Characterization of flours from the aroeira leaf (Schinus terebinthifolius Raddi), obtained by different drying methods.

The present work aimed at the development and characterization of aroeira leaf flour (Schinus terebinthifolius Raddi), obtained by lyophilization and drying in an air circulation oven. The technological, physical, physico-chemical, morphological, functional, and microbiological aspects were analyzed. Physico-chemical analysis identified the following properties with values provided respectively for fresh leaves (FOin) and flours (FES and FLIO): low water activity (0.984, 0.370, 0.387 g/100 g), moisture (64.52, 5.37, 7.97 g /100 g), ash (2.69, 6.51, and 6.89 g/100 g), pH (0.89, 4.45, 4.48 g/100 g), lipids (0.84, 1.67, 5.23 g/100 g), protein (3.29, 8.23, 14.12 g/100 g), carbohydrates (17.02, 53.12, 33.02 g/100 g), ascorbic acid (19.70, 34.20, 36.90 mg/100 g). Sources of fiber from plant leaves and flours (11.64, 25.1, 32.89 g/100 g) showed increased levels of luminosity. For NMR, the presence of aliphatic and aromatic compounds with olefinic hydrogens and a derivative of gallic acid were detected. The most abundant minerals detected were potassium and calcium. Micrographs identified the presence of irregular, non-uniform, and sponge-like particles. The main sugars detected were: fructose, glucose, and maltose. Malic, succinic, citric, lactic, and formic acids were found. Fifteen phenolic compounds were identified in the samples, highlighting: kaempferol, catechin, and caffeic acid. The values ​​found for phenolics were (447, 716.66, 493.31 mg EAG/100 g), flavonoids (267.60, 267.60, 286.26 EC/100 g). Antioxidant activity was higher using the ABTS method rather than FRAP for analysis of FOin, FES, and FLIO. Since the flours of the aroeira leaf have an abundant matrix of nutrients with bioactive properties and antioxidant activity, they have a potential for technological and functional use when added to food.

Nutraceutical formulations combining Limosilactobacillus fermentum, quercetin, and or resveratrol with beneficial impacts on the abundance of intestinal bacterial populations, metabolite production, and antioxidant capacity during colonic fermentation.

This study evaluated the impacts of different nutraceutical formulations combining Limosilactobacillus fermentum 296 (∼10 log CFU/mL), quercetin (QUE, 160 mg), and or resveratrol (RES, 150 mg) on the relative abundance of various intestinal bacterial populations, production of microbial metabolites, and antioxidant capacity during 48 h of in vitro colonic fermentation. The nutraceutical formulations increased the relative abundance of Lactobacillus spp./Enterococcus spp. and Bifidobacterium spp. and decreased the relative abundance of Bacteroides spp./Prevotella spp., Clostridium histolyticum, and E. rectale/C. coccoides during the colonic fermentation. Medium with the formulation containing L. fermentum, QUE, and RES had the highest prebiotic indexes, indicating synergistic or additive interaction between QUE and RES to modulate the intestinal microbiota. The nutraceutical formulations increased the production of bioactive metabolites and antioxidant capacity in the colonic fermentation media. The results indicate the capability of the tested nutraceutical formulations to beneficially modulate the composition and metabolite production of human intestinal microbiota and increase the antioxidant capacity in the intestinal environment.

Antioxidant activity of bioactive compounds isolated from leaves and bark of Gymnanthes lucida Sw

Estudios fitoquímicos sugieren que Gymnanthes lucida Sw. (aité) es un candidato con potencial antioxidante. Se cuantificó el contenido de fenoles y flavonoides totales, y se evaluó la actividad antioxidante de extractos, elagitaninos y cumarinas aisladas de la hoja y la corteza mediante los métodos de secuestro de los radicales 2,2-difenil-1-pricrilhidrazil (DPPH) y ácido 2,2´-azino-bis(3-etilbenzotiazolín)-6-sulfónico (ABTS) y del poder reductor. El extracto de la hoja mostró el mayor contenido de flavonoides y fenoles y la mejor actividad de los extractos DPPH (IC50=12,82 ± 0,12 µg/mL), ABTS (IC50=13,83 ± 3,45 µg/mL) y poder reductor (104% respecto al ácido ascórbico). El ácido elágico (AE) mostró la mayor actividad de las muestras DPPH (IC50=11,75 ± 0,53 µg/mL), ABTS (IC50=11,28 ± 0,28 µg/mL) y poder reductor (107% respecto al ácido ascórbico). Los resultados sugieren que G. lucida es una fuente de antioxidantes donde el AE es el principal responsable de la actividad de la hoja.

Phytochemical investigations suggest that Gymnanthes lucida Sw. (aité) is a potential candidate for obtaining antioxidant principles. Total phenolic and flavonoid content were quantified and in vitro antioxidant capacity was assessed in extracts, ellagitannins, and coumarins isolated from the leaf and bark by three methods: 2,2-diphenyl-1-pricrylhydrazyl (DPPH) and 2,2´-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals scavenging activities and ferric reducing power. The highest phenolic and flavonoid content was observed in the leaf extract which also exhibited the highest activity among the extracts DPPH (IC50=12,82 ± 0,12 µg/mL), ABTS (IC50=13,83 ± 3,45 µg/mL), and reducing power (104% compared to ascorbic acid). Ellagic acid (EA) showed the highest activity, with DPPH (IC50=11,75 ± 0,53 µg/mL), ABTS (IC50=11,28 ± 0,28 µg/mL), and reducing power (107 % compared to ascorbic acid). Results suggest that G. lucida is a natural source of antioxidants where EA is the main secondary metabolite of the leaf responsible for the activity.

Modulation of drug resistance in Staphylococcus aureus by 132-hydroxy-(132-R/S)-pheophytin isolated from Sargassum polyceratium.

Efflux pumps are integral parts of the bacterial plasma membrane that are responsible for many cases of antibiotic resistance. Modulators of drug resistance are regarded as the most suitable new antibacterial therapies. We evaluated the extracts of Sargassum polyceratium and the isolated compound pheophytin (Sp-1) for antibiotic modifying activity in strains of Staphylococcus aureus with efflux pump. The minimum inhibitory concentrations (MICs) for norfloxacin, tetracycline and erythromycin were determined by the microdilution broth method, in the absence and presence of the extract at a sub-inhibitory concentration (MIC/4). The extracts and isolated compounds showed no significant antimicrobial activity, but they changed the antibiotic activity, decreasing bacterial resistance by 2 to 4x. Using a checkerboard method, it was also possible to observe the synergistic effect (ΣFIC ≤ 0.5) between Sp-1 and the antibiotics erythromycin and norfloxacin. The results indicate that the seaweed Sargassum polyceratium and pheophytin are potential sources of an antibiotic adjuvant that modulates bacterial resistance, acting as a putative efflux pump inhibitor.