Search results for: Pth enzymes
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 665

Search results for: Pth enzymes

275 Development and Characterization of Soya Phosphatidylcholine Complex of Coumestans from Eclipta alba for the Management of Hepatotoxicity

Authors: Abhishek Kumar Jain, Anki Jain, Yuvraj Singh Dangi, Brajesh Kumar Tiwari

Abstract:

The plant Eclipta alba Hassk. (Family: Compositae) contains coumestans (wedelolactone and demethyl wedelolactone) used in liver disorders. The objective of the present investigation was to develop a formulation of these coumestans in combination with the soya phosphatidylcholine (PC), in order to overcome the limitation of absorption and to investigate the protective effect of coumestans–phosphatidylcholine complex (C-PC) on carbon tetrachloride induced acute liver damage in rats. Methanolic extract (ME) of the whole plant of Eclipta alba was fractionated with water and then with ehylacetate. Coumestans were characterized in the ethylacetate fraction of methanolic extract (EFME). The C-PC was prepared by dissolving EFME and PC in 1:1 ratio in dichloromethane and heating at 60°C for 2 h. The C-PC was characterized by DSC and FTIR spectroscopy. In vitro drug release from EFME and C-PC through egg membrane was measured using UV-Visible spectrophotometer. The hepatoprotective activity of C-PC (equivalent to 5.35 and 10.7 mg/kg body weight of EFME), ME 250 mg/kg and EFME 5.35 mg/kg was evaluated by measuring various enzymes level. C-PC significantly provided better protection to the liver by restoring the enzyme levels of SGPT, SGOT, ALP and total billirubin with respect to carbon tetrachloride (CCl4) treated group (P < 0.001). Histopathological studies were also performed. The C-PC provided better protection to rat liver than ME and EFME at similar doses as well as shown significant regeneration of hepatocytes, central vein, intact cytoplasm, and nucleus.

Keywords: hepatotoxicity, wedelolactone, soya phosphatidylcholine, eclipta alba

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274 Assessment of the Role of Plasmid in Multidrug Resistance in Extended Spectrum βEtalactamase Producing Escherichia Coli Stool Isolates from Diarrhoeal Patients in Kano Metropolis Nigeria

Authors: Abdullahi Musa, Yakubu Kukure Enebe Ibrahim, Adeshina Gujumbola

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The emergence of multidrug resistance in clinical Escherichia coli has been associated with plasmid-mediated genes. DNA transfer among bacteria is critical to the dissemination of resistance. Plasmids have proved to be the ideal vehicles for dissemination of resistance genes. Plasmids coding for antibiotic resistance were long being recognized by many researchers globally. The study aimed at determining the antibiotic susceptibility pattern of ESBL E. coli isolates claimed to be multidrug resistance using disc diffusion method. Antibacterial activity of the test isolates was carried out using disk diffusion methods. The results showed that, majority of the multidrug resistance among clinical isolates of ESBL E. coli was as a result of acquisition of plasmid carrying antibiotic-resistance genes. Production of these ESBL enzymes by these organisms which are normally carried by plasmid and transfer from one bacterium to another has greatly contributed to the rapid spread of antibiotic resistance amongst E. coli isolates, which lead to high economic burden, increase morbidity and mortality rate, complication in therapy and limit treatment options. To curtail these problems, it is of significance to checkmate the rate at which over the counter drugs are sold and antibiotic misused in animal feeds. This will play a very important role in minimizing the spread of resistance bacterial strains in our environment.

Keywords: Escherichia coli, plasmid, multidrug resistance, ESBL, pan drug resistance

Procedia PDF Downloads 69
273 Functionalized Carbon-Base Fluorescent Nanoparticles for Emerging Contaminants Targeted Analysis

Authors: Alexander Rodríguez-Hernández, Arnulfo Rojas-Perez, Liz Diaz-Vazquez

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The rise in consumerism over the past century has resulted in the creation of higher amounts of plasticizers, personal care products and other chemical substances, which enter and accumulate in water systems. Other sources of pollutants in Neotropical regions experience large inputs of nutrients with these pollutants resulting in eutrophication of water which consume large quantities of oxygen, resulting in high fish mortality. This dilemma has created a need for the development of targeted detection in complex matrices and remediation of emerging contaminants. We have synthesized carbon nanoparticles from macro algae (Ulva fasciata) by oxidizing the graphitic carbon network under extreme acidic conditions. The resulting material was characterized by STEM, yielding a spherical 12 nm average diameter nanoparticles, which can be fixed into a polysaccharide aerogel synthesized from the same macro algae. Spectrophotometer analyses show a pH dependent fluorescent behavior varying from 450-620 nm in aqueous media. Heavily oxidized edges provide for easy functionalization with enzymes for a more targeted analysis and remediation technique. Given the optical properties of the carbon base nanoparticles and the numerous possibilities of functionalization, we have developed a selective and robust targeted bio-detection and bioremediation technique for the treatment of emerging contaminants in complex matrices like estuarine embayment.

Keywords: aerogels, carbon nanoparticles, fluorescent, targeted analysis

Procedia PDF Downloads 243
272 Quantification of Enzymatic Activities of Proteins, Peroxidase and Phenylalanine Ammonia Lyase, in Growing Phaseolus vulgaris L, with Application Bacterial Consortium to Control Fusarium and Rhizoctonia

Authors: Arredondo Valdés Roberto, Hernández Castillo Francisco Daniel, Laredo Alcalá Elan Iñaky, Gonzalez Gallegos Esmeralda, Castro Del Angel Epifanio

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The common bean or Phaseolus vulgaris L. is the most important food legume for direct consumption in the world. Fusarium dry rot in the major fungus disease affects Phaseolus vulgaris L, after planting. In another hand, Rhizoctonia can be found on all underground parts of the plant and various times during the growing season. In recent years, the world has conducted studies about the use of natural products as substitutes for herbicides and pesticides, because of possible ecological and economic benefits. Plants respond to fungal invasion by activating defense responses associated with accumulation of several enzymes and inhibitors, which prevent pathogen infection. This study focused on the role of proteins, peroxidase (POD), phenylalanine ammonia lyase (PAL), in imparting resistance to soft rot pathogens by applied different bacterial consortium, formulated and provided by Biofertilizantes de Méxicanos industries, analyzing the enzyme activity at different times of application (6 h, 12 h and 24 h). The resistance of these treatments was correlated with high POD and PAL enzyme activity as well as increased concentrations of proteins. These findings show that PAL, POD and synthesis of proteins play a role in imparting resistance to Phaseolus vulgaris L. soft rot infection by Fusarium and Rhizoctonia.

Keywords: fusarium, peroxidase, phenylalanine ammonia lyase, rhizoctonia

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271 Binary Metal Oxide Catalysts for Low-Temperature Catalytic Oxidation of HCHO in Air

Authors: Hanjie Xie, Raphael Semiat, Ziyi Zhong

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It is well known that many oxidation reactions in nature are closely related to the origin and life activities. One of the features of these natural reactions is that they can proceed under mild conditions employing the oxidant of molecular oxygen (O₂) in the air and enzymes as catalysts. Catalysis is also a necessary part of life for human beings, as many chemical and pharmaceutical industrial processes need to use catalysts. However, most heterogeneous catalytic reactions must be run at high operational reaction temperatures and pressures. It is not strange that, in recent years, research interest has been redirected to green catalysis, e.g., trying to run catalytic reactions under relatively mild conditions as much as possible, which needs to employ green solvents, green oxidants such O₂, particularly air, and novel catalysts. This work reports the efficient binary Fe-Mn metal oxide catalysts for low-temperature formaldehyde (HCHO) oxidation, a toxic pollutant in the air, particularly in indoor environments. We prepared a series of nanosized FeMn oxide catalysts and found that when the molar ratio of Fe/Mn = 1:1, the catalyst exhibited the highest catalytic activity. At room temperature, we realized the complete oxidation of HCHO on this catalyst for 20 h with a high GHSV of 150 L g⁻¹ h⁻¹. After a systematic investigation of the catalyst structure and the reaction, we identified the reaction intermediates, including dioxymethylene, formate, carbonate, etc. It is found that the oxygen vacancies and the derived active oxygen species contributed to this high-low-temperature catalytic activity. These findings deepen the understanding of the catalysis of these binary Fe-Mn metal oxide catalysts.

Keywords: oxygen vacancy, catalytic oxidation, binary transition oxide, formaldehyde

Procedia PDF Downloads 133
270 Application of Biosensors in Forensic Analysis

Authors: Shirin jalili, Hadi Shirzad, Samaneh Nabavi, Somayeh Khanjani

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Biosensors in forensic analysis are ideal biological tools that can be used for rapid and sensitive initial screening and testing to detect of suspicious components like biological and chemical agent in crime scenes. The wide use of different biomolecules such as proteins, nucleic acids, microorganisms, antibodies and enzymes makes it possible. These biosensors have great advantages such as rapidity, little sample manipulation and high sensitivity, also Because of their stability, specificity and low cost they have become a very important tool to Forensic analysis and detection of crime. In crime scenes different substances such as rape samples, Semen, saliva fingerprints and blood samples, act as a detecting elements for biosensors. On the other hand, successful fluid recovery via biosensor has the propensity to yield a highly valuable source of genetic material, which is important in finding the suspect. Although current biological fluid testing techniques are impaired for identification of body fluids. But these methods have disadvantages. For example if they are to be used simultaneously, Often give false positive result. These limitations can negatively result the output of a case through missed or misinterpreted evidence. The use of biosensor enable criminal researchers the highly sensitive and non-destructive detection of biological fluid through interaction with several fluid-endogenous and other biological and chemical contamination at the crime scene. For this reason, using of the biosensors for detecting the biological fluid found at the crime scenes which play an important role in identifying the suspect and solving the criminal.

Keywords: biosensors, forensic analysis, biological fluid, crime detection

Procedia PDF Downloads 1121
269 Evaluation of DNA Oxidation and Chemical DNA Damage Using Electrochemiluminescent Enzyme/DNA Microfluidic Array

Authors: Itti Bist, Snehasis Bhakta, Di Jiang, Tia E. Keyes, Aaron Martin, Robert J. Forster, James F. Rusling

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DNA damage from metabolites of lipophilic drugs and pollutants, generated by enzymes, represents a major toxicity pathway in humans. These metabolites can react with DNA to form either 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG), which is the oxidative product of DNA or covalent DNA adducts, both of which are genotoxic and hence considered important biomarkers to detect cancer in humans. Therefore, detecting reactions of metabolites with DNA is an effective approach for the safety assessment of new chemicals and drugs. Here we describe a novel electrochemiluminescent (ECL) sensor array which can detect DNA oxidation and chemical DNA damage in a single array, facilitating a more accurate diagnostic tool for genotoxicity screening. Layer-by-layer assembly of DNA and enzyme are assembled on the pyrolytic graphite array which is housed in a microfluidic device for sequential detection of two type of the DNA damages. Multiple enzyme reactions are run on test compounds using the array, generating toxic metabolites in situ. These metabolites react with DNA in the films to cause DNA oxidation and chemical DNA damage which are detected by ECL generating osmium compound and ruthenium polymer, respectively. The method is further validated by the formation of 8-oxodG and DNA adduct using similar films of DNA/enzyme on magnetic bead biocolloid reactors, hydrolyzing the DNA, and analyzing by liquid chromatography-mass spectrometry (LC-MS). Hence, this combined DNA/enzyme array/LC-MS approach can efficiently explore metabolic genotoxic pathways for drugs and environmental chemicals.

Keywords: biosensor, electrochemiluminescence, DNA damage, microfluidic array

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268 FTIR Spectroscopy for in vitro Screening in Microbial Biotechnology

Authors: V. Shapaval, N. K. Afseth, D. Tzimorotas, A. Kohler

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Globally there is a dramatic increase in the demand for food, energy, materials and clean water since natural resources are limited. As a result, industries are looking for ways to reduce rest materials and to improve resource efficiency. Microorganisms have a high potential to be used as bio factories for the production of primary and secondary metabolites that represent high-value bio-products (enzymes, polyunsaturated fatty acids, bio-plastics, glucans, etc.). In order to find good microbial producers, to design suitable substrates from food rest materials and to optimize fermentation conditions, rapid analytical techniques for quantifying target bio products in microbial cells are needed. In the EU project FUST (R4SME, Fp7), we have developed a fully automated high-throughput FUST system based on micro-cultivation and FTIR spectroscopy that facilitates the screening of microorganisms, substrates and fermentation conditions for the optimization of the production of different high-value metabolites (single cell oils, bio plastics). The automated system allows the preparation of 100 samples per hour. Currently, The FUST system is in use for screening of filamentous fungi in order to find oleaginous strains with the ability to produce polyunsaturated fatty acids, and the optimization of cheap substrates, derived from food rest materials, and the optimization of fermentation conditions for the high yield of single cell oil.

Keywords: FTIR spectroscopy, FUST system, screening, biotechnology

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267 Identification and Characterization of Enterobacter cloacae, New Soft Rot Causing Pathogen of Radish in India

Authors: B. S. Chandrashekar, M. K. Prasannakumar, P. Buela Parivallal, Sahana N. Banakar, Swathi S. Patil, H. B. Mahesh, D. Pramesh

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Bacterial soft rot is one of the most often seen diseases in many plant species globally, resulting in considerable yield loss. Radish roots with dark water-soaked lesions, maceration of tissue, and a foul odour were collected in the Kolar region, India. Two isolates were obtained from rotted samples that demonstrated morphologically unpigmented, white mucoid convex colonies on nutrient agar medium. The isolated bacteria (RDH1 and RDH3) were gram-negative, rod-shaped bacteria with biochemically distinct characteristics similar to the type culture of Enterobacter cloacae ATCC13047 and Bergy's handbook of determinative bacteriology. The 16s rRNA gene was used to identify Enterobacter species. On carrot, potato, tomato, chilli, bell pepper, knolkhol, cauliflower, cabbage, and cucumber slices, the Koch′s postulates were fulfilled, and the pathogen was also pathogenic on radish, cauliflower, and cabbage seedlings were grown in a glasshouse. After 36 hours, both isolates exhibited a hypersensitive sensitivity to Nicotianatabacum. Semi-quantitative analysis revealed that cell wall degrading enzymes (CWDEs) such as pectin lyase, polygalacturonase, and cellulase (p=1.4e09) contributed to pathogenicity, whereas isolates produced biofilms (p=4.3e-11) that help in host adhesion. This is the first report in India of radish soft rot caused by E. cloacae.

Keywords: soft rot, enterobacter cloacae, 16S rRNA, nicotiana tabacum, and pathogenicity

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266 The Effect of Wool Mulch on Plant Development in the Light of Soil Physical and Soil Biological Conditions

Authors: Katalin Juhos, Enikő Papdi, Flórián Kovács, Vasileios P. Vasileiadis, Andrea Veres

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Mulching techniques can be a solution for better utilization of precipitation and irrigation water and for mitigating soil degradation and drought damages. Waste fibres as alternative biodegradable mulch materials are increasingly coming to the fore. The effect of wool mulch (WM) on water use efficiency of pepper seedlings were investigated in different soil types (sand, clay loam, peat) in a pot experiment. Two semi-field experiments were also set up to investigate the effect of WM-plant interaction on sweet pepper yield in comparison with agro-textile and straw mulches. Soil parameters (moisture, temperature, DHA, β-glucosidase enzymes, permanganate-oxidizable carbon) were measured during the growing season. The effect of WM on yield and biomass was more significant with less frequent irrigation and the greater the water capacity of soils. The microbiological activity was significantly higher in the presence of plants, because of the water retention of WM, the metabolic products of roots and the more balanced soil temperature caused by plants. On the sandy soil, the straw mulch had a significantly better effect on microbiological parameters and yields than the agro-textile and WM. WM is a sustainable practice for improving soil biological parameters and water use efficiency on soils with a higher water capacity.

Keywords: β-glucosidase, DHA enzyme activity; labile carbon, straw mulch; plastic mulch, evapotranspira-tion coefficient, soil temperature

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265 Energetics of Photosynthesis with Respect to the Environment and Recently Reported New Balanced Chemical Equation

Authors: Suprit Pradhan, Sushil Pradhan

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Photosynthesis is a physiological process where green plants prepare their food from carbon dioxide from the atmosphere and water being absorbed from the soil in presence of sun light and chlorophyll. From this definition it is clear that four reactants (Carbon Dioxide, Water, Light and Chlorophyll) are essential for the process to proceed and the product is a sugar or carbohydrate ultimately stored as starch. The entire process has “Light Reaction” (Photochemical) and “Dark Reaction” (Biochemical). Biochemical reactions are very much complicated being catalysed by various enzymes and the path of carbon is known as “Calvin Cycle” according to the name of its discover. The overall reaction which is now universally accepted can be explained like this. Six molecules of carbon dioxide react with twelve molecules of water in presence of chlorophyll and sun light to give only one molecule of sugar (Carbohydrate) six molecules of water and six molecules of oxygen is being evolved in gaseous form. This is the accepted equation and also chemically balanced. However while teaching the subject the author came across a new balanced equation from among the students who happened to be the daughter of the author. In the new balanced equation in place of twelve water molecules in the reactant side seven molecules can be expressed and accordingly in place of six molecules of water in the product side only one molecule of water is produced. The energetics of the photosynthesis as related to the environment and the newly reported balanced chemical equation has been discussed in detail in the present research paper presentation in this international conference on energy, environmental and chemical engineering.

Keywords: biochemistry, enzyme , isotope, photosynthesis

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264 Sulforaphane Attenuates Fibrosis of Dystrophic Muscle in Mdx Mice via Nrf2-Mediated Inhibition of TGF-β/Smad Signaling

Authors: Chengcao Sun, Cuili Yang, Shujun Li, Ruilin Xue, Yongyong Xi, Liang Wang, Dejia Li

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Backgrounds: A few lines of evidence show that Sulforaphane (SFN) has anti-fibrosis effect in liver tissue via Nrf2-mediated inhibition of TGF-β/Smad signaling. However, its effects on muscular dystrophic fibrosis remain unknown. This work was undertaken to evaluate the effects of SFN on fibrosis in dystrophic muscle. Methods: 3-month-old male mdx mice were treated with SFN by gavage (2 mg/kg body weight per day) for 3 months. Gastrocnemius, tibial anterior and triceps brachii muscles were collected for related analysis. Fibrosis in skeletal muscles was analyzed by Sirius red staining. Histology and morphology of skeletal muscles were investigated by H&E staining. Moreover, the expressions of Nrf2, NQO1, HO-1, and TGF-β/Smad signaling pathway were detected by western blot, qRT-PCR, immunohistochemistry and immunofluorescence assays. Results: Our results demonstrated that SFN treatment significantly decreased and improved morphological features in mdx muscles. Moreover, SFN increased the expression of muscle phase II enzymes NQO1 and HO-1 and significantly decreased the expression of TGF-β1,p-smad2, p-smad3, α-SMA, fibronectin, collagen I, PAI-1, and TIMP-1 in Nrf2 dependent manner. Additionally, SFN significantly decreased the expression of CD45 and TNF-α. Conclusions: Collectively, these results show that SFN can ameliorate muscle fibrosis in mdx mice by Nrf2-induced inhibition of TGF-β/Smad signaling pathway, which indicate Nrf2 may be useful for the treatment of muscular dystrophy.

Keywords: sulforaphane, Nrf2, TGF-β/smad signaling, duchenne muscular dystrophy, fibrosis

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263 Beating Heart Coronary Artery Bypass Grafting on Intermittent Pump Support

Authors: Sushil Kumar Singh, Vivek Tewarson, Sarvesh Kumar, Shobhit Kumar

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Objective: ‘Beating Heart coronary artery bypass grafting on Intermittent Pump Support’ is a more reliable method of coronary revascularization that takes advantage of off and on-pump CABG while eliminating the disadvantage of both techniques. Methods: From January 2015 to December 2021, a new technique, “Intermittent On pump beating heart CABG” using a suction stabilizer was used by putting aortic and venous cannulas electively in all the patients. Patients were supported by a pump intermittently, as and when required (Group 1, n=254). Retrospective data were collected from our record of the patients who underwent off-pump CABG electively by the same surgeon and team (Group 2, n=254). Results: Significant advantage was noted in Group 1 patients in terms of the number of grafts (3.31 ± 1.16 vs. 2.30 ±0.66), grafting of lateral vessels (316 vs.202), mean operating time (1.37 ± 0.23 hrs vs. 2.22 ± 0.45 hrs) and postoperative blood loss (406.30 ± 257.90 ml vs. 567.41 ± 265.20 ml).CPB support time was less than 15 minutes in the majority of patients (n=179, 70.37 %), with a mean of 16.81 minutes. It was required, particularly during the grafting of lateral vessels. A rise in enzymes level (CRP, CKMB, Trop I, and NTPro BNP) was noted in Group 1 patients. But, these did not affect the postoperative course in patients. There was no mortality in Group 1 patients, while four patients in Group 2 died. Coclusions: Intermittent on-pump CABG technique is a promising method of surgical revascularization for all patients requiring CABG. It has shown its superiority in terms of safety, the number of grafts, operating time, and better perioperative course.

Keywords: cardiopulmonary bypass, CABG, beating heart CABG, on-pump CABG

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262 Identification of Potential Small Molecule Regulators of PERK Kinase

Authors: Ireneusz Majsterek, Dariusz Pytel, J. Alan Diehl

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PKR-like ER kinase (PERK) is serine/threonie endoplasmic reticulum (ER) transmembrane kinase activated during ER-stress. PERK can activate signaling pathways known as unfolded protein response (UPR). Attenuation of translation is mediated by PERK via phosphorylation of eukaryotic initiation factor 2α (eIF2α), which is necessary for translation initiation. PERK activation also directly contributes to activation of Nrf2 which regulates expression of anti-oxidant enzymes. An increased phosphorylation of eIF2α has been reported in Alzheimer disease (AD) patient hippocampus, indicating that PERK is activated in this disease. Recent data have revealed activation of PERK signaling in non-Hodgkins lymphomas. Results also revealed that loss of PERK limits mammary tumor cell growth in vitro and in vivo. Consistent with these observations, activation of UPR in vitro increases levels of the amyloid precursor protein (APP), the peptide from which beta-amyloid plaques (AB) fragments are derived. Finally, proteolytic processing of APP, including the cleavages that produce AB, largely occurs in the ER, and localization coincident with PERK activity. Thus, we expect that PERK-dependent signaling is critical for progression of many types of diseases (human cancer, neurodegenerative disease and other). Therefore, modulation of PERK activity may be a useful therapeutic target in the treatment of different diseases that fail to respond to traditional chemotherapeutic strategies, including Alzheimer’s disease. Our goal will be to developed therapeutic modalities targeting PERK activity.

Keywords: PERK kinase, small molecule inhibitor, neurodegenerative disease, Alzheimer’s disease

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261 Identification and Characterization of Inhibitors of Epoxide Hydrolase from Trichoderma reesei

Authors: Gabriel S. De Oliveira, Patricia P. Adriani, Christophe Moriseau, Bruce D. Hammock, Felipe S. Chambergo

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Epoxide hydrolases (EHs) are enzymes that are present in all living organisms and catalyze the hydrolysis of epoxides to the corresponding vicinal diols. EHs have high biotechnological interest for the drug design and chemistry transformation for industries. In this study, we describe the identification of substrates and inhibitors of epoxide hydrolase enzyme from the filamentous fungus Trichoderma reesei (TrEH), and these inhibitors showed the fungal growth inhibitory activity. We have used the cloned enzyme and expressed in E. coli to develop the screening in the library of fluorescent substrates with the objective of finding the best substrate to be used in the identification of good inhibitors for the enzyme TrEH. The substrate (3-phenyloxiranyl)-acetic acid cyano-(6-methoxy-naphthalen-2-yl)-methyl ester showed the highest specific activity and was chosen for the next steps of the study. The inhibitors screening was performed in the library with more than three thousand molecules and we could identify the 6 best inhibitors. The IC50 of these molecules were determined in nM and all the best inhibitors have urea or amide in their structure, because It has been recognized that these groups fit well in the hydrolase catalytic pocket of the epoxide hydrolases. Then the growth of T. reesei in PDA medium containing these TrEH inhibitors was tested, and fungal growth inhibition activity was demonstrated with more than 60% of inhibition of fungus growth in the assay with the TrEH inhibitor with the lowest IC50. Understanding how this EH enzyme from T. reesei responds to inhibitors may contribute for the study of fungal metabolism and drug design against pathogenic fungi.

Keywords: epoxide hydrolases, fungal growth inhibition, inhibitor, Trichoderma reesei

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260 Effect of Feed Additive on Cryopreservation of Barki Ram Semen

Authors: Abdurzag Kerban, Mostfa M. Abou-Ahmed, Abdelrof M. Ghallab, Mona H. Shaker

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Preservation of semen had a major impact on sheep genetic breeding. The aim of this study was to evaluate the effect of protected fat, probiotic and zinc-enriched diets on semen freezability. Twenty two Barki rams were randomly assigned into four groups; Group I (n=5) was fed the basal diet enriched with 3.7% of dry fat/kg concentration/day, Group II (n=5) was fed a basal diet-enriched with 10gm of probiotic /head/day, Group III (n=6) was fed on the basal diet enriched with 100 ppm of 10% zinc chelated with methionine/kg dry matter/day and Group IV (n=6) was served as control. A pool of three to four ejaculates were pooled from rams within a period of ten weeks. Semen was diluted in egg yolk-Tris diluent and processed in 0.25 ml straw. Motility was evaluated after dilution, before freezing and post-thawing at 0, 1, 2 and 3 hour incubation. Viability index, acrosome integrity and leakage of intracellular enzymes (Aspartat aminotransferase and Alkline phosphatase) were also evaluated. Spermatozoa exhibited highly significant (P<0.01) percentages of motility at 0, 1, 2, and 3 hours incubation after thawing, viability index and acrosome integrity in rams fed a diet enriched with protected fat and zinc groups as compared with probiotic and control groups. Also, the mean value of extracellular leakage of AST was significantly lower in fat and zinc group as compared with probiotic and control groups. In conclusion, semen freezability was improved in animals fed a diet fortified with fat and zinc with no significant improvement in animals fed the probiotic-enriched diet.

Keywords: Barki ram semen, freezing, straw, feed additives

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259 Systematic Discovery of Bacterial Toxins Against Plants Pathogens Fungi

Authors: Yaara Oppenheimer-Shaanan, Nimrod Nachmias, Marina Campos Rocha, Neta Schlezinger, Noam Dotan, Asaf Levy

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Fusarium oxysporum, a fungus that attacks a broad range of plants and can cause infections in humans, operates across different kingdoms. This pathogen encounters varied conditions, such as temperature, pH, and nutrient availability, in plant and human hosts. The Fusarium oxysporum species complex, pervasive in soils globally, can affect numerous plants, including key crops like tomatoes and bananas. Controlling Fusarium infections can involve biocontrol agents that hinder the growth of harmful strains. Our research developed a computational method to identify toxin domains within a vast number of microbial genomes, leading to the discovery of nine distinct toxins capable of killing bacteria and fungi, including Fusarium. These toxins appear to function as enzymes, causing significant damage to cellular structures, membranes and DNA. We explored biological control using bacteria that produce polymorphic toxins, finding that certain bacteria, non-pathogenic to plants, offer a safe biological alternative for Fusarium management, as they did not harm macrophage cells or C. elegans. Additionally, we elucidated the 3D structures of two toxins with their protective immunity proteins, revealing their function as unique DNases. These potent toxins are likely instrumental in microbial competition within plant ecosystems and could serve as biocontrol agents to mitigate Fusarium wilt and related diseases.

Keywords: microbial toxins, antifungal, Fusarium oxysporum, bacterial-fungal intreactions

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258 Isolation and Identification Fibrinolytic Protease Endophytic Fungi from Hibiscus Leaves in Shah Alam

Authors: Mohd Sidek Ahmad, Zainon Mohd Noor, Zaidah Zainal Ariffin

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Fibrin degradation is an important part in prevention or treatment of intravascular thrombosis and cardiovascular diseases. Plasmin like fibrinolytic enzymes has given new hope to patient with cardiovascular diseases by treating fibrin aggregation related diseases with traditional plasminogen activator which have many side effects. Various researches involving wide range of sources for production of fibrinolytic proteases, from bacteria, fungi, insects and fermented foods. But few have looked into endophytic fungi as a potential source. Sixteen (16) endophytic fungi were isolated from Hibiscus sp. leaves from six different locations in Shah Alam, Selangor. Only two endophytic fungi, FH3 and S13 showed positive fibrinolytic protease activities. FH3 produced 5.78cm and S13 produced 4.48cm on Skim Milk Agar after 4 days of incubation at 27°C. Fibrinolytic activity was observed; 3.87cm and 1.82cm diameter clear zone on fibrin plate of FH3 and S13 respectively. 18srRNA was done for identification of the isolated fungi with positive fibrinolytic protease. S13 had the highest similarity (100%) to that of Penicillium citrinum strain TG2 and FH3 had the highest similarity (99%) to that of Fusarium sp. FW2PhC1, Fusarium sp. 13002, Fusarium sp. 08006, Fusarium equiseti strain Salicorn 8 and Fungal sp. FCASAn-2. Media composition variation showed the effects of carbon nitrogen on protein concentration, where the decrement of 50% of media composition caused drastic decrease in protease of FH3 from 1.081 to 0.056 and also S13 from 2.946 to 0.198.

Keywords: isolation, identification, fibrinolytic protease, endophytic fungi, Hibiscus leaves

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257 In Vitro Morphogenic Response of the Alginate Encapsulated Nodal Segment and Antioxidative Enzymes Analysis during Acclimatization of Cassia Angustifolia Vahl

Authors: Iram Siddique

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Synthetic seed technology is an alternative to traditional micropropagation for production and delivery of cloned plantlets. Synthetic seeds were produced by encapsulating nodal segments of C. angustifolia in calcium alginate gel. 3% (w/v) sodium alginate and 100 mM CaCl2. 2H2O were found most suitable for encapsulation of nodal segments. Synthetic seeds cultured on half strength Murashige and Skoog (MS) medium supplemented with thidiazuron (5.0 µM) + indole -3- acetic acid (1.0 µM) produced maximum number of shoots (10.9 ± 0.78) after 8 weeks of culture exhibiting (78%) in vitro conversion response. Encapsulated nodal segments demonstrated successful regeneration after different period (1-6 weeks) of cold storage at 4 °C. The synthetic seeds stored at 4 °C for a period of 4 weeks resulted in maximum conversion frequency (93%) after 8 weeks when placed back to regeneration medium. The isolated shoots when cultured on half strength MS medium supplemented with 1.0 µM indole -3- butyric acid (IBA), produced healthy roots and plantlets with well developed shoot and roots were successfully hardened off in plastic pots containing sterile soilrite inside the growth chamber and gradually transferred to greenhouse where they grew well with 85% survival rate. Changes in the content of photosynthetic pigments, net photosynthetic rate (PN), superoxide dismutase (SOD) and catalase (CAT) activity in C. angustifolia indicated the adaptation of micropropagated plants to ex vitro conditions.

Keywords: biochemical studies, nodal segments, rooting, synthetic seeds, thidiazuron

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256 Pharmacogenetics of Uridine Diphosphate Glucuronosyltransferase (UGT1A9) Genetic Polymorphism on Sodium Valproate Pharmacokinetics in Epilepsy

Authors: Murali Munisamy, Gauthaman Karunakaran, Mubarak Al-Gahtany, Vivekanandhan Subbiah, M. Manjari Tripati

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Background: Sodium valproate is a widely prescribed broad-spectrum anti-epileptic drug. It shows high inter-individual variability in pharmacokinetics and pharmacodynamics and has a narrow therapeutic range. We evaluated the effects of polymorphic uridine diphosphate glucuronosyltransferase (UGT1A9) metabolizing enzyme on the pharmacokinetics of sodium valproate in the patients with epilepsy who showed toxicity to therapy. Methods: Genotype analysis of the patients was made with polymerase chain–restriction fragment length polymorphism (RFLP) with sequencing. Plasma drug concentrations were measured with reversed phase high-performance liquid chromatography (HPLC) and concentration–time data were analyzed by using a non-compartmental approach. Results: The results of this study suggested a significant genotypic as well as allelic association with valproic acid toxicity for UGT1A9 polymorphic enzymes. The elimination half-life (t 1/2=40.2 h) of valproic acid was longer and the clearance rate (CL=937 ml/h) was lower in the poor metabolizers group of UGT1A9 polymorphism who showed toxicity than in the intermediate metabolizers group (t1/2=35.5 h, CL=1042 ml/h) or the extensive metabolizers group (t1/2=26. h, CL=1,302 ml/h). Conclusion: Our findings suggest that the UGT1A9 genetic polymorphism plays a significant role in the steady state concentration of sodium valproate, and it thereby has an impact on the toxicity of the sodium valproate used in the patients with epilepsy.

Keywords: UGT1A9, sodium valporate, pharmacogenetics, polymorphism

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255 Quorum-Sensing Driven Inhibitors for Mitigating Microbial Influenced Corrosion

Authors: Asma Lamin, Anna H. Kaksonen, Ivan Cole, Paul White, Xiao-Bo Chen

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Microbiologically influenced corrosion (MIC) is a process in which microorganisms initiate, facilitate, or accelerate the electrochemical corrosion reactions of metallic components. Several reports documented that MIC accounts for about 20 to 40 % of the total cost of corrosion. Biofilm formation due to the presence of microorganisms on the surface of metal components is known to play a vital role in MIC, which can lead to severe consequences in various environmental and industrial settings. Quorum sensing (QS) system plays a major role in regulating biofilm formation and control the expression of some microbial enzymes. QS is a communication mechanism between microorganisms that involves the regulation of gene expression as a response to the microbial cell density within an environment. This process is employed by both Gram-positive and Gram-negative bacteria to regulate different physiological functions. QS involves production, detection, and responses to signalling chemicals, known as auto-inducers. QS controls specific processes important for the microbial community, such as biofilm formation, virulence factor expression, production of secondary metabolites and stress adaptation mechanisms. The use of QS inhibitors (QSIs) has been proposed as a possible solution to biofilm related challenges in many different applications. Although QSIs have demonstrated some strength in tackling biofouling, QSI-based strategies to control microbially influenced corrosion have not been thoroughly investigated. As such, our research aims to target the QS mechanisms as a strategy for mitigating MIC on metal surfaces in engineered systems.

Keywords: quorum sensing, quorum quenching, biofilm, biocorrosion

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254 Antioxidant Property of Honey with Dried Cherry

Authors: Jasna M. Čanadanović-Brunet, Gordana S. Ćetković, Jelena J. Vulić, Sonja M. Djilas, Vesna T. Tumbas Šaponjac, Sladjana M. Stajčić

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Honey serves as a source of natural antioxidants, which are effective in reducing the risk of heart disease, cancer, immune-system decline, cataracts, different inflammatory processes, and also prevent deteriorative oxidation reactions in foods such as enzymatic browning of fruit and vegetables. Honey is a natural saturated sugar solution, but it also contains certain minor constituents, proteins, enzymes, amino and organic acids, lipids, vitamins, phenolic acids, flavonoids and carotenoids. It is consumed in its natural form alone, but also in combination with nuts and various kinds of dried fruits. The aim of this research was to investigate the contribution of dried cherry on phenols (TPh) and flavonoids (Fl) contents and antioxidant activities of honey. Phenolic compounds in Serbian polyfloral (PH), linden (LH) and acacia (AH) honey and also in their mixtures with dried cherry, in 40% mass concentrations (PH40; LH40, AH40), were determined. In comparison to honey, TPh increased 2.25 times for LH40, 2.16 times for AH40 and 1.45 times for PH40, while Fl increased 2.81-fold for PH40, 1.21-fold for LH40 and 1.44-fold for AH40. Antioxidant activity was investigated with two assays, DPPH test and reducing power (RP), and expressed as EC50DPPH and RP0.5 values. The EC50DPPH values were: EC50PH40 = 1.16 mg/ml; EC50LH40= 1.42 mg/ml and EC50AH40= 1.69 mg/ml, while RP0.5 were: RP0.5PH40 = 15.05 mg/ml; RP0.5LH40 = 16.09 mg/ml and P0.5AH40 = 17.60 mg/ml. Our results indicate that supplementation of polyfloral, linden and acacia honey with 40% dried cherry improves antioxidant activity of honey by enriching the phenolic composition.

Keywords: antioxidant activity, dried cherry, honey, phenolics

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253 Effects of Different Mechanical Treatments on the Physical and Chemical Properties of Turmeric

Authors: Serpa A. M., Gómez Hoyos C., Velásquez-Cock J. A., Ruiz L. F., Vélez Acosta L. M., Gañan P., Zuluaga R.

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Turmeric (Curcuma Longa L) is an Indian rhizome known for its biological properties, derived from its active compounds such as curcuminoids. Curcumin, the main polyphenol in turmeric, only represents around 3.5% of the dehydrated rhizome and extraction yields between 41 and 90% have been reported. Therefore, for every 1000 tons of turmeric powder used for the extraction of curcumin, around 970 tons of residues are generated. The present study evaluates the effect of different mechanical treatments (waring blender, grinder and high-pressure homogenization) on the physical and chemical properties of turmeric, as an alternative for the transformation of the entire rhizome. Suspensions of turmeric (10, 20 y 30%) were processed by waring blender during 3 min at 12000 rpm, while the samples treated by grinder were processed evaluating two different Gaps (-1 and -1,5). Finally, the process by high-pressure homogenization, was carried out at 500 bar. According to the results, the luminosity of the samples increases with the severity of the mechanical treatment, due to the stabilization of the color associated with the inactivation of the oxidative enzymes. Additionally, according to the microstructure of the samples, the process by grinder (Gap -1,5) and by high-pressure homogenization allowed the largest size reduction, reaching sizes up to 3 m (measured by optical microscopy). This processes disrupts the cells and breaks their fragments into small suspended particles. The infrared spectra obtained from the samples using an attenuated total reflectance accessory indicates changes in the 800-1200 cm⁻¹ region, related mainly to changes in the starch structure. Finally, the thermogravimetric analysis shows the presence of starch, curcumin and some minerals in the suspensions.

Keywords: characterization, mechanical treatments, suspensions, turmeric rhizome

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252 Electrochemical Study of Ti-O Modified Electrode towards Tyrosinase Catalytic Activity

Authors: Riya Thomas, Denis Music, Tautgirdas Ruzgas

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The detection of tyrosinase holds considerable interest in the domains of food nutrition and human health due to its significant role in causing a detrimental effect on the colour, flavour, and nutritional value of food as well as in the synthesis of melanin causing skin melanoma. Compared to other conventional analytical techniques, electrochemical (EC) sensors are highly promising owing to their quick response, great sensitivity, ease of use, and low cost. Particularly, titania nanoparticle-based electrochemical sensors have drawn special attention in identifying several biomolecules including enzymes, antibodies, and receptors, owing to their enhanced electrocatalytic activity and electron-accepting properties. In this study, Ti-O film-modified electrode is fabricated using reactive magnetron sputtering, and its affinity towards tyrosinase is examined via electrochemical methods. To comprehend the physiochemical and surface properties-governed electrocatalytic activity of modified electrodes, Ti-O films are grown under various compositional ranges and deposition temperature, and their corresponding electrochemical activity towards tyrosinase is studied. Further, to understand the underlying atomistic mechanisms and electronic-scale electrochemical characteristics, density functional theory (DFT) is employed. The main goal of the current work is to determine the correlation between macroscopic measurements and the underlying atomic properties to improve the tyrosinase activity on Ti-O surfaces. Moreover, this work offers an intriguing new perspective on the use of Ti-O-modified electrodes to detect tyrosinase in the areas of clinical diagnosis, skincare, and food science.

Keywords: density functional theory, electrochemical sensor, Ti-O film, tyrosinase

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251 Hepatoprotective Evaluation of Potent Antioxidant Fraction from Urtica dioica L.: In vitro and In vivo Studies

Authors: Bhuwan C. Joshi, Atish Prakash, Ajudhia N. Kalia

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Ethnopharmacological relevance: The plant Urtica dioica L. (Urticaceae) is used in various diseases including hepatic ailments. Traditionally, the leaves and roots of the plant are used in jaundice. Objective: The aim of the present work was to evaluate hepatoprotective potential of potent antioxidant from Urtica dioica L. against CCl4 induced hepatotoxicity in-vitro and in-vivo model. Materials and methods: Antioxidant activity of hydro alcoholic extract and its fractions petroleum ether fraction (PEF), ethyl acetate fraction (EAF), n-butanol fraction (NBF) and aqueous fraction (AF) were determined by DPPH radicals scavenging assay. Fractions were subjected to in-vitro cell line study. Further, the most potent fraction (EAF) was subjected to in-vivo study. The in-vivo hepatoprotective active fraction was chromatographed on silica column to isolate the bioactive constituent(s). Structure elucidation was done by using various spectrophotometric techniques like UV, IR, 1H NMR, 13C NMR and MS spectroscopy. Results and conclusion: The ethyl acetate fraction (EAF) of Urtica. dioica L. possessed the potent antioxidant activity viz. DPPH (IC50 78.99 ± 0.17 µg/ml). The in-vitro cell line study showed EAF prevented the cell damage. The EAF significantly attenuated the increased liver enzymes activities in serum and tissue. Column chromatography of most potent antioxidant fraction (EAF) leads to the isolation of 4-hydroxy-3-methoxy cinnamic acid which is responsible for its hepatoprotective potential. Hence, the present study suggests that EAF has significant antioxidant and hepatoprotective potential on CCl4 induced hepatotoxicity in-vitro and in-vivo.

Keywords: Urtica dioica L., antioxidant, HepG2 cell line, hepatoprotective

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250 Effect of Zinc Nanoparticles on Oxidative Stress-Related Genes and Antioxidant Enzymes Activity in the Brain of Oreochromis Niloticus and Tilapia Zillii

Authors: Salina Saddick, Mohamed Afifi, Osama Abuznadah

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This study was carried out to determine the median lethal concentrations (LC50) of Zinc nanoparticles (ZnNPs) on Oreochromis niloticus and Tilapia zillii. The biochemical and molecular potential effects of ZnNPs (500 and 2000 μg L−1) on the antioxidant system in the brain tissue of O. niloticus and T. zillii were investigated. Four hundred fish were used for acute and sub-acute studies. ZnNP LC50 concentrations were investigated in O. niloticus and T. zillii. The effect of 500 and 2000 μg L−1 ZnNPs on brain antioxidants of O. niloticus and T. zillii was investigated. The result indicated that 69 h LC50 was 5.5 ± 0.6 and 5.6 ± 0.4 for O. nilotica and T. zillii, respectively. Fish exposed to 500 μg L−1 ZnNPs showed a significant increase in reduced glutathione (GSH), total glutathione (tGSH) levels, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activity and gene expression. On the contrary, malondialdehyde (MDA) levels significantly decreased. Meanwhile, fish exposed to 2000 μg L−1 ZnNPs showed a significant decrease of GSH, tGSH levels, SOD, CAT, GR, GPx and GST activity and gene expression. On the contrary, MDA levels significantly increased. It was concluded that, the 96 h LC50 of ZnNPs was 5.5 ± 0.6 and 5.6 ± 0.4 for O. nilotica and T. zillii, respectively. ZnNPs in exposure concentrations of 2000 μg/L induced a deleterious effect on the brain antioxidant system of O. nilotica and T. zillii. In contrast, ZnNPs in exposure concentrations of 500 μg L−1 produced an inductive effect on the brain antioxidant system of O. nilotica and T. zillii.

Keywords: ZnNPs, LC50, antioxidants, O. nilotica

Procedia PDF Downloads 245
249 Olive Oil (Olea europea L.) Protects against Mercury (II) Induced Oxidative Tissue Damage in Rats

Authors: Ahlem Bahi, Youcef Necib, Sakina Zerizer, Cherif Abdennour, Mohamed Salah Boulakoud

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Mercury (II) is a highly toxic metal which induces oxidative stress in the body. In this study, we aimed to investigate the possible protective effect of olive oil, an antioxidant agent, against experimental mercury toxicity in rat model. Administration of mercuric chloride induced significant increase in serum: ALT, AST, and LPA activities; interleukine1, interleukine6, tumor necrosis factor α (TNFα), creatinine, urea, and uric acid levels. Mercuric chloride also induced oxidative stress, as indicate by decreased tissue of GSH level, GSH-Px, and GST activities along with increase the level of lipid peroxidation. Furthermore, treatment with mercuric chloride caused a marked elevation of kidney and liver weight and decreased body weight. Virgin olive oil treatment markedly reduced elevated serum: AST, ALT, and LPA activities; interleukine1, interleukine6, tumor necrosis factor α (TNFα), creatinine, urea, and uric acid levels and contracted the deterious effects of mercuric chloride on oxidative stress markers changes caused by HgCl2 in tissue as compared to control group. Our results implicate that mercury induced oxidative damage in liver and kidney tissue protected by virgin olive oil, with its antioxidant effects.

Keywords: mercury, antioxidant enzymes, pro-inflammatory cytokine, virgin olive oil, lipid peroxidation

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248 Effect of Brown Algae, Ecklonia arborea and Silvetia compressa, in Lipidemic and Hepatic Metabolism in Wistar Rats

Authors: Laura Acevedo-Pacheco, Janet Alejandra Gutierrez-Uribe, Lucia Elizabeth Cruz-Suarez, Segio Othon Serna-Saldivar

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Seaweeds can generate changes in the metabolism of lipids; as a consequence, this may diminish cholesterol and other lipids in the blood. However, the consumption of marine algae may also alter the functions of other organs. Therefore, the objective of this research was to study the effect of two different sorts of algae (Ecklonia arborea and Silvetia compressa) in the metabolism of lipids, as well as, in the physiology of the liver. Wistar male rats were fed for two months with independent diets composed of 20% of fat and 2.5% of E. arborea and S. compressa each. Blood parameters (cholesterol, lipoproteins, triglycerides, hepatic enzymes) and triglycerides in the liver were quantified, and also hepatic histology analyses were performed. While S. compressa reduced 18% total cholesterol compared to the positive control, E. arborea increased it 5.8%. Animals fed with S. compressa presented a decrement, compared to the positive control, not only in low density lipoproteins levels (53%) but also in triglycerides (67%). The presence of steatosis in the histologies and the high levels of triglycerides showed an evident lipid accumulation in hepatic tissues of rats fed with both algae. These results indicate that even though S. compressa showed a promising resource to decrease total cholesterol and low-density lipoproteins in blood, a detrimental effect was observed in liver physiology. Further investigations should be made to find out if toxic compounds associated with these seaweeds may cause liver damage especially in terms of heavy metals.

Keywords: brown algae, Eisenia arborea, hepatic metabolism, lipidemic metabolism, Pelvetia compressa, steatosis

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247 Correlation between Polysaccharides Molecular Weight Changes and Pectinases Gene Expression during Papaya Ripening

Authors: Samira B. R. Prado, Paulo R. Melfi, Beatriz T. Minguzzi, João P. Fabi

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Fruit softening is the main change that occurs during papaya (Carica papaya L.) ripening. It is characterized by the depolymerization of cell wall polysaccharides, especially the pectic fractions, which causes cell wall disassembling. However, it is uncertain how the modification of the two main pectin polysaccharides fractions (water-soluble – WSF, and oxalate-soluble fractions - OSF) accounts for fruit softening. The aim of this work was to correlate molecular weight changes of WSF and OSF with the gene expression of pectin-solubilizing enzymes (pectinases) during papaya ripening. Papaya fruits obtained from a producer were harvest and storage under specific conditions. The fruits were divided in five groups according to days after harvesting. Cell walls from all groups of papaya pulp were isolated and fractionated (WSF and OSF). Expression profiles of pectinase genes were achieved according to the MIQE guidelines (Minimum Information for publication of Quantitative real-time PCR Experiments). The results showed an increased yield and a decreased molecular weight throughout ripening for WSF and OSF. Gene expression data support that papaya softening is achieved by polygalacturonases (PGs) up-regulation, in which their actions might have been facilitated by the constant action of pectinesterases (PMEs). Moreover, BGAL1 gene was up-regulated during ripening with a simultaneous galactose release, suggesting that galactosidases (GALs) could also account for pulp softening. The data suggest that a solubilization of galacturonans and a depolymerization of cell wall components were caused mainly by the action of PGs and GALs.

Keywords: carica papaya, fruit ripening, galactosidases, plant cell wall, polygalacturonases

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246 Toxicological Validation during the Development of New Catalytic Systems Using Air/Liquid Interface Cell Exposure

Authors: M. Al Zallouha, Y. Landkocz, J. Brunet, R. Cousin, J. M. Halket, E. Genty, P. J. Martin, A. Verdin, D. Courcot, S. Siffert, P. Shirali, S. Billet

Abstract:

Toluene is one of the most used Volatile Organic Compounds (VOCs) in the industry. Amongst VOCs, Benzene, Toluene, Ethylbenzene and Xylenes (BTEX) emitted into the atmosphere have a major and direct impact on human health. It is, therefore, necessary to minimize emissions directly at source. Catalytic oxidation is an industrial technique which provides remediation efficiency in the treatment of these organic compounds. However, during operation, the catalysts can release some compounds, called byproducts, more toxic than the original VOCs. The catalytic oxidation of a gas stream containing 1000ppm of toluene on Pd/α-Al2O3 can release a few ppm of benzene, according to the operating temperature of the catalyst. The development of new catalysts must, therefore, include chemical and toxicological validation phases. In this project, A549 human lung cells were exposed in air/liquid interface (Vitrocell®) to gas mixtures derived from the oxidation of toluene with a catalyst of Pd/α-Al2O3. Both exposure concentrations (i.e. 10 and 100% of catalytic emission) resulted in increased gene expression of Xenobiotics Metabolising Enzymes (XME) (CYP2E1 CYP2S1, CYP1A1, CYP1B1, EPHX1, and NQO1). Some of these XMEs are known to be induced by polycyclic organic compounds conventionally not searched during the development of catalysts for VOCs degradation. The increase in gene expression suggests the presence of undetected compounds whose toxicity must be assessed before the adoption of new catalyst. This enhances the relevance of toxicological validation of such systems before scaling-up and marketing.

Keywords: BTEX toxicity, air/liquid interface cell exposure, Vitrocell®, catalytic oxidation

Procedia PDF Downloads 411