Active Compounds in Zingiber officinale as Possible Redox Inhibitors of 5-Lipoxygenase Using an In Silico Approach

5-Lipoxygenase (5-LOX) converts arachidonic acid to lipidic inflammatory mediators such as leukotrienes (LTs). In diseases such as asthma, LTs contribute to a physiopathology that could be reverted by blocking 5-LOX. Natural products with anti-inflammatory potential such as ginger have been used as nutraceuticals since ancient times. 6-Gingerol and 6-shogaol are the most abundant compounds in the ginger rhizome; they possess anti-inflammatory, antioxidant, and chemopreventive properties. In the present study, 6-gingerol and 6-shogaol structures were analyzed and compared with two commercial 5-LOX inhibitors (zileuton and atreleuton) and with other inhibitor candidates (3f, NDGA, CP 209, caffeic acid, and caffeic acid phenethyl ester (CAPE)). The pharmacokinetics and toxicological properties of 6-gingerol, 6-shogaol, and the other compounds were evaluated. Targeted molecular coupling was performed to identify the optimal catalytic pocket for 5-LOX inhibition. The results showed that 6-gingerol and 6-shogaol follow all of the recommended pharmacokinetic parameters. These compounds could be inhibitors of 5-LOX because they present specific interactions with the residues involved in molecular inhibition. The current study demonstrated the potential of 6-gingerol and 6-shogaol as anti-inflammatory agents that inhibit 5-LOX, as they present a high level of performance in the toxicological analysis and could be catabolized by the cytochrome p450 enzymatic complex; however, 6-gingerol was superior in safety compared to 6-shogaol.     

PVA- and PEG-assisted sol-gel synthesis of aluminosilicate precursors for N-A-S-H geopolymer cements

This study investigates critical factors affecting polymer-assisted sol-gel synthesis of synthetic aluminosilicate powders that can be alkali-activated to produce a sodium-stabilized aluminosilicate hydrate (N-A-S-H) geopolymer cement. More specifically, a 2² factorial experiment was conducted to elucidate the influence of polymer architecture (ie, poly(ethylene glycol) (PEG) vs poly(vinyl alcohol) (PVA)), polymer content (ie, low vs high ion-to-polymer-oxide (I/O) atomic ratio), and sol-gel aging pH conditions (ie, low vs high) on the atomic structure of resultant synthetic aluminosilicate powders and geopolymer cements. Molecular structure was investigated using solid-state (single-pulse and ¹H cross-polarization) ²⁹Si and ²⁷Al nuclear magnetic resonance (NMR) and Fourier-transform infrared (FTIR) spectroscopy. The mineralogy of geopolymer cements was assessed with X-ray diffraction and compared to alkali-activated metakaolin-based cements of equivalent stoichiometry. Results demonstrate that polymer architecture (PEG vs PVA) is a key factor in producing (a) undesirable phase segregation (ie, γ-alumina) and (b) incomplete dehydroxylation (ie, vicinal silanol) in synthetic aluminosilicate powders. More specifically, PEG-derived aluminosilicate powders yield partial dissolution and produce geopolymer cements with variable silicate incorporation. Contrastingly, PVA-derived aluminosilicate powders produce geopolymer cements with identical mineralogy to that of metakaolin-based geopolymer cements and exhibit both Brønsted-acid sites near the aluminum nuclei and geminal silanol groups. Sol-gel aging pH conditions reveal the ability to influence the hydroxyl group content, which is an important factor affecting the durability of cementitious materials. Lastly, three plausible mechanisms of metal complexation are hypothesized to permit incorporation of solubilized metal ions via a polymer-assisted sol-gel process.     

Sprague Dawley Rats Show More Severe Bone Loss,Osteophytosis and Inflammation Compared to Wistar Han Rats in a High-Fat,High-Sucrose Diet Model of Joint Damage

In animal models, joint degeneration observed in response to obesogenic diet varies in nature and severity. In this study, we compare joint damage in Sprague Dawley and Wistar-Han rats in response to a high-fat, high-sucrose (HFS) diet groove model of osteoarthritis (OA). Wistar Han (n = 5) and Sprague Dawley (n = 5) rats were fed an HFS diet for 24 weeks. OA was induced 12 weeks after the diet onset by groove surgery in the right knee joint. The left knee served as a control. Outcomes were OARSI histopathology scoring, bone changes by µCT imaging, local (synovial and fat pad) and systemic (blood cytokine) inflammation markers. In both rat strains, the HFS diet resulted in a similar change in metabolic parameters, but only Sprague Dawley rats showed a large, osteoporosis-like decrease in trabecular bone volume. Osteophyte count and local joint inflammation were higher in Sprague Dawley rats. In contrast, cartilage degeneration and systemic inflammatory marker levels were similar between the rat strains. The difference in bone volume loss, osteophytosis and local inflammation suggest that both rat strains show a different joint damage phenotype and could, therefore, potentially represent different OA phenotypes observed in humans.     

Ecotoxicological evaluation of a fish farming effluent treated by Fenton oxidation and coagulation process

ABSTRACT

This study has evaluated the efficiency of Fenton process followed by coagulation to treat real effluent from fish farm. Fenton obtained Chemical Oxygen Demand and turbidity removal of 48% at (0.5 mg L^?1 Fe²⁺ and 10 mmol H₂O₂). Fenton followed by coagulation reduced COD and turbidity by almost 100%. The process also decreased the concentrations of suspended solids, phosphate, nitrate, Biological Oxygen Demand, and nitrite. Ecotoxicology test indicated that the effluent treated with 0.5 mmol L^?1 Fe²⁺ in 10 mmol L^?1 H₂O₂ displayed the lowest toxicity. These findings can indicate an environmental friendly alternative to treat fish farm effluent.     

Evaluation of molar weight and deacetylation degree of chitosan during chitin deacetylation reaction: Used to produce biofilm

Chitosan is a polysaccharide derived from chitin, mainly of crustacean shells and shrimp wastes. The utilization of chitosan is related to the molar weight and deacetylation degree of the biopolymer. The aim of this work is to study the chitin deacetylation reaction, by the viscosity average molar weight and deacetylation degree of chitosan as a function of reaction time. Deacetylation was carried out in concentrated alkaline solution, 421 g L⁻¹, at 130 °C and the reaction occurred during 4 h. Chitosan paste obtained after 20, 90 and 240 min was used to produce biofilms, which were characterized according water vapor permeability and mechanical properties (tensile strength and percentage tensile elongation at break). During the reaction time deacetylation degree reached 93%, and a 50% reduction in the viscosity average molar weight value in relation to the value of the first 20 min of reaction was found Both reactions presented a kinetic behavior of the pseudo-first order. Biofilm produced from the paste of chitosan with high deacetylation degree showed higher water vapor permeability (WVP), tensile strength (TS) and elongation (E) when compared to films with a low deacetylation.     

Microstructural Evolutions During Thermal Aging of Alloy 625: Impact of Temperature and Forming Process

The microstructural evolutions occurring upon thermal aging of alloy 625 sheets were studied in the 823 K to 1173 K (550 °C to 900 °C) temperature range and for durations up to 2000 hours. TTT diagrams of the δ and γ″ phases were established based on high-resolution scanning electron microscopy and associated quantitative image analysis approaches. The evolutions of secondary carbide volume fraction were also characterized. It was observed that the precipitation domains of the γ″ and δ phases are, respectively, 823 K to 1023 K (550 °C to 750 °C) and 923 K to 1173 K (650 °C to 900 °C) and that the γ″ coarsening follows the LSW theory once these particles have an ellipsoidal morphology. The onset of grain growth, accompanied with an increase of the texture index, was observed at a temperature as low as 1173 K (900 °C). It results from the progressive dissolution of grain boundaries’ secondary carbides (especially M₆C carbides) at this temperature, a process that favors a greater mobility of grain boundaries. It is also shown that the forming process (shear spinning), even after a relaxation heat treatment, enhances and stabilizes the precipitation of the δ phase compared to as-rolled + solution heat-treated sheets. It hence slows down the precipitation of the γ″ phase, a result that is in good agreement with a thermal aging that was performed under load (i.e., during a creep test).     

Assessment of exposure of broiler chicken in Brazil to mycotoxins through naturally contaminated feed

The objective of the present study was to assess the degree of exposure of broiler chicken to mycotoxins through naturally contaminated feed and the hygienic quality of feeds. For this purpose the total fungal count and occurrence of fumonisins and aflatoxins were evaluated in four feed types intended for broilers (n?=?158), collected from a poultry breeding farm in northern Paraná State, Brazil. In most feed samples (94 % pre-starter, 91 % starter, 99 % grower and 97 % finisher feeds) the total mould and yeast counts were below 1.0?×?10⁴ CFU/g, the maximum limit established to assure a good hygienic quality of the product. Fumonisins were detected in 94.9 % feed samples at mean levels ranging from 0.52 mg/kg (finisher) to 0.68 mg/kg (pre-starter and grower), while aflatoxins were detected in 72.1 % feed samples at mean levels ranging from 0.0022 mg/kg (pre-starter) to 0.0064 mg/kg (grower). The maximum estimated daily intake of fumonisin B₁ for broilers (0.057 mg/kg body weight/day) was below the Lowest Observed Adverse Effect Level (2 mg/kg bw/day). Concerning aflatoxins, most of the positive samples (97 %) showed aflatoxin levels below the maximum limit allowed by the European Commission 0.02 mg aflatoxin B₁/kg. Nevertheless, a rigorous monitoring program of the feed producing chain is essential in order to minimize human health hazards. To our knowledge, this is the first report on the degree of exposure of broilers to mycotoxins through naturally contaminated feed in Brazil.     

Phosphine-Functionalized Chitosan Microparticles as Support Materials for Palladium Nanoparticles in Heck Reactions

Catalysis Letters - Herein, we investigated the activation and stabilization of Pd nanoparticles using microparticles of chitosan-functionalized with phosphine moieties. The catalytic activity of...     

Storage stability of the natural colourant from Justicia spicigera microencapsulated in protective colloids blends by spray‐drying

Muitle (Justicia spicigera), a Mexican native plant, produces a purple aqueous extract (MAE) because of its anthocyanin content. The aim of this work was to microencapsulate MAE by spray‐drying in two different protective colloids blends in a 1:1 weight ratio: gum Arabic‐mesquite gum (GA50‐MD50) and mesquite gum‐maltodextrin DE10 (MG50‐MD50), yielding the microcapsules M_GA50‐MD50 and M_MG50‐MD50. The minimum integral entropy of the microcapsules was determined at 20, 35 and 40 °C, and the resulting water activities (a_W) were 0.555, 0.592, 0.627 for M_GA50‐MD50 and 0.581, 0.587, 0.648 for M_MG50‐MD50, respectively. These a_W temperature sets were considered as the most adequate conditions for achieving maximum storage stability of the microcapsules. Total anthocyanin content (TAC) and total colour change (ΔE) suffered considerable degradation at all storage conditions, but that degradation was significantly inhibited by encapsulating MAE in the biopolymers blends especially that made up by MG50‐MD50.