Investigation of immunomodulatory and anti-inflammatory effects of eriodictyol through its cellular anti-oxidant activity

Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses against infection or to ameliorate immune-based pathologies. To determine whether eriodictyol has immunomodulatory effects and clarify which types of immune effector cells are stimulated in vitro, we investigated the stimulatory effect of eriodictyol on spleen cells isolated from BALB/c mice. Eriodictyol significantly stimulated splenocyte proliferation. However, only B lymphocytes (not T lymphocytes) could be stimulated by eriodictyol in a dose-related manner. Studies assessing potential effect of eriodictyol on innate immunity reported that eriodictyol enhanced significantly the killing activity of natural killer (NK) cells, T lymphocytes, and macrophages. We also demonstrated that eriodictyol inhibited nitric oxide (NO) production and lysosomal enzyme activity in murine peritoneal macrophages cultured ex-vivo, suggesting a potential anti-inflammatory effect in situ. Eriodictyol revealed also a cellular anti-oxidant activity in splenocytes and macrophages. Furthermore, eriodictyol increased catalase activity in spleen cells. From this data, it can be concluded that eriodictyol exhibited an immunomodulatory effect that could be ascribed in part to a cytoprotective effect related to its anti-oxidant activity.     

Quercetin protects HCT116 cells from Dichlorvos-induced oxidative stress and apoptosis

The present study was designed to assess the possible protective effects of Quercetin (QUER), a flavonoid with well-known pharmacological effects, against Dichlorvos (DDVP)-induced toxicity in vitro using HCT116 cells. The cytotoxicity was monitored by cell viability, reactive oxygen species (ROS) generation, anti-oxidant enzyme activities, malondialdehyde (MDA) production, and DNA fragmentation. The apoptosis was assessed through the measurement of the mitochondrial transmembrane potential (ΔΨm) and caspase activation. The results indicated that pretreatment of HCT116 cells with QUER, 2 h prior to DDVP exposure, significantly decreased the DDVP-induced cell death, inhibited the ROS generation, modulated the activities of catalase (CAT) and superoxide dismutase (SOD), and reduced the MDA level. The reductions in mitochondrial membrane potential, DNA fragmentation, and caspase activation were also attenuated by QUER. These findings suggest that dietary QUER can protect HCT116 cells against DDVP-induced oxidative stress and apoptosis.     

Cognitive Dissonance Resolution Is Related to Episodic Memory

The notion that our past choices affect our future behavior is certainly one of the most influential concepts of social psychology since its first experimental report in the 50 s, and its initial theorization by Festinger within the “cognitive dissonance” framework. Using the free choice paradigm (FCP), it was shown that choosing between two similarly rated items made subjects reevaluate the chosen items as more attractive and the rejected items as less attractive. However, in 2010 a major work by Chen and Risen revealed a severe statistical flaw casting doubt on most previous studies. Izuma and colleagues (2010) supplemented the traditional FCP with original control conditions and concluded that the effect observed could not be solely attributed to this methodological flaw. In the present work we aimed at establishing the existence of genuine choice-induced preference change and characterizing this effect. To do so, we replicated Izuma et al.’ study and added a new important control condition which was absent from the original study. Moreover, we added a memory test in order to measure the possible relation between episodic memory of choices and observed behavioral effects. In two experiments we provide experimental evidence supporting genuine choice-induced preference change obtained with FCP. We also contribute to the understanding of the phenomenon by showing that choice-induced preference change effects are strongly correlated with episodic memory.     

Cryopreservation of microalgae from desert environments of Qatar

The Qatar University Culture Collection of Cyanobacteria and Microalgae (QUCCCM) is a unique resource containing a diverse collection of microalgae and cyanobacteria, isolated from the Qatar desert environment. In order to ensure maximum preservation of this resource, a number of cryopreservation techniques were applied to various strains, and the preservation effectiveness (cell viability and lipid productivity) was determined. The conditions tested were direct, passive, and freeze-cooling cryopreservation (technique), dimethyl sulfate and methanol (cryoprotectant), and 5 and 10 % cryoprotectant concentrations over storage durations of up to 1 year. It was shown that the cryopreservation regime is strain dependent, and strains belonging to the same genera can have different requirements. On the other hand, neutral lipid estimation, via Nile red fluorescence determination of pre- and post-cryopreserved microalgae isolates, confirmed that the lipid production is affected by the applied cryopreservation method.     

Label-free impedimetric immunosensor for ultrasensitive detection of cancer marker Murine double minute 2 in brain tissue

The detection of cancer biomarkers is as important tool for the diagnosis and prognosis of cancer such as brain cancer. Murine double minute 2 (MDM2) has been widely studied as prognostic marker for brain tumor. Here we describe development of a new sensitive label free impedimetric immunosensor for the detection of MDM2 based on cysteamine self assembled monolayers on a clean polycrystalline Au electrode surface. The amine-modified electrodes were further functionalized with antibody using homobifunctional 1,4-phenylene diisothiocyanate (PDITC) linker. The assembly processes of the immunosensor had been monitored with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques using Fe(CN)(6)(3-/4-) solution as redox probe. The impedance changes upon binding of MDM2 protein to the sensor surface was utilized for the detection of MDM2. The increase in relative electron-transfer resistance (ΔR/R(0)%) values was linearly proportional to the concentration of tumor marker MDM2 in the wide dynamic range of 1pg/ml-1μg/ml. The limit of detection was 0.29pg/ml in phosphate buffer saline (PBS) and 1.3pg/ml in mouse brain tissue homogenate, respectively. The immunosensor showed a good performance in comparison with ELISA for the analysis of the MDM2 in the cancerous mouse brain tissue homogenates. Moreover, the immunosensor had a good selectivity against epidermal growth factor receptor (EGFR) protein, long-storage stability and reproducibility. It might be become a promising assay for clinical diagnosis and early detection of tumors.     

Dung beetle assemblages organization in two contrasted areas of the Mediterranean region: affinities and divergences

Quantification of the species richness and diversity is important when comparing sites; these variables are influenced by local and regional factors. The structure of assemblages of dung beetles as well as their species composition and diversity were compared between two sites on both sides of the Mediterranean Sea (France FR and Tunisia TN). From a total of 132 traps, 15,778 specimens were collected belonging to 86 species (46 in FR vs. 40 in TN). Species composition varied highly between FR and TN (only 10 species in common). The temporal occurrence of Aphodiidae and Scarabaeidae showed different patterns due to several factors: phenology of species, geographical distribution and local ecological requirements. When quantifying the beta diversity, the turnover of species was for almost cases higher within the same season than between seasons. Moreover, seasonal turnover was different at both sites. Evenness and rank-abundance analyses demonstrated that autumn-winter was the most constraining season in FR, with one dominant species (Agrilinus constans) in winter assemblages (96.8% of individuals). Conversely summer was the most constraining season in TN, with Onthophagus taurus as dominant species in assemblages (87.7%). The influence of local and historical factors is discussed.     

Genetic Diversity of Food-Isolated Salmonella Strains through Pulsed Field Gel Electrophoresis (PFGE) and Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR)

All over the world, the incidence of Salmonella spp contamination on different food sources like broilers, clams and cow milk has increased rapidly in recent years. The multifaceted properties of Salomnella serovars allow the microorganism to grow and multiply in various food matrices, even under adverse conditions. Therefore, methods are needed to detect and trace this pathogen along the entire food supply network. In the present work, PFGE and ERIC-PCR were used to subtype 45 Salmonella isolates belonging to different serovars and derived from different food origins. Among these isolates, S. Enteritidis and S. Kentucky were found to be the most predominant serovars. The Discrimination Index obtained by ERIC-PCR (0.85) was slightly below the acceptable confidence value. The best discriminatory ability was observed when PFGE typing method was used alone (DI = 0.94) or combined with ERIC-PCR (DI = 0.93). A wide variety of profiles was observed between the different serovars using PFGE or/and ERIC-PCR. This diversity is particularly important when the sample origins are varied and even within the same sampling origin.     

Mutations in BCAP31 Cause a Severe X-Linked Phenotype with Deafness,Dystonia, and Central Hypomyelination and Disorganize the Golgi Apparatus

BAP31 is one of the most abundant endoplasmic reticulum (ER) membrane proteins. It is a chaperone protein involved in several pathways, including ER-associated degradation, export of ER proteins to the Golgi apparatus, and programmed cell death. BAP31 is encoded by BCAP31, located in human Xq28 and highly expressed in neurons. We identified loss-of-function mutations in BCAP31 in seven individuals from three families. These persons suffered from motor and intellectual disabilities, dystonia, sensorineural deafness, and white-matter changes, which together define an X-linked syndrome. In the primary fibroblasts of affected individuals, we found that BCAP31 deficiency altered ER morphology and caused a disorganization of the Golgi apparatus in a significant proportion of cells. Contrary to what has been described with transient-RNA-interference experiments, we demonstrate that constitutive BCAP31 deficiency does not activate the unfolded protein response or cell-death effectors. Rather, our data demonstrate that the lack of BAP31 disturbs ER metabolism and impacts the Golgi apparatus, highlighting an important role for BAP31 in ER-to-Golgi crosstalk. These findings provide a molecular basis for a Mendelian syndrome and link intracellular protein trafficking to severe congenital brain dysfunction and deafness.