Edite Cunha

Phytolacca americana L. (pokeweed) is a widespread invasive species whose berries remain poorly characterized in terms of nutritional value and bioactive potential, although being associated to some traditional uses. This study provides the first integrated characterization of the nutritional profile, mineral composition (ICP-MS), fatty acid profile (GC-FID), vitamin E content (HPLC-DAD-FLD), bioactive compounds and phenolic profile (HPLC-DAD). The studied berries showed high levels of carbohydrates and dietary fiber, along with potassium as the dominant mineral and a lipid fraction enriched in polyunsaturated fatty acids, particularly linoleic and α-linolenic acids. In turn, α- and γ-tocopherol were the only detected vitamers of vitamin E. Hydroalcoholic extracts exhibited high total phenolic, flavonoid, and saponin contents, consistent with the phenolic profile dominated by quercetin, ellagic acid, and rutin. Antioxidant capacity assessed through DPPH• and FRAP assays displayed a strong dose-dependent response, with rapid activity increases at low extract concentrations and saturation at higher doses. Thus, P. americana hydroalcoholic extracts protected erythrocytes from oxidative AAPH- and H2O2-induced hemolysis. These findings highlight P. americana berries as a source of compounds with nutritional and functional relevance, although denoting the need for adequate processing to reduce its potential toxicity. Overall, these results support P. americana as a source of bioactive molecules with prospective applications in food and nutraceutical sectors.

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.

Designing oral formulations for children is very challenging, especially considering their peculiarities and preferences. The choice of excipients, dosing volume and palatability are key issues of pediatric oral liquid medicines. The purpose of the present study is to develop an oral pediatric solution of a model bitter drug (ranitidine) following a patient centric design process which includes the definition of a target product profile (TPP). To conclude on the matching of the developed solution to TPP, its chemical and microbiological stability was analyzed over 30 days (stored at 4 °C and room temperature). Simulation of use was accomplished by removing a sample with a syringe every day. Taste masking was assessed by an electronic tongue. The developed formulation relied on a simple taste masking strategy consisting in a mixture of sweeteners (sodium saccharine and aspartame) and 0.1% sodium chloride, which allowed a higher bitterness masking effectiveness in comparison with simple syrup. The ranitidine solution was stable for 30 days stored at 4 °C. However, differences were noted between the stability protocols (unopened recipient and in-use stability) showing the contribution of the simulation of use to the formation of degradation products. Stock solution was subjected to acid and alkali hydrolysis, chemical oxidation, heat degradation and a photo degradation stability assessment. The developed pediatric solution matched the TPP in all dimensions, namely composition suitable for children, preparation and handling adapted to hospital pharmaceutical compounding and adequate stability and quality. According to the results, in-use stability protocols should be preferred in the stability evaluation of pediatric formulations.

Bacterial spot (BS) of tomato (S. lycopersicum), caused by Xanthomonas spp., namely X. euvesicatoria (Xeu), is one of the major threats for the production of this crop worldwide. Developing new biocontrol solutions against this disease will allow disease management strategies to be less based on Cu compounds. Nanoclays, such as montmorillonite (NMT), have been under investigation for their antimicrobial activity, or as delivery tools/stabilizers for organic compounds, such as essential oils (EOs), that also possess antimicrobial activity against plant pathogens. This work aims to assess how the application of NMT alone or incorporating S. montana EO on Xeu-infected hosts (var. Oxheart) affects the shoots’ redox status and antioxidant defense mechanisms. In vitro shoots, grown on Murashige and Skoog medium, were divided in two groups, Xeu-infected and uninfected (control) shoots. Shoots of each group were then treated with NMT, S. montana EO, EO-NMT. Results show that the NMT was able to reduce Xeu bacterial amount, while reducing ROS production and keeping the transcript levels of the defense-related genes close to those of the control. When applied to uninfected shoots, the treatments triggered the production of ROS and upregulated the phenylpropanoid and hormone pathway, which suggest that they act as defense elicitors. Globally, the results indicate that NMT has the potential to integrate BS management strategies, due to its antimicrobial activity, and that EO and/or nanoclays could be successfully employed as new disease preventive strategies, since they enhance the healthy shoots’ defense, thus potentially limiting the pathogen establishment.

This work is based on the automated evaluation of the influence of several ionic liquids (ILs) on the activity of immobilized glutathione reductase (GR), as an indicator of their toxicity. The reactions involved are the reduction of oxidized glutathione (GSSG) by GR, followed by the oxidation of the formed product (reduced glutathione – GSH) by the sulfhydryl reagent 5,5′-dithio-bis(2-nitrobenzoic acid) (DTNB) to form a yellow derivate 2-nitro-5-thiobenzoic acid (TNB), measurable at 412 nm. The bioassay was performed in a SIA system where the ILs were submitted to a simple and precise on-line dilution strategy before evaluation of their toxicity. The activity assays were implemented in strictly aqueous media and in the presence of increasing concentrations of seven commercially available ILs. EC₅₀ values between 0.24 and 2.55 M were obtained for the tested compounds, revealing distinct inhibitory effects. The least and most toxic ILs found in this study were emim[Ms] and emim[BF₄], respectively. The automated methodology is an interesting analytical tool for the evaluation of GR activity in ILs proving to be robust while presenting good repeatability, with RSD less than 5%, in all the assay conditions, leading also to a reduction of the consumption of solvents as well as of effluent production (2 mL per cycle).

This work is based on the evaluation of the protein binding affinity, partition coefficients (with a biomimetic membrane) and surfactant properties of three pharmaceutically active ionic liquids based on the salicylate anion. Fluorescence spectroscopy was used for the evaluation of the binding of ionic liquids to human serum albumin and for the determination of critical micelle concentrations. Partition coefficients were determined using micelles of hexadecylphosphocholine and UV-Vis derivative spectroscopy. The results indicate that all the compounds bind strongly and spontaneously to human serum albumin and exhibit the ability to form micelles. The determined partition coefficients were up to 6 times higher than those of the starting materials, evidencing that the ionic liquid form has greater affinity for the lipid phase than the inorganic salt form of salicylate. Generally, the studied salicylate ionic liquids exhibit an interesting pharmaceutical profile presenting favorable properties regarding the incorporation of the compounds in antimicrobial pharmaceutical formulations. It was evidenced that the tested ionic liquids can exert direct effects on cell membranes as indicated by their surfactant properties and high ability to partition to hydrophobic environments.