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Chitosan is cancer cytotoxic. It induces apoptosis/necrosis/autophagy and immuno-responses, and mitigates angiogenic and metastasis tendency of cancer cells. The lower molecular weight chitosan induces apoptosis, whereas the higher molecular weight chitosan exerts apoptosis and necrosis. Transforming chitosan into nanoparticles raises its anti-cancer efficacy with mode of cancer cell death governed by particle size to a greater extent than chitosan molecular weight. The larger nanoparticles tend to exert apoptosis. The smaller nanoparticles mediate necrosis. "Drug-free" small nanoparticles constituted of lower molecular weight chitosan are more cytotoxic than those of larger chitosan molecules/particles in vitro and in vivo, with no clear relationship between the deacetylation degree and zeta potential of nanoparticulate chitosan with anti-cancer activity. "Drug-free" chitosan nanoparticles are potentially as viable as the drug-loaded chitosan nanoparticles but with reduced systemic adverse effects. Their anti-cancer efficacy can be modulated through particle dose adjustment with lower risks of harmful effects than drugs and without processing hurdles faced in the development of drug-loaded chitosan nanoparticles such as low aqueous drug solubility, poor drug encapsulation, premature drug release and drug absorption, and drug instability with toxic metabolite formation. [ABSTRACT FROM AUTHOR]

Respiratory distress syndrome and pneumothorax are the foremost causes of death as a result of the changing lifestyle and increasing air pollution. Numerous approaches have been studied for the pulmonary delivery of drugs, proteins as well as peptides using meso /nanoparticles, nanocrystals, and liposomes. These nano/microcarrier systems (NMCs) loaded with drug provide better systemic as well as local action. Furthermore, natural polysaccharide-based polymers such as chitosan (CS), alginate (AG), hyaluronic acid, dextran, and cellulose are highly used for the preparation of nanoparticles and delivery of the drug into the pulmonary tract due to their advantageous properties such as low toxicity, high hydrophobicity, supplementary mucociliary clearance, mucoadhesivity, and biological efficacy. These properties ease the delivery of drugs onto the targeted site. Herein, recent advances in the natural polymer-derived NMCs have been reviewed for their transport and mechanism of action into the bronchiolar region as well as the respiratory region. Various physicochemical properties such as surface charge, size of nanocarrier system, surface modifications, and toxicological effects of these nanocarriers in vitro and in vivo are elucidated as well. Furthermore, challenges faced for the preparation of a model NMCs for pulmonary drug delivery are also discoursed. [ABSTRACT FROM AUTHOR]

The study aims to extract and purify chitosan (CS) from the exoskeleton of crab (C. natator) and develop ibuprofen (IBU) encapsulated CS nanoparticles (IBU-CSNPs). Analysis of purified CS revealed characteristic functional and crystallinity peaks. Moreover, morphological analysis of prepared IBU-CSNPs showed uniform spherical shape with a size range of 40–100 nm whereas encapsulation efficiency (EE%) and loading capacity (LC%) were estimated to be 68.94 ± 1.61% and 28 ± 1.18% respectively. Further, in vitro release profile of IBU from IBU-CSNPs was observed to be in biphasic form with initial release up to 15 h followed by the sustained release in different test conditions. Further, the effects of purified CS on the viability of RAW264.7 cells exhibited no toxic effects in higher concentrations. Furthermore, fluorescein isothiocyanate (FITC) conjugated nanoparticles (FITC-IBU-CSNPs) were investigated on in vivo model of adult zebrafish for time-dependent circulation and accumulation of the drug through the nano-carrier system. It was observed that the drug diffusion from the nanoparticles was in a sustained manner throughout the gastrointestinal region which resulted in suppression of inflammation. Overall, this study provides an effective and facile process for preparing a crab CS-based nano-carrier system used for the delivery of IBU in vivo which may help in the curing of prolonged chronic inflammatory diseases. Moreover, it may also help to reduce adverse effects of these drugs in the gastrointestinal tract such as ulcers and bleeding. [ABSTRACT FROM AUTHOR]

The development of chitinase tailored for the bioconversion of chitin to chitin oligosaccharides has attracted significant attention due to its potential to alleviate environmental pollution associated with chemical conversion processes. In this present investigation, we purified extracellular chitinase derived from marine Bacillus haynesii to homogeneity and subsequently characterized it. The molecular weight of Bh Chi was approximately 35 kDa. Bh Chi displayed its peak catalytic activity at pH 6.0, with an optimal temperature of 37 °C. It exhibited stability across a pH range of 6.0–9.0. In addition, Bh Chi showed activation in the presence of Mn2+ with the improved activity of 105 U mL−1. Ca2+ and Fe2+ metal ions did not have any significant impact on enzyme activity. Under the optimized enzymatic conditions, there was a notable enhancement in catalytic activity on colloidal chitin with K m of 0.01 mg mL−1 and V max of 5.75 mmol min−1. K cat and catalytic efficiency were measured at 1.91 s−1 and 191 mL mg−1 s−1, respectively. The product profiling of Bh Chi using thin layer chromatography and Mass spectrometric techniques hinted an exochitinase mode of action with chitobiose and N-Acetyl glucosamine as the products. This study represents the first report on an exochitinase from Bacillus haynesii. Furthermore, the chitinase showcased promising antifungal properties against key pathogens, Fusarium oxysporum and Penicillium chrysogenum , reinforcing its potential as a potent biocontrol agent. [Display omitted] [ABSTRACT FROM AUTHOR]

In optics, the Fabry–Pérot interferometer is a basic building block, enabling a selection of light with a specific wavelength. We theoretically propose a magnonic version of the Fabry–Pérot interferometer based on two magnetic domain walls. By exploiting the interaction of a domain wall and spin waves, in particular, the phenomenon that a sufficiently narrow domain wall serves as an effective mirror for spin waves as it reflects spin wave almost completely, a magnonic interferometer is contrived by using two parallel domain walls. It allows tunability of the magnon wavelength passing through the interferometer by changing the distance between two domain walls. Our result offers a way to improve the ability of magnonic information processing in a simple magnetic structure. [ABSTRACT FROM AUTHOR]

Chitooligosaccharide (COS) is a derivative of chitosan, which is a natural macromolecular compound. COS has been shown effects in an inflammatory response. Recent reports show that COS derivatives have enhanced anti‐inflammatory activity by inhibiting intracellular signals. Evaluation of the anti‐inflammatory effect of caffeic acid conjugated COS chain (CA‐COS) was performed in this study. The effects of CA‐COS on the inflammatory response were demonstrated in lipopolysaccharide‐stimulated RAW264.7 macrophages. The results showed that CA‐COS inhibited nitric oxide (NO) production and downregulated the gene expression of nitric oxide synthase (iNOS), and cytokines such as tumor necrosis factor‐alpha (TNF‐α), IL‐1β, and IL‐6 without cytotoxic effect. In addition, western blot analysis showed that CA‐COS inhibits the protein expression of iNOS and nuclear factor kappa B (NF‐kB), including p50 and p65, and mitogen‐activated protein kinase (MAPK) signaling pathways. Collectively, these results provide clear evidence for the anti‐inflammatory mechanism of CA‐COS that show great potential as a novel agent for the prevention and therapy of inflammatory diseases. [ABSTRACT FROM AUTHOR]

Demethoxyfumitremorgin C, a secondary metabolite of the marine fungus, Aspergillus fumigatus , had been reported to demonstrate cytotoxic effect on mouse tsFT210 cells. However, no information is available regarding its functional mechanism and the chemo-sensitization effects on different kinds of human cancer cells. We found that treatment of demethoxyfumitremorgin C inhibited the cell viability of PC3 human advanced prostate cancer cells, induced apoptosis as determined by Annexin V/propidium iodide double staining, and decreased mitochondrial membrane potential. Demethoxyfumitremorgin C induced apoptosis was associated with downregulation of anti-apoptotic proteins: Ras, PI3K, Akt, Bcl-xL, and Bcl-2, and upregulation of pro-apoptotic Bax. Demethoxyfumitremorgin C activated caspase-3, -8, and -9, leading to PARP cleavage. Additionally, caspase inhibitors blocked demethoxyfumitremorgin C-induced apoptosis of PC3 cells. These results suggest that demethoxyfumitremorgin C from Aspergillus fumigatus inhibits the proliferation of PC3 human prostate cancer cells via the intrinsic (mitochondrial) and extrinsic pathway, followed by downstream events leading to apoptotic cell death. Demethoxyfumitremorgin C could therefore, serve as a useful agent to treat human advanced prostate cancer. [ABSTRACT FROM AUTHOR]

We theoretically study the interaction of magnons, quanta of spin waves, and a domain wall in a one-dimensional easy-axis antiferromagnet in the presence of an external magnetic field applied along the easy axis. To this end, we begin by obtaining the exact solution for spin waves in the background of a domain wall magnetized by an external field. The finite magnetization inside the domain wall is shown to give rise to reflection of magnons scattering off the domain wall, deviating from the well-known result of reflection-free magnons in the absence of a magnetic field. For practical applications of the predicted reflection of magnons, we show that the magnon reflection contributes to the thermally driven domain-wall motion. Our work leads us to envision that inducing a finite magnetization in antiferromagnetic solitons such as vortices and skyrmions can be used to engender phenomena that do not occur in the absence of magnetization. [ABSTRACT FROM AUTHOR]

Recently, a great deal of interest has been expressed in the cosmetic industry regarding marine-derived cosmetic active ingredients due to their numerous beneficial effects on human skin health. Bioactive substances derived from marine resources have diverse functional roles as natural skin care agents, and these properties can be applied to the development of novel cosmetics as well as nutricosmetics (from edible seaweeds and edible marine animals). This contribution focuses on marine-derived cosmeceutical active ingredients and presents an overview of their health beneficial effects on human skin. [ABSTRACT FROM AUTHOR]

Abstract: Marine microorganisms have received mounting attention in biodiscoveries due to their exclusive physicochemical characteristics which have been acquired as an adaptation to prevailing extreme conditions in the marine environment. It has been noticed that those unique marine microbes and their biologically active metabolites are potential sources to be used as sustainable food and pharmaceutical ingredients. Even though dozens of research articles demonstrate the immense potentials of marine microbial metabolites as lead compounds in drugs and pharmaceutical developments, their role as food ingredients is poorly addressed. However, recent advances in food technology have opened up a number of novel avenues to develop natural substances as food or food ingredients. In this context, this review aims at revealing and discussing prospective applications of marine microorganisms and their metabolites in modern nutraceuticals and functional foods. [Copyright &y& Elsevier]

Abstract: Recently, much attention has been paid by consumers toward natural bioactive compounds as functional ingredients in nutraceuticals. Marine algae are considered as valuable sources of structurally diverse bioactive compounds. Marine algae are rich in sulfated polysaccharides (SPs) such as carrageenans in red algae, fucoidans in brown algae and ulvans in green algae. These SPs exhibit many health beneficial nutraceutical effects such as antioxidant, anti-allergic, anti-human immunodeficiency virus, anticancer and anticoagulant activities. Therefore, marine algae derived SPs have great potential to be further developed as medicinal food products or nutraceuticals in the food industry. This contribution presents an overview of nutraceutical effects and potential health benefits of SPs derived from marine algae. [Copyright &y& Elsevier]

Abstract: Histamine, a potent inflammatory mediator, has been known to cause the pathogenesis of atherosclerosis. In this sense, two bioactive peptides P1 (LDAVNR; 686Da) and P2 (MMLDF; 655Da) purified from gastric enzymatic hydrolysate of Spirulina maxima were examined for their protective effects against early atherosclerotic responses induced by histamine in EA.hy926 endothelial cells. Interestingly, both P1 and P2 exhibited inhibitory activities on the production and expression of IL-6 and MCP-1. Furthermore, P1 and P2 inhibited the production of adhesion molecules including P-selectin and E-selectin, and thus reducing in vitro cell adhesion of monocyte onto endothelial cells. In addition, the production of intracellular reactive oxygen species was observed to reduce in the presence of P1 or P2. Notably, the inhibitory activities of P1 and P2 were found due to down-regulating Egr-1 expression via histamine receptor and PKCδ-dependent MAPKs activation pathway. These results suggest that peptides P1 and P2 from S. maxima are effective to suppress histamine-induced endothelial cell activation that may contribute to the prevention of early atherosclerosis. [Copyright &y& Elsevier]

Abstract: Marine microbes have been a storehouse of bioactive metabolites with tremendous potential as drug candidates. Marine microorganism derived secondary metabolites (chemical compounds/peptides) are considered to be a burning area of research since recent past. Many of such compounds have been proven to be anti-bacterial, anti-fungal, anti-algal, anti-HIV, anti-helminthic, anti-protozoan, anti-tumor and anti-allergic agents. Marine bacteria and fungi have been reported to be the producers of such compounds owing to their defense mechanisms and metabolic by products. Although the number of natural products isolated from these classes of marine microbial flora is large, a limited number of such compounds reach the clinical trial and even less number of them get approved as a drug. Here we discuss the recent studies on the isolation, characterization and the pharmacological significances of anti-bacterial, anti-fungal and anti-infective agents of marine microbial origin. Further, the clinical status of such compounds has also been discussed in comparison with those derived from their terrestrial counterparts. [Copyright &y& Elsevier]

Calcium, being an essential mineral with many important and diversified functions, plays an important role in the health and well being of the human. Marine organisms serve as an alternate source for calcium. Calcium has to be solubilized in the body in order to have the maximum benefits. The increased solubility of calcium from diet contributes to calcium absorption and bioavailability in the body. In this paper, we report various marine sources of calcium, solubilizing the calcium to improve the bioavailability and the applications of calcium as an important mineral in controlling different diseases. [ABSTRACT FROM PUBLISHER]

Abstract: Recently, the isolation and characterization of the biologically active components from seaweeds have gained much attention from various research groups across the world. The marine algae have been studied for biologically active components and phlorotannins are one among them. Among marine algae, brown algal species such as Ecklonia cava, Eisenia arborea, Ecklonia stolinifera and Eisenia bicyclis have been studied for their potential biological activities. Majority of the investigations on phlorotannins derived from brown algae have exhibited their potentiality as antioxidant, anti-inflammatory, antidiabetic, antitumor, antihypertensive, anti-allergic, hyaluronidase enzyme inhibition and in matrix metalloproteinases (MMPs) inhibition activity. In this review, we have made an attempt to discuss the potential biological activities of phlorotannins from marine brown algae and their possible candidature in the pharmaceutical applications. [Copyright &y& Elsevier]

Abstract: Chitosan gallate were synthesized using a free radical-induced grafting reaction. Chitosan gallate showed enhanced water-solubility compared to plain chitosan, and exhibited good thermal stability. The IC50 value of chitosan gallate against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was 17.86μg/mL. In addition, chitosan gallate effectively inhibited the generation of intracellular reactive oxygen species (ROS), and also suppressed lipid peroxidation in RAW264.7 macrophage cells. Chitosan gallate also exhibited the protection effect on genomic DNA damage by induced hydroxyl radical, and up-regulated the protein expression of antioxidant enzymes including superoxide dismutase-1 and glutathione reductase under H2O2-mediated oxidative stress in RAW264.7 macrophage cells. These results indicate that chitosan gallate might be potential antioxidant biomaterials. [Copyright &y& Elsevier]

Abstract: This paper discusses acetylcholinesterase inhibitory properties of gallic acid-grafted-chitosans (GA-g-chitosans) with different grafting ratios. The GA-g-chitosans exhibited potent acetylcholinesterase inhibitory effects in a dose-dependent manner, and their IC50 values ranged from 138.5±0.25 to 397.6±5.2μg/mL. The acetylcholinesterase inhibition kinetics of the GA-g-chitosan (I) by Lineweaver–Burk plots showed a decrease in V max, whereas K m was not altered, thus suggesting a non-competitive mode of inhibition. The inhibition constant, K i, was found to be 64.85μg/mL by the secondary plot of the Lineweaver–Burk plots. In addition, the GA-g-chitosan (I) did not exert any significant cytotoxicity against PC12 cells, and the cellular acetylcholinesterase activity in PC12 cells was significantly inhibited by the GA-g-chitosan (I). This is the first report on acetylcholinesterase inhibition by the grafting of GA onto chitosan, and this compound might be helpful in preventing Alzheimer''s disease by elevating cholinergic transmission. [Copyright &y& Elsevier]

Abstract: Gallic acid-grafted-chitosans (GA-g-chitosans) with four different grafting ratios were prepared by a free radical-induced grafting reaction in order to improve antioxidant and water-solubility. To verify the synthesis of GA-g-chitosans, 1H NMR and thin layer chromatography were employed, and the results revealed that GA was grafted onto the chitosan. The antioxidant properties of the GA-g-chitosans were evaluated using several in vitro models. GA-g-chitosan (I), which has the highest GA content, showed 92.26% scavenging activity against 2,2-diphenyl-1-picrylhydrazyl and 93.15% hydrogen peroxide scavenging activity at 50μg/mL. GA-g-chitosan (I) was also showed higher reducing power compared to others. All GA-g-chitosans showed improved antioxidant capacities compared to plain chitosan treated in the same conditions without gallic acid grafting. Furthermore, the GA-g-chitosans also exhibited good cytocompatibility and effectively inhibited the formation of intracellular reactive oxygen species (ROS) in time- and dose-dependent manner in RAW264.7 macrophages. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study is to investigate the inhibitory effect of phloroglucinol on oxidative stress and inflammation. Phloroglucinol is a monomer of phlorotannins abundant in brown algae. A few effects of phloroglucinol have been reported, but any information on its effect on anti-inflammation related to oxidative stress has not been reported in detail until now. In our study phloroglucinol exhibited inhibitory effects not only on oxidative stress but also on the production of inflammatory mediators such as tumor necrosis factor-α, interleukin-1β, interleukin-6 and prostaglandin E2 in RAW264.7 cells stimulated by lipopolysaccharide. Furthermore, in HT1080 cells, a human fibrosarcoma cell line, phloroglucinol decreased the expression of matrix metalloproteinase that play an important role in chronic inflammation. In the presence of phloroglucinol NF-κB transcription factor that regulates the expression of these inflammatory mediators was inactivated via inhibition of NIK, and activation of AP-1 transcription factor was also reduced via inactivation of ERK, a MAPK. These results suggest that phloroglucinol can provide a therapeutic potential for prevention of chronic inflammation. [Copyright &y& Elsevier]

Abstract: Dioxinodehydroeckol (DHE) isolated from Ecklonia cava, has previously been investigated for its inhibition of the differentiation of 3T3-L1 preadipocytes into adipocytes. Levels of lipid accumulation were measured, along with changes in the expression of genes and proteins associated with adipogenesis and lipolysis. Confluent 3T3-L1 preadipocytes in medium with or without different concentrations of DHE for 7 days were differentiated into adipocytes. Lipid accumulation was quantified by measuring direct triglyceride contents and Oil-Red O staining. The expression of genes and proteins associated with adipogenesis and lipolysis was measured using RT-PCR, quantitative real-time RT-PCR and Western blotting analysis. It was found that the presence of DHE significantly reduced lipid accumulation and down-regulated the expression of peroxisome proliferator-activated receptor-γ (PPARγ), sterol regulatory element-binding protein 1 (SREBP1) and CCAAT/enhancer-binding proteins (C/EBPα) in a dose-dependent manner. Moreover, DHE suppressed regulation of the adipocyte-specific gene promoters such as fatty acid binding protein (FABP4), fatty acid transport protein (FATP1), fatty acid synthase (FAS), lipoprotein lipase (LPL), acyl-CoA synthetase 1 (ACS1), leptin, perilipin and HSL compared to control adipocytes. The specific mechanism mediating the effects of DHE was confirmed by activation of phosphorylated AMP-activated protein kinase (pAMPK). Therefore, these results suggest that DHE exerts anti-adipogenic effect on adipocyte differentiation through the activation and modulation of the AMPK signaling pathway. [Copyright &y& Elsevier]

Abstract: A potent anticoagulant oligopeptide was isolated from the edible parts of blue mussel (Mytilus edulis). M. edulis anticoagulant peptide (MEAP) with an approximately 2.5kDa molecular mass was similar to the amino acid sequence of the EF-hand domain of calmodulin from scallop adductor muscle. MEAP could potently prolong both the thrombin time and the activated partial thromboplastin time, and specifically interact with blood coagulation factors: FIX, FX, and FII. MEAP could inhibit proteolytic activation of FX by the intrinsic FXase and formation of FIIa by a prothrombinase complex in dose-dependant reactions. This study elucidated that MEAP prolonged blood clotting by inhibiting activation of FX in the intrinsic tenase complex (FIXa/VIIIa/PLs) and conversion of FII to FIIa in the prothrombinase complex (FXa/FVa/PLs). [Copyright &y& Elsevier]

Abstract: Ecklonia cava (EC) is a brown alga that evidences radical scavenging activity, bactericidal activity, tyrosinase inhibitory activity, and protease inhibitory activity. However, its anti-allergic effects remain poorly understood. In the current study, we attempted to determine whether pretreatment with EC induces a significant inhibition of asthmatic reactions in a mouse asthma model. Mice sensitized and challenged with ovalbumin (OVA) evidenced typical asthmatic reactions, as follows: an increase in the number of eosinophils in bronchoalveolar lavage fluid; a marked influx of inflammatory cells into the lung around blood vessels and airways, and airway luminal narrowing; the development of airway hyperresponsiveness; the detection of tumor necrosis factor-alpha (TNF-α) and Th2 cytokines, including IL-4 and IL-5 in the bronchoalveolar lavage (BAL) fluid; and the detection of allergen-specific immunoglobulin E (IgE) in the serum. However, the administration of EC extract prior to the final airway OVA challenge resulted in a significant inhibition of all asthmatic reactions. We also demonstrated that EC extracts treatment resulted in significant reductions on matrix metalloproteinase-9 (MMP-9) and Suppressor of cytokine signaling-3 (SOCS-3) expression and a reduction in the increased eosinophil peroxidase (EPO) activity. The treatment of animals with EC extracts resulted in a significant reduction in the concentrations of the Th2 cytokine (IL-4 and IL-5) in the airways, without any concomitant increase in the concentration of Th1 cytokines. These findings indicate that EC extracts may prove useful as an adjuvant therapy for allergic airway reactions via the inhibition of the Th2 response. Accordingly, this study may provide evidence that EC extract performs a critical function in the amelioration of the pathogenetic process of asthma in mice. [Copyright &y& Elsevier]

Abstract: Chitosans with different degree of deacetylation were prepared from crab shell chitin in the presence of alkali. Aminoderivatized chitosan derivatives were prepared in addition of amino functional groups at a hydroxyl site in the chitosan backbone. Six kinds of aminoderivatized chitosan such as aminoethyl-chitosan (AEC90), dimethylaminoethyl-chitosan (DMAEC90), and diethylaminoethyl-chitosan (DEAEC90), which were prepared from 90% deacetylated chitosan, and AEC50, DMAEC50 and DEAEC50, which were prepared from 50% deacetylated chitosan, were prepared and their reactive oxygen species (ROS) scavenging activities were investigated against hydroxyl radical, superoxide anion radical and hydrogen peroxide. The electron spin resonance (ESR) spectrum revealed that AEC90 showed the highest scavenging effects against hydroxyl and superoxide anion radical, the effects were 91.67% and 65.34% at 0.25 and 5mg/mL, respectively. For hydrogen peroxide scavenging effect, DEAEC90 exhibited the strongest activity. These results suggest that the scavenging effect depends on their degree of deacetylation and substituted group. [Copyright &y& Elsevier]

Abstract: Recently, much attention has been given to chitosan and its hydrolyzed products due to their diverse biological activities. For the first time here we report the inhibitory effect of chitooligosaccharides (COS) on activation and expression of matrix metalloproteinase-2 (MMP-2) in primary human dermal fibroblasts (HDFs). COS with 3–5kDa exhibited the highest inhibitory effect on MMP-2 activity in HDFs assessed by gelatin zymography. Interestingly, protein expression of MMP-2 was also inhibited by COS with same molecular weight. This inhibition was caused by the decrease of the gene expression and transcriptional activity of MMP-2. Furthermore, it was found that COS repressed the gene expression of c-fos, a part of AP-1 transcription factor. These results suggest that COS may play an important role in the prevention and treatment of MMP-2 mediated several health problems such as metastasis and wrinkle formation. [Copyright &y& Elsevier]

Abstract: Generation of immense quantity of underutilized marine processing byproducts has long been recognized as wastes and greater efforts were given to use these materials in various applications. With a great number of researches on these byproducts, some biologically active compounds were identified and applicated to the useful compounds for human utilization. Potential applications of proteins, lipids, chitin and minerals in marine bioprocessing leftovers as bioactive materials have increased the value of processing byproducts in recent years. In this review, we have focused on the utilization of marine processing byproducts to screen bioactive compounds and their potential applications. [Copyright &y& Elsevier]

Abstract: Novel water-soluble chitin derivative was prepared by chemical modification to evaluate antioxidant activities by free radical scavenging potential using electron spin resonance spin trapping technique. Aminoethyl-chitin (AEC) exhibited free radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, superoxide, and peroxyl radicals. AEC quenched DPPH and peroxyl radical over 55% and 59% at 4mg/mL, and also suppressed superoixde radical over 58% at 2mg/mL. Especially, AEC was more active against hydroxyl radical, and scavenging ratio was 92.2% at 0.12mg/mL. These results suggested that free amino group in the –CH2CH2NH2 plays an important role in the free radical scavenging activity. In addition, cytotoxic effect of AEC was assessed using human lung fibroblast (MRC-5) cell line, and AEC showed less toxic against MRC-5. [Copyright &y& Elsevier]

Abstract: Aminoethyl-chitin (AEC) was synthesized in an attempt to both increase solubility of chitin in water and biological activity. AEC was obtained by grafting 2-chloroethylamino hydrochloride onto chitin at C-6 position. The structure of AEC was elucidated FT-IR and 1H NMR spectroscopy, and its antimicrobial activity was investigated using three Gram-positive and Gram-negative bacteria. The integrity of the cell membranes of the representatives E. coli and S. aureus was investigated by determining the release of intracellular components of cells. When treated with AEC, release of 260 nm absorbing materials quickly increased both E. coli and S. aureus, but absorbance value was different due to the difference in cell structures. For detailed study, outer membrane (OM) and inner membrane (IM) permeabilization assay were performed using the fluorescent probe 1-N-phenylnaphthylamine (NPN) and the release of cytoplasmic β-galactosidase activity. The results showed that AEC rapidly increased NPN uptake and the release of cytoplasmic β-galactosidase via increasing the permeability of OM and IM. In addition, cytotoxic effect of AEC was assessed using human lung fibroblast (MRC-5) cell line, and AEC showed less toxic against MRC-5. [Copyright &y& Elsevier]

Abstract: Many researchers have focused chitosan as a source of potential bioactive material during past few decades. However, chitosan has several drawbacks to be utilized in biological applications, including poor solubility under physiological conditions. Therefore, a new interest has recently been emerged on partially hydrolyzed chitosan, chitosan oligosaccharides (COS). During the resent past, several technological approaches have been taken to prepare COS and, enzymatic preparation methods captured a great interest due to safe and non-toxic concerns. With time, new improvements were introduced to enzymatic production and presently it has been developed to a continuous production process. Many of the biological activities reported for COS, such as antimicrobial, anticancer, antioxidant, and immunostimulant effects are depend on their physico-chemical properties. In this review, we have summarized different enzymatic preparation methods of COS and some of their reported biological activities. [Copyright &y& Elsevier]

Abstract: BACE1 (the β-site APP-cleaving enzyme) inhibitory activities of water-soluble chitosan derivatives substituted with aminoethyl, dimethylaminoethyl and diethylaminoethyl groups were investigated. AE-chitosan (90%) prepared from 90% deacetylated chitosan showed the strongest BACE1 inhibitory activity than those of other derivatives. The inhibitory pattern was found to be non-competitive by Dixon plot, and the value of the inhibition constant (K i) was 85μg/mL. [Copyright &y& Elsevier]

Abstract: Chitooligosaccharides (COSs) were successfully prepared using an ultrafiltration membrane bioreactor system, and named as COS-I (10–5kDa), COS-II (5–3kDa), COS-III (3–1kDa), and COS-IV (below 1kDa), respectively. In addition, their phosphorylated derivatives were prepared by a P2O5 in methanesulfonic acid solution, and inhibitory activity on the formation of insoluble calcium phosphate of phosphorylated chitooligosaccharides. Phosphorylated COS-IV exhibited the highest inhibitory activity of calcium phosphate precipitation among tested chitooligosaccharides. Its inhibitory activity, especially at the concentration more than 4mg/ml, was similar to that of CPP, which is widely used as a calcium fortifying agent increasing calcium absorbability. Therefore, phosphorylated chitooligosaccharides may be potential inhibitors of calcium phosphate precipitation. [Copyright &y& Elsevier]

Recombinant Escherichia coli JM109 (pZH3-5/pMT), harboring a manganese transport gene (mntA) and a metal-sequestering protein (metallothionein [MT]) gene, was cultivated to accumulate cadmium (Cd) in an aqueous phase. Isopropyl β-D-thiogalactoside (IPTG)-induced cells showed rapid Cd2+ ion accumulation (90% of maximum accumulation in 15 min) and had an accumulation six times higher than that of the control. Under optimum conditions, i.e., pH 7, 37°C and 0.5 (OD600), 1.5 mM IPTG induction resulted in the accumulation of 21.5 μmol Cd/g dry cell. Storage at 37°C for 24 h had no effect on the accumulation. Significantly, Cd was selectively accumulated in a solution containing an equal concentration of three other metals, resulting in more than 90% of the total accumulated metals being Cd. The accumulation of Cd was reduced by the presence of Mn2+ ion whereas no significant effect was observed with Cu2+, Zn2+ and Pb2+ ions. A chelator, EDTA, had no effect on the accumulation up to 100 mM. The bioaccumulation rate followed Michaelis–Menten kinetics (V m=2.7 μmol Cd2+/min·g dry cell, K m=0.67 μM). The equilibrium isotherm showed a Langmuir isotherm. In the membrane reactor experiment, 1 mg/l Cd in an inlet solution decreased to 0.2 mg/l in the effluent, removing 80% of Cd, continuously. These results indicated the potentials of a genetically modified microorganism for the highly selective accumulation of Cd at a low concentration and the future application to the removal and recovery of Cd. [Copyright &y& Elsevier]

We theoretically investigate the transfer of angular momentum between a spin superfluid and a domain wall in an exchange coupled easy-axis and easy-plane magnetic insulator system. A domain wall in the easy-axis magnet absorbs spin angular momentum via disrupting the flow of a superfluid spin current in the easy-plane magnet. Focusing on an open geometry, where the spin current is injected electrically via a nonequilibrium spin accumulation, we derive analytical expressions for the resultant superfluid-mediated motion of the domain wall. The analytical results are supported by micromagnetic simulations. The proposed phenomenon extends the regime of magnon-driven domain-wall motion to the case where the magnons are condensed and exhibit superfluidity. Furthermore, by controlling the pinning of the domain wall, we propose a realization of a reconfigurable spin transistor. The long-distance dissipationless character of spin superfluids can thus be exploited for manipulating soliton-based memory and logic devices. [ABSTRACT FROM AUTHOR]

In this study, sole fish (Psettodes erumei) muscle mass was used for the isolation of inflammation suppressing peptide through the enzymatic hydrolysis process. The amino acid composition revealed high amount of histidine, alanine, lysine in the crude muscle tissue. The anti-inflammatory assays performed on enzymatic hydrolysates showed that protein inhibition and membrane protection activity was highest for 12th h trypsin hydrolysate to be 81.64 ± 1.54% and 73.3 ± 1.03% respectively. This active hour hydrolysate was subjected to partial separation and chromatographic purification where the peak showing the highest anti-inflammatory activity was subjected to liquid chromatography-mass spectrometry (LC–MS/MS) which revealed a short novel peptide sequence of MTQML with a molecular weight 622 Da. The peptide was observed to be functionally stable and in vitro study revealed that the peptide was non-cytotoxic and reduced the expression of nitric oxide as well as nuclear factor kappa B (NFκB) complex. This leads to the downregulation of the NFκB signaling pathway and suppression of inflammation. Furthermore, molecular docking analysis confirmed the binding of peptide to cytokine and NFκB-p65 receptors to their inhibiting site at lower binding energy. This novel bioactive peptide could be used as non-toxic inflammation suppressing therapeutic in nutraceutical as well as pharmaceutical applications. [ABSTRACT FROM AUTHOR]

The oceans have been shown as an almost entire reserve of novel enzymes. Alkaline phosphatase (AP) is a key-enzyme in the marine environment. This review provides an account of the alkaline phosphatase production of marine organisms and is based on reports of different species of marine origin, from primitive bacteria to vertebrates such as fishes. Purification and enzymatic characterization, investigation of activators and inhibitors, use as biosensor based inhibition activities, ecological roles in sea, and eventually potential application of alkaline phosphatase from different species of marine organisms are overviewed. Recent biotechnological progresses require the researches of new enzymes from marine resources that can be used for various applications. Marine enzyme resources might be of great interest for biotechnological processes because of their safety accompanied with natural origin. The specific features presented by marine enzymes can be advantageously used both for process improvement or to develop new processes and products. This review highlights the potential of marine organism as valuable resources of AP. The overview of AP in different marine organisms showed its use in various fields among biotechnology being increased and can be promising candidate in future. [ABSTRACT FROM AUTHOR]

The replacement of conventional autografts and allografts by bone fragments constructed from alternate materials, cells, and molecules (growth factors, drugs, etc.) is an exciting prospect in the field of bone tissue engineering. Bone morphogenetic protein-2 (BMP-2) is a growth factor that has been extensively studied from this point of view. This review analyzes the relevance of chitosan and its derivatives and composites with various materials such as ceramics, heparin, silica, stem cells, titanium implants, etc., in terms of delivering BMP-2 for the purpose of bone regeneration. Chitosan offers the versatility to be modified into any shapes or sizes including conversion to nanoparticles, microspheres, nanofibers, porous scaffolds, and films. The results presented in this review clearly demonstrate that chitosan-based materials are biocompatible and have the potential to systematically and sustainably release BMP-2 where required. This release results in enhanced cell proliferation levels, enhancement of alkaline phosphatase activity, increased differentiation as well as increased mineralization under in vitro and in vivo conditions. This review also shines a spotlight on the currently developed chitosan-based products that are being used for BMP-2 delivery. [ABSTRACT FROM AUTHOR]

Chitin and chitosan based nanocomposite scaffolds have been widely used for bone tissue engineering. These chitin and chitosan based scaffolds were reinforced with nanocomponents viz Hydroxyapatite (HAp), Bioglass ceramic (BGC), Silicon dioxide (SiO 2 ), Titanium dioxide (TiO 2 ) and Zirconium oxide (ZrO 2 ) to develop nanocomposite scaffolds. Plenty of works have been reported on the applications and characteristics of the nanoceramic composites however, compiling the work done in this field and presenting it in a single article is a thrust area. This review is written with an aim to fill this gap and focus on the preparations and applications of chitin or chitosan/nHAp, chitin or chitosan/nBGC, chitin or chitosan/nSiO 2 , chitin or chitosan/nTiO 2 and chitin or chitosan/nZrO 2 in the field of bone tissue engineering in detail. Many reports so far exemplify the importance of ceramics in bone regeneration. The effect of nanoceramics over native ceramics in developing composites, its role in osteogenesis etc . are the gist of this review. [ABSTRACT FROM AUTHOR]

Abstract: Matrix metalloproteinases are endopeptidases which belong to the group of metalloproteinases that contribute for the extra-cellular matrix degradation, and several tissue remodeling processes. An imbalance in the regulation of these endopeptidases eventually leads to several severe pathological complications like cancers, cardiac, cartilage, and neurological related diseases. Hence inhibitory substances of metalloproteinases (MMPIs) could prove beneficial in the management of above specified pathological conditions. The available synthetic MMPIs that have been reported until now have few shortcomings and thus many of them could not make to the final clinical trials. Hence a growing interest among researchers on screening of MMPIs from different natural resources is evident and especially natural products from marine origin. As there has been an unparalleled contribution of several biologically active compounds from marine resources that have shown profound applications in nutraceuticals, cosmeceuticals, and pharmaceuticals, we have attempted to discuss the various MMPIs from edible sea-weeds. [Copyright &y& Elsevier]

Abstract: Chitosan and chitosan derived compounds are marine byproducts which have been shown to exhibit bioactivities including antibacterial, antioxidant, antidiabetic and anti-HIV. Proteins are among the most potent and selective molecules offering an endless potential of different structure and sequence preferences. The tripeptides which consist of tryptophan (W), methionine (M) and glutamine (Q) have been conjugated with chitosan oligomers. Among them QMW-COS and WMQ-COS protected C8166 cells from cell-lytic effects of HIV-1RF strain. Furthermore, these two compounds inhibited HIV-induced syncytia formation. We confirmed the decrease in viral-load in cell culture using p24 ELISA assay. To determine the specific mode of action of QMW-COS and WMQ-COS to inhibit HIV, we checked the inhibitory action of these compounds on viral reverse transcriptase and protease enzymes. However, we could not detect any inhibitory activity of conjugated compounds on recombinant reverse transcriptase and protease enzyme in vitro. When we co-cultured HIV-infected and uninfected C8166 cells, these two compounds actively inhibited the syncytia formation upon co-culture assay. Time-dependent addition of compounds and finally gp120-CD4 ELISA assay revealed that QMW-COS and WMQ-COS are bioactive compounds inhibiting HIV-induced cytopathic effects via exerting their effects on HIV entry stage. [Copyright &y& Elsevier]

Highlights: [•] Gelatin was isolated from sea food processing by-product, skate skin. [•] Two active peptides MVGSAPGVL (829Da) and LGPLGHQ (720Da) were isolated. [•] Peptides showed potent ACE inhibitory activity (IC50 3.09 and 4.22μM). [•] Peptides protected human endothelial cells from oxidative damage. [•] Peptides could be used as antihypertensive agents in cardiovascular diseases. [ABSTRACT FROM AUTHOR]

The damping parameter ${\alpha }_{\mathrm{ FM}}$ in ferrimagnets defined according to the conventional practice for ferromagnets is known to be strongly temperature-dependent and diverge at the angular momentum compensation temperature, where the net angular momentum vanishes. However, recent theoretical and experimental developments on ferrimagnetic metals suggest that the damping parameter can be defined in such a way, which we denote by ${\alpha }_{\mathrm{ FiM}}$ , that it is free of the diverging anomaly at the angular momentum compensation point and is little dependent on temperature. To further understand the temperature dependence of the damping parameter in ferrimagnets, we analyze several datasets from literature for a ferrimagnetic insulator, gadolinium iron garnet, by using the two different definitions of the damping parameter. Using two methods to estimate the individual sublattice magnetizations, which yield results consistent with each other, we find that in all the used datasets, the damping parameter ${\alpha }_{\mathrm{ FiM}}$ does not increase at the angular compensation temperature and shows no anomaly, whereas the conventionally defined ${\alpha }_{\mathrm{ FM}}$ is strongly dependent on the temperature. [ABSTRACT FROM AUTHOR]

In the present study, we isolated collagen from Thunnus obesus bone, which was physiochemically characterized. Two different kinds of methods were used to isolate the collagen; they are the Acid Soluble Collagen (ASC) and Acid Soluble Enzyme Collagen (ASEC) methods. The isolated collagen was characterized with Fourier Transform Infrared Spectroscopy (FT-IR), SDS-polyacrylamide gel electrophoresis (SDS-PAGE), Optical Microscopy (OM) and Scanning Electron Microscopy (SEM). FT-IR results revealed the presence of collagen. SEM and OM results depicted that collagen was in the form of fiber sponge-like scaffolds. The isolated collagen scaffold was checked with pre-osteoblast (MC3T3-E1) cell line for biocompatibility. The in vitro results revealed that the collagen scaffolds were highly biocompatible and nontoxic in nature. Herewith, we are suggesting that marine fish-derived collagen will be an excellent material for leather, film industry, pharmaceutical, cosmetics, biomedical and food applications. [ABSTRACT FROM AUTHOR]

Abstract: Helicobacter pylori infection is one of the most critical causes of stomach cancer. The current study was conducted to explore the protective effects of an isolated active peptide H-P-6 (Pro-Gln-Pro-Lys-Val-Leu-Asp-Ser) from microbial hydrolysates of Chlamydomonas sp. against H. pylori-induced carcinogenesis. The peptide H-P-6 has effectively suppressed H. pylori-induced hyper-proliferation and migration of gastric epithelial cells (AGS). However, the peptide did not inhibit the viability of the bacteria or invasion into AGS cells. Therefore, the effect of the peptide on regulating H. pylori-induced molecular signaling was investigated. The results indicated that H. pylori activates the EGFR tyrosine kinase signaling and nuclear translocation of the β-catenin. The EGFR activation has led to the up-regulation of PI3K/Akt signaling pathway. Moreover, the nuclear translocation levels of β-catenin were significantly increased as a result of Akt mediated down-regulation of GSK3/β protein levels in the cytoplasm. Both of these consequences have resulted in increased expression of cell survival and migration related genes such as c-Myc, cyclin-D, MMP-2 and matrilysin. Interestingly, the isolated peptide potently inhibited H. pylori-mediated EGFR activation and thereby down-regulated the subsequent P13K/Akt signaling leading to β-catenin nuclear translocation. The effect of the peptide was confirmed with the use of EGFR tyrosine kinase inhibitor AG1487 and molecular docking studies. Collectively this study identifies a potent peptide which regulates the H. pylori-induced hyper-proliferation and migration of AGS cells at molecular level. [Copyright &y& Elsevier]

Methicillin-resistant Staphylococcus aureus (MRSA) is the most problematic Gram-positive bacterium in the context of public health due to its resistance against almost all available antibiotics except vancomycin and teicoplanin. Moreover, glycopeptide-resistant S. aureus have been emerging with the increasing use of glycopeptides. Recently, resistant strains against linezolid and daptomycin, which are alternative drugs to treat MRSA infection, have also been reported. Thus, the development of new drugs or alternative therapies is clearly a matter of urgency. In response to the antibiotic resistance, many researchers have studied for alternative antibiotics and therapies. In this review, anti-MRSA substances isolated from marine bacteria, with their potential antibacterial effect against MRSA as potential anti-MRSA agents, are discussed and several strategies for overcoming the antibiotic resistance are also introduced. Our objective was to highlight marine bacteria that have potential to lead in developing novel antibiotics or clinically useful alternative therapeutic treatments. [ABSTRACT FROM AUTHOR]

Abstract: Hydroxyapatite (HAp) is the promising biomaterials to construct the article bone from the last two decades. In the present study, we have developed hydroxyapatite-fucoidan (HApF) nanocomposite for bone tissue engineering and subsequently characterized by different analytical techniques for bone graft substitute. The chemical characterization suggested that the prepared nanocomposite HApF have amorphous nature, crystal size between 41 and 153nm was observed. The biochemical characterization inferred that the prepared nanocomposite were non-toxic and mineralization effect of HApF was observed two times higher then HAp. Hence, HApF is the promising biomaterial and could be used for bone tissue construct. [Copyright &y& Elsevier]

Abstract: The biological importance of antioxidants influenced to synthesize some curcumin-related compounds as potential antioxidants. Accordingly, a series of 2,4-diaryl-3-azabicyco[3.3.1]nonan-9-ones were synthesized with polyphenolic and/or polymethoxyphenyl groups by modified Mannich condensations. The yield was significantly improved using BF3·SiO2 as heterogeneous catalyst under mild conditions. Stereochemistry of all the synthesized compounds was established as twin-chair with an equatorial disposition of the aryl groups, through their NMR and XRD interpretations. The ABNs 8 (curcumin analog) and 10 (bis-demethoxycurcumin analog) showed an effective profile over curcumin, α-tocopherol, and vitamin C by chemical methods. Further, the efficiency of one of the active molecules, ABN 10, was demonstrated by its intracellular ROS inhibition activity on RAW 264.7 macrophage cells by FACS analysis in dose-dependent manner. [Copyright &y& Elsevier]

Seahorse ( Hippocampus Kuda Bleeler) has been used as traditional medicine for thousands of years, in Eastern Asia. In this study of the methanol extract of fresh Hippocampus Kuda, the new compounds 2-ethyldecyl 2-ethylundecyl phthalate ( 1), 2, 12-diethyl-11-methylhexadecyl 2-ethyl-11-methylhexadecylphthalate ( 2), along with a known Bis(2-ethylheptyl) phthalate ( 3) were isolated. They were tested for their antioxidant activities, including lipid peroxidation inhibitory activity, DPPH radical scavenging, hydroxyl radical scavenging, superoxide anion radical scavenging, alkyl radical scavenging, and cellular radicals; these can be detected using a fluorescence probe, 2′,7′-dichlorofluorescin diacetate (DCFH-DA), which could be converted to highly fluorescent dichlorofluorescein (DCF) with the presence of intracellular ROS on mouse macrophages, RAW264.7 cell. Compound ( 2) exhibited the highest antioxidant activity and inhibitory intracellular ROS than another compounds ( 1, 3). Furthermore, MTT assay showed no cytotoxicity on mouse macrophages cell (RAW264.7) and human fetal lung fibroblast cell line (MRC-5). This antioxidant property depends on concentration and increasing with increased amount of the compound. [ABSTRACT FROM AUTHOR]

Abstract: In this study, a bioactive derivative of chitooligosaccharides (3–5kDa) was synthesized via grafting of gallic acid onto chitooligosaccharides (G-COS) to enhance anti-allergic activity. Hence, G-COS was evaluated for its capabilities against allergic reactions in RBL-2H3 mast cells sensitized with dinitrophenyl-specific immunoglobulin E antibody and stimulated by antigen dinitrophenyl-bovine serum albumin. It was revealed that G-COS exhibited significant inhibition on histamine release and production as well as intracellular Ca2+ elevation at the concentration of 200μg/ml. Likewise, the suppressive effects of G-COS on expression and production of interleukin (IL)-4 and tumor necrosis factor (TNF)-α were evidenced. Moreover, G-COS treatment caused a remarkable blockade on degradation of inhibitory κB-α (IκB-α) protein, translocation of nuclear factor (NF)-κB, and phosphorylation of mitogen-activated protein kinases (MAPKs). Notably, the inhibitory activities of G-COS on allergic reactions were found as a consequence of suppression of FcεRI expression in antigen-stimulated cells. Accordingly, G-COS was suggested to be a promising candidate of novel inhibitors against allergic reactions. [Copyright &y& Elsevier]