Oxidative status and intestinal health of gilthead sea bream (Sparus aurata) juveniles fed diets with different ARA/EPA/DHA ratios.

The present work assessed the effects of dietary ratios of essential fatty acids, arachidonic (ARA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), on liver and intestine oxidative status, intestinal histomorphology and gut microbiota of gilthead sea bream. Four isoproteic and isolipidic plant-based diets were formulated containing a vegetable oil blend as the main lipid source. Diets were supplemented with ARA/EPA/DHA levels (%DM) equivalent to: 2%:0.2%:0.1% (Diet A); 1.0%:0.4%:0.4% (Diet B); 0%:0.6%:0.6% (Diet C); 0%:0.3%:1.5% (Diet D) and tested in triplicate groups for 56 days. Lipid peroxidation was higher in fish fed diets C and D while no differences were reported between diets regarding total, oxidized, and reduced glutathione, and oxidative stress index. Glutathione reductase was higher in fish fed diet A than diets C and D. No histological alterations were observed in the distal intestine. Lower microbiota diversity was observed in intestinal mucosa of fish fed diet C than A, while diets C and D enabled the proliferation of health-promoting bacteria from Bacteroidetes phylum (Asinibacterium sp.) and the absence of pathogenic species like Edwardsiella tarda. Overall, results suggest that a balance between dietary ARA/EPA + DHA promotes gilthead sea bream juveniles' health however higher dietary content of n-3 LC-PUFA might limited the presence of microbial pathogens in intestinal mucosa.

Ex vivo nail infection as an effective preclinical method for screening of new topical antifungals.

Onychomycosis are fungal nail infections comprising of about 50% of onychopathies and are commonly caused by dermatophytes. The treatment of this dermatomycosis requires a long period of time and is associated with high rates of recurrence. In view of the need to evaluate the antifungal performance of promising preclinical compounds, we developed, in this study, a practical and accessibleex vivo model for establishing a Trichophyton rubrum onychomycosis framework using porcine hooves. This model has as its main advantage the similar structural and three-dimensional characteristics that the porcine hooves have with the human nail. The proposed model allowed to evaluate the antifungal activity of a new antifungal compound and a reference drug (terbinafine), both already incorporated into a nail lacquer for topical use. Treatments with compound 3-selenocyanate-indole (Se4a) and with terbinafine incorporated into this nail lacquer completely inhibited fungal growth, corresponding to the profile of in vitro activity observed against T. rubrum. This study concludes that the ex vivo porcine hoof model is an effective alternative method for preclinical screening of drugs or new topical compounds developed to combat onychomycosis. Further studies are needed to compare the permeability of porcine hooves with human nails permeability.

A multiple endpoint approach reveals potential in vitro anticancer properties of thymoquinone in human renal carcinoma cells.

Thymoquinone (TQ) is a monoterpene isolated from the oil of Nigella sativa seeds. The aim of this work was to evaluate the cytotoxic effects induced by TQ and its impact on the migration and invasion potential of 786-O human renal cancer cells. These cells were exposed to TQ (1-100 µM) for 24 and 48 h and cell viability assessed using the Crystal Violet and MTS assays. TQ treatment clearly decreased cell viability in a concentration- and time-dependent manner. TQ exposure moderately increased intracellular ROS levels and co-incubation with reduced glutathione markedly increased cell viability. Moreover, the effect of TQ in the cell cycle distribution was evaluated using flow cytometry, and an increase in the sub-G1 population was observed, especially at 30 µM, along with an increase in the % of apoptotic cells. TQ did not show genotoxic effects at a non-cytotoxic concentration (1.0 µM). At this concentration level, TQ significantly decreased the collective migration of 786-O cells, whereas it had no effect in chemotactic migration. TQ also decreased the invasiveness potential of 786-O cells, as evaluated by the transwell invasion assay. Overall, these results suggest that TQ presents an anticancer potential in the context of renal cancer, warranting further investigation.

Solid lipid nanoparticles containing copaiba oil and allantoin: development and role of nanoencapsulation on the antifungal activity.

The aim of this work was to develop solid lipid nanoparticles (SLN) containing copaiba oil with and without allantoin (NCOA, NCO, respectively) and to evaluate their antifungal activity. Nanoparticle suspensions were prepared using a high homogenisation technique and characterised by dynamic light scattering, laser diffraction, nanoparticle tracking analysis, multiple light scattering analysis, high-pressure liquid chromatography, pH and rheology. The antifungal activities of the formulations were tested in vitro against the emergent yeasts Candida krusei and Candida parapsilosis, and the fungal pathogens of human skin Trichophyton rubrum and Microsporum canis. The dynamic light scattering analysis showed z-average diameters (intensity) between 118.63 ± 8.89 nm for the nanoparticles with both copaiba oil and allantoin and 126.06 ± 9.84nm for the nanoparticles with just copaiba oil. The D[4,3] determined by laser diffraction showed similar results of 123 ± 1.73 nm for the nanoparticles with copaiba oil and allantoin and 130 ± 3.6 nm for the nanoparticles with copaiba oil alone. Nanoparticle tracking analysis demonstrated that both suspensions had monomodal profiles and consequently, the nanoparticle populations were homogeneous. This analysis also corroborated the results of dynamic light scattering and laser diffraction, exhibiting a smaller mean diameter for the nanoparticles with copaiba oil and allantoin (143 nm) than for the nanoparticles with copaiba oil (204 nm). The physicochemical properties indicated that the dispersions were stable overtime. Rheology evidenced Newtonian behaviour for both suspensions. Antifungal susceptibility showed a MIC90 of 125 µg/mL (nanoparticles with copaiba oil) and 7.8 µg/mL (nanoparticles with copaiba oil and allantoin) against C. parapsilosis. The nanoparticles with copaiba oil and the nanoparticles with copaiba oil and allantoin presented a MIC90 of 500 µg/mL and 250 µg/mL, respectively, against C. krusei. The MIC90 values were 500 µg/mL (nanoparticles with copaiba oil) and 1.95 µg/mL (nanoparticles with copaiba oil and allantoin) against T. rubrum. Against M. canis, the nanoparticles with copaiba oil and allantoin had a MIC9 of 1.95 µg/mL. In conclusion, nanoencapsulation improved the antifungal activity of copaiba oil, which was enhanced by the presence of allantoin. The MICs obtained are comparable to those of commercial products and can represent promising therapeutics for cutaneous infections caused by yeasts and dermatophytes.