The antidiabetic and anticholinergic effects of chrysin on cyclophosphamide‐induced multiple organ toxicity in rats: Pharmacological evaluation of some metabolic enzyme activities

Chrysin (CH) or 5,7‐dihydroxyflavone is a flavonoid present in various plants, bee propolis, and honey. Cyclophosphamide (CYP) is a chemotherapeutic drug, which is extensively used in the treatment of multiple human malignancies. In our study, we aimed to investigate the effects of CYP and CH on some metabolic enzymes including carbonic anhydrase, aldose reductase, paraoxonase‐1, α‐glycosidase, acetylcholinesterase, and butyrylcholinesterase enzyme activities in the brain, heart, testis, liver, and kidney tissues of rats. Thirty‐five adult male Wistar rats were used. The animals were pretreated with CH (25 and 50 mg/kg b.w.) for seven days before administering a single dose of CYP (200 mg/kg b.w.) on the seventh day. In all the tissues, the treatment of CH significantly regulated these enzyme activities in CYP‐induced rats. These results showed that CH exhibited an ameliorative effect against CYP‐induced brain, heart, liver, testis, and kidney toxicity.     

The effects of inter-annual fluctuations in precipitation,lake surface area,and wind speed on phytoplankton structure in three shallow Mediterranean lakes (Sakarya,Turkey)

Aquatic Ecology - Phytoplankton biomass, diversity, functional groups (FGs), and environmental parameters in three shallow lakes were evaluated to show the inter-annual fluctuations in...     

Recent Developments to Mitigate Selenium Deficiency in Agricultural Eco-Systems

Under changing climate, trace elements like selenium (Se) have emerged as vital constituent of agro-ecosystems enabling crop plants to off-set the adverse effects of suboptimal growth conditions. The available form of selenium is important for boosting its bioavailability to crop plants having varied agro-botanical traits and root architectural systems. As compared to selenite, the selenate has a weaker soil bonding, higher absorption in the soil solution which results in a comparatively absorption by plant roots. Various factors including dry climate, high pH, optimal ambient air temperature, less accumulation of water, and low concentration of organic matter in the soil tend to boost the selenate ratio in the soil. The use of selenium pelleted seeds has emerged as an interesting and viable alternative to alleviate selenium deficiency in agricultural eco-systems. Similarly, the co-inoculation of a mixture of Selenobacteria and Arbuscular mycorrhizal fungi represents an evolving promising strategy for the bio-fortification of wheat plants to produce selenium-rich flour to supplement human dietary needs. Furthermore, in-depth research is required to assure the effectiveness of biological fertilization procedures in field conditions as well as to explore and increase our understanding pertaining to the underlying main mechanisms and channels of selenium absorption in plants. The focus of this review is to synthesize the recent developments on Se dynamics in soil-plant systems and emerging promising strategies to optimize its levels for crop plants. Recent developments regarding the use of micro-organisms as a biotechnological mean to enhance plant nutrition and crop quality have been objectively elaborated. The study becomes even more pertinent for arid and semi-arid agro-ecosystems owing to the potential role of selenium in providing stress tolerance to crop plants. Moreover, this review synthesizes and summarizes the recent developments on climate change and bioavailability, and the protective role of selenium in crop plants.

     

Purification of glutathione S‐transferase enzyme from quail liver tissue and inhibition effects of (3aR,4S,7R,7aS)‐2‐(4‐((E)‐3‐(aryl)acryloyl)phenyl)‐3a,4,7,7a‐tetrahydro‐1H‐4,7‐methanoisoindole‐1,3(2H)‐dione derivatives on the enzyme activity

The use of quail meat and eggs has made this animal important in recent years, with its low cost and high yields. Glutathione S‐transferases (GST, E.C.2.5.1.18) are an important enzyme family, which play a critical role in detoxification system. In our study, GST was purified from quail liver tissue with 47.88‐fold purification and 12.33% recovery by glutathione agarose affinity chromatography. The purity of enzyme was checked by SDS‐PAGE method and showed a single band. In addition, inhibition effects of (3aR,4S,7R,7aS)‐2‐(4‐((E)‐3‐(aryl)acryloyl)phenyl)‐3a,4,7,7a‐tetrahydro‐1H‐4,7methanoisoindole‐1,3(2H)‐dion derivatives ( 1a–g ) were investigated on the enzyme activity. The inhibition parameters (IC₅₀ and K_i values) were calculated for these compounds. IC₅₀ values of these derivatives ( 1a–e ) were found as 23.00, 15.75, 115.50, 10.00, and 28.75 μM, respectively. K_i values of these derivatives ( 1a–e ) were calculated in the range of 3.04 ± 0.50 to 131.50 ± 32.50 μM. However, for f and g compounds, the inhibition effects on the enzyme were not found.     

Gene networks in Drosophila melanogaster: integrating experimental data to predict gene function

Background

Discovering the functions of all genes is a central goal of contemporary biomedical research. Despite considerable effort, we are still far from achieving this goal in any metazoan organism. Collectively, the growing body of high-throughput functional genomics data provides evidence of gene function, but remains difficult to interpret.

Results

We constructed the first network of functional relationships for Drosophila melanogaster by integrating most of the available, comprehensive sets of genetic interaction, protein-protein interaction, and microarray expression data. The complete integrated network covers 85% of the currently known genes, which we refined to a high confidence network that includes 20,000 functional relationships among 5,021 genes. An analysis of the network revealed a remarkable concordance with prior knowledge. Using the network, we were able to infer a set of high-confidence Gene Ontology biological process annotations on 483 of the roughly 5,000 previously unannotated genes. We also show that this approach is a means of inferring annotations on a class of genes that cannot be annotated based solely on sequence similarity. Lastly, we demonstrate the utility of the network through reanalyzing gene expression data to both discover clusters of coregulated genes and compile a list of candidate genes related to specific biological processes.

Conclusions

Here we present the the first genome-wide functional gene network in D. melanogaster. The network enables the exploration, mining, and reanalysis of experimental data, as well as the interpretation of new data. The inferred annotations provide testable hypotheses of previously uncharacterized genes.     

Purification and characterization of glutathione reductase from bovine erythrocytes

Glutathione reductase (E.C.1.8.1.7; GR) was purified from bovine erythrocytes and some characteristics properties of the enzyme were investigated. The purification procedure was composed of preparation of the hemolysate, ammonium sulfate fractionation, affinity chromatography on 2',5'-ADP Sepharose 4B, and gel filtration chromatography on Sephadex G-200. As a result of four consecutive procedures, the enzyme was purified 31,250-fold with a yield of 11.39%. Specific activity at the final step was 62.5 U (mg proteins)(-1). For the enzyme, optimum pH, optimum temperature, optimum ionic strength, and stable pH were found to be 7.3, 55 degrees C, 435 mM, 7.3, respectively. The molecular weight of the enzyme was found to be 118 kDa by Sephadex G-200 gel filtration chromatography and the subunit molecular weight was found to be 58 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). In addition, Km and Vmax values were determined for glutathione disulfide (GSSG) and NADPH. Ki constants and inhibition types were established for glutathione (GSH) and NADP+. Also, effects of NADPH and GSSG were investigated on the enzyme activities.     

The effect of biological sulfate reduction on anaerobic color removal in anaerobic–aerobic sequencing batch reactors

Combination of anaerobic–aerobic sequencing processes result in both anaerobic color removal and aerobic aromatic amine removal during the treatment of dye-containing wastewaters. The aim of the present study was to gain more insight into the competitive biochemical reactions between sulfate and azo dye in the presence of glucose as electron donor source. For this aim, anaerobic–aerobic sequencing batch reactor fed with a simulated textile effluent including Remazol Brilliant Violet 5R (RBV 5R) azo dye was operated with a total cycle time of 12 h including anaerobic (6 h) and aerobic cycles (6 h). Microorganism grown under anaerobic phase of the reactor was exposed to different amounts of competitive electron acceptor (sulfate). Performance of the anaerobic phase was determined by monitoring color removal efficiency, oxidation reduction potential, color removal rate, chemical oxygen demand (COD), color, specific anaerobic enzyme (azo reductase) and aerobic enzyme (catechol 1,2-dioxygenase), and formation of aromatic amines. The presence of sulfate was not found to significantly affect dye decolorization. Sulfate and azo dye reductions took place simultaneously in all operational conditions and increase in the sulfate concentration generally stimulated the reduction of RBV 5R. However, sulfate accumulation under anaerobic conditions was observed proportional to increasing sulfate concentration.     

Laboratory evaluation of Turkish entomopathogenic nematodes for suppression of the chestnut pests,Curculio elephas (Coleoptera: Curculionidae) and Cydia splendana (Lepidoptera: Tortricidae)

The lepidopteran, Cydia splendana, and the coleopteran, Curculio elephas, are the most serious pests of chestnut fruit in Turkey. We evaluated the biological control potential of three Turkish entomopathogenic nematode species, Steinernema feltiae, S. weiseri and Heterorhabditis bacteriophora, against the last instar larvae of C. splendana and C. elephas, both of which occur in the soil from fall (October–November) until mid-summer (August). The optimal temperature for infection, time to death of the hosts, and reproductive potential of the nematodes were determined at 10, 15, 20 and 25°C for both pest species. Cydia splendana was more susceptible to nematode infection than C. elephas. Temperature had a significant effect on the infectivity and development of entomopathogenic nematodes. The cold-adapted S. weiseri and S. feltiae were the most virulent species at 10 and 15°C, whereas the warm-adapted H. bacteriophora was the most effective at 20 and 25°C. In soil pot experiments conducted at 15°C, S. weiseri was the most virulent species against C. elephas and C. splendana. However, our data show that C. elephas larvae had a lower and C. splendana larvae had a higher susceptibility to the nematode species tested. Accordingly, we recommend that future efforts of using entomopathogenic nematodes, especially S. weiseri, be directed against C. splendana and that there be a continued effort to find more virulent nematode isolates against larvae of C. elephas.     

Exact tandem repeats analyzer (E-TRA): A new program for DNA sequence mining

Exact Tandem Repeats Analyzer 1.0 (E-TRA) combines sequence motif searches with keywords such as ‘organs’, ‘tissues’, ‘cell lines’ and ‘development stages’ for finding simple exact tandem repeats as well as non-simple repeats. E-TRA has several advanced repeat search parameters/options compared to other repeat finder programs as it not only accepts GenBank, FASTA and expressed sequence tags (EST) sequence files, but also does analysis of multiple files with multiple sequences. The minimum and maximum tandem repeat motif lengths that E-TRA finds vary from one to one thousand. Advanced user defined parameters/options let the researchers use different minimum motif repeats search criteria for varying motif lengths simultaneously. One of the most interesting features of genomes is the presence of relatively short tandem repeats (TRs). These repeated DNA sequences are found in both prokaryotes and eukaryotes, distributed almost at random throughout the genome. Some of the tandem repeats play important roles in the regulation of gene expression whereas others do not have any known biological function as yet. Nevertheless, they have proven to be very beneficial in DNA profiling and genetic linkage analysis studies. To demonstrate the use of E-TRA, we used 5,465,605 human EST sequences derived from 18,814,550 GenBank EST sequences. Our results indicated that 12.44% (679,800) of the human EST sequences contained simple and non-simple repeat string patterns varying from one to 126 nucleotides in length. The results also revealed that human organs, tissues, cell lines and different developmental stages differed in number of repeats as well as repeat composition, indicating that the distribution of expressed tandem repeats among tissues or organs are not random, thus differing from the un-transcribed repeats found in genomes.