Survey of potential diagnostic metabolite markers in serum of the rat model of alzheimer�s disease using nuclear magnatic resonance (1H-nmr) technique

Introduction: The high prevalence of Alzheimer's disease (AD) in today's societies indicates an urgent need for the development of methods that will help the early diagnosis of the disease. In this study, using proton nuclear magnetic resonance spectrometry (1H-NMR) metabolomics, identification of altered and distinct metabolites in serum of the rat model of AD was performed compared with healthy controls with the aim of introducing potential markers and to further understand the mechanisms of the AD. Materials and Methods: Serum samples from 25 adult male rats (10 healthy and 15 AD) were collected and their metabolites were extracted and analyzed using 1H-NMR technique. Differential metabolite profile was then determined by multivariate statistical analysis. The behavioral screening of the model rats was performed by the paired-associated learning method. Results: The results of the behavioral study showed the impairment of memory abilities in AD rats. Differential metabolites between the two groups were identified by multivariate analysis methods such as OPLS and Random Forest. Importantly, the results showed that there were differences in the pathways related to energy and amino acid metabolism between the control group and the Alzheimer's model. Conclusion: This research opens new horizons to identify biomarkers and physiological pathways involved in Alzheimer�s disease. The introduced metabolites must be confirmed by further studies and might be used as candidate biomarkers for early detection of the disease. © 2021, Semnan University of Medical Sciences. All rights reserved

Effect of ghrelin on serum metabolites in Alzheimer’s disease model rats; a metabolomics studies based on 1H-NMR technique

Objective(s): Alzheimer’s disease (AD) is dysfunction of the central nervous system and as a neurodegenerative disease. The objective of this work is to investigate metabolic profiling in the serum of animal models of AD compared to healthy controls and then to peruse the role of ghrelin as a therapeutic approach for the AD.Materials and Methods: Nuclear magnetic resonance (NMR) technique was used for identification of metabolites that are differentially expressed in the serum of a rat model of the AD with or without ghrelin treatment. Using multivariate statistical analysis, models were built and indicated.Results: There were significant differences and high predictive power between AD and ghrelin-treated groups. The area under curve (AUC) of receiver operating characteristic (ROC) curve and Q2 were 0.870 and 0.759, respectively. A biomarker panel consisting of 14 metabolites was identified to discriminate the AD from the control group. Another panel of 12 serum metabolites was used to differentiate AD models from treated models. Conclusion: Both panels had good agreements with clinical diagnosis. Analysis of the results displayed that ghrelin improved memory and cognitive abilities. Affected pathways by ghrelin included oxidative stress, and osteoporosis pathways and vascular risk factors

Laboratory scale optimization of alkali pretreatment for improvingenzymatic hydrolysis of sweet sorghum bagasse

Sweet sorghum has been identified as a promising feedstock for biological conversion to fuels as wellas other chemicals. The lignocellulosic stalk of sweet sorghum, called sweet sorghum bagasse (SSB) isa potential source of lignocellulosic biofuel. The primary goal of this study was to determine optimalalkali (lime: Ca(OH)2and lye: NaOH) pretreatment conditions to obtain higher yield of total reducingsugar while reducing the lignin content for biofuel production from SSB. Biomass conversion and ligninremoval were simultaneously optimized through four quadratic models analyzed by response surfacemethodology (RSM). The optimal conditions for lime pretreatment was 1.7% (w/v) lime concentration,6.0% (w/v) SSB loading, 2.4 h pretreatment time with predicted yields of 85.6 total biomass conversionand 35.5% lignin reduction. For lye pretreatment, 2% (w/v) alkali, 6.8% SSB loading and 2.3 h durationwere the optimal levels with predicted biomass conversion and lignin reduction of 92.9% and 50.0%,respectively. More intensive pretreatment conditions removed higher amounts of hemicelluloses andcellulose. Fourier transform infrared spectroscopy (FTIR) spectrum and scanning electron microscope(SEM) image revealed compositional and microstructural changes caused by the alkali pretreatment

Current pretreatment technologies for the development of cellulosic ethanol and biorefineries

Lignocellulosic materials, such as forest, agriculture, and agroindustrial residues, are among the most important resources for biorefineries to provide fuels, chemicals, and materials in such a way to substitute for, at least in part, the role of petrochemistry in modern society. Most of these sustainable biorefinery products can be produced from plant polysaccharides (glucans, hemicelluloses, starch, and pectic materials) and lignin. In this scenario, cellulosic ethanol has been considered for decades as one of the most promising alternatives to mitigate fossil fuel dependence and carbon dioxide accumulation in the atmosphere. However, a pretreatment method is required to overcome the physical and chemical barriers that exist in the lignin–carbohydrate composite and to render most, if not all, of the plant cell wall components easily available for conversion into valuable products, including the fuel ethanol. Hence, pretreatment is a key step for an economically viable biorefinery. Successful pretreatment method must lead to partial or total separation of the lignocellulosic components, increasing the accessibility of holocellulose to enzymatic hydrolysis with the least inhibitory compounds being released for subsequent steps of enzymatic hydrolysis and fermentation. Each pretreatment technology has a different specificity against both carbohydrates and lignin and may or may not be efficient for different types of biomasses. Furthermore, it is also desirable to develop pretreatment methods with chemicals that are greener and effluent streams that have a lower impact on the environment. This paper provides an overview of the most important pretreatment methods available, including those that are based on the use of green solvents (supercritical fluids and ionic liquids)

Ultrasound irradiation in the production of ethanol from biomass

Ethanol produced from renewable biomass, such as lignocellulosic feedstock, is one of the alternative energy resources that can be environmentally friendly. However, physical and chemical barriers caused by the close association of the main components of lignocellulosic biomass, as well as starch, hinder the hydrolysis of cellulose and hemicellulose in lignocellulose as well as amylase and amylopectin in starch to fermentable sugars. One of the main goals of pretreatment for enzymatic hydrolysis is to increase the enzyme accessibility for improving digestibility of cellulose and starch. Ultrasound irradiation applied to cellulosic materials and starch-based feedstock was found to enhance the efficiency of hydrolysis and subsequently increase the sugar yield. Prior research conducted on applying ultrasonic technology for cellulose and starch pretreatment has considered a variety of effects on physical and chemical characteristics, hydrolysis efficiency and ethanol yield. This paper reviews the application of ultrasound irradiation to cellulose and starch prior to and during hydrolysis in terms of sugar and ethanol yields. It also addresses characteristics such as accessibility, crystallinity, degree of polymerization, morphological structure, swelling power, particle size and viscosity as influenced by ultrasonic treatment. © 2014 Elsevier Ltd

Modified sensory processing in the barrel cortex of the Rat model of Alzheimer’s disease

Background and Objective: Alzheimer’s disease is caractrized by brain degenerative alterations with subsequent learning and memory loss. Learning and memory is closely associated with brain colinergic system. Colinergic fibers originated from minent basal nucleus which is extended to cortex and hippocampus. This study was conducted to investigate sensory processing in the barrel cortex neurons of Rat model of Alzheimer’s disease. Materials and Methods: In this experimental study, 14 male Wistar Rats weighing 250-350g randomly divided into control and experimental groups. Alzheimer’s disease in Rats induceted, by infusion of ibotenic acid (5 µg/µl in each site) into nucleus basalis of Meynert (NBM) using Hamilton syringe and stereotaxic apparatus. The control group was non-lesion Rats with vehicle treatment. Two weeks after NBM-lesion, each animal was tested by passive avoidance learning (PAL), then neural response assessed by extracellular recording. Results: In cases, ibotenic acid infusion into NBM, significantly reduced memory (P<0.05). The results evoked by multiple whisker stimulation in extracellular single unit recording showed that in Alzheimer’s disease model of animals excitatory receptive field (RF) of neurons were extended but inhibitory RF was decreased (P<0.05). In addition the magnitude of neural response following principal whisker deflection decreased in cases (P<0.05). Conclusion: This study indicated that in animal model of Alzheimer’s disease possibly reduce sensory processing and contact discrimination