Célia Gomes Amorim

This study evaluates Natural Deep Eutectic Solvents (NADES) for extracting antioxidant compounds from Portulaca oleracea dried leaves, compared to traditional ethanol extraction. NADES were synthesized using terpenoids (menthol and β-citronellol) and organic acids (lactic and capric acid), characterized by favorable viscosity, density, and pH, ensuring liquid stability at ambient temperature. NADES extraction outperformed ethanol, with NADES 1 yielding the highest bioactive contents: 83.66 Eq GA/mg, 786.55 Eq Q/mg, and 0.78 Eq C/mg versus ethanol’s 58.49 Eq GA/mg, 363.23 Eq Q/mg, and 0.44 Eq C/mg. HPLC-DAD analysis identified higher levels of phenolic acids (caffeic and syringic acid) and flavonoids (rutin and quercetin) in NADES extracts, compounds absent in ethanol. Antioxidant potential, assessed via IC₅₀ values, confirmed superior activity for NADES extracts (NADES 1-Ext: IC₅₀ 28.10 ± 1.73 µg/µL) compared to ethanol (IC₅₀ 1615.97 ± 5.34 µg/µL), and the Trolox method has confirmed extensively this superiority. Additionally, NADES demonstrated improved antimicrobial effects, varying with microorganisms. Despite their high viscosity potentially limiting extraction efficiency, adjusting temperature offers a promising approach to enhance mass transfer. These findings emphasize NADES as a sustainable alternative for bioactive compound extraction, paving the way for optimizing extraction techniques through viscosity reduction strategies.

The use of polysulfone (PSU) hemodialysis (HD) membranes modified with bioactive compounds has gained relevance in chronic kidney disease (CKD) management. Compounds based on the 4-oxo-β-lactam scaffold have outstanding inhibitory ability and selectivity for human neutrophil elastase (HNE). The present work aimed to evaluate the bioactivity and biocompatibility of PSU-based HD membranes doped with HNE inhibitors (HNEIs). For this, two 4-oxo-β-lactam derivates (D4L-1 and D4L-2) synthesized in house were used, as well as a commercial HNEI (Sivelestat), for comparison purposes. Their HNE inhibition efficacy was evaluated in in vitro and ex vivo (incubations with human plasma) assay conditions. All biomaterials were bioactive and hemocompatible. The inhibitory capacity of the HNEIs and HNEI-PSU membranes in vitro was D4L-1 > D4L-2 > Sivelestat and D4L-2 > Sivelestat > D4L-1, respectively. In ex vivo conditions, both HNEIs and HNEI-PSU materials presented the same relative inhibitory ability (D4L-1 > D4L-2 > Sivelestat). The difference observed between in vitro and ex vivo conditions is most likely due to the inherent lipophilicity/hydrophobicity of each HNEI influencing their affinity and accessibility to HNE when trapped in the membrane. Compared to Sivelestat, both D4L-1 and D4L-2 (and the respective doped membranes) have more potent inhibition capabilities. In conclusion, this work reports the successful development of PSU membranes functionalized with HNEIs.

The evaluation of the biogenic amines (BAs) profile of different types of craft beers is herein presented. A previously developed and validated analytical method based on ion-pair chromatography coupled with potentiometric detection was used to determine the presence of 10 BAs. Good analytical features were obtained for all amines regarding linearity (R² values from 0.9873 ± 0.0015 to 0.9973 ± 0.0015), intra- and inter-day precision (RSD lower than 6.9% and 9.7% for beer samples, respectively), and accuracy (recovery between 83.2–108.9%). Detection and quantification limits range from 9.3 to 60.5 and from 31.1 to 202.3 µg L⁻¹, respectively. The validated method was applied to the analysis of four ale beers and one lager craft beer. Ethylamine, spermidine, spermine, and tyramine were detected in all analyzed samples while methylamine and phenylethylamine were not detected. Overall, pale ale beers had a significantly higher total content of BAs than those found in wheat pale and dark samples. A general least square regression model showed a good correlation between the total content of BAs and the brewing process, especially for Plato degree, mashing, and fermentation temperatures. Knowledge about the type of ingredients and manufacturing processes that contribute to higher concentrations of these compounds is crucial to ensuring consumer safety.

Canine leishmaniosis (CanL) is a vector-borne disease caused by Leishmania infantum. Infection in dogs can result in a disease with non-specific clinical signs or in a subclinical condition. Infection diagnosis is crucial to guide public health measures considering the zoonotic potential of L. infantum. Serological approaches to detect infection with a reduced antigen panel potentially limit the quality of the information obtained. To evaluate the impact of using distinct antigens in a serological survey, a cohort with 390 dogs from endemic regions in Portugal was subjected to a serological evaluation using ELISA and DAT. Using ELISA, six Leishmania-specific antigens in conjunction with a non-related antigen, Escherichia coli soluble antigens, were evaluated. The global seroprevalence was 10.5% for DAT and 15.4 to 23.1% for ELISA, depending on the antigen for the latter. Still, only 8.2% of the animals were seropositive to all Leishmania-specific antigens. Importantly, a further 31.0% presented antigen-dependent seropositivity. Considering this observation, a serological score system was proposed and validated to address the complex serology results. With this system, the overall dog seropositivity was 26.9%. This work highlights the limitations of single-antigen serological surveys and presents an approach that might contribute to the establishment of CanL-specific serological profiles.