Veterinary and Animal Science Research Centre

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Publications

Exploring the Variability in Phenolic Compounds and Antioxidant Capacity in Olive Oil By-Products: A Path to Sustainable Valorization

Publication . Paié-Ribeiro, Jessica; Baptista, Filipa; Gomes, Maria José Marques; Teixeira, Alfredo; Pinheiro, Victor; Outor-Monteiro, Divanildo; Barros, Ana Novo

The olive oil industry generates large volumes of by-products, creating notable environmental and economic concerns. Among these, olive cake (OC)—a primary by-product of olive oil extraction—stands out due to its high content of bioactive compounds and potential for value-added recycling. This study focused on characterizing six OC samples from the Trás-os-Montes and Alto Douro regions, collected at different processing times and mills. The samples included two derived from pressing (COC), two from two-phase centrifugation (TPOC; one partially pitted and one dehydrated), and two exhausted OC (EOC) samples. Fundamental analyses assessed total phenols, ortho-diphenols, flavonoids, antioxidant capacity, and tannin content. Results revealed significant variation (p < 0.05) in phenolic composition, namely ortho-diphenols and flavonoid levels among the samples. EOC 2 exhibited the highest concentrations (19.61, 21.82, and 20.12 mg CAT/g, respectively), while COC 2 had the lowest (5.08, 5.08, and 2.76 mg GA/g, respectively). This correlated with elevated antioxidant activity in EOC 2, as measured by FRAP, DPPH, and ABTS assays (129.98, 78.00, and 56.65 μmol Trolox/g). In contrast, COC 1 and COC 2 displayed the lowest antioxidant activities (32.61 μmol Trolox/g in FRAP and 17.24 and 18.98 μmol Trolox/g in DPPH). Tannin analysis showed the highest total tannin content in the dehydrated and pitted OC samples (250.31 and 240.89 mg CAT/100 g), with COC 2 showing the lowest (88.17 mg CAT/100 g). Condensed tannin content varied significantly, with EOC 2 presenting the highest level (328.17 mg CAT/100 g) and COC 2 the lowest one (20.56 mg CAT/100 g). Through HPLC-PDA-MS, 22 compounds were identified, with luteolin and verbascoside being particularly prevalent. This in-depth characterization supports the potential valorization of olive by-products, advancing sustainability and promoting a circular economy in the olive oil sector.

2024Journal article

Open access

Antigenotoxic and cosmetic potential of elderberry (Sambucus nigra) extract: protection against oxidative DNA damage

Publication . Gonçalves, Sara; Peixoto, Francisco P.; Silveira, Tayse Ferreira; Barros, Lillian; Gaivão, Isabel

The integrity of the genome is under constant threat from both endogenous and exogenous factors that induce oxidative stress and accelerate ageing. The demand for natural and organic cosmetics is rising due to the harmful effects of synthetic genotoxic agents on human health and the environment. Elderberry (Sambucus nigra L.), a fruit rich in bioactive compounds such as polyphenols, has demonstrated significant antioxidant properties. This study aimed to evaluate elderberry extract’s chemical characterization and biological activities in peripheral blood mononuclear cells exposed to streptonigrin and H2O2, both known for causing DNA damage. The antigenotoxic evaluation and antioxidant assays (ABTS and DPPH) were conducted to assess its biological properties. Using the Comet assay enhanced with formamidopyrimidine- DNA glycosylase (Fpg) to detect oxidized purines, we found that elderberry extract significantly reduced DNA damage. These findings suggest that elderberry has potential as a natural alternative to synthetic ingredients in cosmetics, offering protective benefits against DNA damage and contributing to antiageing and skin health.

2024Journal article

Restricted access

Understanding the uptake of diagnostics for sustainable gastrointestinal nematode control by European dairy cattle farmers: a multi-country cross-sectional study

Publication . Vande Velde, Fiona; Hektoen, Lisbeth; Phythian, Claire J.; Rinaldi, Laura; Bosco, Antonio; Hinney, Barbara; Gehringer, Martin; Strube, Christina; May, Katharina; Knubben-Schweizer, Gabriela; Martins, Oliva M. D.; Mateus, Teresa L.; Simion, Violeta; Charlier, Johannes; Bartley, David J.; Claerebout, Edwin

To mitigate emerging anthelmintic resistance (AR) in cattle, sustainable gastrointestinal nematode control strategies should be adopted. A multi-centre study was set up to understand the factors affecting European dairy cattle farmers’ adoption of diagnostics and to gauge for differences between regions. The data were collected through a multilingual survey by participating countries of the European Co-operation in Science and Technology (COST) action COMbatting Anthelmintic Resistance in ruminants (COMBAR). Four countries provided sufficient data to be included in the data analysis: Norway, Italy, Germany and Austria. Three models were estimated and validated through structural equation modelling. Norway, along with Germany and Austria (pooled dataset) showed similar trends that align with previous studies. AR risk perception had no influence on the adoption intention of diagnostics, a positive influence was found for attitude towards diagnostics and subjective norms (i.e., perceived opinion of others), and a negative influence of attitudes towards anthelminthics. Additionally, routine (i.e., perception of the current treatment) had an indirect effect on adoption intention through attitudes. Italy’s data deviated from these findings, presenting a positive effect of the perceived severity of AR, and perceived behavioural control (i.e., perceived ability to perform a specific behaviour) on adoption intention of diagnostics. Finally, Norway’s data set allowed for inclusion of a measurement of current behaviour in the model, identifying a direct positive effect of the perceived actual behaviour of other farmers on their own behaviour.

2023Journal article

Open access

Multidrug-Resistant Escherichia coli Accumulated by Freshwater Bivalves: An Underestimated Risk for Public Health?

Publication . Martins, Joana; Gonçalves, Ana; Fernandes, Conceição; Cabecinha, Edna; Monteiro, Sandra Mariza; Guedes, Hugo; Almeida, Gonçalo; Garcia, Juliana; Silva, Gabriela Jorge da; Varandas, Simone; Saavedra, Maria José

As bioindicators, freshwater bivalves are crucial for the assessment of the contamination impact on different levels of biological integration. Escherichia coli is used as a bioindicator of water fecal contamination, representing a critical global concern, especially with the rise of multidrugresistant (MDR) strains. Phylogenetic diversity, pathotypic characterization, and antibiotic resistance profiles of E. coli isolated from freshwater bivalves (Anodonta anatina) were assessed. Samples were collected from the Tua River in Northern Portugal, from two different sites, Chelas and Barcel, representing different degrees of contamination. Antimicrobial susceptibility testing was performed by the disk diffusion method, and characterizations of the phylogenetic groups and pathotypes were assessed by PCR-multiplex and real-time PCR-multiplex, respectively. Results showed that 60% of isolates were characterized as MDR, including resistance to carbapenems, considered the last resort against multidrug-resistant bacteria. Within this study, it was also possible to verify the antimicrobial resistance (AMR) profile differences between the two sampling sites, with bivalve isolates from the Chelas site showing a higher percentage of antibiotic resistance. Among the E. coli isolates, the highest prevalence (55%) was observed in group B1, followed by group D or E (15%), group A (10%), and group E or Clade I (10%). None of the isolates were classified as diarrheagenic E. coli (DEC). This work highlights the potential transmission of antimicrobial-resistant bacteria through bivalves in the food chain. The ‘One Health’ approach is crucial for combating antimicrobial resistance, namely in edible freshwater species, emphasizing active surveillance to protect human, animal, and environmental health against the spread of antibiotic-resistant bacteria in aquatic environments.

2024Journal article

Open access

Realistic Aspects of Cardiac Ultrasound in Rats: Practical Tips for Improved Examination

Publication . Silva, Jessica; Ginja, Mário; Oliveira, Paula A.; Duarte, José Alberto; Faustino-Rocha, Ana

Echocardiography is a reliable and non-invasive method for assessing cardiac structure and function in both clinical and experimental settings, offering valuable insights into disease progression and treatment efficacy. The successful application of echocardiography in murine models of disease has enabled the evaluation of disease severity, drug testing, and continuous monitoring of cardiac function in these animals. However, there is insufficient standardization of echocardiographic measurements for smaller animals. This article aims to address this gap by providing a guide and practical tips for the appropriate acquisition and analysis of echocardiographic parameters in adult rats, which may also be applicable in other small rodents used for scientific purposes, like mice. With advancements in technology, such as ultrahigh-frequency ultrasonic transducers, echocardiography has become a highly sophisticated imaging modality, offering high temporal and spatial resolution imaging, thereby allowing for real-time monitoring of cardiac function throughout the lifespan of small animals. Moreover, it allows the assessment of cardiac complications associated with aging, cancer, diabetes, and obesity, as well as the monitoring of cardiotoxicity induced by therapeutic interventions in preclinical models, providing important information for translational research. Finally, this paper discusses the future directions of cardiac preclinical ultrasound, highlighting the need for continued standardization to advance research and improve clinical outcomes to facilitate early disease detection and the translation of findings into clinical practice.

2024Journal article

Open access