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Dive into the research topics where Eliana Pereira is active.

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Featured researches published by Eliana Pereira.


Food Chemistry | 2013

Chemical composition of wild and commercial Achillea millefolium L. and bioactivity of the methanolic extract, infusion and decoction

Maria Inês Dias; Lillian Barros; Montserrat Dueñas; Eliana Pereira; Ana Maria Carvalho; Rita C. Alves; M. Beatriz P.P. Oliveira; Celestino Santos-Buelga; Isabel C.F.R. Ferreira

Medicinal plants used in folk medicine are being increasingly studied and used on pharmaceutical, food and nutraceutical fields. Herein, wild and commercial samples of Achillea millefolium L. (yarrow) were chemically characterized with respect to their macronutrients, free sugars, organic acids, fatty acids and tocopherols. Furthermore, in vitro antioxidant properties (free radicals scavenging activity, reducing power and lipid peroxidation inhibition) and antitumour potential (against breast, lung, cervical and hepatocellular carcinoma cell lines) of their methanolic extract, infusion and decoction (the most consumed forms) was evaluated and compared to the corresponding phenolic profile obtained by high performance liquid chromatography and mass spectrometry. Data obtained showed that the chemical profiles of wild and commercial samples, and also their methanolic extract, infusion and decoction were similar, varying only in the quantities found. Commercial yarrow have higher content of fat and saturated fatty acids, proteins, ash, energy value, sugars and flavonoids, while the wild sample revealed higher levels of carbohydrates, organic acids, unsaturated fatty acids, tocopherols and phenolic acids. The heterogeneity among the antioxidant and antitumour results of the samples and some low correlations with total phenolic compounds indicates that specific compounds, rather than the totality of them, are involved in the bioactive properties of samples.


Molecules | 2011

Biomolecule Profiles in Inedible Wild Mushrooms with Antioxidant Value

Filipa S. Reis; Eliana Pereira; Lillian Barros; Maria João Sousa; Anabela Martins; Isabel C.F.R. Ferreira

The use of natural products isolated from mushrooms, included inedible species, against infection, cancer diseases and other oxidative-stress related diseases is one of the cornerstones of modern medicine. In the present work, the antioxidant molecule profiles of inedible mushroom species were evaluated and compared with those of edible species. The order of antioxidant abundance found in inedible wild mushrooms was: phenolics > flavonoids > ascorbic acid > tocopherols > carotenoids, similar to that of edible species. Furthermore the same energetic biomolecules were found including the disaccharide trehalose, the monosaccharide alcohol derivative mannitol and the fatty acids palmitic, oleic and linoleic acids. Fomitopsis pinicola revealed a very high phenolics concentration (388 mg GAE/g extract) and powerful antioxidant properties, mainly reducing power (EC50 value 60 μg/mL similar to the standard Trolox®). It could find applications in the prevention of free radical-related diseases as a source of bioactive compounds.


Molecules | 2017

Is Gamma Radiation Suitable to Preserve Phenolic Compounds and to Decontaminate Mycotoxins in Aromatic Plants? A Case-Study with Aloysia citrodora Paláu

Eliana Pereira; Lillian Barros; Amilcar L. Antonio; Sandra Cabo Verde; Celestino Santos-Buelga; Isabel C.F.R. Ferreira; Paula Rodrigues

This study aimed to determine the effect of gamma radiation on the preservation of phenolic compounds and on decontamination of dry herbs in terms of ochratoxin A (OTA) and aflatoxin B1 (AFB1), using Aloysia citrodora Paláu as a case study. For this purpose, artificially contaminated dry leaves were submitted to gamma radiation at different doses (1, 5, and 10 kGy; at dose rate of 1.7 kGy/h). Phenolic compounds were analysed by HPLC-DAD-ESI/MS and mycotoxin levels were determined by HPLC-fluorescence. Eleven phenolic compounds were identified in the samples and despite the apparent degradation of some compounds (namely verbasoside), 1 and 10 kGy doses point to a preservation of the majority of the compounds. The mean mycotoxin reduction varied between 5.3% and 9.6% for OTA and from 4.9% to 5.2% for AFB1. It was not observed a significant effect of the irradiation treatments on mycotoxin levels, and a slight degradation of the phenolic compounds in the irradiated samples was observed.


Antioxidants | 2013

Relevance of the Mention of Antioxidant Properties in Yogurt Labels: In Vitro Evaluation and Chromatographic Analysis

Eliana Pereira; Lillian Barros; Isabel C.F.R. Ferreira

The purpose of the inclusion of fruit (natural additives) in yogurt aims to increase its antioxidant activity and functionality. Herein, a comparative study of the antioxidant potential of yogurts with pieces of various fruits was performed, including yogurts with mention of antioxidant properties in the label. Free radicals scavenging activity, reducing power and inhibition of lipid peroxidation were evaluated by in vitro assays, as were the contents in antioxidants such as phenolics, flavonoids, sugars and tocopherols. After analyzing thirteen yogurts containing fruit pieces and a natural one (control), the most interesting were yogurts with pieces of berries (for phenolics, flavonoids and 2,2-dipheny-1-picrylhydrazyl (DPPH) scavenging activity), pineapple (for reducing power), blackberry (for β-carotene bleaching inhibition), blackberry “antioxidant” (for tocopherols) and cherry (for sugars). The mention of “antioxidant” in the label was relevant for tocopherols, sugars, DPPH scavenging activity and reducing power. No synergisms were observed in yogurts prepared with pieces of different fruits. Nevertheless, the addition of fruit pieces to yogurt was favorable for antioxidant content, increasing the protection of the consumer against diseases related to oxidative stress.


Food Research International | 2017

Extensive profiling of three varieties of Opuntia spp. fruit for innovative food ingredients

Bruno Melgar; Eliana Pereira; M. Beatriz P.P. Oliveira; Esperanza M. Garcia-Castello; Antonio D. Rodriguez-Lopez; Marina Soković; Lillian Barros; Isabel C.F.R. Ferreira

Consumer interest in the use of natural ingredients is creating a growing trend in the food industry, leading to research into the development of natural products such as colorants, antimicrobials and antioxidant compounds. This work involves an extensive morphological (using physico-chemical assays), chemical (antioxidant activity assays) and microbiological (Gram-positive and negative strains) characterization of prickly peras (Opuntia ficus-indica (OFI) var. sanguigna, gialla and Opuntia engelmannii) fruits. Through chromatographic assays, these species have shown interesting contents of hydrophilic (sugars, organic acids and betalains) and lipophilic (tocopherols and fatty acids) compounds. While Opuntia engelmannii exhibited higher content of betacyanins and mucilage, OFI varieties sanguigna and gialla displayed greater organic acid content. The sanguigna variety also showed the highest α-tocopherol content. All this compounds could be the responsible of enhancing the bioactivity of this variety, which can be observed in its antimicrobial potential, tested in the studied strains too. Results revealed that Opuntia spp. could be used as a nutraceutical and/or food additive, maintaining and promoting health and life quality.


Food Research International | 2017

Hibiscus sabdariffa L. as a source of nutrients, bioactive compounds and colouring agents

Inès Jabeur; Eliana Pereira; Lillian Barros; Ricardo C. Calhelha; Marina Soković; M. Beatriz P.P. Oliveira; Isabel C.F.R. Ferreira

The nutritional and bioactive composition of plants have aroused much interest not only among scientists, but also in peoples daily lives. Apart from the health benefits, plants are a source of pigments that can be used as natural food colorants. In this work, the nutritional composition of Hibiscus sabdariffa L. was analysed, as well as its bioactive compounds and natural pigments. Glucose (sugar), malic acid (organic acid), α-tocopherol (tocopherol) and linoleic acid (fatty acid) were the major constituents in the corresponding classes. 5-(Hydroxymethyl) furfural was the most abundant non-anthocyanin compound, while delphinidin-3-O-sambubioside was the major anthocyanin both in its hydroethanolic extract and infusion. H. sabdariffa extracts showed antioxidant and antimicrobial activities, highlighting that the hydroethanol extract presents not only lipid peroxidation inhibition capacity, but also bactericidal/fungicidal inhibition ability for all the bacteria and fungi tested. Furthermore, both extracts revealed the absence of toxicity using porcine primary liver cells. The studied plant species was thus not only interesting for nutritional purposes but also for bioactive and colouring applications in food, cosmetic and pharmaceutical industries.


Molecules | 2018

Phenolic Composition and Bioactivity of Lavandula pedunculata (Mill.) Cav. Samples from Different Geographical Origin

Catarina Lopes; Eliana Pereira; Marina Soković; Ana P. Carvalho; Ana Maria Barata; Violeta Lopes; Filomena Rocha; Ricardo C. Calhelha; Lillian Barros; Isabel C.F.R. Ferreira

The aim of this study was to characterize the phenolic composition and evaluate the bioactivity of several samples of Lavandula pedunculata (Mill.) Cav, and to compare aqueous and hydroethanolic extracts. Plant materials were obtained by growing some accessions (seed samples) of various wild populations from different regions of Portugal conserved at the Portuguese Genebank in Braga. Phenolic compounds were analised by HPLC-DAD-ESI/MSn, antioxidant potential through in vitro assays (DPPH radical scavenging activity, reducing power and inhibition of lipid peroxidation), cytotoxicity on tumor cells (MCF-7, NCI-H460, HeLa and HepG2) and non-tumor (PLP2) cells, anti-inflammatory activity in rat RAW 264.7 macrophages, by the ability to inhibit NO production and antimicrobial potential by the microdilution method with INT dye (iodonitrotetrazolium chloride). Thirteen compounds were identified, being salvianolic acid B, rosmarinic acid and luteolin-7-O-glucuronide, the main compounds present, with values ranging between 44.3–582, 50.9–550, and 24.36–101.5 mg/g extract, respectively. L. pedunculata aqueous extract revealed a higher antioxidant potential (EC50 values between 14 to 530 μg/mL), which could be related to its higher concentration in phenolic compounds; however, the hydroethanolic extract showed a higher anti-inflammatory (lower EC50 values than 124 μg/mL) potential and antiproliferative capacity (lower GI50 values than 34 μg/mL). Thus, this study highlights the bioactive effects of this species and opens up possibilities of uses in food and pharmaceutical formulations. However, there are potential differences in such properties according to geographical origin of plant material, as in general, the samples from Alentejo presented higher results in all the bioactivities, compared with Trás-os-Montes samples.


Food Chemistry | 2019

Optimization of heat- and ultrasound-assisted extraction of anthocyanins from Hibiscus sabdariffa calyces for natural food colorants

José Pinela; M.A. Prieto; Eliana Pereira; Inés Jabeur; Maria Filomena Barreiro; Lillian Barros; Isabel C.F.R. Ferreira

Heat- and ultrasound-assisted extraction methods were applied to recover anthocyanins from Hibiscus sabdariffa calyces. The extraction variables, time (t), ethanol proportion (S), and temperature (T) or ultrasonic power (P), were combined in a 5-level experimental design and analysed by response surface methodology for process optimization. The delphinidin-3-O-sambubioside (C1) and cyanidin-3-O-sambubioside (C2) levels were monitored by LC-DAD-ESI/MSn and used as response criteria. The developed models were successfully fitted to the experimental data and used to determine optimal extraction conditions. UAE was the most efficient method yielding 51.76 mg C1 + C2/g R under optimal conditions (t = 26.1 min, P = 296.6 W and S = 39.1% ethanol, v/v). The dose-response effects of the solid/liquid ratio on the extraction rate were also determined. The anthocyanin levels herein reported are higher than those found in the literature, which support the potential use of H. sabdariffa as a sustainable source of natural colorants with application in different industrial sectors.


Food Research International | 2018

Evaluation of gamma-irradiated aromatic herbs: Chemometric study of samples submitted to extended storage periods

Eliana Pereira; Amilcar L. Antonio; João C.M. Barreira; Sandra Cabo Verde; Lillian Barros; M. Beatriz P.P. Oliveira; Isabel C.F.R. Ferreira

The preserving capacity of gamma radiation (10 kGy) on the chemical, nutritional and antioxidant components of Aloysia citrodora Paláu, Melissa officinalis L., Melittis melissophyllum L. and Mentha piperita L., stored for 12 and 18 months, was evaluated. Despite the maintenance of the main characteristics during the first 12 months of storage, the additional 6 months induced several significant changes in individual compounds. In general, the analyzed species reacted dissimilarly throughout time, but it was possible to verify that the fatty acids, tocopherols and antioxidant capacity presented the most significant changes after 18 months of storage, inclusively in samples submitted to gamma radiation. In fact, the applied treatment (10 kGy) did not seem to be effective to prevent the decrease of free sugars, organic acids and tocopherols, especially considering the 18 months period. On the other hand, the evolution in color parameters indicated a greener color (yet slightly more yellow) among irradiated samples. Likewise, gamma radiation had a positive effect on oleic acid, β-carotene bleaching inhibition (in infusions), DPPH scavenging activity and reducing power (in methanolic extracts). Nevertheless, it might be generally concluded that gamma radiation is less suitable than electron-beam to maintain the characteristics of dried herbs during extended storage periods.


Annals of the Rheumatic Diseases | 2016

AB0424 Retrospective Evaluation of Mycophenolate Mofetil Infectious Side Effects on Lupus Nephritis Patients

T. Meirinhos; Eva Mariz; I. Castro Ferreira; Ricardo Neto; Eliana Pereira; L. Costa

Background Systemic lupus erythematosus (SLE) is a multifaceted autoimmune disease driven by auto-reactive immune cells, in particular B cells that target multiple organ systems leading to severe complications. A main complication of SLE is nephritis, formally known as lupus nephritis (LN). MMF is a selective, non-competitive and reversible inhibitor of inosine monophosphate dehydrogenase. MMF provided to be useful in the treatment of patients affected by SLE, especially in those with LN. MMF demonstrated a more favorable safety profile compared with cyclophosphamide, especially in terms of alopecia and infertility rates. Nonetheless, the use of MMF in LN has not been extensively evaluated in terms of safety and infection rates. Objectives To study the prevalence of infections complications in a cohort of adult LN patients under MMF maintenance therapy. Methods Retrospective study, enrolling patients attending a Rheumatology/Nephrology department, diagnosed with SLE (American College of Rheumatology criteria) and LN, under MMF maintenance therapy. Drug variables: dose of MMF, time of exposure. Clinical variables: age, gender, race, disease duration, histological classification (renal biopsy), specific organ involvement, other therapeutics for SLE, serum urea and creatinine, 24h proteinuria, and urinary sediment. Statistical analysis with Microsoft Excel 2010; appropriate statistical tests were used; p value<0.05 with a 95% confidence interval will be assumed. Results 44 SLE patients were enrolled, 37 were female (84.1%); mean age was 38.4±11.9 years and mean disease duration was 122.9±108 months. All the patients were white. 35 patients (80%) had class 4 LN, 5 had class 5 and histological classification was unknown in 4 patients. 34 (77%) patients had extra renal disease, 23 with joint disease and 14 with cutaneous involvement. Mean MMF dose was 1018±876mg. 35 (79%) patients were doing steroid therapy, mean dose 5.58±3.87mg and 39 (88.6%) patients under Hidroxicloroquine therapy. We identify 25 infectious events, 4 (16%) needing hospitalization, none death. Mean time to infection after MMF introduction was 12.16±16.3 months. The most frequent infections include urinary tract infections (UTI) (8 patients), cutaneous Herpes Zoster (4 patients) and respiratory tract infections (4 patients). We found a positive correlation between the occurrence of infection in the first 8 months of therapy and 24h Proteinúria and dsDNA in the beginning of therapy (p=0.04 and p=0.03, respectively). Hidroxicloroquine seem to have a protective effect against infections, but no statistic association was found. We found no association between infections and MMF/steroid dose or renal function. Conclusions We found significant morbidity associated with an increase incidence of infection after introduction of MMF, especially in the first months of therapy and patients with more active disease in the beginning of MMF. No mortality was associated with these infectious complications, and the hospital admission rate was low. References Afzali B, Shah S, Chowdhury P, et al. Low-dose mycophenolate mofetil is an effective and safe treatment to permit phased reduction in calcineurin inhibitors in chronic allograft nephropathy. Transplantation 2005; 79: 304–309. Disclosure of Interest None declared

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Isabel C.F.R. Ferreira

Instituto Politécnico Nacional

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Lillian Barros

Instituto Politécnico Nacional

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Amilcar L. Antonio

Instituto Politécnico Nacional

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João C.M. Barreira

Instituto Politécnico Nacional

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Sandra Cabo Verde

Instituto Superior Técnico

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Ricardo C. Calhelha

Instituto Politécnico Nacional

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Albino Bento

Instituto Politécnico Nacional

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Isabel C.F.R. Ferreira

Instituto Politécnico Nacional

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