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Browsing by Author "Lopes, Andreia"

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  • Natural products from extreme marine environments: searching for potential industrial uses within extremophile plants
    Publication . Lopes, Andreia; Rodrigues, Maria João; Pereira, Catarina; Oliveira, Marta; Barreira, Luísa; Varela, J.; Trampetti, Francesca; Custódio, Luísa
    Extremophile plants, halophytes in particular, still remain largely unexplored and underutilized despite their high potential as source of industrial raw materials like natural antioxidants in industries related to pharmaceutical, cosmetics and functional ingredients. The goal of this study was to explore the phenolic content and the in vitro antioxidant and tyrosine inhibition properties of polyphenol-rich extracts of twenty-one extremophile plant species collected in saline habitats of the South of Portugal (Algarve). Aqueous acetone extracts of Lithrum salicaria, Cladium mariscus, Frankenia laevis, F. pulverulenta, Limoniastrum monopetalum, Aster tripolium and Typha domigensis had remarkable levels of total phenolics (>= 230 mg GAE/g DW); Halopeplis amplexicaulis, Cladium mariscus,F. puiverulenta and Salsola vermiculata contained high levels of flavonoids (>= 10 mg RE/g DW); tannins peaked in T. domingensis and C. mariscus (>= 35 mg CE/g DW) and L. salicaria and A. tripolium had the upmost hydrocinamic acids content (>= 60 mg CAE/g DW). Overall L. salicaria had the highest antioxidant activity and only P. lentiscus had the capacity to inhibit tyrosinase. As the most bioactive extracts were not cytotoxic towards mammalian cell lines, our results suggest that several halophytes present in Southern Portugal could be used in the food and/or cosmetic industries.
    2016-12Journal article Restricted Show more
  • Unlocking the in vitroanti- inflammatory and antidiabetic potential of Polygonum maritimum
    Publication . Rodrigues, Maria Joao; Custodio, Luisa; Lopes, Andreia; Oliveira, Marta; Neng, Nuno R.; Nogueira, Jose M. F.; Martins, Alice; Rauter, Amelia P.; Varela, Joao; Barreira, L.
    Context: Several Polygonum species (Polygonaceae) are used in traditional medicine in Asia, Europe and Africa to treat inflammation and diabetes. Objective: Evaluate the in vitro antioxidant, anti-inflammatory and antidiabetic potential of methanol and dichloromethane extracts of leaves and roots of the halophyte Polygonum maritimum L. Material and methods: Antioxidant activity was determined (up to 1mg/mL) as radical-scavenging activity (RSA) of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), copper (CCA) and iron (ICA) chelating activities and iron reducing power (FRAP). NO production was measured in lipopolysaccharide (LPS)-stimulated macrophages for 24 h at concentrations up to 100 mu g/mL and antidiabetic potential was assessed by alpha-amylase and alpha-glucosidase inhibition (up to 10 g/mL) assays. The phytochemical composition of the extracts was determined by gas chromatography-mass spectrometry (GC-MS). Results: The methanol leaf extract had the highest activity against DPPH center dot (IC50 = 26 mu g/mL) and ABTS1(+)center dot (IC50 = 140 mu g FRAP (IC50 = 48 mu g/mL) and CCA (IC50 = 770 mu g/mL). Only the dichloromethane leaf extract (LDCM) showed anti-inflammatory activity (IC50 = 48 mu g/mL). The methanol root (IC50 = 19 mu g/mL) and leaf (IC50 = 29 mu g/mL) extracts strongly inhibited baker's yeast alpha-glucosidase, but LDCM had higher rat's alpha-glucosidase inhibition (IC50 = 2527 mu g/mL) than acarbose (IC50 = 4638 mu g/mL). GC-MS analysis identified beta-sitosterol, stigmasterol, 1-octacosanol and linolenic acid as possible molecules responsible for the observed bioactivities. Conclusions: Our findings suggest P. maritimum as a source of high-value health promoting commodities for alleviating symptoms associated with oxidative and inflammatory diseases, including diabetes.
    2017Journal article Open Access Show more