Biochemistry
Milad Saffary; Zolfaghar Lotfi; Amir Arasteh
Abstract
Aloysia citrodora is very important in Iranian traditional medicine. The aim of this study was to produce silver nanoparticles with aqueous extract of A. citrodora and investigate its antioxidant and inhibitory effects on the amyloid nanofibers from BSA as model protein. For synthesis of silver nanoparticles, ...
Read More
Aloysia citrodora is very important in Iranian traditional medicine. The aim of this study was to produce silver nanoparticles with aqueous extract of A. citrodora and investigate its antioxidant and inhibitory effects on the amyloid nanofibers from BSA as model protein. For synthesis of silver nanoparticles, aqueous A. citrodora extract was prepared and one mM silver nitrate was added to solution. To confirm the presence and determine the size of silver nanoparticles, UV-Vis spectroscopy and TEM were used. The antioxidant effect of the extract was evaluated by DPPH and the production of amyloid fibers was measured by Congored absorption method. The toxicity effect of nanoparticles on neuroblasts was investigated by MTT method and the inhibitory properties of the extract on amyloid production were investigated by TEM. Caryophyllene (7.66%), phytol (7.47%) and limonene (2.68%) were the most abundant compounds. TEM also confirmed spherical crystalline nanoparticles with a size between 30–70 nm. By increasing the concentration of the extract, the antioxidant properties of nanoparticles increased, so that 97.35% of DPPH free radicals were inhibited at a concentration of 1 mg/ml. The highest inhibition of amyloid fibrils production was observed at concentration of 2 mg/ml by 96%, and the highest level of cytotoxicity at a concentration of 2 and with an IC50 of 2.25 mg/ml. The results showed that nanoparticles from A. citrodora leaves with anti–amyloid, antioxidant and anticancer properties can be considered as a new bio–nanomaterial in reducing Alzheimer's and cancer complications.
tahereh Nikkhah; Amir Arasteh
Abstract
Diabetes and liver diseases are serious problems and threaten the health of communities. Nettle has been introduced in traditional Iranian medicine as a blood glucose lowering drug. There are conflicting scientific reports about the effects of reducing the blood sugar of nettle, but this plant has good ...
Read More
Diabetes and liver diseases are serious problems and threaten the health of communities. Nettle has been introduced in traditional Iranian medicine as a blood glucose lowering drug. There are conflicting scientific reports about the effects of reducing the blood sugar of nettle, but this plant has good antioxidant and anti-inflammatory properties to reduce liver damage. Current study, examines the anti-diabetic and liver protective effects of the aqueous extract of urtica dioica in vistar male rats. The mice were divided into five groups and in order to investigation of anti-diabetic and liver protective effects, test groups obtained daily 2.5 and 5 ml/kg of the aqueous extract of urtica dioica orally for 14 and 32 days, respectively. Blood glucose was measured with a glucometer and liver enzyme activity was measured with ParsAzmoon kits. The results were analyzed using Student's T–Test and ANOVA using SPSS software version 21. Blood sugar levels in first and second test groups (170 and 122 mg/dl) showed a significant decrease compared to the negative control group (446 mg/dl). The activity of liver enzymes in the first and second test groups also showed a significant decrease compared to the negative control group. The aqueous extract of urtica dioica has beneficial effects in managing diabetes and maintaining the health of liver cells against toxic compounds.
Fereshteh Fallah Digsara; Amir Arasteh
Abstract
Soybean (Glycine max) is a plant of the legume family and one of the most important oil plants. Soybean is rich in various proteins and phytochemicals, especially isoflavones. The aim of this study was to investigate the antioxidant and inhibitory effects of hydro-alcoholic extract of soybean seed on ...
Read More
Soybean (Glycine max) is a plant of the legume family and one of the most important oil plants. Soybean is rich in various proteins and phytochemicals, especially isoflavones. The aim of this study was to investigate the antioxidant and inhibitory effects of hydro-alcoholic extract of soybean seed on acetyl cholinesterase and production of amyloid nanobiofibrils in bovine serum albumin protein as a model protein. First, the yellow soybean seeds was powdered, then its hydro-alcoholic extract was prepared. The extracts composition were obtained by GC-MS spectroscopy. Anti-Alzheimer's effects were performed by measuring antioxidant activity by DPPH method, Inhibition of acetylcholinesterase by ellman method and inhibition of the production of amyloid nanobiofibrils by congored absorption method. Transmission electron microscopy was used to confirm the presence of amyloid fibrils. The presence of genistein active component in yellow soybean seed extract was confirmed by 2.97% and palmitic and linoleic acids by 3.11 and 10.69%, respectively. Investigation of antioxidant activity of soybean extract in different doses showed that with increasing the concentration of the extract, the percentage of antioxidant activity also increases. Investigation of acetylcholinesterase inhibition using a substrate analogue called acetylthiocholine iodide (ATCI) showed that with increasing the concentration of the extract, the amount of enzyme inhibition increases. The amounts of extract at high concentrations reduced the production of amyloid nanofibrils. This was confirmed by electron microscope images.Yellow soybeans, with their good antioxidant and inhibitory effects on the acetylcholinesterase enzyme, can be a good candidate for reducing the side effects of Alzheimer's.
Sara Ttajdoust; Amir Arasteh; Seyedeh Mohadeseh Mousavi Eshkiky
Abstract
Nigella sativa is an annual herbaceous plantthat has various pharmacological effects. In this research study, anti–microbial and anti–Alzheimer effects of aqueous and hydro–alcoholic extracts of N. sativa were evaluated. After identification of hydro–alcoholic extract compounds ...
Read More
Nigella sativa is an annual herbaceous plantthat has various pharmacological effects. In this research study, anti–microbial and anti–Alzheimer effects of aqueous and hydro–alcoholic extracts of N. sativa were evaluated. After identification of hydro–alcoholic extract compounds by GC–MS, anti–microbial activity indices including well diffusion, MIC and MBC for E. coli and S. aureus, were carried out by tube and agar dilution methods. In Anti–Alzheimer's effects of hydro–alcoholic extract of N. sativa on bovine serum albumin were examined using Congo–red spectrophotometry and transmission electron microscopy. Oleic acid (52.18%) followed by palmitic (19.77%) and linoleic acid (14.96%) were the major fatty acids in the extract. The amounts of MIC and MBC for both E. coli and S. aureus were 30.6 and 61 mg.ml-1 respectively in hydro–alcoholic extract. Well diffusion method showed highest antimicrobial activity against S. aureus with inhibition zone diameter of 22.67±0.29 mm, but aqueous extract did not any effects on bacteria. Congo–red spectrophotometry results showed that the absorbance of the protein sample (as a measure of amyloid fibril presence) was reduced by increasing the concentration of N. sativa extract and the lowest percentage of adsorption, compared to the control (extract less), was observed at the highest concentration of extract (20 μL). These results were confirmed by transmission electron microscope. The present study shows that the N. sativa seed, as a natural and valuable source, can be used for controlling the microbial infections and reducing symptoms in patients with Alzheimer's disease.
Amir Arasateh; Samira Vaziri; Mohammad Fazilati; Habib-ollah Nazem
Volume 7, Issue 1 , September 2018, , Pages 55-72
Abstract
Abstract Amyloids are created from various proteins in denaturant conditions. Highly active surface, makes these materials suitable for enzyme immobilization. The aim of this research was to study the production of amyloid fibrils and investigate the possibility of using them as a matrix for enzyme immobilization. ...
Read More
Abstract Amyloids are created from various proteins in denaturant conditions. Highly active surface, makes these materials suitable for enzyme immobilization. The aim of this research was to study the production of amyloid fibrils and investigate the possibility of using them as a matrix for enzyme immobilization. Response surface methodology (RSM) was used to generate the maximum amyloid content. The results of the Congored spectrometry and circular dichroism (CD) were analyzed by Design Expert 7 software (Trial version) and transmission electron microscopy was used to confirm the presence of amyloid fibrils. The immobilization was done by creating glutaraldehyde mediated crosslink of enzyme on the amyloid fibrils and kinetic factors including activity, specific activity, optimal temperature and pH and thermal stability were compared with the free enzyme. The highest amyloid content was obtained after 72.6 hours agitation of bovine serum albumin at 4.35 mg.ml-1 in mixed citrate–phosphate buffer pH=4.49 at 80 ºC and immobilized lipase was improved relative to free lipase in the case of activity, specific activity, Km and Vmax, optimal temperature and pH and thermal stability at 40 ºC. Amyloid fibrils as a rich material of chemical groups can be suitable for stabilization. This protein matrix can be a good inVivo candidate as a bio–compatible scaffold for enzyme immobilization. Amyloids with a diameter less than 100 nanometers, as new nano–materials, not only increase the stability of lipase but also enhance other kinetic properties as a new nano–matrix.
Amir Arasteh; Zolfaghar Lotfi; Mohammad Fazilati; Habibollah Nazem
Volume 6, Issue 3 , March 2018, , Pages 11-25
Abstract
The urease enzyme (EC.3.5.1.5) is from hydrolase group that catalyzes urea hydrolysis to ammonia and carbon dioxide. This enzyme has various applications in nitrogen metabolism, vaccine preparation, urea diagnosis kits, drinking industries, and so on. In this study, amyloid nano-fibrils from bovine serum ...
Read More
The urease enzyme (EC.3.5.1.5) is from hydrolase group that catalyzes urea hydrolysis to ammonia and carbon dioxide. This enzyme has various applications in nitrogen metabolism, vaccine preparation, urea diagnosis kits, drinking industries, and so on. In this study, amyloid nano-fibrils from bovine serum albumin were used as a new scaffold for immobilizing the urease enzyme. The production of amyloid nano–fibers has been optimized with three techniques of Congord specrophotometry, Spectrofluorimetry and Spectropolarimetry, and the resulting fibrils have been confirmed by electron microscopy images. Then the urease enzyme was immobilized on the amyloid fibrils using glutaraldehyde molecules via cross-linked bridges and their kinetic factors were compared with the free enzyme. The highest amount of amyloid fibrils was obtained after 48 hours incubation of bovine serum albumin at a concentration of 10 mg.ml-1 and 70 ºC in a citrate-phosphate buffer pH 4. The immobilized enzyme had more reusability and stability than the free form and showed a higher activity and a smaller Km. Optimum temperature was improved from 40 ºC to 70 ºC and optimum pH was also improved from 6–7 to 6–9 in immobilized enzyme. In conclusion, amyloid fibrils with different chemical groups have been suitable for immobilization of urea enzyme. Improvement of kinetic properties and stability of urease enzyme by immobilizing on amyloid fibers allows for the widespread use of this enzyme in the related industries.
Amir Arasteh; Zolfaghar Lotfi; Mohammad Fazilat; Habibollah Nazem
Volume 6, Issue 2 , December 2017, , Pages 127-137
Abstract
Amyloid fibrils are a class of protein nanoparticles in which native proteins are converted into dense fibers. The aggregation can be pathogenic or non-pathogenic. Recently, these fibrils have been considered for the production of Bio–nanomaterials due to their unique structure. In this study, ...
Read More
Amyloid fibrils are a class of protein nanoparticles in which native proteins are converted into dense fibers. The aggregation can be pathogenic or non-pathogenic. Recently, these fibrils have been considered for the production of Bio–nanomaterials due to their unique structure. In this study, Bovine serum albumin was used as a model protein to optimize the fibrillation process. Concentrations of 2-10 mg/ml were prepared in buffer at different pH values of 3-7 and placed at 0-70 ºC for 0 to 48 hours, and the amounts of produced amyloid fibrils were analyzed by spectrophotometry, fluorimetry and circular dichroism. The spectra obtained from the Congo red absorption method were compared on the basis of the maximum wavelength and absorption at maximum wavelengths with a sample containing Congo red. The concentration of 10 mg/ml of protein, which was 48 hours in buffer at pH = 4 at 50 ºC, produced the highest amounts of amyloid. Optimum conditions were obtained by ThT fluorescence and circular dichroism at a concentration of 10 mg/ml, pH = 4, 70 ºC and 48 hours. The presence of the fibers was confirmed by transmission electron microscope images. The insoluble structure and dimensions of amyloid fibrils can be describe them as new Bio–nanomaterials. Optimizing the production of these structures allows them to be produced at higher scales.
