Percorrer por autor "Matos, Beatriz"
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- Bioaccessibility and cytotoxicity of arsenic and mercury in cooked seafood : implications for food safety and human health riskPublication . Ventura, Marta; Assunção, Ricardo; Matos, Beatriz; Coelho, Inês; Delgado, Inês; Gueifão, Sandra; Santiago, Susana; Castanheira, Isabel; Martins, MartaSeafood is an important component of healthy dietary patterns. However, it can also serve as a dietary source of toxic elements that bioaccumulate in aquatic environments and biomagnify through the food web. This study quantified arsenic (As) and mercury (Hg) in cooked seafood, assessed their bioaccessibility, and evaluated the cytotoxic potential of the bioaccessible fractions using the human intestinal HT-29 cell line. The highest As concentrations were found in bivalves (3.7 ± 0.2 mg kg−1), and the highest Hg concentrations in scabbardfish (0.57 ± 0.01 mg kg−1). The bioaccessibility of As was substantially higher (ranging from 91 ± 2% to 127 ± 6%) than that of Hg (ranging from 4.8 ± 0.3% to 24 ± 8%). The highest bioaccessibility was observed in fresh tuna, 127 ± 6% and 24 ± 8% for As and Hg, respectively. Cytotoxicity assays at 24 h, 48 h, and 72 h indicated that bioaccessible Hg concentrations remained below cytotoxic thresholds. These results highlight the importance of integrating bioaccessibility and toxicological indicators into the evaluation of seafood safety.
- Consulta de saúde infantil: 2 mesesPublication . Matos, Beatriz; Resina, Matilde; Matias, Mariana; Lopes, Marta; Loureiro, Fernanda
- Interaction of polycyclic aromatic hydrocarbon compounds in fish primary hepatocytes : from molecular mechanisms to genotoxic effectsPublication . Bramatti, Isabella; Matos, Beatriz; Figueiredo, Neusa; Pousão-Ferreira, Pedro; Branco, Vasco; Martins, MartaPolycyclic Aromatic Hydrocarbons (PAHs) are persistent pollutants normally found in the environment as complex mixtures. Although several individual PAHs are classified as mutagenic and carcinogenic pollutants, the interaction effects between compounds in a mixture may trigger different toxicological mechanisms and, consequently, yield different effects to organisms which are not accounted for in risk assessment guidelines. Given the ubiquity of PAHs, understanding the mechanistic features of their mixtures is a pressing research need. Therefore, the present work aimed to disclose the interaction effects of three PAHs with different carcinogenic potential and chemical structure, in primary hepatocyte cells of gilt-headed seabreams (Sparus aurata). Hepatocytes were exposed to Phenanthrene (Phe), Benzo[a]pyrene (B[a]P) and Benzo[b]fluoranthene (B[b]F) and their mixtures at different proportions and several cellular responses were analyzed: cellular viability, CYP1A1 activity (EROD assay) and protein expression level (Western blot); transcript (mRNA) levels of CYP1A1, EPXH1 and GST-3 (qRT-PCR); genotoxic effects (DNA strand breakage) by the Comet assay. Results show that B[a]P induced CYP1A1 gene and protein expression increasing its activity and, therefore, increasing the production of metabolites that trigger genotoxic DNA damage (%). Most importantly, mixtures containing Phe and B[a]P increased even further CYP1A1 mRNA levels and DNA damage (up to 70 %) which suggests that, although Phe is considered a non-carcinogenic PAH, it potentiates CYP1A1 synthesis induced by B[a]P, increasing its genotoxicity. These findings indicate that the upregulation of CYP1A1 by carcinogenic PAHs will not weaken even when in mixtures with non-carcinogenic PAHs. On contrary, non-carcinogenic PAHs may potentiate the genotoxic effect of carcinogenic PAH and therefore mixture composition should be taken in account when assessing PAH toxicity. In fact, our results point to the need of redefining Environmental Risk Assessment protocols for mixtures of carcinogenic pollutants.
- Study of quantum dots (CdS, ZnS) toxicity in Danio rerio : preliminary resultsPublication . Matos, Beatriz; Martins, Marta; Diniz, Mário S.