Browsing by Author "Ferreira, Isabel M. P. L. V. O."
Now showing 1 - 10 of 15
Results Per Page
Sort Options
- Assessment of paracetamol toxic effects under varying seawater pH conditions on the marine polychaete hediste diversicolor using biochemical endpointsPublication . Daniel, David; Nunes, Bruno; Pinto, Edgar; Ferreira, Isabel M. P. L. V. O.; Correia, Alberto TeodoricoIncreasing atmospheric carbon dioxide (CO2) levels are likely to lower ocean pH values, after its dissolution in seawater. Additionally, pharmaceuticals drugs are environmental stressors due to their intrinsic properties and worldwide occurrence. It is thus of the utmost importance to assess the combined effects of pH decreases and pharmaceutical contamination, considering that their absorption (and effects) are likely to be strongly affected by changes in oceanic pH. To attain this goal, individuals of the marine polychaete Hediste diversicolor were exposed to distinct pH levels (8.2, 7.9, and 7.6) and environmentally relevant concentrations of the acidic drug paracetamol (PAR: 0, 30, 60, and 120 µg/L). Biomarkers such as catalase (CAT), glutathione S-transferases (GSTs), acetylcholinesterase (AChE), and cyclooxygenase (COX) activities, as well as peroxidative damage (through thiobarbituric acid reactive substance (TBARS) quantification), were quantified to serve as ecotoxicological endpoints. Data showed a general increase in CAT and a decrease in GST activities (with significant fluctuations according to the tested conditions of PAR and pH). These changes are likely to be associated with alterations of the redox cycle driven by PAR exposure. In addition, pH levels seemed to condition the toxicity caused by PAR, suggesting that the toxic effects of this drug were in some cases enhanced by more acidic conditions. An inhibition of AChE was observed in animals exposed to the highest concentration of PAR, regardless of the pH value. Moreover, no lipid peroxidation was observed in most individuals, although a significant increase in TBARS levels was observed for polychaetes exposed to the lowest pH. Finally, no alterations of COX activities were recorded on polychaetes exposed to PAR, regardless of the pH level. The obtained results suggest that seawater acidification is detrimental to marine wildlife, since it may enhance toxic effects caused by environmental realistic concentrations of acidic drugs, such as PAR. This work was crucial to evidence that ocean acidification, in the context of a global change scenario of increased levels of both atmospheric and oceanic CO2, is a key factor in understanding the putative enhanced toxicity of most pharmaceutical drugs that are of an acidic nature.
- Bisphenol A migration from plastic materials: direct insight of ecotoxicity in Daphnia magnaPublication . Mansilha, Catarina; Silva, Poliana; Rocha, Sónia; Gameiro, P.; Domingues, Valentina F.; Pinho, Carina; Ferreira, Isabel M. P. L. V. O.Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) whose migration from food packaging is recognized worldwide. However, the real overall food contamination and related consequences are yet largely unknown. Among humans, children’s exposure to BPA has been emphasized because of the immaturity of their biological systems. The main aim of this study was to assess the reproductive impact of BPA leached from commercially available plastic containers used or related to child nutrition, performing ecotoxicological tests using the biomonitoring species Daphnia magna. Acute and chronic tests, as well as single and multigenerational tests were done. Migration of BPA from several baby bottles and other plastic containers evaluated by GC-MS indicated that a broader range of foodstuff may be contaminated when packed in plastics. Ecotoxicological test results performed using defined concentrations of BPA were in agreement with literature, although a precocious maturity of daphnids was detected at 3.0 mg/L. Curiously, an increased reproductive output (neonates per female) was observed when daphnids were bred in the polycarbonate (PC) containers (145.1±4.3 % to 264.7±3.8 %), both in single as in multigenerational tests, in comparison with the negative control group (100.3±1.6 %). A strong correlated dose-dependent ecotoxicological effect was observed, providing evidence that BPA leached from plastic food packaging materials act as functional estrogen in vivo at very low concentrations. In contrast, neonate production by daphnids cultured in polypropylene and non-PC bottles was slightly but not significantly enhanced (92.5±2.0 % to 118.8±1.8 %). Multigenerational tests also revealed magnification of the adverse effects, not only on fecundity but also on mortality, which represents a worrying trend for organisms that are chronically exposed to xenoestrogens for many generations. Two plausible explanations for the observed results could be given: a non-monotonic dose–response relationship or a mixture toxicity effect.
- Essential and non-essential/toxic trace elements in whey protein supplementsPublication . Pinto, Edgar; Ferreira, Isabel M. P. L. V. O.; Almeida, AgostinhoTwenty-six (26) trace elements (essential and non-essential/toxic) were determined in 49 whey protein (WP) supplements available for sale in the Portuguese market by inductively coupled plasma – mass spectrometry. The most abundant essential trace element was Fe (13.7 ± 16.7 μg/g) and the least abundant was Co (0.040 ± 0.028 μg/g).
- Fast and reliable ICP-MS quantification of palladium and platinum-based drugs in animal pharmacokinetic and biodistribution studiesPublication . Vojtek, Martin; Pinto, Edgar; Gonçalves-Monteiro, Salomé; Almeida, Agostinho; Marques, M. P. M.; Mota-File, Hélder; Ferreira, Isabel M. P. L. V. O.; Diniz, CarmenPalladium-(Pd)-based drugs are emerging as alternatives to platinum (Pt) anticancer chemotherapeutics, which increases the need for efficient and suitable procedures of Pd analysis in reduced amounts of pre-clinical animal samples. Herein, an ICP-MS (inductively coupled plasma-mass spectrometry) method was developed and validated for simple and fast analysis of Pd/Pt-based drugs in 11 distinct biological matrices (adipose tissue, muscle, liver, kidney, spleen, testis, heart, lungs, brain, blood and serum).
- Fish Oil Enzymatic Esterification for Acidity ReductionPublication . Mata, Teresa M.; Correia, Daniela; Andrade, Soraia; Casal, Susana; Ferreira, Isabel M. P. L. V. O.; Matos, Elisabete; Martins, António A.; Caetano, NídiaThe reduction of the fish oil acidity is a significant problem in the rendering industry, as the oil’s range of applications and market value strongly depend on this parameter. In particular, the lower the acidity, the larger the oil’s market value. This work aims to study the potential of enzymatic esterification for reducing the fish oil acidity, by converting the free fatty acids into esters. Thus, four commercial lipases were used and a parametric study was performed to identify the best operating conditions, varying the reaction temperature, enzyme/oil mass ratio and alcohol/FFA mass ratio. All experiments were performed in duplicate with a very good reproducibility of results. Results showed that Lipozyme TL 100L contributed to greater acidity reduction (75% from an initial acid value of 10–14 mg KOH/g oil) for esterification at 40 °C, using ethanol 96% v/v, enzyme/oil and alcohol/FFA mass ratios of 0.01 and 3.24 w/w, respectively, reaching 3.13 mg KOH/g oil of final acid value or 1.57% FFA content. The reaction kinetics were also studied and it was found that a second order rate law as a function of the alcohol and oil concentrations is more adequate, with 35.44 kJ/mol of activation energy and 1.94 × 103 L mol− 1 min− 1 of pre-exponential factor. In conclusion, this work shows that the enzymatic esterification to reduce the fish oil acidity is technically feasible, increasing its market value.
- Groundwater from infiltration galleries used for small public water supply systems: contamination with pesticides and endocrine disruptorsPublication . Mansilha, Catarina; Melo, A.; Ferreira, Isabel M. P. L. V. O.; Pinho, O.; Domingues, Valentina F.; Pinho, C.; Gameiro, P.Infiltration galleries are among the oldest known means used for small public water fountains. Owing to its ancestral origin they are usually associated with high quality water. Thirty-one compounds, including pesticides and estrogens from different chemical families, were analysed in waters from infiltration galleries collected in Alto Douro Demarcated Wine region (North of Portugal). A total of twelve compounds were detected in the water samples. Nine of these compounds are described as presenting evidence or potential evidence of interfering with the hormone system of humans and wildlife. Although concentrations of the target analytes were relatively low, many of them below their limit of quantification, four compounds were above quantification limit and two of them even above the legal limit of 0.1 lg/L: dimethoate (30.38 ng/L), folpet (64.35 ng/L), terbuthylazine-desethyl (22.28 to 292.36 ng/L) and terbuthylazine (22.49 to 369.33 ng/L).
- Influence of mixtures of acenaphthylene and benzo[a] anthracene on their degradation by Pleurotus ostreatus in sandy soilPublication . Rocha, Inês; Pinto, Edgar; Ferreira, Isabel M. P. L. V. O.; Vieira Da Silva, Manuela; Oliveira, Rui S.Purpose Polycyclic aromatic hydrocarbons (PAHs) are a class of organic compounds commonly found as soil contaminants. Fungal degradation is considered as an environmentally friendly and cost-effective approach to remove PAHs from soil. Acenaphthylene (Ace) and Benzo[a]anthracene (BaA) are two PAHs that can coexist in soils; however, the influence of the presence of each other on their biodegradation has not been studied. The biodegradation of Ace and BaA, alone and in mixtures, by the white rot fungus Pleurotus ostreatus was studied in a sandy soil. Materials and methods Experimental microcosms containing soil spiked with different concentrations of Ace and BaAwere inoculated with P. ostreatus. Initial (t 0) and final (after 15 days of incubation) soil concentrations of Ace and BaA were determined after extraction of the PAHs. Results and discussion P. ostreatus was able to degrade 57.7% of the Ace in soil spiked at 30 mg kg−1 dry soil and 65.8% of Ace in soil spiked at 60 mg kg−1 dry soil. The degradation efficiency of BaA by P. ostreatus was 86.7 and 77.4% in soil spiked with Ace at 30 and 60 mg kg−1 dry soil, respectively. After 15 days of incubation, there were no significant differences in Ace concentration between soil spiked with Ace and soil spiked with Ace + BaA, irrespective of the initial soil concentration of both PAHs. There were also no differences in BaA concentration between soil spiked with BaA and soil spiked with BaA + Ace. Conclusions The results indicate that the fungal degradation of Ace and BaA was not influenced by the presence of each other’s PAH in sandy soil. Bioremediation of soils contaminated with Ace and BaA using P. ostreatus is a promising approach to eliminate these PAHs from the environment.
- Influence of mixtures of acenaphthylene and benzo[a]anthracene on their degradation by Pleurotus ostreatus in sandy soilPublication . Rocha, Inês; Pinto, Edgar; Ferreira, Isabel M. P. L. V. O.; Vieira Da Silva, Manuela; Oliveira, Rui S.Polycyclic aromatic hydrocarbons (PAHs) are a class of organic compounds commonly found as soil contaminants. Fungal degradation is considered as an environmentally friendly and cost-effective approach to remove PAHs from soil. Acenaphthylene (Ace) and Benzo[a]anthracene (BaA) are two PAHs that can coexist in soils; however, the influence of the presence of each other on their biodegradation has not been studied. The biodegradation of Ace and BaA, alone and in mixtures, by the white rot fungus Pleurotus ostreatus was studied in a sandy soil.
- Interlaboratory validation of an environmental monitoring method for trace analysis of endocrine disrupting compoundsPublication . Mansilha, Catarina; Rocha, Sónia; Gameiro, P.; Pinho, Carina; Ferreira, Isabel M. P. L. V. O.; Silva, Poliana; Domingues, Valentina F.Environmental pollution continues to be an emerging study field, as there are thousands of anthropogenic compounds mixed in the environment whose possible mechanisms of toxicity and physiological outcomes are of great concern. Developing methods to access and prioritize the screening of these compounds at trace levels in order to support regulatory efforts is, therefore, very important. A methodology based on solid phase extraction followed by derivatization and gas chromatography-mass spectrometry analysis was developed for the assessment of four endocrine disrupting compounds (EDCs) in water matrices: bisphenol A, estrone, 17b-estradiol and 17a-ethinylestradiol. The study was performed, simultaneously, by two different laboratories in order to evaluate the robustness of the method and to increase the quality control over its application in routine analysis. Validation was done according to the International Conference on Harmonisation recommendations and other international guidelines with specifications for the GC-MS methodology. Matrix-induced chromatographic response enhancement was avoided by using matrix-standard calibration solutions and heteroscedasticity has been overtaken by a weighted least squares linear regression model application. Consistent evaluation of key analytical parameters such as extraction efficiency, sensitivity, specificity, linearity, limits of detection and quantification, precision, accuracy and robustness was done in accordance with standards established for acceptance. Finally, the application of the optimized method in the assessment of the selected analytes in environmental samples suggested that it is an expedite methodology for routine analysis of EDC residues in water matrices.
- Nutritional characterization of Strychnos madagascariensis fruit flour produced by Mozambican communities and evaluation of Its contribution to nutrient adequacyPublication . Chemane, Sandra S. I.; Ribeiro, Mafalda; Pinto, Edgar; Pinho, Susana C. M.; Martins, Zita Sá; Almeida, Agostinho; Ferreira, Isabel M. P. L. V. O.; Khan, Maida; Pinho, Olívia; Casal, Susana; Viegas, OlgaThe indigenous fruit Strychnos madagascariensis is usually processed to flour, called nfuma, being highly consumed during staple food shortage. This study aimed to evaluate the nutritional composition of nfuma and its nutrient adequacy. Flours from four districts of Mozambique were analyzed using AOAC methods for proximate composition, HPLC for sugar, amino acids (AA), vitamin E and carotenoids and ICP-MS and FAAS for minerals. The results showed that nfuma stands out for its high content of fat (26.3–27.8%), mainly oleic acid, fiber (>6%), vitamin E (6.7 to 8.0 mg/100 g) and carotenes (2.2 to 2.6 mg/100 g). The main amino acids of nfuma protein were Arg, Asp and Glu, and Lys was the limiting one. The mineral composition reveals K (~1200 to 1700 mg/100 g) as the main macromineral followed by Mg > Ca > Na. The main trace element was Mn (~4 mg/100 g) followed by Fe > Zn > Cu > Cr > Co. Aluminum (~3 mg/100 g) was the main non-essential element and Rb, Ni, Sr, Ba, V, Cd were also quantified. Assuming the daily consumption of 50 g, nfuma provides 82% of Vitamin A dietary reference value for toddlers, while the consumption of 100 g contributes to 132% and 60% of Mn and vitamin A DRV for adults, respectively. Despite the nutritional advantages of nfuma, this flour can be a source of Ni, highlighting the importance of the study of good practices in its preparation to decrease the exposure to non-essential elements.