muramidase and 1-1-diphenyl-2-picrylhydrazyl

Lysozymes, which are secreted in many organisms, including invertebrates, mammals, plants, bacteria and fungus, exhibit antimicrobial, antiviral, antioxidant, and anti-inflammatory activities. Splys-i is an invertebrate-type (i-type) lysozyme isolated from Scylla paramamosain in 2017 and is involved in immune defense against bacteria. However, the antibacterial, antioxidant, and anti-inflammatory activities of Splys-i remain to be elucidated. In the current study, the expression parameters (including IPTG concentration, induction temperature, and induction duration) of Splys-i in Escherichia coli were optimized to achieve high-level yield through shake-flask cultivation with approximately 120 mg of Splys-i obtained from 1 L of LB medium. The purified Splys-i displayed low cytotoxicity to RAW264.7 macrophage cells and low hemolytic activity against erythrocytes of mouse, rat, and rabbit, respectively, and exhibited potent antibacterial activity against both Gram-positive and -negative bacteria with minimum concentrations ranging from 15 to 90 μg/mL. The antibacterial property of Splys-i was also unaffected when treated with various temperature, pHs, and salinity, respectively, and Splys-i showed resistance to proteinase digestion. Radical-scavenging rate assay (including ABTS

Topics: Amino Acid Sequence; Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents; Antioxidants; Arthropod Proteins; Benzothiazoles; Biphenyl Compounds; Brachyura; Cloning, Molecular; Erythrocytes; Escherichia coli; Gene Expression; Genetic Vectors; Hydrogen-Ion Concentration; Mice; Muramidase; NF-KappaB Inhibitor alpha; Picrates; Rabbits; Rats; RAW 264.7 Cells; Recombinant Proteins; Sulfonic Acids; Temperature; Transcription Factor RelA

In this manuscript, lysozyme/κ-carrageenan (LYS-CRG) complexes were prepared and used to encapsulate curcumin. The LYS-CRG complexes demonstrate good encapsulation of curcumin (CUR), and the encapsulation efficiency (EE) and loading capacity (LC) reach 96.2% and 2.31%, respectively. The encapsulated CUR has high antioxidant activity, while the thermal stability and photostability of CUR are also increased. The LYS-CRG complexes could effectively improve the storage stability of CUR and increase its retention rate. In simulated gastric fluid, only 17.91% CUR in the CUR-LYS-CRG complex nanoparticles is released in 3 h, while in the simulated intestinal fluid, the CUR release rate quickly reaches 62.56% in 1.5 h. The release rate tends to be stable within 1.5 h to 3 h and the final release rate reaches 67.23%, suggesting that the formation of CUR-LYS-CRG complex nanoparticles does not affect CUR release in the simulated intestinal fluid.

Topics: Biphenyl Compounds; Carrageenan; Curcumin; Delayed-Action Preparations; Drug Carriers; Drug Liberation; Emulsions; Free Radical Scavengers; Light; Muramidase; Nanoparticles; Nephelometry and Turbidimetry; Particle Size; Picrates

The desideratum aim of the present context was to isolate a promising antagonist probiotic bacterium from fermented food item as biocontrol agent against uropathogens. Among diversified isolates evaluated for antagonistic trait, Staphylococcus succinus strain AAS2 was found to be an auspicious candidate against urinary tract infection (UTI) causing bacterial pathogens, being the most active against Staphylococcus aureus with substantial activity of 352.5 ± 5.4 AU/mL. Further, the in vitro probiotic attributes of strain AAS2 were assessed using systematic methodology. The isolate exhibited tolerance to acidic condition (up to pH 3.0) and simulated gastric juice (at pH 3.0) with fairly high survival logarithmic cell counts of 5.3 ± 0.15 and 5.23 ± 0.02 log cfu/mL, respectively. Additionally, strain AAS2 showed capability to resist 0.5% w/v bile salt too. It also revealed significant values of auto-aggregation (32.5 ± 1.3-56.5 ± 1.4%) and cell surface hydrophobicity (38.35 ± 1.4%) properties. The isolate showed resistivity towards phenol (6.8 ± 0.08 log cfu/mL) and lysozyme (58.6 ± 1.6%). Further, the susceptibility trait of strain AAS2 to conventional antibiotics made this isolate a promising probiotic bacterium. Most importantly, the isolate depicted DPPH (2,2-Diphenyl-1-picrylhydrazyl) and hydroxyl radical scavenging activities in a concentration dependent manner, thereby exhibiting its propitious antioxidative properties. In a nutshell, the outcomes of this investigation divulge the plausible use of S. succinus strain AAS2 as biocontrol agent against uropathogens, and recommended further applications in pharmaceutics due to its pronounced probiotic traits.

Topics: Anti-Bacterial Agents; Antibiosis; Bile Acids and Salts; Biphenyl Compounds; DNA, Bacterial; Fermented Foods; Food Microbiology; Gastric Juice; Humans; Hydrogen-Ion Concentration; Hydrophobic and Hydrophilic Interactions; Hydroxyl Radical; India; Microbial Sensitivity Tests; Microbial Viability; Muramidase; Phenol; Picrates; Probiotics; Staphylococcus; Staphylococcus aureus; Urinary Tract Infections

A recently proposed paradigm suggests that, like their dietary counterparts, digestion of gastrointestinal endogenous proteins (GEP) may also produce bioactive peptides. With an aim to test this hypothesis, in vitro digests of four GEP namely; trypsin (TRYP), lysozyme (LYS), mucin (MUC), serum albumin (SA) and a dietary protein chicken albumin (CA) were screened for their angiotensin-I converting (ACE-I), renin, platelet-activating factor-acetylhydrolase (PAF-AH) and dipeptidyl peptidase-IV inhibitory (DPP-IV) and antioxidant potential following simulated in vitro gastrointestinal digestion. Further, the resultant small intestinal digests were enriched to obtain peptides between 3-10 kDa in size. All in vitro digests of the four GEP were found to inhibit ACE-I compared to the positive control captopril when assayed at a concentration of 1 mg/mL, while the LYS < 3-kDa permeate fraction inhibited renin by 40% (±1.79%). The LYS < 10-kDa fraction inhibited PAF-AH by 39% (±4.34%), and the SA < 3-kDa fraction inhibited DPP-IV by 45% (±1.24%). The MUC < 3-kDa fraction had an ABTS-inhibition antioxidant activity of 150 (±24.79) µM trolox equivalent and the LYS < 10-kDa fraction inhibited 2,2-Diphenyl-1-picrylhydrazyl (DPPH) by 54% (±1.62%). Moreover, over 190 peptide-sequences were identified from the bioactive GEP fractions. The findings of the present study indicate that GEP are a significant source of bioactive peptides which may influence gut function.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Albumins; Amino Acid Sequence; Animals; Antioxidants; Biphenyl Compounds; Chickens; Dipeptidyl Peptidase 4; Humans; Intestinal Mucosa; Mucins; Muramidase; Peptides; Peptidyl-Dipeptidase A; Picrates; Renin; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Swine

Amyloid protein depositions play crucial roles in a variety of degenerative disorders composing amyloidosis. There is a great interest in developing small molecule inhibitors of amyloidogenic processes. We examined the inhibitory effects of echinacoside (ECH) with different concentrations and at different fiber-forming stages in vitro utilizing the hen egg-white lysozyme (HEWL) model system. We also evaluated the antioxidant capacity of ECH by using elimination tests for the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (HO) free radicals. We investigated the protection provided by ECH against neurotoxicity induced by β-amyloid protein (Aβ). Through spectroscopic analyses, electron microscopy, cell viability assay, and hemolysis assay, we found that ECH dose dependently inhibited HEWL aggregation, and this inhibition occurred in different fiber-forming stages. ECH could also scavenge the DPPH and OH free radicals in a concentration-dependent manner. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 2',7'-dichlorodihydrofluoresceindiacetate (DCFH-DA) fluorescent measurement results indicated that ECH could increase viability of rat pheochromocytoma PC12 cells injured by Aβ and suppress the increase in intracellular reactive oxygen species (ROS) triggered by Aβ. The present study findings facilitate a better understanding of the interaction between ECH and amyloid-forming proteins and also shed light on the protection of ECH against amyloid fibril-induced neuronal cell death.

Topics: Amyloid beta-Peptides; Amyloidosis; Animals; Antioxidants; Biphenyl Compounds; Cell Death; Cell Survival; Glycosides; Humans; Hydroxyl Radical; Muramidase; PC12 Cells; Picrates; Protective Agents; Rats; Reactive Oxygen Species

Chito-oligosaccharides (COS) are being used as important functional materials for many applications due to their bioactivities. The aim of this research has been to assess the relationship between the physico-chemical characteristics, average molecular weight (Mw), acetylation degree (DA), polymerization degree (DP) and specially sequence composition determined by MALDI-TOF MS and the antioxidant properties of COS. These oligosaccharides were obtained by enzymatic depolymerization with chitosanase and lysozyme using a specific chitosan and its reacetylated product. The COS fraction below 5 kDa obtained from chitosanase depolymerization showed the highest capacity to scavenge DPPH radicals and to reduce Fe(3+). A correlation was found between the relative amount of molecules with a given A/D (acetylated vs deacetylated units) ratio within the COS and their antioxidant activity, which could be used to predict the antioxidant behavior of a fraction of chito-oligosaccharides.

Topics: Animals; Antioxidants; Biphenyl Compounds; Chemical Phenomena; Chickens; Chromans; Chromatography, Gel; Chromatography, High Pressure Liquid; Free Radical Scavengers; Glycoside Hydrolases; Magnetic Resonance Spectroscopy; Molecular Weight; Muramidase; Oligosaccharides; Penaeidae; Picrates; Polymerization; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

One pot synthesis of three structurally different Ni(II) thiosemicarbazone complexes 1, 2 and 3 were obtained from the reaction between [NiCl(2)(PPh(3))(2)], 1,2-bis(diphenylphosphino)ethane, and [H(2)-(Sal-tsc)]. The obtained products were characterized by various spectral and analytical techniques. From the X-ray crystallographic analysis, an unexpected N-arylation on the coordinated salicylaldehydethiosemicarbazone was found in complex 2. The comparative biological evolutions such as DNA/protein binding, antioxidant, cytotoxicity (MTT, LDH, and NO) and cellular uptake studies have been examined for [Ni(Sal-tsc)(PPh(3))] (1) and [(Ni(Sal-tsc))(2)(μ-dppe)] (3). When comparing the cytotoxicity of the complexes, 1 exhibited higher activity than 2 and 3 and by comparing with standard cis-platin, both of them were found to exhibit better activity under identical conditions.

Topics: Biphenyl Compounds; Cell Line, Tumor; Cell Survival; Crystallography, X-Ray; DNA; Free Radicals; Humans; L-Lactate Dehydrogenase; Ligands; Muramidase; Nickel; Nitric Oxide; Picrates; Thiosemicarbazones

A method was devised to quantitate N-acetoxy-N-acetyl-2-aminofluorene (N-AcO-AAF) induced crosslinking of the ionic complex between [methyl-3H]thymidine labeled pBR322 DNA and lysozyme. This involved chromatography of the modified complex on Sephadex CM 25 with a high salt buffer that dissociated the non-covalently bound complex and permitted early elution of unbound [3H]DNA. The crosslinked complex was then eluted with buffer at pH 10.5. The amount of crosslinking was a function of the carcinogen concentration in the reaction mixture containing the complex. Addition of the spin trap nitrosobenzene or the radical trap 2,2-diphenyl-1-picrylhydrazyl to the complex prior to the addition of N-AcO-AAF decreased crosslinking. Reaction of the carcinogen with a solution of [methyl-3H]thymidine labeled Escherichia coli DNA led to the formation of tritiated water that was azeotropically distilled from the mixture. If nitrosobenzene was added prior to the carcinogen, the amount of tritium water released was depressed. Addition of N-AcO-AAF to a mixture of acrylamide and bisacrylamide increased its relative viscosity. Far u.v. irradiation of the complex or reacting it with ammonium persulfate that dissociates to the sulfate anion radical, SO(4), induced crosslinking. While these observations support a free radical mechanism for crosslinking, whether the free radicals arise from heterolytic or homolytic cleavage of N-AcO-AAF remains undetermined.

Topics: 2-Acetylaminofluorene; Acetoxyacetylaminofluorene; Ammonium Sulfate; Biphenyl Compounds; Chromatography, Ion Exchange; Cross-Linking Reagents; DNA; DNA, Bacterial; Escherichia coli; Free Radicals; Hydrazines; Muramidase; Nitrobenzenes; Picrates; Plasmids