Piedade Barros

Prof. Dr. Piedade Barros

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Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 1998 in Biomarkers
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Journal Article
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Lucia GuilherminoLucia Guilhermino
Lucia Guilhermino
PBPiedade Barros
Piedade Barros
MSM. C. Silva
M. C. Silva
ASAmadeu Soares
Amadeu Soares
Recently there has been evidence that contaminants other than organophosphate and carbamate pesticides may inhibit the activity of the enzyme acetylcholinesterase (AChE) both under in vitro and in vivo conditions. In this study we investigated the in vitro effect of three detergents \[dodecyl benzyl sulphonate (DBS), sodium dodecyl sulphate (SDS) and a mixture commonly used as domestic detergent (X)] and three metals \[molybdenum, barium and chromium (VI)] on AChE activity of Mytilus galloprovincialis haemolymph. All the detergents tested significantly inhibited the activity of the enzyme. The lowest observed effect concentrations were equal to 12 5 for DBS and 50 mg l-1 for SDS and X. Among the metals, molybdenum and barium had no effect on AChE activity, whereas chromium (VI) significantly depressed the activity of the enzyme at concentrations equal to or higher than 25 mg l-1. These results suggest that the use of AChE as a specific biomarker for organophosphate and carbamate pesticides should be questioned and that the use of this enzyme as a biomarker could be extended.

28 September 2012 in Marine Drugs
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Journal Article
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Margarida CostaMargarida Costa
Margarida Costa
JCJoão Costa-Rodrigues
João Costa-Rodrigues
MFMaria Helena V Fernandes
Maria Helena V Fernandes
PBPiedade Barros
Piedade Barros
Vitor VasconcelosVitor Vasconcelos
Vitor Vasconcelos
Rosário MartinsRosário Martins
Rosário Martins
Marine cyanobacteria have been considered a rich source of secondary metabolites with potential biotechnological applications, namely in the pharmacological field. Chemically diverse compounds were found to induce cytoxicity, anti-inflammatory and antibacterial activities. The potential of marine cyanobacteria as anticancer agents has however been the most explored and, besides cytotoxicity in tumor cell lines, several compounds have emerged as templates for the development of new anticancer drugs. The mechanisms implicated in the cytotoxicity of marine cyanobacteria compounds in tumor cell lines are still largely overlooked but several studies point to an implication in apoptosis. This association has been related to several apoptotic indicators such as cell cycle arrest, mitochondrial dysfunctions and oxidative damage, alterations in caspase cascade, alterations in specific proteins levels and alterations in the membrane sodium dynamics. In the present paper a compilation of the described marine cyanobacterial compounds with potential anticancer properties is presented and a review on the implication of apoptosis as the mechanism of cell death is discussed.

31 December 2013 in Marine Drugs
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Journal Article
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Margarida CostaMargarida Costa
Margarida Costa
MGMónica Pereira Garcia
Mónica Pereira Garcia
JCJoão Costa-Rodrigues
João Costa-Rodrigues
MCMaria Sofia Costa
Maria Sofia Costa
MRMaria João Ribeiro
Maria João Ribeiro
Rosário MartinsRosário Martins
Rosário Martins
The oceans remain a major source of natural compounds with potential in pharmacology. In particular, during the last few decades, marine cyanobacteria have been in focus as producers of interesting bioactive compounds, especially for the treatment of cancer. In this study, the anticancer potential of extracts from twenty eight marine cyanobacteria strains, belonging to the underexplored picoplanktonic genera, Cyanobium, Synechocystis and Synechococcus, and the filamentous genera, Nodosilinea, Leptolyngbya, Pseudanabaena and Romeria, were assessed in eight human tumor cell lines. First, a crude extract was obtained by dichloromethane:methanol extraction, and from it, three fractions were separated in a Si column chromatography. The crude extract and fractions were tested in eight human cancer cell lines for cell viability/toxicity, accessed with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and lactic dehydrogenase release (LDH) assays. Eight point nine percent of the strains revealed strong cytotoxicity; 17.8% showed moderate cytotoxicity, and 14.3% assays showed low toxicity. The results obtained revealed that the studied genera of marine cyanobacteria are a promising source of novel compounds with potential anticancer activity and highlight the interest in also exploring the smaller filamentous and picoplanktonic genera of cyanobacteria.

1 April 2018 in Science of The Total Environment
Verified
Journal Article
Open access
IBI. Bragança
I. Bragança
PLPaulo Costa Lemos
Paulo Costa Lemos
PBPiedade Barros
Piedade Barros
Cristina Delerue-MatosCristina Delerue-Matos
Cristina Delerue-Matos
VDValentina Fernandes Domingues
Valentina Fernandes Domingues
Pyrethroid pesticides residues have been frequently detected in soils and have been recognized to contribute to soil toxicity. The phytotoxic impact of pesticides was evaluated in Cucumis sativus (C. sativus) seeds. Percentage of seed germination, root elongation, shoot length and leaf length were considered as endpoints to assess the possible acute phytotoxicity of soil by the exposure to pyrethroid pesticides (cypermethrin, deltamethrin and cyhalothrin) and its metabolite phenoxybenzoic acid (3-PBA), in a concentration range between 50 and 500μgkg-1. For germination percentage, it was only observed a negative impact when seeds were exposed to the metabolite. Cypermethrin showed impact in the three studied endpoints of seed development, while deltamethrin merely affected the root length. Concerning pigments content, it can be said that chlorophylls and total carotenoids median values increased for cypermethrin and deltamethrin. This increase was more pronounced to deltamethrin in joint effect with the organic solvent dimethyl sulphoxide (DMSO). When exposed to cyhalothrin and 3-PBA, no statistically significant differences were observed for C. sativus seeds to all the assessed endpoints of seed development and the investigated pigments content. This research brings new data concerning the relative sensitivity of C. sativus seeds to pyrethroids pesticides commonly found in agricultural facilities, as well as critical understanding and development of using C. sativus for phytotoxicity assessments efforts for pesticide exposures.


18 December 2025 in Microorganisms
Verified
Journal Article
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RAReihaneh Ashouritoustani
Reihaneh Ashouritoustani
CPCláudia Pinho
Cláudia Pinho
AOAna Isabel Oliveira
Ana Isabel Oliveira
PBPiedade Barros
Piedade Barros
ACAgostinho Cruz
Agostinho Cruz
Oral candidiasis, mainly from Candida albicans, affects immunocompromised individuals, the elderly, and denture wearers. Probiotics offer immunomodulatory and microbiota-balancing benefits as potential antifungal alternatives. However, the comparative impact of different probiotic delivery methods remains inadequately explored. This systematic review evaluated the effectiveness of various probiotic delivery methods in reducing Candida colonization and clinical symptoms in oral candidiasis. Following PRISMA 2020 guidelines, a systematic review search across multiple databases included human clinical studies based (Medline, Web of Science, ScienceDirect, and ProQuest) on PICO criteria across all age groups. Outcomes assessed included Candida load, oral microbiota changes, symptom improvement, and disease recurrence. Of 297 articles screened, 10 met inclusion criteria. Delivery methods investigated included lozenges, capsules, yogurt, and cheese. Most studies reported reductions in Candida colony-forming units (CFUs) or prevalence, mainly for C. albicans and for non-albicans species, with probiotics such as Lactobacillus reuteri, L. rhamnosus, L. acidophilus, and Bifidobacterium strains. Some studies reported improved immunological markers, while symptom relief, especially when probiotics were combined with antifungals. Probiotics reduce Candida colonization and symptoms, with potential prolonged effects. They show promise as adjunctive therapies, but standardized, large-scale trials are needed for optimization.