Application of Polygonum minus Extract in Enhancing Drought Tolerance in Maize by Regulating Osmotic and Antioxidant System

Drought stress is a major factor affecting plant growth and crop yield production.Plant extracts as natural biostimulants hold great potential to strengthen plants to overcome drought impacts.To explore the effect of Polygonum minus extract(PME)in enhancing drought tolerance in plants,a study was set up in a glasshouse environment using 10 different treatment combinations.PME foliar application were designed in CRD and effects were closely observed related to the growth,physiology,and antioxidant system changes in maize(Zea mays L.)under well-watered and drought conditions.The seaweed extract(SWE)was used as a comparison.Plants subjected to drought stress exhibited a significant reduction in fresh weight,dry weight,relative water content(RWC),and soluble sugar,but they stimulated the phenolic,flavonoid,proline,glutathione(GSH),malondialdehyde(MDA)and antioxidant enzyme(catalase,CAT;peroxidase,POD;superoxide dismutase,SOD)activities.Foliar application of PME improved fresh and dry weight(FW:33.1%~41.4%;DW:48.0%~43.1%),chlorophyll content(Chl b:87.9%~100.76%),soluble sugar(23.6%~49.3%),and soluble protein(48.6%~56.9%)as well as antioxidant enzyme activities(CAT and POD)compared to CK under drought conditions.while decreasing the level of MDA.Notably,the mitigating effect of PME application with high concentration was more effective than those of SWE.Our study reveals that PME could alleviate drought stress by regulating osmoprotectant content and antioxidant defense system and can be used as an economical and environmentally friendly biostimulants for promoting maize growth under drought stress.

Molecular pathogenesis and clinical conse-quences of iron overload in liver cirrhosis

BACKGROUND: The liver, as the main iron storage compart-ment and the place of hepcidin synthesis, is the central organ involved in maintaining iron homeostasis in the body. Exces-sive accumulation of iron is an important risk factor in liver disease progression to cirrhosis and hepatocellular carcinoma. Here, we review the literature on the molecular pathogenesis of iron overload and its clinical consequences in chronic liver diseases. DATA SOURCES: PubMed was searched for English-language articles on molecular genesis of primary and secondary iron overload, as well as on their association with liver disease pro-gression. We have also included literature on adjuvant thera-peutic interventions aiming to alleviate detrimental effects of excessive body iron load in liver cirrhosis. RESULTS: Excess of free, unbound iron induces oxidative stress, increases cell sensitivity to other detrimental factors, and can directly affect cellular signaling pathways, resulting in accelerated liver disease progression. Diagnosis of liver cirrhosis is, in turn, often associated with the identiifcation of a pathological accumulation of iron, even in the absence of genetic background of hereditary hemochromatosis. Iron depletion and adjuvant therapy with antioxidants are shown to cause signiifcant improvement of liver functions in patients with iron overload. Phlebotomy can have beneifcial effects on liver histology in patients with excessive iron accumulation combined with compensated liver cirrhosis of different etiology. CONCLUSION: Excessive accumulation of body iron in liver cirrhosis is an important predictor of liver failure and avail-able data suggest that it can be considered as target for adju-vant therapy in this condition.

Microbial synthesis of zinc oxide nanoparticles and their potential application as an antimicrobial agent and a feed supplement in animal industry: a review

In recent years, zinc oxide nanoparticles(ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles(NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods.Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, nontoxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal’s body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.

Comparative studies of versatile extracellular proteolytic activities of lactic acid bacteria and their potential for extracellular amino acid productions as feed supplements

Background:Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets.However,the current technologies rely heavily on non-food grade microorganism and chemical synthesis for the production of AA.Several studies reported that lactic acid bacteria (LAB) have the capability of producing AA owing to their well-established proteolytic system and amino acid biosynthesis genes.Hence,the objectives of this study were to explore the extracellular proteolytic activity of LAB isolated from various Malaysian fermented foods and their potential to produce AA extracellularly as feed supplements.Results:All the studied LAB isolates were versatile extracellular protease producers,whereby extracellular protease activities were detected from acidic to alkaline pH (pH 5,pH 6.5,pH 8) using qualitative and quantitative proteolytic assays.The highest proteolytic activity at pH 5 (15.76 U/mg) and pH 8 (19.42 U/mg) was achieved by Lactobacillus plantarum RG14,while Lactobacillus plantarum RS5 exhibited the highest proteolytic activity of 17.22 U/mg at pH 6.5.As for the results of AA production conducted in de Man,Rogosa and Sharpe medium and analysed by high pressure liquid chromatography system,all LAB isolates were capable of producing an array of AA.Generally,Pediococcus sp.showed greater ability for AA production as compared to Lactobacillus sp.Moreover,the studied LAB were able to produce a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.P.pentosaceus TL-3 recorded the highest methionine and threonine productivity of 3.72 mg/L/h and 5.58 mg/L/h respectively.However,L.plantarum I-UL4 demonstrated a lysine productivity of 1.24 mg/L/h,while P.acidilactici TP-6 achieved up to 1.73 mg/L/h of tryptophan productivity.Conclusion:All the 17 studied LAB isolates possessed versatile extracellular proteolytic system and have vast capability of producing various amino acids including a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.Despite AA production was strain dependent,the studied LAB isolates possessed vast potential and can be exploited further as a bio-agent or an alternative amino acids and bioactive peptide producers.

Function of flavonoids on different types of programmed cell death and its mechanism:a review

Cell death in the living system plays a vital role in maintaining the homeostasis and balancing the cell count in the body.Programmed cell death(PCD)is a crucial component of several development and defense mechanisms.PCD is also important in terms of aging which avoids the accumulation of cellular damage by maintaining cell division.Depending on the execution of cell death and its role in destruction,PCD is categorized into several subtypes.The major different forms of PCD in animals are apoptosis,autophagy and necrosis,which can be distinct in morphological terms.More intense investigations of cell death have given close insight showing other important types of cellular destruction and their pivotal roles in treating disease conditions like cancer.Flavonoids have been acquired a great interest for disease therapies and chemoprevention through activation of several PCD mechanisms.The significant potential of natural flavonoids in the induction of distinct signaling cascades is being a massive approach for targeting uncontrolled cell growth.For these reasons,understanding PCD mechanisms is a promising approach for the interventions in treating cancer.Thus,it is intriguing that understanding the different forms of PCD mechanism induced by flavonoids with more accurate descriptions on the biochemical and cellular processes are gaining more significance in cancer research.Here,we provide a brief overview on the different types of PCD and aim to discuss the functional role of flavonoids in promoting different types of cell death as well as an extensive brief review on their mechanism of action has been highlighted.

Factors affecting the accumulation of 9-methoxycanthin-6-one in callus cultures of Eurycoma longifolia

A study was conducted to improve 9-methoxycanthin-6-one productivity （potential anti-tumour compound） from callus cultures of Emycorna longifolia （Tongkat All）. Several factors affecting 9-methoxycanthin-6-one production in callus cultures such as different medium compositions and physical factors were investigated and analyzed. Results show that a higher production of 9-methoxycanthin-6-one （3.84 mg-g-1 DW （Dry Weight）） is obtained from callus cultured in 1/4 MS basal media. At fructose of 2% （w/v）, the production of 9-methoxycanthin-6-one （4.59 mgg-1DW） is promoted to gain the highest yield, compared to other carbon sources tested. The addition of 2.0-mg·L^-1 dicamba also increases 9-methoxycanthin-6-one production （12.3 mg·g^-1 DW）. Higher production of 9-methoxycanthin-6-one was obtained at pH 5.5 （1.53 mg·g^-1 DW）. Production of 9-methoxycanthin-6-one （2.34 mg-g^-1 DW） in callus cultures is also increased when the medium is added with 1×10 ^-1μM phenylalanine. This study suggests that the successful production of 9-methoxycanthin-6-one in vitro cultures has a potential in large-scale production using bioreactor technology.

Impact of Helicobacter pylori on the healing process of the gastric barrier

AIM To determine the impact of selected well defined Helicobacter pylori(H. pylori) antigens on gastric barrier cell turnover.METHODS In this study,using two cellular models of gastric epithelial cells and fibroblasts,we have focused on exploring the effects of well defined H. pylori soluble components such as glycine acid extract antigenic complex(GE),subunit A of urease(Ure A),cytotoxin associated gene A protein(Cag A) and lipopolysaccharide(LPS) on cell turnover by comparing the wound healing capacity of the cells in terms of their proliferative and metabolic activity as well as cell cycle distribution. Toxic effects of H. pylori components have been assessed in an association with damage to cell nuclei and inhibition of signal transducer and activator of transcription 3(STAT3) phosphorylation. RESULTS We showed that H. pylori GE,Cag A and Ure A promoted regeneration of epithelial cells and fibroblasts,which is necessary for effective tissue healing. However,in vivo increased proliferative activity of these cells may constitute an increased risk of gastric neoplasia. In contrast,H. pylori LPS showed a dose-dependent influence on the process of wound healing. At a low concentration(1 ng/m L) H. pylori LPS accelerated of healing epithelial cells,which was linked to significantly enhanced cell proliferation and MTT reduction as well as lack of alterations in cell cycle and downregulation of epidermal growth factor(EGF) production as well as cell nuclei destruction. By comparison,H. pylori LPS at a high concentration(25 ng/m L) inhibited the process of wound repair,which was related to diminished proliferative activity of the cells,cell cycle arrest,destruction of cell nuclei and downregulation of the EGF/STAT3 signalling pathway.CONCLUSION In vivo H. pylori LPS driven effects might lead to the maintenance of chronic inflammatory response and pathological disorders on the level of the gastric mucosal barrier.

Quantitative determination of erlotinib in human serum using competitive enzyme-linked immunosorbent assay

A selective and sensitive competitive enzyme-linked immunosorbent assay(ELISA) method was developed and validated for the quantification of erlotinib in 50 mL of samples of human serum. Anti-erlotinib serum was obtained by immunizing mice with an antigen conjugated with bovine serum albumin and 3,4-bis(2-methoxyethoxy)benzoic acid using the N-succinimidyl ester method. Enzyme labeling of erlotinib with horseradish peroxidase was similarly performed using 3,4-bis(2-methoxyethoxy)benzoic acid. A simple competitive ELISA for erlotinib was developed using the principle of direct competition between erlotinib and the enzyme marker for anti-erlotinib antibody, which had been immobilized on the plastic surface of a microtiter plate. Serum erlotinib concentrations lower than 40 ng/mL were reproducibly measurable using the ELISA. This ELISA was specific to erlotinib and showed very slight cross-reactivity(6.7%) with a major metabolite, O-desmethyl erlotinib. Using this assay, drug levels were easily measured in the blood of mice after oral administration of erlotinib at a single dose of 30 mg/kg. ELISA should be used as a valuable tool for therapeutic drug monitoring and in pharmacokinetic studies of erlotinib.

T4-like coliphage ΦKAZ14 virulent to pathogenic and extended spectrum β-lactamase-producing Escherichia coli of poultry origin

Dear Editor,Bacteriophages(otherwise called phages)are a type of virus that infect bacteria.This viral type has found useful applications in the control of bacterial pathogens in foods and food processing environments.In addition,phages may be useful to prevent colonization and shedding of bacteria into the surrounding environment.

The high incidence of acute hemolysis due to favism in Ahvaz,Iranclinical features and laboratory findings

Objective:To collect comprehensive information about the features of favic patients in Ahvaz (Capital of Khouzestan,Iran) and analyze the extent of the differences with their corresponding in other regions.Methods:A total of 103 patients with acute hemolysis admitted to pediatric division of Abouzar Hospital located in the city of Ahvaz,Iran during 21st of June 2008 to 20th of June 2009 were analyzed retrospectively.Results:95.14% of the patients had favism while 4.86% of them underwent hemolysis due to other reasons.These patients were male(68.93%) and female children(31.06%) admitted mostly during the spring season.The three main symptoms were urine discoloration,jaundice and vomiting.At the admission time,the main hematologic findings were as follows:G6PD sufficient status(45.63%),G6PD deficient status(54.36%) and hemoglobin concentration:2.5-11.8(mean±SD:6.45±2.12) g/dL.Conclusions:In conclusion,Ahvaz was determined as a black zone for favism in which the disease can be considered a life threatening health problem.Moreover,slight differences were observed in the three main symptoms compared with favic patients in other regions.

Influence of biofilm-forming lactic acid bacteria against methicillin-resistan Staphylococcus aureus(MRSA S547)

Objective: To investigate the antibacterial effect of selected lactic acid bacteria(LAB)biofilms on the planktonic and biofilm population of methicillin-resistant Staphylococcus aureus(MRSA)(S547).Methods: In this study, biofilm-forming LAB were isolated from tairu and kefir. Isolate Y1 and isolate KF were selected based on their prominent inhibition against test pathogens(using spot-on-agar method and agar-well-diffusion assay) and efficient biofilm production(using tissue culture plate method). They were then identified as Lactobacillus casei(L. casei) Y1 and Lactobacillus plantarum(L. plantarum) KF, respectively using16 S r DNA gene sequencing. The influence of incubation time, temperature and aeration on the biofilm production of L. casei Y1 and L. plantarum KF was also investigated using tissue culture plate method. The inhibitory activity of both the selected LAB biofilms was evaluated against MRSA(Institute for Medical Research code: S547) using L. plantarum ATCC 8014 as the reference strain.Results: L. casei Y1 showed the highest reduction of MRSA biofilms, by 3.53 log at48 h while L. plantarum KF records the highest reduction of 2.64 log at 36 h. In inhibiting planktonic population of MRSA(S547), both L. casei Y1 and L. plantarum KF biofilms recorded their maximum reduction of 4.13 log and 3.41 log at 24 h, respectively. Despite their inhibitory effects being time-dependent, both LAB biofilms exhibited good potential in controlling the biofilm and planktonic population of MRSA(S547).Conclusions: The results from this study could highlight the importance of analysing biofilms of LAB to enhance their antibacterial efficacy. Preferably, these protective biofilms of LAB could also be a better alternative to control the formation of biofilms by pathogens such as MRSA.

Cloning of a novel phytase from an anaerobic rumen bacterium, Mitsuokella jalaludinii, and its expression in Escherichia coli

The ful length phytase gene of Mitsuokel a jalaludini was successful y cloned and was found to be 1 047 bp in length, with 348 amino acids, and was designated as PHY7 phytase gene. A comparison of the sequence of PHY7 phytase gene of M. jalaludini with various microbial phytase gene sequences showed that it was not similar to those from other bacteria except Selenomonas ruminatium, thus suggesting that they may both express a new class of phytase. The PHY7 phytase gene was subsequently subcloned into bacterial expression vector, pET32a, for expression in Escherichia coli strain Ro-setta-gami. Expression of the recombinant phytase gene was optimised and characterised. The recombinant phytase was estimated to be approximately 55 kDa by SDS-PAGE analysis. The recombinant phytase exhibited optimum activity at 55°C, pH 4.5 and showed good pH stability from pH 3.5 to 5.5 (>78%relative activity). Metal ions such as Ca2+, Mg2+, and K+were found to exert signiifcant stimulatory effect on the recombinant phytase activity while Cu2+, Fe3+, and Zn2+greatly inhibited the enzyme activity. The recombinant phytase showed moderate resistance to trypsin proteolysis, but susceptible to pepsin proteolysis. The results of the study showed that several characteristics of recombinant phytase were slightly different from the native enzyme. Unfavourable characteristics such as reduced pH stability and metal ion effects should be taken into consideration during feed enzyme formulation.

Antimicrobial activity and mode of action of terpene linalyl anthranilate against carbapenemase-producing Klebsiella pneumoniae

Mining of plant-derived antimicrobials is the major focus at current to counter antibiotic resistance. This study was conducted to characterize the antimicrobial activity and mode of action of linalyl anthranilate(LNA) against carbapenemase-producing Klebsiella pneumoniae(KPC-KP). LNA alone exhibited bactericidal activity at 2.5%(V/V), and in combination with meropenem(MPM) at 1.25%(V/V). Comparative proteomic analysis showed a significant reduction in the number of cytoplasmic and membrane proteins,indicating membrane damage in LNA-treated KPC-KP cells. Up-regulation of oxidative stress regulator proteins and down-regulation of oxidative stress-sensitive proteins indicated oxidative stress. Zeta potential measurement and outer membrane permeability assay revealed that LNA increases both bacterial surface charge and membrane permeability. Ethidium bromide influx/efflux assay showed increased uptake of ethidium bromide in LNA-treated cells, inferring membrane damage. Furthermore, intracellular leakage of nucleic acid and proteins was detected upon LNA treatment. Scanning and transmission electron microscopies again revealed the breakage of bacterial membrane and loss of intracellular materials. LNA was found to induce oxidative stress by generating reactive oxygen species(ROS) that initiate lipid peroxidation and damage the bacterial membrane. In conclusion, LNA generates ROS, initiates lipid peroxidation, and damages the bacterial membrane, resulting in intracellular leakage and eventually killing the KPC-KP cells.

Potentials of <i>Melastoma malabathricum</i>Linn. Flower and Fruit Extracts as Antimicrobial Infusions

Melastoma malabathricum Linn. is a shrub that belongs to the family Melastomataceae and a common herbal plant used in folk medicines to treat inflamed wounds. This study was carried out with the aim to evaluate the inhibitory activities of different concentrations of the M. malabathricum Linn. flower and fruit crude extracts against a variety of microorganisms. The inhibitory effects of both extracts were tested against the microorganisms using the disc diffusion method. The lowest concentrations of the extracts producing inhibition zones against the test microorganisms were used to determine their Minimum Inhibitory Concentrations (MICs) and Minimum Microbicidal Concentrations (MMCs). Both crude extracts showed strong inhibitory activities against Gram-positive bacteria. The range of MIC values for the crude flower and fruit extracts on all the bacteria tested were 12.5 to 100.0 mg/ml. Overall, Gram-positive bacteria were more susceptible to the crude extracts compared to Gram-negative species, potentiating a possible use of the extracts to inhibit or kill potential pathogens.

Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

Bacterial leaf blight of rice (BLB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent.IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC_3F_3 lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC_3F_3 5.1.5.1, BC_3F_3 5.1.5.12, BC_3F_3 8.5.6.44, BC_3F_3 9.5.4.1 and BC_3F_3 9.5.4.23) were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

Investigation of the immune effects of Scutellaria baicalensis on blood leukocytes and selected organs of the chicken＇s lymphatic system

Background： The health of chickens and the welfare of poultry industry are central to the efforts of addressing global food security. Therefore, it is essential to study chicken immunology to maintain and improve its health and to find novel and sustainable solutions. This paper presents a study on investigation of the effect of Scutellaria baicalensis root（SBR） on the immune response of broiler chicken, especially on lymphocytes and heterophils reactivity, regarding their contribution to the development of immunity of the chickens.Methods： The 121-day-old Hubbard Hi-Y male broiler hybrids were randomly assigned to four treatment groups,three SBR supplemented groups（0.5, 1.0, and 1.5% of SBR） and one control group. Each treatment was replicated five times with six birds per replicate pen in a battery brooder. Blood was collected after 3-（rd） and 6-（th）wk of the experiment, and hemoglobin and hematocrit values were determined, as well as total leukocyte count and differential count were performed. Nitroblue tetrazolium test and phagocytosis assay as nonspecific immune parameters and humoral immune responses to the antigenic challenge by sheep red blood cells were performed.Moreover, the ability of peripheral blood lymphocytes to form radial segmentation（RS） of their nuclei was analyzed.Body weight and relative weight of spleen, liver, and bursa of Fabricius were recorded.Results： Results showed that mean heterophile/lymphocyte ratio increased in the SBR groups compared to the control group and the blood of the chickens showed lymphocytic depletion. The results also demonstrated that the relative weight of bursa of Fabricius and spleen in groups fed with SBR significantly decreased compared to the control group. This study also showed that the addition of SBR significantly inhibited the formation of RS of nuclei compared to some cytotoxic substances.Conclusion： We found that SBR supplementation should be carefully evaluated when given to poultry. The excess intake of SBR supplementation may cause immunologic inhibition and may negatively affect the development of immune organs. SBR has inhibited the formation of radial segmentation nuclei showing antimetastatic properties and also the phagocytosis of chicken heterophils.

Screening of Total Organophosphate Pesticides in Agricultural Products with a Cellular Biosensor

Organophosphates belong to the most important pesticides used in agricultural practice worldwide. Although their analytical determinations are quite feasible with various conventional methods, there is a lack of efficient screening methods, which will facilitate the rapid, high-throughput detection of organophosphates in different food commodities. This study presents the construction of a rapid and sensitive cellular biosensor test based on the measurement of changes of the cell membrane potential of immobilized cells, according to the working principle of the Bioelectric Recognition Assay (BERA). Two different cell types were used, derived either by animal (neuroblastoma) or plant cells (tobacco protoplasts). The sensor was applied for the detection of a mixture of two organophosphate pesticides, diazinon and chlorpyrifos in two different substrates (tomato, orange). The pesticides in the samples inhibited the activity of cell membrane-bound acetylcholinesterase (AChE), thus causing a measurable membrane depolarization in the presence of achetylcholine (Ach). Based on the observed patterns of response, we demonstrate that the sensor can be used for the qualitative and, in some concentrations, quantitative detection of organophosphates in different substrates with satisfactory reproducibility and sensitivity, with a limit of detection at least equal to the official Limit of Detection (LOQ). The assay is rapid with a total duration of 3 min at a competitive cost. The sensitivity of the biosensor can be further increased either by incorporating more AChE-bearing cells per test reaction unit or by using cells engineered with more potent AChE isoforms. Standardization of cultured cell parameters, such as age of the cells and subculture history prior to cell immobilization, combined with use of planar electrodes, can further increase the reproducibility of the novel test.

Antioxidant efficiency of lycopene on oxidative stress-induced damage in bovine spermatozoa

Background： Lycopene（LYC） is a natural carotenoid with powerful reactive oxygen species（ROS） scavenging activities. The aim of this study was to investigate if lycopene has the ability to reverse ROS-mediated alterations to the motility, viability and intracellular antioxidant profile of bovine spermatozoa subjected to ferrous ascorbate（Fe AA）. Spermatozoa were washed out of fresh bovine semen, suspended in 2.9 % sodium citrate and subjected to LYC treatment（0.25, 0.5, 1 or 2 mmol/L） in the presence or absence of Fe AA（150 μmol/L Fe SO4 and 750 μmol/L ascorbic acid） during a 6 h in vitro culture. Spermatozoa motion characteristics were assessed using the Sperm Vision？computer-aided sperm analysis（CASA） system. Cell viability was examined with the metabolic activity（MTT） assay,ROS generation was quantified via luminometry and the nitroblue-tetrazolium（NBT） test was applied to quantify the intracellular superoxide formation. Cell lysates were prepared at the end of the in vitro culture to investigate the intracellular activity of superoxide dismutase（SOD）, catalase（CAT）, glutathione peroxidase（GPx） as well as the concentrations of glutathione（GSH） and malondialdehyde（MDA）.Results： FeA A treatment led to a reduced spermatozoa motility（P 〈 0.001）, viability（P 〈 0.001） and a decline of the antioxidant capacity of spermatozoa（P 〈 0.001） but increased the ROS generation（P 〈 0.001）, superoxide production（P 〈 0.001） and lipid peroxidation（P 〈 0.001）. LYC administration resulted in a preservation of the spermatozoa motion parameters（P 〈 0.001）, mitochondrial activity（P 〈 0.001） and antioxidant characteristics（P 〈 0.001 with respect to SOD;P 〈 0.01 in relation to CAT; P 〈 0.05 as for GPx and GSH） with a concentration range of 1 and 2 mmol/L LYC revealed to be the most effective.Conclusions： Our results suggest that LYC exhibits significant ROS-scavenging and antioxidant properties which may prevent spermatozoa alterations caused by oxidative stress, and preserve the functionality of male reproductive cells.

Engineering catalytic efficiency of thermophilic lipase from <i>Geobacillus zalihae</i>by hydrophobic residue mutation near the catalytic pocket

In-silico and experimental investigations were conducted to explore the effects of substituting hydrophobic residues;Val, Met, Leu, Ile, Trp and Phe into the oxyanion Q114 of T1 lipase. We hypothesized that the oxyanion Q114, involved in substrate binding is also associated with modulation of conformational stability and in conferring specific enzyme attributes. The insilico investigations accurately predicted the quality of the protein packing in some of the variants. Our study found by altering the hydrophobicity of the oxyanion 114, remarkably altered enzyme conformational stability and catalytic attributes. Substitution with Leu resulted improvements in four out of the six tested characteristics. The hydrophobic Leu might have improved local structure folding and increased hydrophobic interactions with other residues in the vicinity of the mutation. The Met variant showed higher activity over the wild-type in hydrolyzing a wider range of natural oils. The bulky amino acids, Phe and Trp negatively affected T1 lipase and resulted in the largest disruption of protein stability and inferior enzyme characteristics. We have successfully illustrated that a single point residue changes at oxyanion 114 could result in a myriad of enzyme attributes, which implied there was some interplay between hydrophobicity and conformation for lipase catalytic functions.

Modelling the prevalence of hepatitis C virus amongst blood donors in Libya:An investigation of providing a preventive strategy

AIM: To determine hepatitis C virus(HCV) seroprevalence among the Libyan population using blood donors and applying the autoregressive integrated moving average(ARIMA) model to predict future trends and formulate plans to minimize the burden of HCV infection.METHODS: HCV positive cases were collected from 1008214 healthy blood donors over a 6-year period from 2008 to 2013. Data were used to construct the ARIMA model to forecast HCV seroprevalence among blood donors. The validity of the model was assessed using the mean absolute percentage error between the observed and fitted seroprevalence. The fitted ARIMA model was used to forecast the incidence of HCV beyond the observed period for the year 2014 and further to 2055.RESULTS: The overall prevalence of HCV among blood donors was 1.8%, varying over the study period from 1.7% to 2.5%, though no significant variation was found within each calendar year. The ARIMA model showed a non-significant auto-correlation of the residuals, and the prevalence was steady within the last 3 years as expressed by the goodness-of-fit test. The forecast incidence showed an increase in HCV seropositivity in 2014, ranging from 500 to 700 per 10000 population, with an overall prevalence of 2.3%-2.7%. This may be extended to 2055 with minimal periodical variation within each 6-year period.CONCLUSION: The applied model was found to be valuable in evaluating the seroprevalence of HCV among blood donors, and highlighted the growing burden of such infection on the Libyan health care system. The model may help in formulating national policies to prevent increases in HCV infection and plan future strategies that target the consequences of the infection.