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

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. 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.

Bioactive polyphenols from muscadine grape and blackcurrant stably concentrated onto protein-rich matrices for topical applications.

OBJECTIVES: Natural botanical agents that are antimicrobial, or that modulate skin hyperpigmentation via tyrosinase inhibition, are increasingly sought in the cosmetic industry. METHODS: In this study, an efficient tactic is demonstrated for concentrating and stabilizing skin-beneficial bioactive compounds from muscadine grape and blackcurrant juice or muscadine pomace, into hemp flour (HF), hemp protein isolate (HPI) and soy protein isolate (SPI) matrices suitable for cosmetic applications. RESULTS: Anthocyanins were most efficiently captured from blackcurrant juice into HF (8.39 mg g(-1) ). HPI most effectively captured total phenolics from muscadine pomace (72.32 and 77.32 mg g(-1) from Noble and Carlos, respectively), while the three matrices incorporated highest levels of ellagic acid, gallic acid, and PAC B1 from Noble muscadine grape juice. The enriched matrices demonstrated effective in vitro inhibition of tyrosinase (up to 57.29% for blackcurrant juice-HPI matrix), and in general, juice sources provided greater inhibition on L-dopamine oxidation by tyrosinase than pomace sources. The polyphenol-enriched matrices effectively inhibited microbial proliferation in a screening assay against Staphylococcus aureus bacteria, whereas untreated HF, HPI or SPI did not inhibit bacterial growth. CONCLUSION: The technology of combining and stably concentrating phytoactive polyphenols with proteins has potential use for cosmetic topical applications.