Biochemistry
Mostafa Zakariazadeh; Reza Haji Hosseini; Reza Khodarahmi; Somaieh Soltani
Abstract
Alzheimer's disease is the most prevalent neurodegenerative disorder affecting the central nervous system. It is crucial to prevent and treat this disease. One of the objectives in treating Alzheimer's disease is to impede the function of the butyrylcholinesterase enzyme. Phloretin and trilobatin are ...
Read More
Alzheimer's disease is the most prevalent neurodegenerative disorder affecting the central nervous system. It is crucial to prevent and treat this disease. One of the objectives in treating Alzheimer's disease is to impede the function of the butyrylcholinesterase enzyme. Phloretin and trilobatin are natural polyphenolic dihydrochalcone compounds. Trilobatin is the glycosylated derivative of phloretin. Studies have indicated the efficacy of these compounds in enhancing learning and memory as well as neuroprotective properties. The effect of these compounds on the inhibition of butyrylcholinesterase activity has been investigated in this study. The results were compared in terms of inhibitory activity and molecular mechanism of interaction for each compound. It was found that phloretin and trilobatin inhibited enzyme activity by 42% and 25%, respectively. Prediction of compounds ADMET parameters was done. Molecular docking was utilized to survey the binding mode of compounds, interaction type, and calculate the binding free energy. According to the molecular docking result, the mean binding free energy for the enzymes' interaction with phloretin and trilobatin was calculated to be -6.64(±0.35) and -5.92(±0.93) kcal/mol, respectively. The presence of a glycosylated group in the trilobatin structure increases the number of rotatable bonds, hydrophilicity, and steric hindrance. It seems that these factors reduce the inhibition activity of trilobatin against enzyme in comparison to phloretin. Based on the presented study, these compounds generally don’t have high inhibitory activity, but they can be regarded as key components in the development of novel anti-Alzheimer's drugs or as components of natural anti-Alzheimer's supplements.
Medical physiology
Sima Nasri; Mohammad Oraki; Nadereh Amin
Abstract
Aging is a natural process and increase of age in synchronized societies is associated with behavioral and physiological challenges. The most important of these challenges are the three indicators of perceived stress, depression and cortisol hormone. This research was conducted to compare levels of cortisol ...
Read More
Aging is a natural process and increase of age in synchronized societies is associated with behavioral and physiological challenges. The most important of these challenges are the three indicators of perceived stress, depression and cortisol hormone. This research was conducted to compare levels of cortisol hormone with perceived stress and depression in elderly women living in private old people’s homes and private houses in Tehran. The statistical population included elderly women aged between 65 to 75 years old that were residents of the private old people’s homes and private houses in Tehran. Data were collected by the Beck Depression Inventory, Perceived Stress Scale developed by Sheldon Cohen, and determination of serum cortisol levels in the laboratory. The results of this study showed that levels of cortisol hormone and depression in elderly women living in the private old people’s homes and private houses had a significant difference (p <0.05). The perceived stress variable had no significant difference. The difference in depression rate may be due to family relationships and the presence of family members at the private houses, and non-existence of difference in the perceived stress rate and its inverse ratio with increase of age may be due to the experience and credibility of events in the world. Considering the impact of the living environment on the psychological problems in the elderly, national measures should be taken to improve the quality of life of the elderly and to empower them through social and governmental movements.
Biophysics
AbdolJabbar Shokri; Shahryar Saeedyan; Hamed Heidari; Aram Azizi; Zohre-Sima Gilani
Abstract
Breast cancer remains a significant global health concern, necessitating the development of innovative treatment approaches. Magnetic nanoparticles (MNPs) have emerged as a promising tool in cancer therapy due to their unique properties and controllable behavior under external magnetic fields. In this ...
Read More
Breast cancer remains a significant global health concern, necessitating the development of innovative treatment approaches. Magnetic nanoparticles (MNPs) have emerged as a promising tool in cancer therapy due to their unique properties and controllable behavior under external magnetic fields. In this paper, a two-dimensional simulation model has been used to investigate the potential of magnetic nanoparticles for breast tumor treatment. The model considers factors such as the type and size of nanoparticles, the behavior of the particles in the presence of an applied magnetic field, and the effects of MNPs on tumor tissue. Additionally, the duration of time that nanoparticles are exposed to alternating electromagnetic fields was modeled using the finite element method and Comsol Multiphysics software package. The calculation results demonstrate that the extent of tumor and healthy tissue destruction depends on the type of nanoparticles. Furthermore, an increase in the diameter of nanoparticles leads to a decrease in the percentage of tumor tissue destruction. It is important to note that increasing the amount of heating only results in more destruction of healthy tissues, thus the most significant destruction occurred within 50 minutes.
Jalil Sarhangzadeh; Ahad Sotoudeh
Abstract
Brown bear (Ursus arctos) is classified as a Least Concern (LC) species of the International Union for Conservation of Nature (IUCN), but its distribution have decreased as the largest carnivore in the country during last decades, and hence it is important to protect its habitats. In this research, the ...
Read More
Brown bear (Ursus arctos) is classified as a Least Concern (LC) species of the International Union for Conservation of Nature (IUCN), but its distribution have decreased as the largest carnivore in the country during last decades, and hence it is important to protect its habitats. In this research, the habitat suitability of brown bear in Arasbaran biosphere reserve, as one of the most important habitats of this species in the northwest of Iran, was considered. For the habitat suitability modeling of this species, Ecological Niche Factor Analysis (ENFA) method and ENFA software were used. Results showed that 23.6% (20245ha) of Arasbaran biosphere reserve were suitable for species. The suitable habitats were recognized to be in areas with elevation range of 900 to 2400 meters above sea level, 30 to 70 percent of slope. In addition, the variables of forest with 75-100% canopy cover, semi-humid climate, elevation range of 1500-2000 meters above sea level, Northern hillsides, 45 to 70 percent of slope, humid climate, permanent rivers, forest with 50-75% canopy cover have the most effect on the selection of the species habitat. The suitable habitats for brown bear are generally distributed in the Oskuloo, Makidi, Hejrandost, Aliabad, Naposhteh, Balasang, Ilankesh, Abasabad and Khril. Prevention of development (Tourism) in the suitable habitats of brown bear, and, determination of corridors and movement routs of the species outside of the Arasbaran Biosphere Reserve in future studies were suggested in the route of this research.
Animal physiology
Seyed Reza Pourrabie
Abstract
Alzheimer's disease is one of the most common neurodegenerative diseases. Beta-amyloid plaques and neurofibrillary tangles are two important factors in Alzheimer's disease. Many cellular changes, such as oxidative stress, neuronal inflammation, and mitochondrial disorders are also seen in Alzheimer's ...
Read More
Alzheimer's disease is one of the most common neurodegenerative diseases. Beta-amyloid plaques and neurofibrillary tangles are two important factors in Alzheimer's disease. Many cellular changes, such as oxidative stress, neuronal inflammation, and mitochondrial disorders are also seen in Alzheimer's disease, which lead to neuronal death. Kaempferol, one of the plant flavonoids derived from the chamomile plant, has important effects on disorders related to brain diseases such as Alzheimer's disease due to the production of antioxidants.In this study, the effects of chamomile plant flavonoids on memory disorders in Alzheimer's rats were studied. For prepare and purify kaempferol, the hydroalcoholic extract of the collected chamomiles, and quantitative-qualitative analysis of the chemical substances of the chamomile extract using gas chromatograph connected to mass spectrometer (GC/MS) method were used. In this study, we used of 56 adult male rats were divided into 7 groups including control - vehicle 1 (kaempferol solvent) - vehicle 2 (streptozotocin drug solvent) - Alzheimer's - kaempferol 120mg/kg - kaempferol 250mg/kg - kaempferol 400mg/kg. Diabetes was induced by injecting a single dose of 60 mg/kg streptozotocin intraperitoneally. Kaempferol were administered for 15 days. The shuttle box device was used to measure memory and learning, and the delay time in the shuttle box was recorded. The results were analyzed by SPSS 22 software, ANOVA and Tokay tests. The significance of the data difference was considered at the p ≤ 0.05 levels. The results of the data analysis showed that the doses of 400 mg/kg and 250 mg/kg of kaempferol of chamomile plant significantly increased the delay time in entering the dark section at p≤0.001 compared to the control group and improved spatial memory in rats. Which does this effect is probably due to the presence of compounds such as quercetin and phytoestrogens. Also, oxidative stress parameters were significantly reduced in Alzheimer's groups treated with chamomile flavonoids (P < 0.001) . The results of the experiments show that plant flavonoids are able to restore the spatial memory and oxidative stress parameters of the groups treated with streptozotocin to normal levels.
Biochemistry
Asieh Emami Nejad; Mohammad Fazilati; Hossein Salavati; Habiballah Nazem
Abstract
The use of protease enzymes and their stabilization has been greatly expanded due to application in various industries. Alkaline serine protease enzymes are very important due to their thermal stability, activity and stability. In this study, a new approach to increase the half-life of alkaline serine ...
Read More
The use of protease enzymes and their stabilization has been greatly expanded due to application in various industries. Alkaline serine protease enzymes are very important due to their thermal stability, activity and stability. In this study, a new approach to increase the half-life of alkaline serine protease enzymes using selenium and calcium nanoparticles was presented. Due to its high biocompatibility, toxicity, and low cost, these nanoparticles have become one of the most prominent non-metallic oxide nanoparticles, which, with their antioxidant and anti-inflammatory properties, can protect against the destruction of enzymes by free radicals. The results showed that these nanoparticles can significantly increase the half-life of these enzymes. On the other hand, the serine protease enzyme immobilized on selenium nanoparticles has unique biochemical characteristics in the presence and absence of calcium. The obtained results indicate that the stabilized enzyme has high activity and stability in a wide range of temperatures and pH compared to pure and impure-free enzyme. The results showed that the enzyme immobilized on selenium nanoparticles increased its activity by more than 99% in the presence of calcium at the temperature of 45°C. On the other hand, the half-life of the free enzyme increased from 95 minutes in the pure form to 115 minutes in the form immobilized on nanoparticles in the presence of calcium. These results indicate that the presence of nanoparticles can prevent the destruction of enzymes by free radicals.
Biochemistry
Shahin Ahmadi; Shahram Lotfi; leila shamakhi; Ali Azimi
Abstract
The increasing use of pesticides following the rising in agricultural, demand has threatened non-target organisms such as avian species and disrupted the ecological system. Therefore, considering the application methods and the nature of chemical pesticides, testing their toxicity level on birds, and ...
Read More
The increasing use of pesticides following the rising in agricultural, demand has threatened non-target organisms such as avian species and disrupted the ecological system. Therefore, considering the application methods and the nature of chemical pesticides, testing their toxicity level on birds, and protecting various species of endangered birds is an essential requirement from the point of view of ecosystem safety. In this study, quantitative structure-toxicity relationships modeling was done for the first time to estimate the toxicity of 244 types of pesticides on five different species of birds consist of bobwhite quail (C. virginianus), mallard duck (A. platyrhynchos), house sparrow (P. domesticus), ring-necked pheasant (P. colchicus), and Japanese quail (C. japonica). All data were randomly divided into four series including active training, passive training, calibration, and test sets. Hybrid optimal descriptors, resulting from the combination of quasi-SMILES descriptors and hydrogen- suppressed graph (HSG) based on a new target function, were used to generate QSTR models. Four target functions (TF0, TF1, TF2, TF3) were used to develop QSTR models and the predictive potential of these models was evaluated using a validation set. The QSTR models designed using TF3 target function with the range of R2 = 0.7218-0.8131 and Q2 = 0.7031-0.7878 for the validation set were statistically the best models. Statistically, the best model is model number six, with R2 values for active training, passive training, calibration, and validation sets equal to 0.836, 0.852, 0.806, and 0.813, respectively. The mean absolute error (MAE) values for the sets of active training, passive training, calibration and validation are 0.371, 0.342, 0.409 and 0.362, respectively, indicating the accuracy of the model created to predict the toxicity of pesticides against five species of endangered birds. From the results of this modeling, important descriptors were identified for increasing and decreasing the average effective toxicity concentration (pLD50) of pesticides. Using the QSTR models obtained from this study, it becomes possible to predict the toxicity (pLD50) of new pesticides even before their synthesis by only having the SMILES symbol of the pesticides, which can help to reduce time, resources, costs and the need for laboratory animals.
