Protective effect of Nasturtium officinale R. Br and quercetin against cyclophosphamide-induced hepatotoxicity in rats

Molecular Biology Reports - Cyclophosphamide (CPA) is used in the management of autoimmune conditions and malignant illnesses. However, its therapeutic use is limited because of its severe side...     

Antihemolytic and antioxidant activities of <Emphasis Type="Italic">Allium paradoxum</Emphasis>

Antioxidant activity of the aerial part and bulbs of Allium paradoxum was investigated by eight in vitro assay systems. Extracts showed good antioxidant activity. IC₅₀ for 1,1-diphenyl-2-picryl hydrazyl radical-scavenging activity was 890.9±43.2 and 984.9±33.5 μg/ml for the aerial part and bulbs, respectively. The aerial parts have better reducing power than bulb extracts but not comparable with Vitamin C (P>0.001). Extracts showed weak Fe²⁺ chelating ability, the IC₅₀ being 959±47 and 530±24 μg/ml for bulbs and aerial parts, respectively. Both tested extracts exhibited good hydrogen peroxide scavenging in a concentration dependent manner. They exhibited good antioxidant activity against the hemoglobin-induced linoleic acid system that was comparable with vitamin C (P>0.01). They showed good activity against cumene hydro peroxide induced hemolysis in RBCs. In addition, they possessed antihemolytic activity. The extract from aerial parts had significantly higher total phenol and flavonoid content than did bulbs. Amounts of eight elements (Cu, Mn, Zn, Fe, Ni, Pb, Cd and Cr) were also determined in the bulb and aerial part using atomic absorption spectroscopy. They contained higher Fe and Mn contents than other elements.     

De novo biosynthesis of dihydrosphingosine-1-phosphate by sphingosine kinase 1 in mammalian cells

Sphingosine kinase 1 (SK1) is one of the two known kinases, which generates sphingosine-1-phosphate (S1P), a potent endogenous lipid mediator involved in cell survival, proliferation, and cell-cell interactions. Activation of SK1 and intracellular generation of S1P were suggested to be part of the growth and survival factor-induced signaling, and overexpression of SK1 provoked cell tumorigenic transformation. Using a highly selective and sensitive LC-MS/MS approach, here we show that SK1 overexpression, but not SK2, in different primary cells and cultured cell lines results in predominant upregulation of the synthesis of dihydrosphingosine-1-phosphate (DHS1P) compared to S1P. Stable isotope pulse-labeling experiments in conjunction with LC-MS/MS quantitation of different sphingolipids demonstrated strong interference of overexpressed SK1 with the de novo sphingolipid biosynthesis by deviating metabolic flow of newly formed sphingoid bases from ceramide formation toward the synthesis of DHS1P. On the contrary, S1P biosynthesis was not directly linked to the de novo sphingoid bases transformations and was dependent on catabolic generation of sphingosine from complex sphingolipids. As a result of SK1 overexpression, migration and Ca2+-response of human pulmonary artery endothelial cells (HPAEC) to stimulation with external S1P, but not thrombin, was strongly impaired. In contrast, selective increase in intracellular content of DHS1P or S1P through the uptake and phosphorylation of corresponding sphingoid bases had no effect on S1P-induced signaling or facilitation of wound healing. Furthermore, infection of human bronchial epithelial cells (HBEpC) with RSV A-2 virus increased SK1-mediated synthesis of DHS1P and S1P, whereas TNF-alpha enhanced only S1P production in HPAEC. These findings uncover a new functional role for SK1, which can control survival/death (DHS1P-S1P/ceramides) balance by targeting sphingolipid de novo biosynthesis and selectively generating DHS1P at a metabolic step preceding ceramide formation.     

Synthesis and biological evaluation of some new 1,4-dihydropyridines containing different ester substitute and diethyl carbamoyl group as anti-tubercular agents

Tuberculosis is a leading infectious cause of death worldwide. Because of the concern of the resistance to most of the commonly used drugs displayed by the considered mycobacteria, most efforts have been done to introduce new anti-tubercular agents. Recent studies showed that 1,4-dihydropyridine-3,5-dicarbamoyl derivatives with lipophilic groups have significant anti-tubercular activity. In this study, we synthesized new derivatives of 1,4-dihydropyridines in which different alkyl and aryl esters and diethyl carbamoyl are substituted in C-3 and C-5 of the DHP ring. In addition nitroimidazole ring is substitutes at C-4 position. These asymmetric analogues were synthesized by a modified Hantzsh reaction using procedure reported by Meyer. The in vitro anti-tubercular activity of compounds against Mycobacterium tuberculosis was evaluated. The results indicate that the compounds containing aromatic esters are more potent than alkyl ones. The most potent aromatic compound (R = 3-phenylpropyl) exhibits comparable anti-tubercular activity (MIC = 1 μmol/ml) with reference compound isoniazide (INH) (MIC = 1 μmol/ml). Conformational analysis, SAR studies of these compounds showed that increasing in lipophilicity and rotable bonds of these compounds resulted in increasing anti-tubercular activity.     

Differential expression of eight defensin genes of N. benthamiana following biotic stress, wounding, ethylene, and benzothiadiazole treatments

Eight Nicotiana benthamiana defensin genes were identified that could be divided into two classes with class II defensins being longer than class I defensins due to an additional acidic C-terminal domain. Class I defensins were NbDef1.1, NbDef1.2, NbDef1.3, NbDef1.4, NbDef1.5, and NbDef1.6, and class II were Nbdef2.1 and NbDef2.2. Relative RT-PCR showed that NbDef1.1, NbDef1.2, and NbDef1.4 had relatively similar expression levels in healthy leaves, stems, roots, flowers, and seeds. However, Nbdef1.3, NbDef1.5, and NbDef1.6 had varying degrees of tissue specific expression, and Nbdef2.1 and NbDef2.2 had strictly flower-specific expression. None of the defensins were significantly induced by infection by Colletotrichum destructivum or C. orbiculare. However, infection by Pseudomonas syringae pv. tabaci resulted in increased expression of Nbdef1.2 and Nbdef2.2, and decreased expression of NbDef1.1, NbDef1.4, and NbDef1.6. In the hypersensitive response of N. benthamiana containing Pto with P. syringae pv. tabaci containing AvrPto, only NbDef2.2 was significantly up-regulated. Expression of the genes was also affected by abiotic treatments. Both wounding and ethylene treatments resulted in a strong induction of NbDef2.2 and a moderate to weak induction of NbDef1.1, NbDef1.2, and NbDef1.4. Only weak or no induction was observed with treatment with benzothiadiazole. The expression of these eight defensin genes demonstrates that only a small fraction of the members of a defensin gene family will respond to a particular hemibiotrophic pathogen as well as to abiotic stress or signaling molecules. An erratum to this article can be found at     

Evaluation and optimization of factors affecting the performance of a flow-through system based on immobilized acetylcholineesterase as a biosensor

A flow-through system based on acetylcholineesterase (AChE) was studied. The system was prepared by mixing AChE and a multiwall carbon nanotube (MWCNT). Two important parameters, the ratios of AChE:MWCNT (X₁) and AChE-MWCNT:sol-gel (X₂) were optimized using response surface methodology. The results revealed that an enzyme immobilized within the MWCNT-sol-gel was more effective compared to one conducted with sol-gel. The optimum feed flow rate was 0.4 mL/min and ATChI concentration was found to be 1 mM. The optimum ratios of X₁ and X₂ for immobilization on ceramic packing were 1.07 and 0.43, respectively. The sensitivity of this flow-through system was 1.82 × 10⁻⁵/μM and long-term stability analyzed after 120 days was 74% of initial absorbance. With respect to an incubation time of 14 min, the detection limit for paraoxon was 7.3 × 10⁻¹² mol.     

Habitat associations of wild goat in central Iran: implications for conservation

Wild goat (Capra aegagrus) is one of the highly valued but threatened ungulates of Iran. Seasonal habitat use of wild goat was studied from October 2006 to September 2008 in Haftad Gholleh Protected Area, central Iran. We developed averaged logistic regression models based on Akaike Information Criterion weights for each season. The obtained habitat suitability models showed high sensitivity (greater than 88%) for all evaluation datasets. Wild goat habitat use was positively related with steep slopes, areas near rocky substrates and water sources, west-facing slopes and areas far from roads in all seasons. Core zones of protected area covered nearly 70% of suitable habitats for wild goats, predicted by logistic regression models. Northern core zone covered more than 61% of predicted suitable habitats, which should receive more attention in management actions. The southern core zone boundaries should be considered to increase the encompassed suitable habitats. There was a substantial overlap between seasonal suitable habitats with the highest overlap observed between spring and summer and summer and fall.     

Diaspora, a large family of Ty3 - gypsy retrotransposons in Glycine max, is an envelope-less member of an endogenous plant retrovirus lineage

Background  

The chromosomes of higher plants are littered with retrotransposons that, in many cases, constitute as much as 80% of plant genomes. Long terminal repeat retrotransposons have been especially successful colonizers of the chromosomes of higher plants and examinations of their function, evolution, and dispersal are essential to understanding the evolution of eukaryotic genomes. In soybean, several families of retrotransposons have been identified, including at least two that, by virtue of the presence of an envelope-like gene, may constitute endogenous retroviruses. However, most elements are highly degenerate and are often sequestered in regions of the genome that sequencing projects initially shun. In addition, finding potentially functional copies from genomic DNA is rare. This study provides a mechanism to surmount these issues to generate a consensus sequence that can then be functionally and phylogenetically evaluated.