Evaluation of antioxidant properties and total phenolic contents of some strains of microalgae

Antioxidant activities of both cells and extracellular substances were evaluated in 12 soil-isolated strains of microalgae according to FRAP and DPPH-HPLC assays. Their total phenolic contents were also determined by Folin–Ciocalteu method. Extractions were performed with hexane, ethyl acetate, and water. The results of FRAP assay showed that algal cells contained considerable amounts of antioxidants from 0.56 ± 0.06 to 31.06 ± 4.00 μmol Trolox g⁻¹ for Microchaete tenera hexane extract and Chlorella vulgaris water extract, respectively. In water fractions of extracellular substances, the antioxidants were from 1.30 ± 0.15 μmol Trolox g⁻¹ for Fischerella musicola to 73.20 ± 0.16 μmol Trolox g⁻¹ for Fischerella ambigua. Also, DPPH-HPLC assay represented high antioxidant potential of water fractions. The measured radical-scavenging activities of the studied microalgae were at least 0.15 ± 0.02 in Nostoc ellipsosporum cell mass to a maximum of 109.02 ± 8.25 in C. vulgaris extracellular substance. The amount of total phenolic contents varied in different strains of microalgae and ranged from zero in hexane extract to 19.15 ± 0.04 mg GAE g⁻¹ in C. vulgaris extracellular water fraction. Significant correlation coefficients between two measured parameters indicated that phenolic compounds were a major contributor to the microalgal antioxidant capacities.     

Adaptive Staircase Measurement of Hand Proprioception

Clinicians and researchers often need to measure proprioception (position sense), for example to monitor the progress of disease, to identify the cause of movement or balance problems, or to ascertain the effects of an intervention. While researchers can use sophisticated equipment to estimate proprioceptive acuity with good precision, clinicians lack this option and must rely on the subjective and imprecise methods currently available in the clinic. Here we describe a novel technique that applies psychometric adaptive staircase procedures to hand proprioception with a simple tablet-style apparatus that could easily be adapted for the clinic. We report test-retest reliability, inter-rater reliability, and construct validity of the adaptive staircase method vs. two other methods that are commonly used in clinical settings: passive motion direction discrimination (PMDD) and matching. As a first step, we focus on healthy adults. Subjects ages 18–82 had their proprioception measured with each of the three techniques, at the metacarpophalangeal joint in the second finger of the right hand. A subset completed a second session in which the measures were repeated, to assess test-retest reliability. Another subset had the measurements done by two different testers to assess inter-rater reliability. Construct validity was assessed using stepwise regression on age and activity level, and correlations calculated across the three methods. Results suggest that of the three methods, the adaptive staircase method yields the best test-retest reliability, inter-rater reliability, and construct validity. The adaptive staircase method may prove to be a valuable clinical tool where more accurate assessment of proprioception is needed.     

The effect of N-Acetyl cysteine on the expression of Fxr (Nr1h4), LXRα (Nr1h3) and Sirt1 genes,oxidative stress,and apoptosis in the liver of rats exposed to different doses of cadmium

Molecular Biology Reports - The aim of this study was to consider the expression of farnesoid X receptor (Fxr), liver X receptor (LXRα) and sirtuin 1 (Sirt1), oxidative stress, inflammation,...     

Sequential Dosing in Chemosensitization: Targeting the PI3K/Akt/mTOR Pathway in Neuroblastoma

Breaking resistance to chemotherapy is a major goal of combination therapy in many tumors, including advanced neuroblastoma. We recently demonstrated that increased activity of the PI3K/Akt network is associated with poor prognosis, thus providing an ideal target for chemosensitization. Here we show that targeted therapy using the PI3K/mTOR inhibitor NVP-BEZ235 significantly enhances doxorubicin-induced apoptosis in neuroblastoma cells. Importantly, this increase in apoptosis was dependent on scheduling: while pretreatment with the inhibitor reduced doxorubicin-induced apoptosis, the sensitizing effect in co-treatment could further be increased by delayed addition of the inhibitor post chemotherapy. Desensitization for doxorubicin-induced apoptosis seemed to be mediated by a combination of cell cycle-arrest and autophagy induction, whereas sensitization was found to occur at the level of mitochondria within one hour of NVP-BEZ235 posttreatment, leading to a rapid loss of mitochondrial membrane potential with subsequent cytochrome c release and caspase-3 activation. Within the relevant time span we observed marked alterations in a ∼30 kDa protein associated with mitochondrial proteins and identified it as VDAC1/Porin protein, an integral part of the mitochondrial permeability transition pore complex. VDAC1 is negatively regulated by the PI3K/Akt pathway via GSK3β and inhibition of GSK3β, which is activated when Akt is blocked, ablated the sensitizing effect of NVP-BEZ235 posttreatment. Our findings show that cancer cells can be sensitized for chemotherapy induced cell death – at least in part – by NVP-BEZ235-mediated modulation of VDAC1. More generally, we show data that suggest that sequential dosing, in particular when multiple inhibitors of a single pathway are used in the optimal sequence, has important implications for the general design of combination therapies involving molecular targeted approaches towards the PI3K/Akt/mTOR signaling network.     

Electrochemical impedimetric immunosensor for insulin like growth factor-1 using specific monoclonal antibody-nanogold modified electrode

An electrochemical impedimetric immunosensor was developed for ultrasensitive determination of insulin-like growth factor-1 (IGF-1) based on immobilization of a specific monoclonal antibody on gold nanoparticles (GNPs) modified gold electrode. Self-assembly of colloidal gold nanoparticles on the gold electrode was conducted through the thiol groups of 1,6-hexanedithiol (HDT) monolayer as a cross linker. The redox reactions of [Fe(CN)(6)](4-)/[Fe(CN)(6)](3-) on the electrode surface was probed for studying the immobilization and determination processes, using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The interaction of antigen with grafted antibody recognition layer was carried out by soaking the modified electrode into antigen solution at 37°C for 3 h. The immunosensor showed linearity over 1.0-180.0 pg mL(-1) and the limit of detection was 0.15 pg mL(-1). The association constant between IGF-1 and immobilized antibody was calculated to be 9.17×10(11) M(-1). The proposed method is a useful tool for screening picogram amounts of IGF-1 in clinical laboratory as a diagnostic test.     

Circulating exosomal miRNAs in cardiovascular disease pathogenesis: New emerging hopes

Cardiovascular diseases (CVDs) are one of the leading causes of morbidity and mortality. Standard therapies have failed to significantly increase patients’ survival. Moreover, the majority of conventional screening procedures are ineffective for the diagnosis of CVDs at early stages. Accumulating evidence suggests that numerous cell types release a class of nano-sized vesicles named exosomes into the extracellular space. Exosomes are widely distributed in various body fluids and contain a number of diverse biomolecules such as proteins, lipids, and both mRNA and noncoding RNAs which reflect host-cell molecular architecture. MicroRNAs (miRNAs), which can be found in exosomes, could be taken up by both neighboring and distal cells. Not only has recent evidence indicated the regulatory role of exosomal miRNAs in the pathogenesis of CVD, but it has also been shown that differential expression of exosomal miRNAs in CVDs has made them promising biomarkers for early detection of CVDs. Owing to these remarkable features, exosomal miRNAs have emerged as hot spots in research. This review summarizes the role of exosomal miRNAs in the pathogenesis of CVDs and discusses their potential application in the clinical setting as both therapeutic and diagnostic tools.     

Design,Synthesis, Molecular Docking,and Cholinesterase Inhibitory Potential of Phthalimide‐Dithiocarbamate Hybrids as New Agents for Treatment of Alzheimer's Disease

A novel series of phthalimide‐dithiocarbamate hybrids was synthesized and evaluated for in vitro inhibitory potentials against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The anti‐cholinesterase results indicated that among the synthesized compounds, the compounds 7g and 7h showed the most potent anti‐AChE and anti‐BuChE activities, respectively. Molecular docking and dynamic studies of the compounds 7g and 7h , respectively, in the active site of AChE and BuChE revealed that these compounds as well interacted with studied cholinesterases. These compounds also possessed drug‐like properties and were able to cross the BBB.     

Effects of Haematococcus pluvialis in maternal diet on reproductive performance and egg quality in rainbow trout (Oncorhynchus mykiss)

The aim of this study was to clarify the effects of dietary Haematococcus pluvialis (H.p) on reproductive performance in female rainbow trout and egg quality in terms of antioxidant system and biochemical parameters. 60 rainbow trout (2475.5 ± 64.4 g) were randomly assigned to 2 groups in triplicates and fed diet containing 3 g H.p kg(-1) feed equivalent to 30 mg astaxanthin kg(-1) die or control diet for 30 days. On days 20 and 30 during feeding trial, mature fish were weighed and sampled for stripping. Results indicated that supplementation of H.p did not improve total egg weight, egg number per gram and fecundity. There were few changes in triglyceride and total protein content in fish eggs. Level of glucose decreased markedly on day 30 while on day 20 of feeding trial, a non-significant decrease was shown in treatment group. On day 20, the level of malondialdehyde (MDA) indicating lipid peroxidation product significantly decreased in eggs of the treatment group. The activities of enzymes of the antioxidant system did not change during this study, even though slight increase in glutathione peroxidase in treatment group was revealed during this study. In conclusion, this study showed that female rainbow trout appear to benefit from inclusion of H.p in diet during their reproductive stages in terms of improved egg quality.