Percorrer por autor "Neng, Nuno"
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- Isololiolide, a carotenoid metabolite isolated from the brown alga Cystoseira tamariscifolia, is cytotoxic and able to induce apoptosis in hepatocarcinoma cells through caspase-3 activation, decreased Bcl-2 levels, increased p53 expression and PARP cleavagePublication . Vizetto-Duarte, C; Custódio, Luísa; Gangadhar, Katkam N.; Lago, João Henrique G.; Dias, Catarina; Matos, Ana Marta; Neng, Nuno; Nogueira, José Manuel Florêncio; Barreira, Luísa; Albericio, Fernando; Rauter, Amelia P.; Varela, JoãoBackground: Brown macroalgae have attracted attention because they display a wide range of biological activities, including antitumoral properties. In this study we isolated isololiolide from Cystoseira tamariscifolia for the first time.Purpose: To examine the therapeutical potential of isololiolide against tumor cell lines.Methods/Study design: The structure of the compound was established and confirmed by 1D and 2D NMR as well as HRMS spectral analysis. The in vitro cytotoxicity was analyzed by colorimetric 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide assay in tumoral as well as in non-tumoral cell lines. Cell cycle arrest and induction of apoptosis were assessed by flow cytometry. Alteration of expression levels in proteins important in the apoptotic cascade was analyzed by western blotting.Results: Isololiolidewas isolated for the first time from the brown macroalga C. tamariscifolia. Isololiolide exhibited significant cytotoxic activity against three human tumoral cell lines, namely hepatocarcinoma HepG2 cells, whereas no cytotoxicity was found in non-malignant MRC-5 and HFF-1 human fibroblasts. Isololiolide completely disrupted the HepG2 normal cell cycle and induced significant apoptosis. Moreover, western blot analysis showed that isololiolide altered the expression of proteins that are important in the apoptotic cascade, increasing PARP cleavage and p53 expression while decreasing procaspase-3 and Bcl-2 levels.Conclusion: Isololiolide isolated from C. tamariscifolia is able to exert a selective cytotoxic activity on hepatocarcinoma HepG2 cells as well as induce apoptosis through the modulation of apoptosis-related proteins. (C) 2016 Elsevier GmbH. All rights reserved.
- NaCl elicitation enhances metabolite accumulation and stress resilience in Inula crithmoides L. shoot cultures: implications for its nutritional and medicinal valuePublication . Rodrigues, Maria João; Neng, Nuno; Custódio, LuísaThis study explored the impact of sodium chloride (NaCl) elicitation on the accumulation of primary and secondary metabolites and the oxidative stress responses of Inula crithmoides L. (golden samphire) in vitro shoot cultures. Elicitation involved applying different concentrations of NaCl (0, 50, 100, and 200 mM) for 4 weeks. This was followed by assessing its impact on plant growth, physiological parameters (pigments, hydrogen peroxide content, total soluble sugars and proteins, and proline), and secondary metabolism (phenylalanine ammonia-lyase activity, shikimic acid, phenolics, flavonoids, and hydroxycinnamic acids) in the shoots. The extracts were also analysed using high-performance liquid chromatography (HPLC). The NaCl elicitation did not affect shoot growth but increased physiological functions such as photosynthesis and oxidative stress management under moderate salinity levels. In addition, NaCl treatments increased the synthesis of soluble sugars and proteins, particularly proline, as well as bioactive phenolics such as gentisic acid, chlorogenic acid, 4-hydroxybenzoic acid, luteolin-7-O-glucoside, and naringenin-7-O-glucoside. The NaCl elicitation in golden samphire shoot cultures offers a significant method for enhancing the production of important nutritional and bioactive compounds. This underscores the species' potential for cultivation in saline environments and provides valuable prospects for its utilization in the health and nutrition sectors.
- Optimizing germination and cultivation of edible halophytes using effluents from an IMTA systemPublication . Castañeda-Loaiza, Viana; Rodrigues, Maria João; Neng, Nuno; Quintas, Célia; Ratao, Isabel; Custódio, LuísaBACKGROUND: Halophytes offer nature-based solutions to food insecurity and soil degradation, while their integration into integrated multi-trophic aquaculture (IMTA) systems promotes circular economy practices. This study aimed to optimize the germination and cultivation of edible halophytic species, namely Limbarda crithmoides, Suaeda vera and Mesembryanthemum nodiflorum, using effluents from an IMTA system. Germination was conducted under different substrates (perlite, vermiculite, coco peat, sand and combinations), irrigation (fresh or brackish water) and seed pre-treatments (scarification, gibberellic acid and thermal shock). Cultivation assays assessed plant responses to salinity (25.5–53.4 dS m−1 ) and density (75–600 plants m−2 ) using IMTA-derived aquaculture effluents for irrigation. RESULTS: Salinity significantly reduced seed germination. Limbarda crithmoides had the highest germination rate (61.1%) in vermiculite under freshwater irrigation, whereas S. vera achieved optimal performance in a substrate of sand, organic peat and perlite. Thermal shock slightly improved M. nodiflorum germination. Moderate salinities (35.1–40.7 dS m−1 ) resulted in higher survival and productivity, particularly for S. vera, which showed >86% survival and higher chlorophyll content. At high densities, L. crithmoides and S. vera maintained >75% survival, while M. nodiflorum at 75 plants m−2 effectively reduced nitrate and ammonia concentrations in effluents. All species produced biomass with adequate nutritional and microbiological profiles suitable for human consumption, rich in protein, dietary fiber and bioactive compounds. Suaeda vera at 300 plants m−2 exhibited the highest total content of phenolic compounds. CONCLUSION: This study outlines a sustainable approach to cultivating edible halophytes in IMTA systems, with applications in saline farming, functional foods and aquaculture wastewater treatment.