title: Effects of boiling and in vitro gastrointestinal digestion on the antioxidant activity of Sonchus oleraceus leaves.
abstract: Leaves of Sonchus oleraceus L. are especially rich in phenolic compounds and have potent extractable antioxidants. However, it is not known how their antioxidant activity changes after cooking and gastrointestinal digestion. We recorded the profile of phenolics and their associated antioxidant activity in both raw and boiled S. oleraceus leaf extracts after in vitro gastric and intestinal digestion, and quantified their antioxidant potentials using Caco-2 and HepG2 cells. Boiling significantly diminished the oxygen radical absorbance capacity (ORAC) and concentrations of ascorbate and chicoric acid in the soluble fractions. In contrast, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and concentrations of caftaric and chlorogenic acids were unaffected. Phenolics in the soluble fraction were absorbed into cultured human cells and exerted antioxidant activity. Only chlorogenic acid content remained stable during gastrointestinal digestion. S. oleraceus appears to be an excellent dietary source of phenolic antioxidants.
authors.affiliation: School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand. maheshinimawalagedera@yahoo.com.
authors.forename: S M M R
authors.initials: SM
authors.lastname: Mawalagedera
authors.affiliation: School of Pharmacy, University of Otago, P.O. Box 913, Dunedin 9015, New Zealand.
authors.forename: Zong-Quan
authors.initials: ZQ
authors.lastname: Ou
authors.affiliation: School of Pharmacy, University of Otago, P.O. Box 913, Dunedin 9015, New Zealand.
authors.forename: Arlene
authors.initials: A
authors.lastname: McDowell
authors.affiliation: School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand. maheshinimawalagedera@yahoo.com.
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Gould
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000378:metabolism; D018938:Caco-2 Cells; D003296:Cooking; D004063:Digestion; D041981:Gastrointestinal Tract / Q000378:metabolism*; D056945:Hep G2 Cells; D006358:Hot Temperature; D006801:Humans; D008954:Models, Biological; D010936:Plant Extracts / Q000737:chemistry* / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry* / Q000378:metabolism; D031184:Sonchus / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D010936:Plant Extracts