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Chitosan with 80% degree of deacetylation was hydrolyzed by cellulase of Trichoderma viride to prepare chitooligosaccharides (COSs) by the fractionation of the COSs with ultrafiltration membrane. The antioxidant activities of the COSs were clarified in this study by reducing power and free radical scavenging ability assay by UV-VIS absorption spectrum. The results show that the COS 1 (10,000-5,000 Da), COS 2 (5,000-3,000 Da), COS 3 (3,000-1,000 Da) and COS 4 (less than1,000 Da) segments have antioxidant properties.The antioxidant activitives of the COSs increased with the increment of concentration, and they also depended on molecular weight.

Astaxanthin is increasingly attracting commercial interest for its application in the nutraceutical and pharmaceutical industries. This study aimed to produce astaxanthin from molasses with our newly mutated strain of Rhodosporidium toruloides G17 and to evaluate biological activities of the produced astaxanthin. To maximize the astaxanthin yield, the response surface methodology was used so as to optimize the culture conditions. A maximum astaxanthin yield of 1262.08 ± 14.58 µg/L was achieved by growing R. toruloides G17 in a molasses-based medium containing 49.39 g/L reducing sugar, 1.00 g/L urea, 4.15 g/L MgSO4·7H2O, and 10.05% inoculum ratio. The produced astaxanthin was then purified and studied for its antioxidant and anticancer activities. This compound exhibited 123-fold higher antioxidant activity than α-tocopherol, with an IC50 value of 0.97 ± 0.01 µg/mL. The astaxanthin also showed a potent inhibitory ability against the following three cancer cell lines: HeLa, A549, and MCF7, with IC50 values of 69.07 ± 2.4 µg/mL, 55.60 ± 2.64 µg/mL, and 56.38 ± 4.1 µg/mL, respectively. This study indicates that astaxanthin derived from our newly mutated R. toruloides G17 is a promising anticancer and antioxidant agent for further pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to investigate the antioxidant and anti-inflammatory activities of aminoethyl-chitooligosaccharides (AE-COS) in murine microglial cells (BV-2). At the high concentration of 100μg/ml, the inhibition of reactive oxygen species, DNA, protein and lipid oxidation were determined in BV-2 cells, at the rates of 77%, 80%, 85% and 85%, respectively. Furthermore, AE-COS was studied for its capabilities against lipopolysaccharide-induced inflammatory responses in BV-2 cells. It was found that AE-COS reduced the level of nitric oxide (NO) and prostaglandin E2 production by diminishing the expression of inducible NO synthase and cyclooxygenase-2 without significant cytotoxicity. Moreover, the inhibitory activities of AE-COS on generation of tumor necrosis factor-alpha and interleukin-1beta were performed. Collectively, these results indicate that AE-COS possess potential antioxidant and anti-inflammatory activities in brain microglia, and could be a useful therapeutic agent for the treatment of neuroinflammatory diseases. [Copyright &y& Elsevier]

Abstract: The aim of this study is to investigate the inhibitory effects of aminoethyl-chitooligosaccharides (AE-COS) on oxidative stress in mouse macrophages (RAW 264.7 cells). The inhibitory effects of AE-COS on DNA and protein oxidation were studied in RAW 264.7 cells. Furthermore, free radical scavenging effect of AE-COS were determined in RAW264.7 cells by 2′,7′-dichlorofluorescein (DCF) intensity and intracellular glutathione (GSH) level. AE-COS also inhibited myeloperoxidase (MPO) activity in human myeloid cells (HL-60). These results suggest that AE-COS acts as a potential free radical scavenger in RAW 264.7 cells. [Copyright &y& Elsevier]

Abstract: The aim of this research is to identify the cellular antioxidant effects of chitin oligosaccharides (NA-COS; M w 229.21–593.12Da) produced by acidic hydrolysis of crab chitin. The inhibitory effect of NA-COS on myeloperoxidase (MPO) activity in human myeloid cells (HL-60) and oxidation of DNA and protein in mouse macrophages (Raw 264.7) were identified. Furthermore, their direct radical scavenging effect by 2′,7′-dichlorofluorescein (DCF) intensity and intracellular glutathione (GSH) level were significantly increased in a time dependent manner, respectively. These results suggest that NA-COS act as a potent antioxidant in live cells. [Copyright &y& Elsevier]

Chitosan is a natural nontoxic biopolymer produced by alkaline deacetylation of chitin. Chitin and chitosan are insoluble in water as well as most organic solvents. Chito-oligomers (COS), depolymerized products of chitosan, has received much attention in biomedical, food, pharmaceutical, agricultural and environmental industries due to their biocompatible, biodegradable, non-toxic and non-allergenic natures. Chitosan and its derivatives have been shown to possess diverse biological activities, including antioxidant, anti-hypertensive, anti-coagulant, anti-diabetic, anti-obesity, anti-allergic, anti-inflammatory, anti-microbial, anti-cancer, neuroprotective and matrix metalloproteinases inhibitory effects. Thus, this overview mainly focuses on biological effects of chitosan and its derivatives as well as presents their potential applications as ingredients in functional foods and nutraceuticals for the prevention or treatment of chronic diseases. [ABSTRACT FROM AUTHOR]

Abstract: Marine organisms have been recognized as rich sources of bioactive compounds with valuable nutraceutical and pharmaceutical potentials. Recently, marine bioactive peptides have gained much attention because of their numerous health beneficial effects. Notably, these peptides exhibit various biological activities such as antioxidant, anti-hypertensive, anti-human immunodeficiency virus, anti-proliferative, anticoagulant, calcium-binding, anti-obesity and anti-diabetic activities. This review mainly presents biological activities of peptides from marine organisms and emphasizing their potential applications in foods as well as pharmaceutical areas. [Copyright &y& Elsevier]

In this study, gallic acid-conjugated chitooligosaccharides (gallate-COS) was evaluated for its enhancing capabilities in free radical scavenging and anti-inflammatory activities in human lung epithelial A549 cells. It was found that gallate-COS possesses significantly high DPPH radical scavenging activity and protective effect against H 2 O 2 -induced DNA damage. Likewise, gallate-COS decreased the production of intracellular reactive oxygen species in H 2 O 2 -stimulated A549 cells. Moreover, the suppressive effects of gallate-COS on COX-2 expression and PGE 2 production from LPS-stimulated A549 cells were evidenced. Finally, the productions of cytokines including IL-8 and TNF-α were also inhibited by gallate-COS in a dose-dependent manner. Collectively, these results suggest that gallate-COS could be used as a functional ingredient with potent antioxidant and anti-inflammatory benefits. [ABSTRACT FROM AUTHOR]

Unregulated activation of microglia is the major cause of neuronal degeneration in Alzheimer’s and Parkinson’s diseases. Excessive reactive oxygen species (ROS) generation is a common risk factor for chronic diseases, including neurodegeneration. In this study, N -acetyl chitooligomers (NA-COS, below 1 and 1–3 kDa) were produced from crab chitin using an ultrafiltration membrane system and investigated for their capabilities against H 2 O 2 -induced oxidative stress in murine microglia (BV-2 cells). NA-COS significantly decreased the oxidation of DNA by diminishing the intracellular ROS production. Furthermore, NA-COS upregulated the protein and gene expressions of antioxidant enzymes (superoxide dismutase and glutathione), thereby enhancing the intracellular antioxidant. Notably, NA-COS inhibit NF-κB activation by blocking degradation of the inhibitor of kappaB-alpha (IκB-α) and translocation of nuclear factor NF-κB (p65 and p50). Collectively, NA-COS could be potential agents for the prevention of neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Abstract: In this research, a novel derivative of chitooligosaccharides (COS) was synthesized by covalently linking gallic acid and COS (gallate-COS) via carbodiimide to improve cellular antioxidant activity. The direct intracellular radical scavenging effect of gallate-COS by 2′,7′-dichlorofluorescin diacetate (DCFH-DA) method, and the inhibition of oxidation of cellular macromolecules, such as DNA, protein and lipid in mouse macrophages (RAW264.7 cells) were determined. Furthermore, with the treatment of gallate-COS, the expression levels of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione (GSH) were significantly increased according to reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. In addition, gallate-COS decreased reactive oxygen species induced activation of the nuclear transcription factor (NF-κB). Collectively, these results suggest that gallate-COS can be used as a potential natural compound-based antioxidant in the functional food and pharmaceutical industries. [Copyright &y& Elsevier]