RESUMEN
Selenium methionine (SeMet) is an essential micronutrient required for normal body function and is associated with additional health benefits. However, oral administration of SeMet can be challenging due to its purported narrow therapeutic index, low oral bioavailability, and high susceptibility to oxidation. To address these issues, SeMet was entrapped in zein-coated nanoparticles made from chitosan using an ionic gelation formulation. The high stability of both the SeMet and selenomethionine nanoparticles (SeMet-NPs) was established using cultured human intestinal and liver epithelial cells, rat liver homogenates, and rat intestinal homogenates and lumen washes. Minimal cytotoxicity to Caco-2 and HepG2 cells was observed for SeMet and SeMet-NPs. Antioxidant properties of SeMet were revealed using a Reactive Oxygen Species (ROS) assay, based on the observation of a concentration-dependent reduction in the build-up of peroxides, hydroxides and hydroxyl radicals in Caco-2 cells exposed to SeMet (6.25-100 µM). The basal apparent permeability coefficient (Papp) of SeMet across isolated rat jejunal mucosae mounted in Ussing chambers was low, but the Papp was increased when presented in NP. SeMet had minimal effects on the electrogenic ion secretion of rat jejunal and colonic mucosae in Ussing chambers. Intra-jejunal injections of SeMet-NPs to rats yielded increased plasma levels of SeMet after 3 h for the SeMet-NPs compared to free SeMet. Overall, there is potential to further develop SeMet-NPs for oral supplementation due to the increased intestinal permeability, versus free SeMet, and the low potential for toxicity.
Asunto(s)
Nanopartículas , Selenio , Ratas , Humanos , Animales , Selenometionina/farmacología , Células CACO-2 , Antioxidantes/farmacología , Suplementos DietéticosRESUMEN
Selenoamino acids (SeAAs) have been shown to possess antioxidant and anticancer properties. However, their bioaccessibility is low and they may be toxic above the recommended nutritional intake level, thus improved targeted oral delivery methods are desirable. In this work, the SeAAs, Methylselenocysteine (MSC) and selenocystine (SeCys2) were encapsulated into nanoparticles (NPs) using the mucoadhesive polymer chitosan (Cs), via ionotropic gelation with tripolyphosphate (TPP) and the NPs produced were then coated with zein (a maize derived prolamine rich protein). NPs with optimized physicochemical properties for oral delivery were obtained at a 6: 1 ratio of Cs:TPP, with a 1:0.75 mass ratio of Cs:zein coating (diameter ~260â¯nm, polydispersivity index ~0.2, zeta potential >30â¯mV). Scanning Electron Microscopy (SEM) analysis showed that spheroidal, well distributed particles were obtained. Encapsulation Efficiencies of 80.7% and 78.9% were achieved, respectively, for MSC and SeCys2 loaded NPs. Cytotoxicity studies of MSC loaded NPs showed no decrease in cellular viability in either Caco-2 (intestine) or HepG2 (liver) cells after 4 and 72â¯h exposures. For SeCys2 loaded NPs, although no cytotoxicity was observed in Caco-2 cells after 4â¯h, a significant reduction in cytotoxicity was observed, compared to pure SeCys2, across all test concentrations in HepG2 after 72â¯h exposure. Accelerated thermal stability testing of both loaded NPs indicated good stability under normal storage conditions. Lastly, after 6â¯h exposure to simulated gastrointestinal tract environments, the sustained release profile of the formulation showed that 62⯱â¯8% and 69⯱â¯4% of MSC and SeCys2, had been released from the NPs respectively.
Asunto(s)
Anticarcinógenos/análisis , Antivirales/análisis , Cistina/análisis , Suplementos Dietéticos , Compuestos de Organoselenio/análisis , Selenocisteína/análisis , Células CACO-2 , Supervivencia Celular/efectos de los fármacos , Quitosano/química , Cistina/análogos & derivados , Geles/química , Células Hep G2 , Humanos , Microscopía Electrónica de Rastreo , Nanopartículas/química , Tamaño de la Partícula , Polifosfatos/análisis , Selenocisteína/análogos & derivados , Zeína/químicaRESUMEN
BACKGROUND: Acrylamide as a possible carcinogen is known to form in heated carbohydrate-rich food such as potato chips. In this study, the effect of three potato varieties (Agria, Sante and Savalan) and two blanching conditions (75 °C for 9 min and 83 °C for 2.5 min) on the concentration of precursors and acrylamide reduction in potato chips was investigated. RESULTS: Results revealed that potato variety and blanching time-temperature were important parameters for acrylamide formation in potato chips. Acrylamide content in Sante variety potatoes, which contained the highest amount of reducing sugars, was found to be the highest (8825 µg kg(-1)). However, Savalan, containing the highest asparagine concentration, showed the lowest amount of acrylamide due to its lower reducing sugar content. Blanching reduced acrylamide formation; it was more efficient at 75 °C for 9 min, with an average reduction of 74%. The effect of three frying temperatures (170, 180 and 190 °C) on acrylamide formation was also studied just for the Agria potato variety. Increasing frying temperature led to a significant increase in acrylamide formation. CONCLUSION: Potato variety and processing conditions were important parameters for acrylamide formation in potato chips. The combination of a suitable variety and appropriate processing conditions could considerably reduce acrylamide content.
Asunto(s)
Acrilamida , Culinaria , Calor , Tubérculos de la Planta/química , Solanum tuberosum/química , Acrilamida/efectos adversos , Asparagina/análisis , Sacarosa en la Dieta/análisis , Irán , Solanum tuberosum/clasificación , Especificidad de la EspecieRESUMEN
The thermal degradation kinetics of pectin methylesterase (PME) from carrot and lettuce were studied. Fresh extracts were exposed to temperatures from 55 to 70 degrees C until the enzyme was inactivated. A model based on the presence of two forms of the enzyme, one active and one non-active, is proposed. The natural variability of the PME activity was taken into the model in the form of normally distributed random effects. The common model parameters obtained (cleavage constant (0.0395+/-0.0062 s(-1)), degradation constant (0.556+/-0.112 s(-1)), cleavage energy of activation (469+/-23 kJ mol(-1)) and degradation energy of activation (488+/-18 kJ mol(-1))) show that the PME degradation kinetics of the two vegetables can be explained with a single set of parameters.