Percorrer por autor "Rocha, Maria Isabel"
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- Halophytes: Gourmet food with nutritional health benefits?Publication . Barreira, Luísa; Resek, Eva; Rodrigues, Maria Joao; Rocha, Maria Isabel; Pereira, Hugo; Bandarra, Narcisa; da Silva, Manuela Moreira; J. C. or Varela J. or Varela J.C.S., Varela; Custodio, LuisaAlthough little is known about their nutritional composition, Sarcocornia perennis subsp. perennis, S. perennis subsp. alpini and Salicornia ramosissima (Salicorniaceae) as well as Arthrocnemum macro-stachyum (Amaranthaceae) are consumed in gourmet cuisine. In spite of belonging to different families, these halophytes share morphological and organoleptic characteristics. This work explored the nutritional properties and the antioxidant potential of these species using five integrative methods. All species had a nutritional profile suitable for human consumption with high levels of protein (5.20-13.2 g/100 g dw) and n-3 polyunsaturated fatty acids (FA), particularly or alpha-linolenic acid (19.3-25.9% of total FA), and low concentration of toxic metals (below the limits imposed by the European Commission). These halophytes are also a good source of minerals, particularly sodium (64.1-109 mg/gdw), and S. ramosissima is an excellent source of manganese (204 mu g/g dw). However, due care should be taken not to exceed the legal limits for sodium ingestion. These plants showed also significant antioxidant potential, with high radical scavenging activity (RSA), iron reducing power and total phenolics content (20.5-49.2 mg GAE/g). A. macrostachyum had the highest RSA (lC(50-DPPH) = 0.84 mg/mL; IC50-NO = 0.60 mg/mL), and iron reducing potential (IC50= 0.84 mg/mL) along with high levels of alpha- and gamma-tocopherol (8.74 and 4.71 mg/100 g dw, respectively). (C) 2017 Elsevier Inc. All rights reserved.
- Methanol extracts from Cystoseira tamariscifolia and Cystoseira nodicaulis are able to inhibit cholinesterases and protect a human dopaminergic cell line from hydrogen peroxide-induced cytotoxicityPublication . Custódio, Luísa; Silvestre, Laura; Rocha, Maria Isabel; Rodrigues, Maria Joao; Vizetto-Duarte, C; Pereira, Hugo; Barreira, Luísa; Varela, J.Context Marine macroalgae contain several bioactive molecules that may be developed as functional foods, but information about their neuroprotective potential is scarce.Objective The objective of this study is to determine the in vitro antioxidant and neuroprotective features of marine algae from the southern coast of Portugal and to assess the total content of different types of bioactives.Materials and methods Methanol extracts from 21 macroalgal species from the southern Portugal were evaluated for in vitro antioxidant and acetylcholinesterase (AChE) inhibition. Active extracts were further evaluated for inhibitory activity against butyrylcholinesterase (BuChE) and tyrosinase (TYRO), and for their ability to attenuate hydrogen peroxide (H2O2)-induced toxicity in SH-SY5Y cells. The total contents of different phenolic groups were determined for the most active extracts.ResultsCystoseira tamariscifolia (Hudson) Papenfuss (Sargassaceae) had the highest antiradical activity (92%, 1mg/mL). Cystoseira nodicaulis (Withering) M. Roberts (Sargassaceae) (75%) and Cystoseira humilis Schousboe ex Kutzing (Sargassaceae) (70%) had the highest iron-chelating activity at 10mg/mL. Cystoseira baccata (S.G. Gmelin) P.C. Silva (Sargassaceae) was more active towards copper (66%, 10mg/mL). Cystoseira tamariscifolia had the highest AChE inhibitory capacity (85%, 10mg/mL). Cystoseira tamariscifolia and C. nodicaulis were also active against BuChE and TYRO, and were able to protect SH-SY5Y cells against oxidative stress induced by H2O2. Cystoseira tamariscifolia had the highest content of all the groups of phenolics, and was particularly enriched in hydroxycinnamic acids (106mg CAE/g DW).Discussion and conclusion Results indicate that C. tamariscifolia and C. nodicaulis are important sources of nutraceutical compounds and may be considered functional foods that could improve cognitive functions.