title: Direct and indirect antioxidant activity of polyphenol- and isothiocyanate-enriched fractions from Moringa oleifera.
abstract: Moringa oleifera Lam. is a fast-growing, tropical tree with various edible parts used as nutritious food and traditional medicine. This study describes an efficient preparatory strategy to extract and fractionate moringa leaves by fast centrifugal partition chromatography (FCPC) to produce polyphenol and isothiocyanate (ITC) rich fractions. Characterization and further purification of these fractions showed that moringa polyphenols were potent direct antioxidants assayed by oxygen radical absorbance capacity (ORAC), whereas moringa ITCs were effective indirect antioxidants assayed by induction of NAD(P)H quinone oxidoreductase 1 (NQO1) activity in Hepa1c1c7 cells. In addition, purified 4-[(α-l-rhamnosyloxy)benzyl]isothiocyanate and 4-[(4'-O-acetyl-α-l-rhamnosyloxy)benzyl]isothiocyanate were further evaluated for their ORAC and NQO1 inducer potency in comparison with sulforaphane (SF). Both ITCs were as potent as SF in inducing NQO1 activity. These findings suggest that moringa leaves contain a potent mixture of direct and indirect antioxidants that can explain its various health-promoting effects.
authors.affiliation: Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey , 59 Dudley Road, New Brunswick, New Jersey 08901, United States.
authors.forename: Tugba Boyunegmez
authors.initials: TB
authors.lastname: Tumer
authors.forename: Patricio
authors.initials: P
authors.lastname: Rojas-Silva
authors.forename: Alexander
authors.initials: A
authors.lastname: Poulev
authors.forename: Ilya
authors.initials: I
authors.lastname: Raskin
authors.forename: Carrie
authors.initials: C
authors.lastname: Waterman
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D002460:Cell Line; D017879:Isothiocyanates / Q000737:chemistry* / Q000302:isolation & purification; D051379:Mice; D029588:Moringa oleifera / Q000737:chemistry*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000032:analysis / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D059808:Polyphenols / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000975:Antioxidants; D017879:Isothiocyanates; D010936:Plant Extracts; D059808:Polyphenols; C037152:isothiocyanic acid; D016660:NAD(P)H Dehydrogenase (Quinone)
keywords: 4-[(4′-O-acetyl-α-l-rhamnosyloxy)benzyl]isothiocyanate; 4-[(α-l-rhamnosyloxy)benzyl]isothiocyanate; FCPC; Moringa oleifera; NQO1; antioxidants; isothiocyanates; polyphenols