Synthesis and in vitro evaluation of novel 1,2,4-triazine derivatives as neuroprotective agents

The role of novel triazine derivatives against oxidative stress exerted by hydrogen peroxide on differentiated rat pheochromocytoma (PC12) cell line was examined and a consistent protection from H₂O₂-induced cell death, associated with a marked reduction in caspase-3 activation, was observed. Moreover, activation of NF-κB, a known regulator of a host of genes that involves in specific stress and inflammatory responses by H₂O₂, was greatly impaired by triazine pretreatment in differentiated PC12 cells. Neuroprotective effect of such compounds may represent a promising approach for treatment of neurodegenerative diseases.     

Lipoxygenase inhibiting and antioxidant oligostilbene and monoterpene galactoside from Paeonia emodi

Paeoninol and paeonin C, oligostilbene and monoterpene galactoside, have been isolated from the methanolic extract of the fruits of Paeonia emodi. Their structures have been assigned on the basis of spectral analysis including 1D and 2D NMR techniques. In addition, 4-hydroxybenzoic acid 3, gallic acid 4 and methyl gallate 5 have also been reported for the first time from this species. Compounds 1 and 2 have displayed potent inhibitory potential against enzyme lipoxygenase in a concentration-dependent fashion with the IC(50) values 0.77 and 99.5 microM, along with ABTS(.+) radical quenching activity with IC(50) values of 147.5 and 498.2 microM, respectively.     

Biodiesel production via transesterification of palm olein using waste mud crab (Scylla serrata) shell as a heterogeneous catalyst

A recent rise in crab aquaculture activities has intensified the generation of waste shells. In the present study, the waste shells were utilized as a source of calcium oxide to transesterify palm olein into methyl esters (biodiesel). Characterization results revealed that the main component of the shell is calcium carbonate which transformed into calcium oxide when activated above 700 °C for 2 h. Parametric studies have been investigated and optimal conditions were found to be methanol/oil mass ratio, 0.5:1; catalyst amount, 5 wt.%; reaction temperature, 65 °C; and a stirring rate of 500 rpm. The waste catalyst performs equally well as laboratory CaO, thus creating another low-cost catalyst source for producing biodiesel. Reusability results confirmed that the prepared catalyst is able to be reemployed up to 11 times. Statistical analysis has been performed using a Central Composite Design to evaluate the contribution and performance of the parameters on biodiesel purity.     

Induced in vitro differentiation of neural-like cells from human exfoliated deciduous teeth-derived stem cells

Stem cells from human exfoliated deciduous teeth (SHED) are highly proliferative, clonogenic and multipotent stem cells with a neural crest cell origin. Additionally, they can be collected with minimal invasiveness in comparison with other sources of mesenchymal stem cells (MSCs). Therefore, SHED could be a desirable option for potential therapeutic applications. In this study, SHEDs were established from enzyme-disaggregated deciduous dental pulp obtained from 6 to 9 year-old children. The cells had typical fibroblastoid morphology and expressed antigens characteristic of MSCs, STRO1, CD146, CD45, CD90, CD106 and CD166, but not the hematopoietic and endothelial markers, CD34 and CD31, as assessed by FACS analysis. Differentiation assessment revealed a strong osteogenic and adipogenic potential of SHEDs. In order to further evaluate the in vitro differentiation potential of SHED into neural cells, a simple short time growth factor-mediated induction was used. Immunofluorescence staining and flow cytometric analysis revealed that SHED rapidly expressed nestin and b-III tubulin, and later expressed intermediate neural markers. In addition, the intensity and percentages of nestin and b-III tubulin and mature neural markers (PSA-NCAM, NeuN, Tau, TH, or GFAP) increased significantly following treatment. Moreover, RT-PCR and Western blot analyses showed that the neural markers were strongly up-regulated after induction. In conclusion, these results provide evidence that SHED can differentiate into neural cells by the expression of a comprehensive set of genes and proteins that define neural-like cells in vitro. SHED cells might be considered as new candidates for the autologous transplantation of a wide variety of neurological diseases and neurotraumatic injuries.     

Effects of arginine on heat-induced aggregation of concentrated protein solutions

Arginine is one of the commonly used additives to enhance refolding yield of proteins, to suppress aggregation of proteins, and to increase solubility of proteins, and yet the molecular interactions that contribute to the role of arginine are unclear. Here, we present experiments, using bovine serum albumin (BSA), lysozyme (LYZ), and β-lactoglobulin (BLG) as model proteins, to show that arginine can enhance heat-induced aggregation of concentrated protein solutions, contrary to the conventional belief that arginine is a universal suppressor of aggregation. Results show that the enhancement in aggregation is caused only for BSA and BLG, but not for LYZ, indicating that arginine's preferential interactions with certain residues over others could determine the effect of the additive on aggregation. We use this previously unrecognized behavior of arginine, in combination with density functional theory calculations, to identify the molecular-level interactions of arginine with various residues that determine arginine's role as an enhancer or suppressor of aggregation of proteins. The experimental and computational results suggest that the guanidinium group of arginine promotes aggregation through the hydrogen-bond-based bridging interactions with the acidic residues of a protein, whereas the binding of the guanidinium group to aromatic residues (aggregation-prone) contributes to the stability and solubilization of the proteins. The approach, we describe here, can be used to select suitable additives to stabilize a protein solution at high concentrations based on an analysis of the amino acid content of the protein.     

Development of an Indicator to Monitor Mediterranean Wetlands

Wetlands are sensitive ecosystems that are increasingly subjected to threats from anthropogenic factors. In the last decades, coastal Mediterranean wetlands have been suffering considerable pressures from land use change, intensification of urban growth, increasing tourism infrastructure and intensification of agricultural practices. Remote sensing (RS) and Geographic Information Systems (GIS) techniques are efficient tools that can support monitoring Mediterranean coastal wetlands on large scales and over long periods of time. The study aims at developing a wetland indicator to support monitoring Mediterranean coastal wetlands using these techniques. The indicator makes use of multi-temporal Landsat images, land use reference layers, a 50m numerical model of the territory (NMT) and Corine Land Cover (CLC) for the identification and mapping of wetlands. The approach combines supervised image classification techniques making use of vegetation indices and decision tree analysis to identify the surface covered by wetlands at a given date. A validation process is put in place to compare outcomes with existing local wetland inventories to check the results reliability. The indicator´s results demonstrate an improvement in the level of precision of change detection methods achieved by traditional tools providing reliability up to 95% in main wetland areas. The results confirm that the use of RS techniques improves the precision of wetland detection compared to the use of CLC for wetland monitoring and stress the strong relation between the level of wetland detection and the nature of the wetland areas and the monitoring scale considered.     

Distribution of Copper, Iron, and Zinc in Biological Samples (Scalp Hair, Serum, Blood, and Urine) of Pakistani Viral Hepatitis (A–E) Patients and Controls

The aim of the present study was to compare the level of copper (Cu), iron (Fe) and zinc (Zn) in biological samples (serum, blood, urine, and scalp hair) of patients suffering from different viral hepatitis (A, B, C, D, and E; n?=?521) of both gender age ranged 31–45 years. For comparative study, 255 age-matched control subjects, of both genders residing in the same city were selected as referents. The elements in the biological samples were analyzed by flame atomic absorption spectrophotometry, prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and with those values obtained by conventional wet acid digestion method on same CRMs. The results of this study showed that the mean values of Cu and Fe were higher in blood, sera, and scalp hair samples of hepatitis patients, while Zn level was found to be lower than age-matched control subjects. The urinary levels of these elements were found to be higher in the hepatitis patients than in the age-matched healthy controls (p?<?0.05). These results are consistent with literature-reported data, confirming that the deficiency of zinc and hepatic iron and copper overload can directly cause lipid peroxidation and eventually hepatic damage.