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This study aimed to evaluate the antioxidant and anti‐inflammatory effects of glucosamine nanoparticles (GNPs) grafted with gallic acid (GNPs‐g‐GA). Glucosamine hydrochloride (G‐HCl) was produced from shrimp shell, and then GNPs synthesized using ionic gelation method. GNPs‐g‐GA was prepared by coupling GNPs with GA via 1‐ethy‐3‐(3‐dimethylaminopropyl)‐carbodiimide (EDC) in combination with N‐hydroxysuccinimide (NHS) cross‐linking agents. The results indicated that the grafting of GA onto GNPs at different ratios increased the average size of the nanoparticles from 195.7 to 294.2 nm with various grafting degrees ranging from 73.3 to 146.4 mg GA/g GNPs‐g‐GA. The SEM images revealed the formation of spherical‐shaped GNPs‐g‐GA nanoparticles with approximate sizes ranging from 275.3 to 303.6 nm. The appearance of characteristic signals in the FT‐IR (C=C, C–O/C–C, and NH2) and 1H‐NMR (H‐2 and H‐6 at 6.95 ppm) spectra and the red shift in UV‐Vis spectrum provided further support of GNPs‐g‐GA successful synthesis. DPPH radical scavenging (from 20.0 to 70.4%) and ABTS radical scavenging (from 18.7 to 79.0%) activities and reducing power (nearly fivefold) sharply improved in GNPs‐g‐GA. Moreover, GNPs‐g‐GA was found nontoxic and drastically reduced the level of nitric oxide release and downregulated the synthesis of TNF‐α, IL‐1β, and IL‐6 in LPS‐induced RAW2647 murine macrophage cells through NF‐κB and MAPKs signaling pathways. Overall, these results suggested that the grafting of GNPs and GA is an effective strategy for the suppression of inflammation response and oxidation reaction in osteoarthritis. [ABSTRACT FROM AUTHOR]

Polysaccharides are one of the biomacromolecules that, in addition to their peculiar physicochemical properties, possess promising biological capabilities depend on chemical structure. The purpose of the present study was to evaluate the effect of membrane ultrafiltration on antioxidant properties of hydrolysed fucoidan from brown seaweed Nizamuddinia zanardinii. After removing pigments and low molecular weight compounds, the extracted crude fucoidan, was hydrolysed by 0.01N hydrochloric acid at 100°C for 20 minutes (FH20). Then, FH20 was fractionated using ultrafiltration with 2, 10, 30, 100 kDa membranes. The average molecular weight of fractions was 553.7, 39.2, 12.4 and 4.6x10³ g/mol in KDa>100, 100-30 KDa, 30-10 KDa and 2-10 KDa, respectively. After separation based on molecular weight, the obtained fractions, compared to FH20, which were significantly capable of inhibiting DPPH free radicals (85.05-37.69%), ABTS radicals (89.65-55.43%) and reduction Fe3+ ions (absorption of 0.72-0.07). In the meantime, 2-10 KDa fraction had the greatest potential in inhibiting DPPH free radicals (85.05-74.12%), ABTS free radicals (89.65-75.16%) and reducing Fe3+ ions (absorption of 0.21-0.72). Overall, the results of this study showed that reducing the molecular weight of fucoidan to a specific range could lead to significant increase of antioxidant activity. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of different concentrations of green lentil acetone extract (GLA) (250, 500, 750, and 1000 μg/mL) and protein of green lentil (PGL) (1, 2, 3, and 4 g/100 g MP) on the functional attributes of myofibrillar protein (MP). GLA extract and PGL significantly affected the structure of MP by decreasing the carbonyl and sulfhydryl contents. Intrinsic fluorescence quenching studies showed that static quenching was involved in MP-GLA extract and MP-PGL complexes. Compared to the control (MP), the addition of GLA extract and PGL decreased the surface hydrophobicity, which correlated with the decrease in protein solubility. The MP-GLA and MP-PGL had lower cooking losses and slightly higher water-holding capacities P < 0.05 . FTIR spectroscopy demonstrated changes in MP secondary structure with the addition of GLA extract and PGL. GLA extract and PGL also decreased the thermal stability of MP and showed significant synergism in enhancing the radical scavenging activity of MP. Taken together, the results indicated that a high concentration of GLA extract (1000 μg/mL) and PGL (4 g/100 g MP) improved the functional properties of MP, and GLA extract was the most effective. [ABSTRACT FROM AUTHOR]