سال:1395 | دوره: | شماره: |تعداد مقالات:7

Fasting has numerous biological, physical and mental health advantages or that as some physicians cure their patients by prescribing fasting to them. Fasting protects people from many diseases such as cancer, cardiovascular diseases, and diabetes complications. The main fasting health-promoting effects includes amplification of neurotrophic factors, activation of neuroendocrine system, the response of hormetic stress, decrement in mitochondrial oxidative stress, and autophagy promotion. This article briefly describes the molecular view of the effects of fasting on human health, according to our laboratory results, which are obtained by biophysical and biochemical methods. Based on our results, the presence of 3-β-hydroxybutyrate (BHB) as a liver produced metabolite in the fasting condition protects the body against toxicity of human serum albumin and insulin glycation products. Our results demonstrated that, BHB protects protein against sugar binding, inhibits the alteration of the protein structure and diminishes AGEs formation. By this way, BHB inhibits friend to foe transformation in proteins to protect us against diabetic complications.

The myocardial effect of snake venoms is considered as one of the most common pathogenesis in many cases of snake envenomation. This study was undertaken to investigate the effects of the Iranian cobra (Naja naja oxiana) venom on cardiac function in experimental animals. The blood samples from all the rabbits were collected before venom injection, and then 140 μ g kg-1 venom of snake (Naja naja oxiana) was injected intramuscularly to the rabbits. Following venom injection the blood was collected again at 1, 3 and 24 h. Electrocardiogram (ECG) was recorded during the experiment. The levels of serum enzymes lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB) and creatine phosphokinase (CPK) were determined. Statistical analyses were carried out by SPSS version 21 software. CPK enzyme showed a significant increase at 1 and 3 h after venom injection. The level of CK-MB also rose significantly after 1 h following venom injection. However, even at 24 h the level of CPK was not changed significantly, and the rise in CK-MB at 3 and 24 h following venom injection was not significant statistically. Although there was a rise in LDH level following venom injection but it was not significant. The ECG also confirmed changes in heart rhythmic and showed bradycardia and T tall. Based on the results obtained in the present study, it seems that the Naja naja oxiana venom has acute effect on cardiac system during the first few hours of snake bite.

Enzyme-based biofuel cells (EBFCs) are systems that use a variety of organic compounds to produce electricity through oxidoreductase enzymes, such as oxidase or dehydrogenase as biocatalysts immobilized on electrodes. In this study, a single-chamber EBFC consisting of carbon electrodes that operating at ambient temperature in phosphate buffer, pH 7 is reported. The EBFC anode was based on glucose oxidase (GOx) enzyme from Aspergilus niger immobilized on carbon fiber electrode based on carbon nanotube (CNT) and Nafion. The cathode was air-breathing based on Pt/C. The GOx/CNT/Nafion-based bioanode and air-breathing cathode were combined into a functional EBFC. The operation of EBFC was carefully investigated by use of glucose/O2 as substrate and oxidant, respectively. The maximum power delivered by the assembled biofuel cell in stationary state, reached 106. 4 μ W cm-2 at 0. 45 V with 0. 2 M glucose at 25 ° C. Also the best Results of the fabricated cell show that present biofuel cell could be used as a power source to generate electricity for small power bioelectronic devices.

The present work describes the construction of a new modified electrode by casting the appropriate mixture of a metallocene, which has been introduced in the experimental part, as a mediator at the surface of glassy carbon (GC) electrode. The proposed modified GC electrode was used for the determination of ascorbic acid (AA) in phosphate buffer (PB) solution (pH = 4. 0). When compared to bare GC electrode, the modified electrode not only shifted the oxidation potential of AA towards less positive potential but also enhanced its oxidation peak current. Further, the oxidation of AA was highly stable at modified electrode. The optimum analytical conditions were sought. The oxidation peak of AA increases linearly while increasing its concentration with a correlation coefficient of 0. 9993 and a detection limit (3σ ) was found to be quite desirable. The present modified electrode was also successfully used for the determination of AA in the presence of common interferences such as starch, glucose, citric acid Na+, K+, Mg2+ and Ca2+. The proposed modified electrode was successfully demonstrated towards the determination of AA in pharmaceutical samples. It should be noted that procedure for preparation of this modified electrode is simple, inexpensive and rapid.

Human serum albumin nanoparticles (HSA-NPs) were synthesized using the modified desolvation method. Fourier transform infrared spectroscopy (FT-IR), electronic absorption spectroscopy (UV-Vis), Zeta Sizer as well as field emission scanning electron microscope (FESEM) of the sample confirmed the formation of HSA NPs with an average size of 68 nm. The obtained results shown that HSA-NPs was successfully synthesized. The cytotoxic study of HSA-NPs in the HFFF2, normal cell lines was conducted and cell viability percentage demonstrated more than 90% within 24 h. Therefore, the synthesized NPs were nontoxic compared to the control samples. Furthermore, the release of the oxaliplatin as an anticancer drug incorporated in HSA NPs was also investigated in physiological conditions. The drug loading (DL) and drug entrapment efficiency (DEE) were enhanced and the DL of 0. 9% and DEE of 51% are achievable. The Higuchi model was shown the best fitting compared to the different kinetically release model. This result and result of cyclic voltammetry indicated that the drug release mechanism followed by diffusion manner. Therefore, our present study showed that the biocompatible HSA NPs could improve prolonged release of oxaliplatin as anticancer drugs.

Crystalline surface layer proteins (S-layer proteins) have considerable potential for the crystalline arrays in biotechnology, biomimetics and nonlife applications, including areas such as microelectronics and molecular nanotechnology. The extensive application potential of surface layers in nanobiotechnology is according to the particular inherent attributes of the single molecular arrays consisted of uniform protein or glycoprotein subunits. Most important, functional groups on the protein lattice are arrayed in well-specified positions and orientations. Many applications of S-layers are related to the ability of isolated subunits to recrystallize into single molecular arrays in suspension, suitable surfaces or interfaces. Utilization of the s-layers as template to pattern inorganic nanostructures, requires the separation and purification of these proteins and study of their structures on solid surfaces. The hexagonally packed intermediate (Hpi) protein of Deinococcus radiodurans belongs to the category of S-layer proteins which form crystalline two-dimensional arrays on bacterial cell surfaces. In this study, Deinococcus radiodurans R1 S-layer was purified and SDS-PAGE of purified HPI layer was analyzed by Core Laboratory Image Quantification Software. And also, secondary structure of Isolated HPI layer was evaluated by Circular Dichroism. and Zeta potential measurement was carried out to define surface charge of HPI surface layer sheets. In addition, hexagonally pattern of HPI sheets have been studied by atomic force microscopy and field emission scanning electron microscopy. According to our results, isolated HPI layer from Deinococcus radiodurans R1 can be used as template to array nanoparticles in future works.

Chlamydomonas reinhardtii is a novel recombinant eukaryotic expression system with many advantages including fast growth rate, rapid scalability, absence of human pathogens and the ability to fold and assemble complex proteins accurately, however, obstacle relatively low expression level necessitates optimizing foreign gene expression in this system. The Green Fluorescent Protein (GFP) from the jellyfish Aequorea victoria is a substantial reporter molecule for monitoring gene expression and protein localization. The fluorescence of GFP requires only UV or blue light, and, therefore, the in vivo observation of GFP expression is easy with no need for complex and costly apparatus.