RESUMEN
A bacterium strain isolated from freshwater sediment of San Pablo river of Santiago de Cuba, Cuba was identified as a Bacillus sp. by Matrix-Assisted Laser Desorption/Ionization Time Of Flight Mass Spectrometry. A 16S rRNA gene analysis showed that the isolate A3 belongs to the operational group Bacillus amyloliquefaciens, while the phylogenetic analysis of the gyrA gene sequence grouped it within B. amyloliquefaciens subsp. plantarum cluster, referred now as Bacillus velezensis. In vitro antibacterial studies demonstrated the capacity of the isolate A3 to produce bioactive metabolites against Bacillus subtilis ATCC 11,778, Bacillus cereus ATCC 6633, and Staphylococcus aureus ATCC 25,923 by cross-streak, overlay, and microdilution methods. The strain also showed a high potential against the multidrug-resistant Staphylococcus aureus ATCC 700,699, ATCC 29,213, and ATCC 6538. At pH 8 and 96 h in the medium 2 of A3 culture conditions, the produced metabolites with antibacterial potential were enhanced. Some alterations in the morphology of the phytopathogens Aspergillus niger ATCC 9642, Alternaria alternata CECT 2662, and Fusarium solani CCEBI 3094 were induced by the cell-free supernatant of B. velezensis A3. A preliminary study of the nature of the bioactive compounds produced by the strain A3 showed the presence of both lipids and peptides in the culture. Those results highlight B. velezensis A3 as a promissory bacterium capable to produce bioactive metabolites with antibacterial and antifungal properties against pathogens.
Asunto(s)
Bacillus , Staphylococcus aureus Resistente a Meticilina , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/metabolismo , Filogenia , Bacillus/genética , Bacillus/metabolismo , Hongos/genética , Bacillus subtilis/metabolismo , Antibacterianos/química , Agua DulceRESUMEN
A compositional study was performed on fruiting-body powder of the culinary-medicinal oyster mushroom Pleurotus ostreatus for applications as a nutraceutical/functional food. Carbohydrates (55 g/100 g dry weight [dw]) and proteins (27.45 g/100 g dw, with an in vitro digestibility of 75%) appear to be the major components, but fat content was low (4 g/100 g dw). Pleurotus powder has important micronutrients such as minerals (Fe, Cu, Zn, Mn, Mg, and Co) and ascorbic acid, as well as nonnutrients (i.e., phenolics) with antioxidant potential. A powder-derived aqueous extract had a phenolic compound content of 138 mg/100 g that showed 2,2-diphenyl-1-picrylhydrazyl radical scavenging and inhibition of membrane-lipid peroxidation activities of 58.3% and 61.4%, respectively. The presence of ß-1,3-1,6-D-glucans was also demonstrated (1.54 g/100 g). An acute toxicity test proved that Pleurotus powder was safe after oral administration to both male and female mice at a dose of 2000 mg/kg. The combination of rich nutritional composition, bioactivity, and safety in P. ostreatus fruiting-body powder highlights its potential as a nutraceutical agent promoting health and life quality.
Asunto(s)
Antioxidantes/química , Suplementos Dietéticos/análisis , Pleurotus/química , Animales , Antioxidantes/toxicidad , Suplementos Dietéticos/toxicidad , Femenino , Cuerpos Fructíferos de los Hongos/química , Masculino , Ratones , Ratones Endogámicos BALB C , Minerales/análisis , Polvos/química , Polvos/toxicidadRESUMEN
This study examined the phytochemical profile and the in vitro anti-proliferative effects of a hot water mycelial extract from the edible mushroom Pleurotus sp. on NB4 human leukemia cells. Flow-cytometry analyses were used to measure cell viability, cell cycle, and apoptosis in cells incubated 24 h with the extract at doses of 100 and 200 µg/mL. Pleurotus sp. extract reduced cell viability, particularly at the concentration of 200 µg/mL to 82% compared to control cells, and induced apoptosis demonstrated by an increase in the number of annexin V-FITC+ cells (25% at 200 µg/mL). The NB4 cells were arrested in the G2/M phase thus supporting a cell-cycle dependent anticancer mechanism. Although carbohydrates (76.8%, w/w) appear to be the most important antitumor compound, secondary metabolites-like phenolics would also contribute to the anti-proliferative activity. The results indicate that Pleurotus sp. mycelia obtained by submerged fermentation may be an interesting renewable resource for developing functional foods and new antitumor therapeutic agents.
Asunto(s)
Proliferación Celular/efectos de los fármacos , Inhibidores de Crecimiento/farmacología , Leucemia/fisiopatología , Micelio/química , Extractos Vegetales/farmacología , Pleurotus/química , Verduras/química , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Cuba , Inhibidores de Crecimiento/química , Inhibidores de Crecimiento/aislamiento & purificación , Humanos , Leucemia/tratamiento farmacológico , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificaciónRESUMEN
This study examined the effects of oral administration of an enzymatic protein hydrolysate from green microalga Chlorella vulgaris (Cv-PH) on the nutritional recovery of malnourished Balb/c mice after a 3-day fasting period. Mice were refed with commercial diet supplemented or not supplemented with Cv-PH (500 mg/kg) for 8 days. Regardless of the diet used during refeeding, animal body weights and serum protein concentrations did not differ between groups. Mice given Cv-PH had a significant increase in hemoglobin concentrations. Most serum amino acid levels were similar in the control and Cv-PH animals. Starved mice refed with Cv-PH showed normal liver functions, as judged by liver weight, protein concentration, and the enzymatic activities of cholinesterase and arginase. Cv-PH increased DNA, protein content, and gut-mucosal weight. In addition, brush-border oligosaccharidase activities were also higher in the Cv-PH group. These findings suggest that Chlorella protein hydrolysate can be used to develop specific formulations suitable for pharmacologic nutrition.
Asunto(s)
Chlorella vulgaris/química , Suplementos Dietéticos , Desnutrición/tratamiento farmacológico , Microalgas/química , Hidrolisados de Proteína/administración & dosificación , Administración Oral , Aminoácidos/sangre , Animales , Proteínas Sanguíneas/análisis , Proteínas Sanguíneas/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Dieta , Femenino , Mucosa Intestinal/metabolismo , Hígado/metabolismo , Ratones , Ratones Endogámicos BALB CRESUMEN
CONTEXT: Although new methods for the induction of malnutrition disorders in laboratory animals have been developed, the bulk of the models described in the literature are essentially based on dietary restriction/starvation principle. In this context, little data are available about the metabolic and the immune system parameters of Balb/c mice under starvation/refeeding. OBJECTIVE: This study examined the effects of starvation and refeeding on the biochemical and immunological status of undernourished Balb/c mice. METHODS: Female Balb/c mice, weighing 20 g, were starved for 3 days and then refed with commercial pelleted diet for 8 days. The variables considered were as follows: body weight; serum protein and amino acid concentrations; liver protein content, and cholinesterase and arginase activities; jejunal protein and DNA contents as well as oligosaccharidase levels; hematological parameters (bone marrow and peripheral blood cellularity); peritoneal macrophage activation; and humoral and cell-mediated immune functions. RESULTS: Profound alterations in both biochemical and immunological conditions appeared after the starvation period. Refeeding resulted in the normalization of serum albumin levels, the intestinal DNA content and the gut-mucosal associated enzymatic activities, the blood lymphocyte counts, and the number of peritoneal macrophages. The markers of liver metabolic function (cholinesterase and arginase activities), and those of bone marrow hemopoiesis and the adaptive immune response (T-dependent antibody titres and delayed-type hypersensitivity response) remained altered after refeeding compared with control mice. CONCLUSION: These findings suggest that fasted mice can be used as an animal model of acute starvation that might prove useful in evaluating the effectiveness of nutritional and immunopharmacological interventions.