Marine and Environmental Sciences Centre

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Publications

Fatty acids composition in yellow-legged (Larus michahellis) and lesser black-backed (Larus fuscus) gulls from natural and urban habitats in relation to the ingestion of anthropogenic materials

Publication . Lopes, Catarina S.; Antunes, Raquel C. C.; Paiva, Vitor H.; Goncalves, Ana M. M.; Correia, Jorge Manuel de Jesus; Ramos, Jaime A.

Urban habitats offer spatially and temporally predictable anthropogenic food sources for opportunistic species, such as several species of gulls that are known to exploit urban areas and take advantage of accessible and diverse food sources, reducing foraging time and energy expenditure. However, human-derived food may have a poorer nutritional quality than the typical natural food resources and foraging in urban habitats may increase birds' susceptibility of ingesting anthropogenic debris materials, with unknown physiological consequences for urban dwellers. Here we compare the fatty acids (FA) composition of two opportunistic gull species (the yellow-legged gull, Larus michahellis, and the lesser black-backed gull, Larus fuscus) from areas with different levels of urbanization, to assess differences in birds' diet quality among foraging habitats, and we investigate the effects of ingesting anthropogenic materials, a toxicological stressor, on gulls' FA composition. Using GC–MS, 23 FAs were identified in the adipose tissue of both gull species. Significant differences in gulls' FA composition were detected among the three urbanization levels, mainly due to physiologically important highly unsaturated FAs that had lower percentages in gulls from the most urbanized habitats, consistent with a diet based on anthropogenic food resources. The deficiency in omega (ω)-3 FAs and the higher ω-6:ω-3 FAs ratio in gulls from the most urbanized location may indicate a dietinduced susceptibility to inflammation. No significant differences in overall FA composition were detected between gull species.While we were unable to detect any effect of ingested anthropogenic materials on gulls' FA composition, these data constitute a valuable contribution to the limited FA literature in gulls.We encourage studies to explore the long-term physiological effects of the lower nutritional quality diet for urban dwellers, and to detect the sub-lethal impacts of the ingestion of anthropogenic materials

2022-02-25Journal article

Open access

Nanoplastics activate a TLR4/p38-mediated pro-inflammatory response in human intestinal and mouse microglia cells

Publication . Antunes, Joana; Sobral, Paula; Martins, Marta; Branco, Vasco

The crescent presence of nanoplastics in the environment raises concerns regarding their potential impact on health. This study exposed human colon adenocarcinoma cells (HT29) and microglia cells (N9) to nanoplastics (25 nm, 50 nm, and 100 nm Polystyrene) to investigate their inflammatory responses, which are vital for body's defence. Although cytotoxicity remained generally low, HT29 cells exhibited a notable upregulation of p50 and p38 expression, concomitant with elevated TLR4 expression, in contrast with N9 cells that showed a less pronounced upregulation of these proteins. Additionally, nanoplastic exposure increased IL-1ß levels, partially attenuated by pre-exposure to TLR4 or p38 inhibitors. Intriguingly, N9 cells exposed to nanoplastics exhibited substantial increases in iNOS mRNA. This effect was entirely prevented by pre-exposure to TLR4 or p38 inhibitors, while TNF-α mRNA levels remained relatively stable. These findings underscore the potential of nanoplastics to activate inflammatory pathways, with response kinetics varying depending on the cell type.

2023-10Journal article

Open access

A multivariate approach to chlorophyll a fluorescence data for trace element ecotoxicological trials using a model marine diatom

Publication . Duarte, Bernardo; Gameiro, Carla; Utkin, Andrei Borissovitch; Matos, Ana Rita; Caçador, Isabel; Fonseca, Vanessa; Cabrita, Maria Teresa

The increasing uncontrolled development of human activities and consequent increase in the production and release into the marine realm of potentially harmful substances highlights the need to develop efficient and high-throughput screening (HTS) tools. Bio-optical tools, such as laser-induced fluorescence (LIF) and pulse amplitude modulated (PAM) fluorometry, emerge as efficient non-invasive techniques for toxicophenomic evaluation in ecotoxicological trials. Both techniques generate large datasets that can be applied in multivariate analysis to evaluate canonical classification efficiency of the exposure types and levels to which photosynthetic organisms, such as diatoms, are subjected to. In the present work, marine diatom cultures were exposed to two trace elements known to have physiological roles and different toxicity ranges (Zn and Cu), and to two other trace elements without known metabolic functions and very different toxicological profiles (Cr and Hg). All the tested approaches were able to disentangle the control groups from the test groups. Moreover, the application of LIF raw-data showed that this technique had the higher classification efficiency, providing very good separation of the different doses applied of each trace element tested. Additionally, PAM chlorophyll fast induction kinetics raw data also produced good classification efficiencies and provided data that can be useful for interpreting the physiological shifts induced by trace element exposure. In sum, LIF and PAM techniques appear as completely non-invasive HTS techniques that, when applied together, produce a correct toxicophenomic classification and disentangle the physiological effects behind the observed phenomic changes. Therefore, they are worth to be included in future ecotoxicological assessment test protocols.

2021Journal article

Restricted access

Investigations of Olive Oil Industry By-Products Extracts with Potential Skin Benefits in Topical Formulations

Publication . Nunes, Andreia; Gonçalves, Lídia; Marto, Joana; Martins, Ana; Silva, Alexandra N.; Pinto, Pedro; Martins, Marta; Fraga, Carmo; Ribeiro, Helena

The by-products of olive oil industry are a major ecological issue due to their phenolic content, highly toxic organic load, and low pH. However, they can be recovered and reused, since their components have antioxidant, anti-inflammatory, and photoprotector properties. In this work, oil-in-water creams containing three different olive oil industry by-products extracts were produced without the use of organic solvents. First, the extracts were thoroughly characterized in vitro for cytotoxicity, inhibition of skin enzymes, and antioxidant and photoprotection capacities. Safety studies were then performed, including ocular and skin irritation tests, ecotoxicity evaluation, and in vivo Human Repeat Insult Patch Test. The results obtained in this initial characterization supported the incorporation of the extracts in the cream formulations. After preparation, the creams were characterized for their organoleptic, physicochemical, droplet size and rheological properties, and microbial contamination. The results showed that all formulations were semi-solid creams, with stable pH, compatible with the skin, without microbial contamination, and with the expected droplet size range. The rheological analysis showed shear-thinning behavior with yield stress, with the viscosity decreasing with increasing shear rate. The oscillatory results suggest that the creams have a strong network structure, being easily rubbed into the skin. Finally, compatibility, acceptability and antioxidant efficacy were evaluated in vivo, in human volunteers. No adverse reactions were observed after application of the formulations on skin and the cream with the highest concentrations of phenolic compounds showed the highest antioxidant efficiency. In conclusion, the results suggest that olive oil industry by-products extracts have valuable properties that favor their re-use in the cosmetic industry. The example presented here showed their successful incorporation into creams and their impact in these formulations’ appearance, pH, and rheological performance, as well as their in vivo compatibility with skin and antioxidant efficiency.

2021-03Journal article

Open access

Untargeted metabolomics reveals antidepressant effects in a marine photosynthetic organism: the diatom Phaeodactylum tricornutum as a case study

Publication . Duarte, Bernardo; Feijão, Eduardo; Cruz de Carvalho, Ricardo; Duarte, Irina A.; Marques, Ana Patrícia; Maia, Marisa; Hertzog, Jasmine; Matos, Ana Rita; Cabrita, Maria Teresa; Caçador, Isabel; Figueiredo, Andreia; Silva, Marta Sousa; Cordeiro, Carlos; Fonseca, Vanessa F.

The increased use of antidepressants, along with their increased occurrence in aquatic environments, is of concern for marine organisms. Although these pharmaceutical compounds have been shown to negatively affect marine diatoms, their mode of action in these non-target, single-cell phototrophic organisms is yet unknown. Using a Fourier-transform ion cyclotron-resonance mass spectrometer (FT-ICR-MS) we evaluated the effects of fluoxetine in the metabolomics of the model diatom Phaeodactylum tricornutum, as well as the potential use of the identified metabolites as exposure biomarkers. Diatom growth was severely impaired after fluoxetine exposure, particularly in the highest dose tested, along with a down-regulation of photosynthetic and carbohydrate metabolisms. Notably, several mechanisms that are normally down-regulated by fluoxetine in mammal organisms were also down-regulated in diatoms (e.g., glycerolipid metabolism, phosphatidylinositol signalling pathway, vitamin metabolism, terpenoid backbone biosynthesis and serotonin remobilization metabolism). Additionally, the present work also identified a set of potential biomarkers of fluoxetine exposure that were up-regulated with increasing fluoxetine exposure concentration and are of high metabolic significance following the disclosed mode of action, reinforcing the use of metabolomics approaches in ecotoxicology.

2022Journal article

Open access