Open Access Pub publishes peer-reviewed, free-to-read open-access articles. Showing
articles matching polysaccharide — open any to read the full text,
or download the PDF or XML.
Mar 2019 DOI 10.14302/issn.2379-7835.ijn-19-2639
McCarthy OliviaCorresponding author
Diabetes Research Group, Medical School, Swansea University, Swansea, UK
Nine healthy individuals with a mean ± SD BMI of 22.0 ± 0.7 kg/m² and age of 20 ± 0.2 years, participated in this single-blind randomised, crossover trial investigating the impact of ingesting two different honeys (1) Tropical Forest Honey (TFH) and (2) Manuka Honey; strength 12+ (MAN) on circulating levels of plasma interferon gamma following ex-vivo lipopolysaccharide (LPS) stimulation. Blood samples were prepared into duplicate aliquots of whole blood (800 μl) and 100 μg/l of LPS was added to samples to give a final volume of 1 ml. Levels of IFN-γ in plasma fractions were measured via commercially available sandwich ELISA and all comparisons were made with paired data using the Wilcoxon Signed Rank test taking a significance level of 5%. Whilst significant intra-and-interpersonal variation was observed, IFN-γ concentrations remained statistically unchanged 48 hours after the ingestion of either honey (p=0.15). Thus, in this instance the type of honey did not influence the IFN-γ response to plasma samples spiked with LPS.
May 2018 DOI 10.14302/issn.2832-5311.jpcd-18-2077
Farkaš VladimírCorresponding author
Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, 84538 Bratislava, Slovakia
Polysaccharide transglycosylases (PTGs) are a unique group of glycoside hydrolases playing important roles in the formation and modification of plant and fungal cell walls. Their action involves cutting the molecule of the polysaccharide substrate at the glycosidic bond, followed by transfer of the newly formed reducing-end fragment to the non-reducing end of another polysaccharide molecule, with the formation of a new glycosidic bond. As there is no net increase in the number of reducing ends in the system, conventional reductometric methods used to assess the activity of glycoside hydrolases are ineffective. Since the PTGs participate in vital processes, such as the elaboration of cell walls in plants and fungi, and are not present in animal cells, they are considered as possible targets for future specific fungicides and herbicides. Biochemical studies of PTGs, as well as the search for their inhibitors, require the availability of convenient and efficient methods for their assay. In this review we briefly describe the principles of methods used to detect and to determine the activity of this important group of enzymes.
Mar 2018 DOI 10.14302/issn.2575-1212.jvhc-18-2013
A Halawa AmalCorresponding author
Department of Forensic Medicine and Toxicology, Faulty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
Lipopolysaccharide (LPS) is a component of the outer membrane of gram negative bacteria. LPS challenging allows switching transcription of proinflammatory cytokines on via over stimulation of Toll-like receptors (TLRs) signaling pathway with subsequent pathogenic inflammatory response. We investigated the possible reproductive toxicity of LPS in male Wister albino rats. Oxidative stress markers, antioxidant status and caspase-3 activity were analyzed in testicular tissues of rats exposed to either saline or LPS (4 mg/kg BW, ip; 0.18 of the LD50). The samples were collected at 6 h and 72 h after injection of LPS. A significant reduction in testicular reduced glutathione (GSH), glutathione-S-transferase (GST) and superoxide dismutase (SOD) was observed at 72 h compared to control group. Total antioxidant capacity was decreased at 6 h with additional significant reduction at 72 h. Catalase activity was reduced significantly at both 6 and 72 h. Malondialdehyde (MDA) was increased (P ≤ 0.05) in LPS injected rats without variation between 6 and 72 h. A significant increase in nitric oxide (NO) was observed at 72 h after injection. A time-dependent increase in LPS-treated groups was observed in the concentration of caspase-3.Histopathological analysis revealed degenerative changes and necrosis of seminiferous tubules after 6 h with further accumulation of eosinophilic edematous transudate in its lumen after 72 h. In conclusion, by increasing time of exposure, LPS induced lipid peroxidation, oxidative stress, reduced testicular antioxidant capacity and encouraged testicular apoptosis which could be possible mechanisms for impairment of testicular function.
Aug 2017 DOI 10.14302/issn.2471-2140.jaa-17-1541
Yu ZhiCorresponding author
College of Horticulture and Forestry Science, Huazhong Agricultural University, Key Laboratory of Horticultural Plant Biology, Ministry of Education, No. 1 Shizishan Street, Hongshan District, Wuhan City, Hubei Province, China 430070
In the present study, we investigated the chemical compositions, in vitro antioxidant and in vivo hepatoprotective activities of two tea polysaccharides (TPS), which were extracted from two different tea cultivars, Yingshuang (Camellia Senesis, T01) and Yunnan Dayezhong (Camellia Senesis, T09). Compared with T09-TPS, T01-TPS had lower contents of neutral sugar, protein, uronic acid and polyphenol. However, T01-TPS showed stronger scavenging abilities for transient free radicals of hydroxyl radical and superoxide anion radicals and lipid peroxidation inhibition effect, but weaker scavenging ability for stable free radical of DPPH. For hepatoprotective activity in vivo, the results demonstrated that both T01-TPS and T09-TPS could significantly prevent the increase of serum alanine aminotransferase and, aspartate aminotransferase levels, decrease the liver index, reduce the formation of malonydialdehyde and enhance the activities of superoxide dismutase, glutathione peroxidase and peroxidase in carbon tetrachloride-induced liver injury mice. These results suggest that T01-TPS and T09-TPS have potent antioxidant and hepatoprotective activities.
Jun 2023
Rifkatu Kambel DogaraCorresponding author
The increasing demand for environmentally-friendly materials has led to a surge in research on the production of biodegradable polymers. In this study, we investigate the synthesis of a biodegradable polymer by graft copolymerization of gum Arabic (GA) and polyethylene glycol (PEG). GA, a natural polysaccharide and PEG, a synthetic water-soluble polymer, were used as the backbone and graft monomer, respectively. The graft copolymerization was carried out using benzoyl peroxide as an initiator and performed under nitrogen atmosphere. The resulting polymer was characterized by Fourier transform infrared (FTIR) spectroscopy, Xray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The FTIR spectra confirmed the formation of the graft copolymer, and TGA analysis showed that the copolymer had higher thermal stability than GA. The DTA thermograms indicated two thermal events. The evaporation of water and organic polyethylene glycol components was measured, and the first mass loss was due to the loss of adsorbed and structural water in the gum Arabic, which occurred between 31.87 and 180°C, while the second, corresponding to the pyrolysis of polyethylene glycol functional groups and polysaccharide decomposition, resulted in a 70% mass loss. SEM morphological analysis of gum Arabic showed aggregates of high irregularity in particle shape. The cracks and holes obtained in the Gum Arabic micrograph disappeared from the new gum Arabic-graft-polyethylene glycol, leaving a smooth surface with scattered particles in the image, which was due to the grafting copolymer. From the XRD patterns, the percentages of the amorphous and crystalline phases were determined. The results show that gum Arabic has a 78% degree of crystallinity, whereas gum Arabic-graft-polyethylene glycol has the lowest value of 51%. Biodegradation activity was observed using the fungus Aspergillus flavus on different days on gum Arabic-g-polyethylene glycol. The results clearly showed inhibition zones with a change in the state of the copolymer from solid to liquid from days 8 to 14. These results indicate that the GA-PEG copolymer has potential as a biodegradable material for use in various applications, such as packaging, agriculture, and medical industries.
Mar 2021 DOI 10.14302/issn.2575-1212.jvhc-21-3767
Abdishakur Hassan FaysalCorresponding author
Advanced Scientific Group, Abu Dhabi, United Arab Emirates
Antibodies and antibody fragments, especially single-domain antibodies known as nanobodies, are important tools in diagnostics, research, and therapeutics. In a conventional antibody, light and heavy chains contribute to the formation of the antigen binding site. In addition to conventional antibodies, old and new world camels also have heavy-chain antibodies (hcAbs), which lack the light-chain antibodies that usually bind to the antigen, as well as single domain antibodies, the VHH domain, which are the smallest antigen-binding fragments and have high solubility, stability, and specificity. A VHH library against E. coli lipopolysaccharide (LPS) was produced using the camel immune system. E. coli strains from dead camel calves were isolated to extract the LPS and used to immunize a 2-year-old female camel. After isolating mononuclear lymphocytes for RNA extraction and amplification of the VHH gene, the PCR product was cloned into the pF1AT7 Flexi vector and transformed into JM109 E. coli competent cells by heat shock, resulting in a comprehensive VHHs library with 6.9 × 104 cfu/µg. The VHHs were expressed and screened with ELISA and PCR. Eleven colonies were positive by PCR, six of which were sequenced and submitted to Genbank compared with GenBank data to confirm the production of nanobodies with a similarity >90%.
Dec 2019 DOI 10.14302/issn.2690-4829.jen-19-3105
Brumm PhillipCorresponding author
C5-6 Technologies LLC, 5627 Old Oak Drive, Fitchburg, WI 53711, USA
Trichoderma reeseiβ-glucosidase (Bgl1) is one of four enzymes demonstrated to act synergistically to degrade cellulose both in vitro and in vivo. Our work attempted to better understand the substrate specificity and potential biotechnological applications of Bgl1. T. reesei Bgl1H cleaves over 80% of the β-(1-4) and β-(1-3) linkages in β-glucan and 14% of the β-(1-4) linkages in amorphous cellulose, significantly more than any tested bacterial β-glucosidase. Bgl1H cleaves 50% of the β-(1-4) linkages in xyloglucan when supplemented with cellulase and α-xyloside. Approximately 20% conversion to glucose was obtained from insoluble β-(1,3)-linked curdlan using only Bgl1H; addition of a curdlanase resulted in conversion of approximately 70% of the curdlan to glucose. Bgl1H also produces xylose from xylooligosaccharides and debranched xylans. For both glucans and xylans, the relative rates of hydrolysis increase with increasing polysaccharide chain lengths. Bgl1H is able to partially degrade β-glucan in a variety of grain components; addition of endo-acting enzymes improved the enzyme’s performance on these grain components. The ability of this enzyme to produce monosaccharides from undigestible polysaccharides suggest it may have potential in improving utilization of carbohydrates in animal feed, fermentations, and other biotechnological applications.