ABSTRACT
Glycosaminoglycans (GAGs) play an important role in lipoprotein metabolism. In liver, it facilitates the uptake of remnants through receptor-independent endocytosis. However, changes in liver GAGs during diet-induced hypercholesterolemia with normal levels of fat feeding are unknown. Present paper highlights the effect of diet-induced hypercholesterolemia with normal levels (5%) of fat on liver GAGs and other associated lipoprotein receptors. Hypercholesterolemia was induced in rats by feeding diet supplemented with 0.5% cholesterol and 0.125% bile salts. Hypercholesterolemia showed significantly decreased GAGs of both heparan sulfate (HS) and chondroitin sulfate/dermatan sulfate (CS/DS) classes of molecules. Quantitative real-time polymerase chain reaction analysis of GAG biosynthetic enzymes and other genes revealed significant changes in expression profile. The decrease in GAGs was prevented by simvastatin treatment; a drug that inhibits endogenous cholesterol synthesis that was used as a positive control in our study. Furthermore, there was a comparatively decreased binding of GAGs from hypercholesterolemic rats to lipoprotein lipase. LRP1 which plays a major role in lipoprotein uptake was also significantly decreased, and it was attenuated in simvastatin-treated hypercholesterolemic rats. Furthermore, LDLR and ApoE were also decreased significantly in liver of hypercholesterolemic rats. Thus, diet-induced hypercholesterolemia results in dysregulation of cholesterol homeostasis apparently through changes in GAGs in conjunction with other associated players.
Subject(s)
Diet , Glycosaminoglycans/metabolism , Hypercholesterolemia/metabolism , Liver/metabolism , Receptors, Lipoprotein/metabolism , Animals , Hypercholesterolemia/etiology , RatsABSTRACT
Antioxidants present in various plant tissues exhibit health benefits by scavenging reactive oxygen species generated under various pathophysiological conditions. In the present study, bioactive compounds from black gram husk were extracted with water and the protection of black gram husk (BGH) extract against oxidative damage in DNA and erythrocytes were studied. BGH extract had total polyphenol content of 59 mg of gallic acid equivalents (GAE). The phenolic acids identified in the extract using RP-HPLC were gallic, protocatechuic, gentisic and ferulic acids. The extract showed good antioxidant properties. The IC(50) value for DPPH radical scavenging activity was found to be 3.92 µg of GAE. The BGH extract also showed α-glucosidase inhibition and the IC(50) value was found to be 2.78 µg of GAE. The oxidative hemolysis caused by hydrogen peroxide in rat erythrocytes was inhibited by BGH extract in a dose dependent manner. The IC(50) values for BGH extract and BHA for hemolysis were 11.5 and 14 µg of GAE, respectively. Morphological changes in erythrocyte membrane caused by hydrogen peroxide were protected by BGH extract. As BGH extract exhibited various antioxidant properties in different systems, it could be used as a functional food or nutraceutical product for health benefits.
Subject(s)
DNA Damage , DNA/drug effects , Erythrocytes/drug effects , Fabaceae/chemistry , Free Radicals , Oxidative Stress/drug effects , Plant Extracts/pharmacology , Animals , Antioxidants/pharmacology , Electrophoresis, Agar Gel , Electrophoresis, Polyacrylamide Gel , Erythrocytes/ultrastructure , Hemolysis/drug effects , Microscopy, Electron, Scanning , RatsABSTRACT
BACKGROUND: Chapati preparation involves various processing steps such as mixing the flour into dough, sheeting and baking. During these processing steps, flour components are likely to undergo changes in their nutrient and polyphenol composition and their antioxidant properties due to phenol-mediated crosslinking of proteins and carbohydrates. Therefore, in the present study, changes in nutritional, nutraceutical and antioxidant properties of chapatis prepared from doughs treated with amylases and xylanase were determined. RESULTS: An increase in insoluble dietary fibre content and a decrease in soluble polyphenol content were observed during preparation of control chapatis from whole wheat flours. However, significant increases in soluble dietary fibre and soluble polyphenol contents were observed in chapatis prepared from amylase-treated doughs compared with control chapatis. Extracts of chapatis prepared from amylase- and xylanase-treated doughs showed better antioxidant properties than extracts of control chapatis. Among these enzyme treatments, chapatis prepared from amylase-treated doughs showed better antioxidant properties than chapatis prepared from xylanase-treated doughs. High-performance liquid chromatography analysis of extracts of chapatis prepared from doughs treated with amylases showed the presence of potential antioxidant phenolic acids such as caffeic, gentisic and syringic acids in addition to the phenolic acids present in control chapatis. CONCLUSION: Treatment of doughs with amylases increased the contents of soluble dietary fibre and soluble polyphenols as well as improving the antioxidant properties of chapatis.
Subject(s)
Antioxidants/analysis , Bread/analysis , Dietary Fiber/analysis , Endo-1,4-beta Xylanases/metabolism , Flour/analysis , Polyphenols/analysis , alpha-Amylases/metabolism , Antioxidants/chemistry , Antioxidants/isolation & purification , Antioxidants/metabolism , Aspergillus oryzae/enzymology , Bacillus subtilis/enzymology , Bacterial Proteins/metabolism , Caffeic Acids/analysis , Caffeic Acids/chemistry , Caffeic Acids/isolation & purification , Chromatography, High Pressure Liquid , Diet/ethnology , Dietary Fiber/metabolism , Food Handling , Fungal Proteins/metabolism , Gallic Acid/analogs & derivatives , Gallic Acid/analysis , Gallic Acid/chemistry , Gallic Acid/isolation & purification , Gentisates/analysis , Gentisates/chemistry , Gentisates/isolation & purification , India , Polyphenols/chemistry , Polyphenols/isolation & purification , Polyphenols/metabolism , Quality Control , SolubilityABSTRACT
Parkinson's disease (PD) is a neurodegenerative disease with multiple etiologies. Advanced glycation end products (AGEs) accumulate in the aging brain and could be one of the reasons for age-related diseases like PD. Oxidative stress also leads to the formation of AGEs and may be involved in neurodegeneration by altering the properties of proteins. α-Synuclein is involved in pathogenesis of PD and there are limited studies on the role of AGE-α-synuclein in neurodegeneration. We studied the aggregation and DNA binding ability of AGE-α-synuclein in vitro. α-Synuclein is glycated using methylglyoxal and formation of AGE-α-synuclein is characterized using fluorescence studies, intrinsic tyrosine fluorescence, and fructosamine estimation. The results indicated that AGE-α-synuclein aggregates into smaller globular-like aggregates compared to fibrils formed with native α-synuclein. Further, it is found that AGE-α-synuclein induced conformational changes in scDNA from B-form to B-C-A mixed conformation. Additionally, AGE-α-synuclein altered DNA integrity as evidenced by the melting temperature, ethidium bromide, and DNAse I sensitivity studies. AGE-α-synuclein converted biphasic Tm to higher monophasic Tm. The Tm of AGE-α-synuclein-scDNA complex is more than that of native α-synuclein-scDNA complex, indicating that AGE-α-synuclein stabilized the uncoiled scDNA. AGE-α-synuclein could stabilize the uncoiled scDNA, as shown by the decrease in the number of ethidium bromide binding molecules per base pair of DNA. DNAse I sensitive studies indicated that both AGE-α-synuclein-scDNA and α-synuclein-scDNA are resistant to DNAse I digestion. The relevance of these findings to neuronal cell death is discussed.
