Compounds leached from quinoa seeds inhibit matrix metalloproteinase activity and intracellular reactive oxygen species

Synopsis Objective Quinoa ( C henopodium quinoa W illd.) is a seed crop rich in bioactive compounds including phytoecdysones (especially 20‐hydroxyecdysone, 20 HE ), 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 ) m RNA 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 m RNA expression was assessed in human dermal fibroblasts ( HDF ) via q RT ‐ 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 m RNA 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 20 HE significantly inhibited intracellular ROS production. Conclusion 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.