ABSTRACT
Microgreens are novel foods with high concentrations of bioactive compounds and can be grown easily and sustainably. Among all the microgreens genera produced, Brassicaceae stand out because of the wide evidence about their beneficial effects on human health attributed to phenolic compounds, vitamins, and particularly glucosinolates and their breakdown products, isothiocyanates and indoles. The phytochemical profile of each species is affected by the growing conditions in a different manner. The agronomic practices that involve these factors can be used as tools to modulate and enhance the concentration of certain compounds of interest. In this sense, the present review summarizes the impact of substrates, artificial lighting, and fertilization on bioactive compound profiles among species. Since Brassicaceae microgreens, rich in bioactive compounds, can be considered functional foods, we also included a discussion about the health benefits associated with microgreens' consumption reported in the literature, as well as their bioaccessibility and human absorption. Therefore, the present review aimed to analyze and systematize cultivation conditions of microgreens, in terms of their effects on phytochemical profiles, to provide possible strategies to enhance the functionality and health benefits of Brassicaceae microgreens.
ABSTRACT
Sediment organic matter (SOM) plays an important role in capturing polybrominated diphenyl ethers (PBDEs) due to its affinity to hydrophobic and lipophilic compounds. Previous publications about correlations between PBDE concentrations and SOM content showed discrepancies among the results, reporting either significant positive correlations or no correlations at all. This work aimed to provide a deeper insight into SOM characteristics that might determine the concentrations of PBDEs in sediments. Sediment samples from Mendoza province, Argentina, were analyzed to contrast two models, environmental and experimental, using multivariate learning methods. Mendoza has been going through increasing events of drought and water scarcity, hence the occurrence, transport, and fate of contaminants as PBDEs in aquatic environments is of superlative importance. Principal component analysis (PCA) and partial least squares regression (PLS) were used to evaluate the correlations between physicochemical properties of sediments, semi-quantitative Fourier transform infrared (FTIR) area ratios obtained from SOM spectra, and PBDE concentrations in sediments. Moreover, a linear model was proposed to determine SOM density using FTIR area ratios and it was used as an additional variable in multivariate analyses. The results obtained from PCA and PLS were consistent and revealed that PBDE concentrations in sediments were correlated with a more degraded SOM, characterized by shorter and more branched hydrocarbon chains. PBDE concentrations were also correlated with higher SOM density values, which in turn were correlated with SOM degradation. These findings extend previous understanding and emphasize that not only is the organic matter content a factor in determining PBDE concentrations in sediments, but also and more significantly, its degree of degradation.
ABSTRACT
Resumen Introducción y objetivo: Los procesos de aprendizaje y motivación han sido centrales para la comprensión de los mecanismos que subyacen al tabaquismo. En particular, existe evidencia creciente sobre la importancia de valores motivacionales de incentivo para entender el inicio y mantenimiento del tabaquismo. El objetivo general de este experimento fue evaluar el papel de la nicotina aguda sobre el valor de incentivo de una recompensa natural, (comida) asociada con un estímulo ambiental, (palanca experimental). Método: Se utilizaron ratas Wistar. Se administró nicotina (0.4 mg/kg) de manera aguda en momentos específicos del entrenamiento, utilizando un procedimiento de diez sesiones de adquisición y cuatro sesiones extinción en una tarea pavloviana de automoldeamiento. El diseño experimental incluyó tres grupos, el grupo control de solución salina y grupos de nicotina durante la adquisición y la extinción. Resultados: Se encontró que la administración aguda de nicotina, de manera específica y en comparación con los otros dos grupos experimentales, resultó en un efecto de retardo durante la fase de extinción, y que una administración similar de nicotina no resultó en efectos observables durante el desempeño comportamental en adquisición. Conclusiones: Estos resultados apoyan el papel de la nicotina como fortalecedora del valor de incentivo de las claves ambientales durante la extinción para una tarea de automoldeamiento.
Abstract Introduction and goal: Learning and motivational processes have been central for a modern understanding of tobacco addiction. There is evidence that supports the importance of incentive motivational processes for the maintenance of tobacco addiction. The main goal of the present experiment was to evaluate the effects of acute nicotine on the incentive value of a natural reward, (food) paired with an environmental cue (pressing lever). Method: Wistar rats were used. Accute nicotine (0.4 mg/kg) was administered on key sessions, using a pavlovian autoshaping procedure involving ten acquisition and four extinction sessions. The experimental design included three groups, a saline administration control group and groups with specific nicotine administration during either acquisition or extinction. Results: We found that acute administration of nicotine, in contrast with saline only or previous nicotine administration during acquisition, had an enhancing effect on responding for the environmental cue during autoshaping extinction, but we did not find evidence that acute nicotine affected acquisition performance. Conclusion: Our results are consistent with a role of nicotine enhancing the incentive value of stimuli during extinction from a pavlovian autoshaping task.
Subject(s)
Nicotine , Tobacco Use Disorder , Extinction, Biological , MotivationABSTRACT
CYP2A6 is a human enzyme responsible for the metabolic elimination of nicotine, and it is also involved in the activation of procarcinogenic nitrosamines, especially those present in tobacco smoke. Several investigations have reported that reducing this enzyme activity may contribute to anti-smoking therapy as well as reducing the risk of promutagens in the body. For these reasons, several authors investigate selective inhibitors molecules toward this enzyme. The aim of this study was to evaluate the interactions between a set of organosulfur compounds and the CYP2A6 enzyme by a quantitative structure-activity relationship (QSAR) analysis. The present work provides a better understanding of the mechanisms involved, with the final goal of providing information for the future design of CYP2A6 inhibitors based on dietary compounds. The reported activity data were modeled by means of multiple regression analysis (MLR) and partial least-squares (PLS) techniques. The results indicate that hydrophobic and steric factors govern the union, while electronic factors are strongly involved in the case of monosulfides.
