography. In enzyme inhibitory assays, all PSP samples inhibited the enzymes α-amylase, α-glucosidase and xanthine oxidase. Additionally, the cell signaling cellular antioxidant properties of the PSP extracts were investigated in cultured cells. PSP induced the transcription factor Nrf2, which regulates the expression of genes encoding heme oxygenase 1 (Hmox1), glutamate-cysteine ligase catalytic subunit (Gclc) and paraoxonase 1 (PON1). Furthermore, PSP enhanced cellular glutathione concentrations and decreased lipid peroxidation in cultured hepatocytes. Overall, these results suggest that PSP extracts exhibit enzyme inhibitory and cellular antioxidant properties, especially PSP CF.
authors.affiliation: Institute of Human Nutrition and Food Science, University of Kiel, Germany. Electronic address: esatbeyoglu@foodsci.uni-kiel.de.
authors.forename: Tuba
authors.initials: T
authors.lastname: Esatbeyoglu
authors.affiliation: Institute of Food Chemistry, Technische Universität Braunschweig, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Rodríguez-Werner
authors.affiliation: Institute of Human Nutrition and Food Science, University of Kiel, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Schlösser
authors.affiliation: Institute of Food Chemistry, Technische Universität Braunschweig, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Winterhalter
authors.affiliation: Institute of Human Nutrition and Food Science, University of Kiel, Germany.
authors.forename: Gerald
authors.initials: G
authors.lastname: Rimbach
mesh_terms: D000872:Anthocyanins / Q000032:analysis; D005591:Chemical Fractionation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005978:Glutathione / Q000378:metabolism; D027723:Ipomoea batatas / Q000737:chemistry*; D015227:Lipid Peroxidation; D010084:Oxidation-Reduction; D059808:Polyphenols / Q000032:analysis*; D014969:Xanthine Oxidase / Q000378:metabolism; D000516:alpha-Amylases / Q000378:metabolism; D000520:alpha-Glucosidases / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D059808:Polyphenols; D014969:Xanthine Oxidase; D000516:alpha-Amylases; D000520:alpha-Glucosidases; D005978:Glutathione
keywords: Anthocyanins; Cell culture; Chlorogenic acids; Enzyme inhibitory activity; HPLC; Membrane chromatography