In vitro Screening of Glutathione- S -Transferase Inhibition by Different Extracts of Verbascum sinuatum

Background and Aim: The concern toward using herbs as enzyme inhibitors such as glutathione-s-transferases (GSTs) may result in the improvement of proliferative diseases. Moreover, it may overcome the problem of multidrug resistance tumors. Based on that, this experiment was conducted to detect the impact of using aqueous, ethanol and methanol extracts from Verbascum sinuatum L. (Scrophulariaceae) that grow wild in Palestine as enzymatic inhibitors. Materials and Methods: The impacts of these three extracts at four studied concentrations (250, 500, 750 and 1000 µg/mL) on the activity of purified hepatic glutathione-s-transferases were estimated spectrophotometrically by using-chloro-2,4-dinitro-benzene (CDNB) as substrate. Results: The results of the present research indicated that all the three prepared extracts of V. sinuatum could inhibit the activity of GSTs at all examined concentrations. Moreover, according to the results, the alcoholic extracts from the studied plant species were more influential in the activity of GSTs than the aqueous ones. However, minor inhibitory variations were observed between methanol and ethanol extracts. It is notable that all the studied extracts manifested inhibitory effects in a dose-dependent manner. Conclusion: The results of this study emphasized the possibility of utilizing V. sinuatum extracts in pharmaceutical industry of new medications to fight drug resistant tumors in general and GST-induced tumors in particular

Biopolymers-oil interactions in expanded systems

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Thermogravimetric analysis of water release from wheat flour and wheat bran suspensions

Bran is hygroscopic and competes actively for water with other key components in baked cereal products like starch and gluten. Thermogravimetric analysis (TGA) of flour–water mixtures enriched with bran at different incorporation levels was performed to characterise the release of compartmentalised water. TGA investigations showed that the presence of bran increased compartmentalised water, with the measurement of an increase of total water loss from 58.30 ± 1.93% for flour only systems to 71.80 ± 0.37% in formulations comprising 25% w/w bran. Deconvolution of TGA profiles showed an alteration of the distribution of free and bound water, and its interaction with starch and gluten, within the formulations. TGA profiles showed that water release from bran-enriched flour is a prolonged event with respect to the release from non-enriched flour, which suggests the possibility that bran may interrupt the normal characteristic processes of texture formation that occur in non-enriched products

Caracterización de mezclas de almidones de mango y plátano pregelatinizados mediante diferentes condiciones de extrusión

Se prepararon almidones pregelatinizados (AP) a partir de mezclas de almidones de plátano y mango usando un extrusor de doble tornillo. Las variables independientes fueron ambos almidones y la velocidad del tornillo. Se estudiaron las características moleculares de los AP mediante difracción de rayos X y espectroscopia de infrarrojo con transformada de Fourier. También se determinó grado de gelatinización, índice de absorción en agua (IAA), índice de solubilidad en agua (ISA), y el contenido de almidón resistente (AR). Los almidones nativos de plátano y mango presentaron un patrón de difracción de rayos X tipo C y A, el cual se perdió en el proceso de extrusión. Estos resultados se corroboraron con el estudio de espectroscopia de infrarrojo, ya que la relación de absorbancias en los AP fue <1, indicando que se perdió la cristalinidad. El IAA y el ISA aumentaron a medida que la velocidad del tornillo y el porcentaje de almidón de mango en la mezcla se incrementaron. Se obtuvo una gelatinización casi completa en todas las muestras extrudidas. El contenido de AR se incrementó a medida que aumentó el contenido de almidón de plátano en el AP. Se obtuvieron AP con propiedades funcionales y un contenido de AR que sugiere aplicaciones en la industria de alimentos como un ingrediente nutraceútico

Analysis of the continuous phase of the modified waxy maize starch suspension

The continuous phase of the suspension of swollen-in-water modified waxy maize starch was analysed. The composition, concentration and molecular weight of the substance released from modified starch granules were determined. Starch granules were swollen in excess water at 73 °C and held at this temperature for 1 min. Centrifugation was used to separate the granules from the supernatant; the latter was then submitted to physico-chemical analysis. Surface tension measurements showed that the supernatant was different from pure water indicating the presence of dissolved polymeric material(s). Differential Scanning Calorimetry and iodine staining results revealed the presence of amylopectin. Analytical Ultracentrifugation and Size Exclusion Chromatography coupled with a Multi-angle Laser Light Scattering were used to determine the sedimentation coefficient and weight-average molecular weight of the soluble amylopectin fraction as well as giving an indication of solution concentration. The molecular weight of dissolved amylopectin was around 1.5 × 106 g/mol and its concentration in the supernatant varied from 0.6 to 6.7 mg/mL for initial 10 mg/mL and 50 mg/mL starch suspensions, respectively. The sedimentation coefficient, weight-average molecular weight and amylopectin concentration in the supernatant all increased non-linearly with the initial starch concentration in the suspension. © 2009 Elsevier Ltd. All rights reserved

Functionally Related Genes Cluster into Genomic Regions That Coordinate Transcription at a Distance in Saccharomyces cerevisiae

The two-dimensional, physical positioning of genes along a chromosome can impact proper transcriptional regulation throughout a genomic region. The transcription of neighboring genes is correlated in a genome-wide manner, which is a characteristic of eukaryotes. Many coregulated gene families can be found clustered with another member of the same set—which can result in adjacent gene coregulation of the pair. Due to the myriad gene families that exhibit a nonrandom genomic distribution, there are likely multiple mechanisms working in concert to properly regulate transcriptional coordination of functionally clustered genes. In this study, we utilized budding yeast in an attempt to elucidate mechanisms that underlie this coregulation: testing and empirically validating the enhancer-promoter hypothesis in this species and reporting that functionally related genes cluster to genomic regions that are more conducive to transcriptional regulation at a distance. These clusters rely, in part, on chromatin maintenance and remodelers to maintain proper transcriptional coordination. Our work provides insight into the mechanisms underlying adjacent gene coregulation.Balancing gene expression is a fundamental challenge of all cell types. To properly regulate transcription on a genome-wide level, there are myriad mechanisms employed by the cell. One layer to this regulation is through spatial positioning, with particular chromosomal loci exerting an influence on transcription throughout a region. Many coregulated gene families utilize spatial positioning to coordinate transcription, with functionally related genes clustering together which can allow coordinated expression via adjacent gene coregulation. The mechanisms underlying this process have not been elucidated, though there are many coregulated gene families that exhibit this genomic distribution. In the present study, we tested for a role for the enhancer-promoter (EP) hypothesis, which demonstrates that regulatory elements can exert transcriptional effects over a broad distance, in coordinating transcriptional coregulation using budding yeast, Saccharomyces cerevisiae. We empirically validated the EP model, finding that the genomic distance a promoter can affect varies by locus, which can profoundly affect levels of transcription, phenotype, and the extent of transcriptional disruption throughout a genomic region. Using the nitrogen metabolism, ribosomal protein, toxin response, and heat shock gene families as our test case, we report functionally clustered genes localize to genomic loci that are more conducive to transcriptional regulation at a distance compared to the unpaired members of the same families. Furthermore, we report that the coregulation of functional clusters is dependent, in part, on chromatin maintenance and remodeling, providing one mechanism underlying adjacent gene coregulation