title: Compounds leached from quinoa seeds inhibit matrix metalloproteinase activity and intracellular reactive oxygen species.
abstract: OBJECTIVE
  Quinoa (Chenopodium quinoa Willd.) is a seed crop rich in bioactive compounds including phytoecdysones (especially 20-hydroxyecdysone, 20HE), polyphenols, proteins and essential fatty acids. We previously reported a method to leach and concentrate quinoa bioactives into a complex phytochemical mixture termed quinoa leachate (QL). Here, we aimed to determine the effect of QL and its chemically distinct fractions on five biochemical endpoints relevant to skin care applications: (i) cell viability, (ii) matrix metalloproteinase (MMP) mRNA expression, (iii) MMP enzymatic activity, (iv) tyrosinase enzymatic activity and (v) intracellular reactive oxygen species (ROS) production.
  
  
  METHODS
  Quinoa leachate was fractionated and chemically characterized using column chromatography and liquid chromatography-mass spectrometry (LC-MS). Cell viability was determined using a MTT assay in four mammalian cell lines. MMP-1 mRNA expression was assessed in human dermal fibroblasts (HDF) via qRT-PCR. The enzymatic activity of MMP-9 and tyrosinase was measured using fluorometric and colorimetric in vitro assays, respectively. Lipopolysaccharide (LPS)-induced ROS production was determined in human dermal fibroblasts by fluorescence intensity of an oxidant-sensitive probe.
  
  
  RESULTS
  Quinoa leachate was separated into three fractions: (i) carbohydrate-rich fraction (QL-C; 71.3% w/w of QL); (ii) phytoecdysone, polyphenol and protein-rich fraction (QL-P, 13.3% w/w of QL); (iii) oil-rich fraction (QL-O, 10.8% w/w of QL). QL did not reduce cell viability in any of the four cell lines tested. QL, QL-P and QL-O each significantly inhibited MMP-1 mRNA expression in HDF at a concentration of 5 μg mL(-1) . QL and QL-P also significantly inhibited MMP-9 enzymatic activity, whereas QL-P demonstrated significant tyrosinase enzymatic inhibition. Furthermore, QL, QL-P, QL-O and 20HE significantly inhibited intracellular ROS production.
  
  
  CONCLUSIONS
  This study is the first to demonstrate the MMP, tyrosinase and ROS inhibiting properties of multiple different phytochemical components derived from quinoa seeds. Our work indicates that quinoa phytochemicals may play a role in the treatment and prevention of skin ageing through a multiplicity of effects.
authors.affiliation: Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, NJ, 08901, USA.
authors.forename: B L
authors.initials: BL
authors.lastname: Graf
authors.forename: D M
authors.initials: DM
authors.lastname: Cheng
authors.forename: D
authors.initials: D
authors.lastname: Esposito
authors.forename: T
authors.initials: T
authors.lastname: Shertel
authors.forename: A
authors.initials: A
authors.lastname: Poulev
authors.forename: N
authors.initials: N
authors.lastname: Plundrich
authors.forename: D
authors.initials: D
authors.lastname: Itenberg
authors.forename: N
authors.initials: N
authors.lastname: Dayan
authors.forename: M A
authors.initials: MA
authors.lastname: Lila
authors.forename: I
authors.initials: I
authors.lastname: Raskin
mesh_terms: D002478:Cells, Cultured; D027465:Chenopodium quinoa / Q000196:embryology*; D002853:Chromatography, Liquid; D006801:Humans; D013058:Mass Spectrometry; D020781:Matrix Metalloproteinase 1 / Q000187:drug effects* / Q000235:genetics; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors; D011480:Protease Inhibitors / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012639:Seeds / Q000737:chemistry*
chemical_list: D011480:Protease Inhibitors; D017382:Reactive Oxygen Species; D014442:Monophenol Monooxygenase; D020781:Matrix Metalloproteinase 1
keywords: ageing; cell culture; chemical analysis; oxidative damage; phytochemistry; phytoecdysteroid