In vivo immunological activity of chitosan-derived nanoparticles.

Chitosan has been studied as an immunomodulator, but few studies have used chitosan derivatives as adjuvants alone. After a preliminary study, we found that nanoparticles prepared from chitosan derivatives had better cellular immune activity when used as an adjuvant. Therefore, animal experiments were conducted to further investigate the performance and mechanism of these nanoparticles as immune adjuvants. We injected mice with the chitosan nanoparticle vaccine and measured the expression levels of immunoglobulins, immune factors, and immune genes in tissues and tissue sections. The results showed that C236-HACC-OVA (C2,3,6-chitosan sulfate-chitosan quaternary ammonium salt-ovalbumin) and NO-HACC-OVA (NO-carboxymethyl chitosan-chitosan quaternary ammonium salt-ovalbumin) nanoparticles can significantly improve the secretion of the immune factors IL-6, TNF, and IL-1ß. The level of IgG1 was highly significant after administering both nanoparticles, but IgG2 was not significant in mice. Three immune factors (IL-4, IL-6, and IL-17) were secreted at high levels in mouse serum at a nanoparticle dose of 0.3 mg/mouse. These nanoparticles also have high safety in the liver, kidney, and spleen of mice. This study proves the possibility of using chitosan derivative nanoparticles as vaccine adjuvants. These data further indicate that chitosan derivative nanoparticles have potential for use as vaccine adjuvants and demonstrate that polysaccharides have a unique position in green vaccine research.

Therapeutic potential of enzymatically extracted eumelanin from squid ink in type 2 diabetes mellitus ICR mice: Multifaceted intervention against hyperglycemia, oxidative stress and depression.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a prevalent metabolic disease that poses significant health risks due to its numerous complications. However, the effects of eumelanin on oxidative stress, hyperglycemia and depression in diabetic mice have not been extensively studied. RESULTS: Our study employed an enzymatic approach to extract eumelanin from squid ink and characterized it using spectroscopic techniques. Remarkably, eumelanin extracted with alkaline-neutral-flavor protease (ANF) displayed superior inhibitory activity against α-glucosidase and α-amylase, while enhancing glucose utilization and hepatic glycogen synthesis in human hepatocellular carcinoma cell line (HepG2) insulin resistance model. Further evaluation of ANF in a T2DM ICR mouse model demonstrated its significant potential in alleviating hyperglycemia, reducing glycosylated serum protein levels, improving glucose tolerance and modulating total cholesterol and low-density lipoprotein levels, as well as antioxidant indices at a dosage of 0.04 g kg-1 . Additionally, ANF exhibited positive effects on energy levels and reduced immobility time in antidepressant behavioral experiments. Moreover, ANF positively influenced the density and infiltration state of renal cells, while mitigating inflammatory enlargement and deformation of liver cells, without inducing any adverse effects in mice. CONCLUSION: Overall, these findings underscore the significant therapeutic potential of ANF in the treatment of T2DM and its associated complications. By augmenting lipid and glucose metabolism, mitigating oxidative stress and alleviating depression, ANF emerges as a promising candidate for multifaceted intervention. © 2023 Society of Chemical Industry.

The synthesis, characterization and immunological activity of mucopolysaccharide-quaternized chitosan nanoparticles.

In this study, nanoparticles were prepared by using positively charged quaternized chitosan and negatively charged mucopolysaccharide such as chondroitin sulfate, heparin and hyaluronic acid. The nanoparticles have a stable nanostructure with particle size in 336.2-424.5 nm, potential in 18.5-31.1 mV and polydispersity index PDI of 0.172-0.335. Moreover, their encapsulation efficiency was 68.77 % and 64.89 %, and they have low endotoxin and good stability. It can significantly promote the expression of IL-6, TNF-α, and IL-1ß of DCS cells. Moreover, the in vivo immune activity of heparin-quaternized chitosan-OVA nanoparticles against BALB/C mice was showed that, the nanoparticles could significantly promote the secretion of immunoglobulins in mice including IgG1 and IgG2. And nanoparticle also can promote the production of immune factors. Meanwhile, the expression of immune factor genes was also elevated. Furthermore, the results of tissue section experiments showed that the nanoparticles are safety of the body.

Hepatoprotective Effect of Oyster Peptide on Alcohol-Induced Liver Disease in Mice.

Alcohol-induced liver disease (ALD) has become one of the major global health problems, and the aim of this study was to investigate the characterization of the structure as well as the hepatoprotective effect and mechanism of oyster peptide (OP, MW < 3500 Da) on ALD in a mouse model. The results demonstrate that ethanol administration could increase the activities of aspartate aminotransferase (AST), alanine transaminase (ALT), γ-Glutamyl transferase (GGT), reactive oxygen species (ROS), malondialdehyde (MDA), and triglycerides (TG), as well as increase the interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor (TNF-α) levels (p < 0.01), and reduce the activity of superoxide dismutase (SOD) and the concentration of glutathione (GSH). Those changes were significantly reversed by the application of different doses of OP. Furthermore, the mRNA expressions of nuclear factor elythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and quinone oxidoreductase1 (NQO1) were significantly up-regulated in OP groups, and the mRNA expressions of nuclear factor kappa-light chain enhancer of B cells (NF-κB), TNF-α, and IL-6 were markedly reduced in OP groups compared to that of the model group. Thus, OP had a significant protective effect on ALD through the enhancement of the in vivo antioxidant ability and the inhibition of the inflammatory response as possible mechanisms of action, which therefore suggests that OP might be useful as a natural source to protect the liver from alcohol damage.

Role of Fucoxanthin towards Cadmium-induced renal impairment with the antioxidant and anti-lipid peroxide activities.

Kidney damages caused by cadmium are considered to be one of the most dangerous consequences for the human body. This study aimed to investigate the protective effects of fucoxanthin supplementation on mice models subjected to cadmium-induced kidney damage. The mice treated with cadmium chloride (CdCl2) were observed to have significantly reduced the cross-section area of glomeruli. Cadmium exposure has also caused the damage of the structural integrity of mitochondria and increased blood urea nitrogen (BUN), kidney injury molecule 1 (KIM1), and neutrophil gelatinase associated lipocalin (NGAL) levels. Peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) levels in cadmium-exposed mice were markedly declined. Caspase3, caspase8, and caspase9 gene expressions in association with apoptosis were dramatically elevated in renal tissues. The CdCl2 treated mice were orally administered with 50 mg/kg Shenfukang, 10 mg/kg, 25 mg/kg, and 50 mg/kg fucoxanthin for 14 days. The results revealed that high doses of fucoxanthin administration significantly decreased BUN, KIM1, NGAL levels, increasing POD, SOD, CAT, and ascorbate APX levels. Fucoxanthin administration also promoted recovery of the renal functions, micro-structural organization, and ultra-structural organization in the renal cells. In summary, the ameliorative effects of fucoxanthin supplementation against cadmium-induced kidney damage were mediated via inhibiting oxidative stress and apoptosis, promoting the recovery of structural integrity of mitochondria.

Preparation of New Sargassum fusiforme Polysaccharide Long-Chain Alkyl Group Nanomicelles and Their Antiviral Properties against ALV-J.

Avian leukosis virus subgroup J (ALV-J) is an immunosuppressive virus which has caused heavy losses to the poultry breeding industry. Currently, there is no effective medicine to treat this virus. In our previous experiments, the low-molecular-weight Sargassum fusiforme polysaccharide (SFP) was proven to possess antiviral activity against ALV-J, but its function was limited to the virus adsorption stage. In order to improve the antiviral activity of the SFP, in this study, three new SFP long-chain alkyl group nanomicelles (SFP-C12M, SFP-C14M and SFP-C16M) were prepared. The nanomicelles were characterized according to their physical and chemical properties. The nanomicelles were characterized by particle size, zeta potential, polydispersity index, critical micelle concentration and morphology. The results showed the particle sizes of the three nanomicelles were all approximately 200 nm and SFP-C14M and SFP-C16M were more stable than SFP-C12M. The newly prepared nanomicelles exhibited a better anti-ALV-J activity than the SFP, with SFP-C16M exhibiting the best antiviral effects in both the virus adsorption stage and the replication stage. The results of the giant unilamellar vesicle exposure experiment demonstrated that the new virucidal effect of the nanomicelles might be caused by damage to the phospholipid membrane of ALV-J. This study provides a potential idea for ALV-J prevention and development of other antiviral drugs.

Characterization of Different Salt Forms of Chitooligosaccharides and Their Effects on Nitric Oxide Secretion by Macrophages.

In this paper, chitooligosaccharides in different salt forms, such as chitooligosaccharide lactate, citrate, adipate, etc., were prepared by the microwave method. They were characterized by SEM, FTIR, NMR, etc., and the nitric oxide (NO) expression was determined in RAW 264.7 cells. The results showed that pure chitooligosaccharide was an irregular spherical shape with rough surface, and its different salt type products are amorphous solid with different honeycomb sizes. In addition to the characteristic absorption peaks of chitooligosaccharides, in FTIR, the characteristic absorption of carboxyl group, methylene group, and aromatic group in corresponding acid appeared. The characteristic absorption peaks of carbon in carboxyl group, hydrogen and carbon in methyl, methylene group, and aromatic group in corresponding acid also appeared in NMR. Therefore, the sugar ring structure and linking mode of chitooligosaccharides did not change after salt formation of chitooligosaccharides. Different salt chitooligosaccharides are completely different in promoting NO secretion by macrophages, and pure chitooligosaccharides are the best.

The immunostimulatory effects of hydroxypropyltrimethyl ammonium chloride chitosan-carboxymethyl chitosan nanoparticles.

In this study, we generated chitosan nanoparticles by exploiting the electrostatic interactions between positively charged hydroxypropyltrimethyl ammonium chloride chitosan (HACC) and negatively charged carboxymethyl chitosan (CMC), and examined the effects of altering the molecular weight and carboxymethyl substitution sites of the chitosan molecules. Particle size, potential, and encapsulation efficiency of the various chitosan nanoparticles were examined; the particle size range was 162.40-332.80 nm, the charge range was 19.50-40.60 mV, and the encapsulation efficiency range was 48.4-70.7%. We then examined the immunostimulatory effects of the nanoparticle variants on dendritic cells (DCs); we found that the site of carboxymethyl substitution significantly affected the immunostimulatory effects of the nanoparticles. Two nanoparticle types, 200 kDa N,O-carboxymethyl chitosan-HACC (NO-CMC-HACC) and N-carboxymethyl chitosan-HACC (N-CMC-HACC), greatly promoted the expression of interleukin-6, tumor necrosis factor, and interleukin-1ß in DCs. Moreover, NO-CMC-HACC nanoparticles caused an increase in major histocompatibility complex-II (MHC-II), CD11c, CD80, and CD86 secretion in DCs, indicating that these nanoparticles promoted antigen presentation. We then examined chitosan nanoparticle uptake by DCs using laser confocal microscopy; we found that the NO-CMC-HACC nanoparticles were more readily absorbed by DCs compared to the N-CMC-HACC nanoparticles. Therefore, we concluded that 200 kDa NO-CMC-HACC nanoparticles exhibited strong potential as immunological adjuvants.

Immunostimulatory effect of N-2-hydroxypropyltrimethyl ammonium chloride chitosan-sulfate chitosan complex nanoparticles on dendritic cells.

In this study, we synthesized negatively charged chitosan sulfate and positively charged hydroxypropyltrimethyl ammonium chloride chitosan (HACC), and then prepared chitosan derivatives with positive and negative ions as nanoparticles (NPs) by ovalbumin encapsulation using the polyelectrolyte method. NPs with different substitution sites and molecular weights (MW) were prepared by varying conditions. We then determined the zeta potential average, diameter, encapsulation effect, and their immunostimulatory effects on dendritic cells (DCs). The results showed that chitosan-derivative NPs ranged in size from 153.33 to 320.90 nm; all NPs were positive, with charges ranging from 17.10 to 39.30 mV and the encapsulation rates of 65 %-75 %. Three NPs greatly promoted the expression and secretion of interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and interleukin-1ß (IL-1ß) in DC cells: C2,3,6 chitosan sulfate-HACC (C2,3,6-HACC; 200 kDa), C3,6 chitosan sulfate-HACC (C3,6-HACC; 200 kDa) and C6 chitosan sulfate-HACC (C6-HACC; 50 kDa). We also found that 200-kDa C2,3,6-HACC and 50-kDa C6-HACC NPs greatly increased secretion of the major histocompatibility complex-II (MHC-II), CD40, CD80, and CD86, indicating that these NPs promote effective antigen presentation, further increasing immunity effects. Finally, we applied laser confocal photography and determined that NPs entered the cell to promote the regulation of cellular immune activity; this discovery lays a foundation for further research on their mechanism of their action. Therefore, C2,3,6-HACC and C6-HACC NPs have the potential as immunological adjuvants.

Optimization of Oyster (Crassostrea talienwhanensis) Protein Hydrolysates Using Response Surface Methodology.

Oyster (Crassostrea talienwhanensis) protein was hydrolyzed by trypsin to produce peptides with different response values, and response surface methodology (RSM) was applied to optimize the hydrolysis conditions. The highest degree of hydrolysis (DH) of the oyster peptide (OP) was obtained at an enzyme concentration of 1593.2 U/g, a pH of 8.2, a hydrolysis temperature of 40.1 °C, a hydrolysis time of 6.0 h, and a water/material ratio of 8.2. The greatest hydroxyl-radical-scavenging activity of OP was obtained at an enzyme concentration of 1546.3 U/g, a pH of 9.0, a hydrolysis temperature of 50.2 °C, a hydrolysis time of 5.1 h, and a water/material ratio of 5.6. The largest branched-chain amino acid (BCAA) content of OP was obtained at an enzyme concentration of 1323.8 U/g, a pH of 8.3, a hydrolysis temperature of 41.7 °C, a hydrolysis time of 6.7 h, and a water/material ratio of 4.8. The three experimental values were significantly in agreement with the predicted values within the 95% confidence interval. Furthermore, ultrafiltration and chromatographic methods were used to purify the OP, and 13 peptides that were rich in Lys, Arg, His, and Thr were identified by LC-MS/MS. The results of this study offer different optimum hydrolysis conditions to produce target peptides from oyster protein by using RSM, and this study provide a theoretical basis for the high-value utilization of oyster protein.

Integrated proteomics and metabolomics analysis reveals the antifungal mechanism of the C-coordinated O-carboxymethyl chitosan Cu(II) complex.

With wide application in agriculture, copper fungicides have undergone three stages of development: inorganic copper, synthetic organic copper, and natural organic copper. Using chitin/chitosan (CS) as a substrate, the natural organic copper fungicide C-coordinated O-carboxymethyl chitosan Cu(II) complex (O-CSLn-Cu) was developed in the laboratory. Taking Phytophthora capsici Leonian as an example, we explored the antifungal mechanism of O-CSLn-Cu by combining tandem mass tag (TMT)-based proteomics with non-targeted liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. A total of 1172 differentially expressed proteins were identified by proteomics analysis. According to the metabolomics analysis, 93 differentially metabolites were identified. Acetyl-CoA-related and membrane localized proteins showed significant differences in the proteomics analysis. Most of the differential expressed metabolites were distributed in the cytoplasm, followed by mitochondria. The integrated analysis revealed that O-CSLn-Cu could induce the "Warburg effect", with increased glycolysis in the cytoplasm and decreased metabolism in the mitochondria. Therefore, P. capsici Leonian had to compensate for ATP loss in the TCA cycle by increasing the glycolysis rate. However, this metabolic shift could not prevent the death of P. capsici Leonian. To verify this hypothesis, a series of biological experiments, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), and enzyme activity measurements were carried out. The results suggest that O-CSLn-Cu causes mitochondrial injury, which consequently leads to excessive ROS levels and insufficient ATP levels, thereby killing P. capsici Leonian.

The bioactivity of new chitin oligosaccharide dithiocarbamate derivatives evaluated against nematode disease (Meloidogyne incognita).

Plant-parasitic nematodes cause substantial crop losses annually; however, current nematicides are environmentally unfriendly and highly toxic to nontarget organisms. The development of green efficient nematicides from multifunctional natural bioactive substances such as chitin oligosaccharide (COS) is promising. In this paper, COS dithiocarbamate derivatives (COSDTC, COSDTA, COSDTB) were synthesized to increase nematicidal activity (against Meloidogyne incognita), and their structures were characterized by FTIR, NMR, TGA/DTG and elemental analysis. Furthermore, the nematicidal activities, egg hatching inhibitory activities, plant growth adjustment abilities, cytotoxicity and phytotoxicity of the derivatives were evaluated. The primary mechanism was assessed by heavy metal ion absorption and GSH-binding assays. The results showed COS dithiocarbamate derivatives could possess multiple efficacies, including high nematicidal activities and egg hatching inhibitory activities, plant growth regulating effects, low cell toxicities and phytotoxicities. Additionally, it was inferred that nematicidal activity may be correlated with GSH-binding activity but not heavy metal ion complexation. COS modification has immense potential for controlling plant-parasitic nematodes.

The antiviral property of Sargassum fusiforme polysaccharide for avian leukosis virus subgroup J in vitro and in vivo.

Avian Leukosis Virus Subgroup J (ALV-J) is an oncogenic retrovirus, mainly spread by vertical and horizontal transmission, which have caused severe losses in world poultry industry. Sargassum fusiforme polysaccharide (SFP), a marine algae sulfated polysaccharide, has attracted more attention due to its variously biological activities. In this study, the anti-ALV-J property of SFP was assessed in vivo and in vitro. The results demonstrated that different Mw of SFPs showed virustatic activity to ALV-J in vitro by combining with the virus when ALV-J adsorbed onto the host cells. When treated with SFPs, the ALV-J gene and protein expression reduced clearly and SFP-3 (Molecular weight 9 kDa) had the best antiviral effect. Results in vivo showed that the immunosuppression of the ALV-J infected chickens were relieved by SFP-3. Moreover, SFP-3 obviously inhibit the viral shedding and alleviated the organs damage caused by ALV-J. This study offered a new method for ALV-J treatment and enriched the potential application of SFP.

Preparation and Identification of Antioxidative Peptides from Pacific Herring (Clupea pallasii) Protein.

The aim of this study was to isolate and purify antioxidative peptides from Pacific herring (Clupea pallasii) protein. Five enzymes (pepsin, trypsin, papain, flavourzyme, and neutrase) were used for protein hydrolysis, and Pacific herring protein hydrolysates (PHPH) were separated by ultrafiltration. The fraction with the molecular weight below 3500 Da exhibited the highest in vitro antioxidant activities and cellular antioxidant activity. The PHPH was isolated and purified by consecutive chromatographic methods including gel filtration chromatography and reverse high-performance liquid chromatography (RP-HPLC). The purified antioxidant peptides were identified as Leu-His-Asp-Glu-Leu-Thr (MW = 726.35 Da) and Lys-Glu-Glu-Lys-Phe-Glu (MW = 808.40 Da), and the IC50 values of cellular antioxidant activity were 1.19 ± 0.05 mg/mL and 1.04 ± 0.06 mg/mL. The results demonstrate that is possible to produce natural antioxidative peptides from Pacific herring protein via enzymatic hydrolysis and purification.

Partial Characterization, the Immune Modulation and Anticancer Activities of Sulfated Polysaccharides from Filamentous Microalgae Tribonema sp.

Recently, Tribonema sp., a kind of filamentous microalgae, has been studied for biofuel production due to its accumulation of triacylglycerols. However, the polysaccharides of Tribonema sp. and their biological activities have rarely been reported. In this paper, we extracted sulfated polysaccharides from Tribonema sp. (TSP), characterized their chemical composition and structure, and determined their immunostimulation and anticancer activities on RAW264.7 macrophage cells and HepG2 cells. The results showed that TSP is a sulfated polysaccharide with a Mw of 197 kDa. TSP is a heteropolysaccharide that is composed mainly of galactose. It showed significant immune-modulatory activity by stimulating macrophage cells, such as upregulating interleukin 6 (IL-6), interleukin 10 (IL-10), and tumor necrosis factor α (TNF-α). In addition, TSP also showed significant dose-dependent anticancer activity (with an inhibition rate of up to 66.8% at 250 µg/mL) on HepG2 cells as determined by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cycle analysis indicated that the anticancer activity of TSP is mainly the result of induced cell apoptosis rather than affecting the cell cycle and mitosis of HepG2 cells. These findings suggest that TSP might have potential as an anticancer resource, but further research is needed, especially in vivo experiments, to explore the anticancer mechanism of TSP.

Immunostimulatory Effects of Chitooligosaccharides on RAW 264.7 Mouse Macrophages via Regulation of the MAPK and PI3K/Akt Signaling Pathways.

Chitooligosaccharides (COS), the hydrolyzed products of chitin and chitosan, can be obtained by various methods. In this study, water-soluble COS were prepared from α- and ß-chitosan by microwave-assisted degradation and their immunostimulatory effects were investigated in RAW 264.7 macrophages. The results indicated that α-COS were more active than ß-COS in promoting the production of nitric oxide (NO) and cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6). Quantitative real-time reverse transcription polymerase chain reaction and Western blotting indicated that COS also enhanced the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-α. Further analyses demonstrated that COS induced the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38, p85 and Akt, and the nuclear translocation of p65, indicating that they are able to activate the mitogen-activated protein kinases (MAPKs) and phosphoinositide 3-kinases (PI3K)/Akt signaling pathways dependent on nuclear factor (NF)-κB activation. In conclusion, COS activate RAW 264.7 cells via the MAPK and PI3K/Akt signaling pathways and are potential novel immune potentiators.

Vascular targeted chitosan-derived nanoparticles as docetaxel carriers for gastric cancer therapy.

A gastric cancer angiogenesis marker peptide, GX1, is promising to be a desirable ligand for anti-angiogenesis targeted drug of gastric cancer treatment. In this study, GX1 was utilized to fabricate a multifunctional vascular targeting docetaxel (DCT)-loaded nanoparticle with N-deoxycholic acid glycol chitosan (DGC) as the carrier and GX1-PEG-deoxycholic acid (GPD) conjugate as the targeting ligand. The mean size of obtained GX1-DGC-DCT was 150.9 nm with a narrow size distribution and their shape was spherical with smooth surface texture. The in vitro drug release test revealed a sustained release manner and an acid pH could accelerate the release compared with the neutral pH. Furthermore, GX1-DGC-DCT showed stronger cytotoxicity against co-cultured gastric cancer cells and human umbilical vein endothelial cells (co-HUVEC) than DCT within 100 µM. In addition, GX1 efficiently enhanced the cellular uptake of nanoparticles in co-HUVEC cells as confirmed by confocal fluorescence scanning microscopy. Moreover, in vivo delivery of GX1-DGC-DCT was demonstrated to inhibit tumor growth in SGC791 tumor-bearing mice with tumor inhibition rate (TIR) of 67.05% and no weight loss of mice was observed. The anti-tumor effects were further confirmed by H&E and TUNEL analysis. Therefore, this new drug delivery system represents a potential strategy for gastric cancer therapy.

Hydroxypropyltrimethyl ammonium chloride chitosan activates RAW 264.7 macrophages through the MAPK and JAK-STAT signaling pathways.

Hydroxypropyltrimethyl ammonium chloride chitosan (HACC) is a water-soluble derivative of chitosan. To investigate the immunostimulatory effects of HACC, quaternized chitosans with different molecular weights were prepared and their effects on RAW 264.7 macrophages were compared. The results showed that HACC promoted nitric oxide (NO) production in a molecular weight- and dose-dependent manner. Lower molecular weight HACC was more active in promoting NO production. Furthermore, flow cytometry analysis showed that HACC significantly promoted the production of interleukin-6 and tumor necrosis factor-α. These results were further demonstrated by quantitive real-time reverse transcription polymerase chain reaction and western blot analysis. Moreover, western blotting revealed that HACC induced the phosphorylation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38, and signal transducer and activator of transcription (STAT) proteins. In conclusion, HACC activated RAW 264.7 cells through the mitogen-activated protein kinases and Janus kinase/STAT pathways.

Antiviral Activity against Avian Leucosis Virus Subgroup J of Degraded Polysaccharides from Ulva pertusa.

Avian Leukosis Virus Subgroup J (ALV-J), a retrovirus of avian, has caused enormous economics losses to poultry industry around the world. Polysaccharides from marine algae are featured diversity bioactivities. To find the potential effect to prevent ALV-J spread, in this study, polysaccharides from Ulva pertusa (UPPs) and four low molecular weight (Mw) U. pertusa polysaccharides (LUPPs) were prepared and their functions on ALV-J were investigated. Firstly, LUPPs were obtained by hydrogen peroxide (H2O2) oxidative degradation. The effects of degradation conditions on Mw of the UPP were also investigated. Results showed that the H2O2 oxidative degradation method could degrade UPP effectively, and the degradation was positively related to H2O2 concentration and temperature and negatively to pH. The chemical characteristics of UPP and LUPPs were also determined. Afterwards, the anti-ALV-J activity of the polysaccharides were carried out in vitro. Results showed that UPP and LUPPs could inhibit ALV-J and LUPP-3 and Mw of 4.3 kDa exerted the strongest suppression. The action phase assay showed that LUPP-3 could bind with the viral particles and prevented ALV-J adsorption onto the host cells. And the ALV-J relative gene and gp85 protein expression were significantly suppressed after being administration with LUPP-3. Therefore, the low Mw polysaccharides from U. pertusa have great potential as an anti-ALV-J drug alternative.

Synthesis, characterization, and antifungal evaluation of diethoxyphosphoryl polyaminoethyl chitosan derivatives.

Botrytis cinerea, Phytophthora capsici Leonian, and Fusarium solani are important plant pathogenic fungi which can cause great crop losses worldwide, but their control methods are limited. It is necessary to develop efficient and green fungicides from abundant marine resources. Chitosan is a non-toxic, biodegradable, biocompatible marine polysaccharide which has prospective applications in agriculture. In this paper, to increase the antifungal activity of chitosan for application, novel water-soluble functional chitosan derivatives were synthesized by grafting polyaminoethyl and diethoxyphosphoryl groups in accordance with a strategy of improving protonation potential. The derivatives were characterized by FTIR, NMR, XRD, SEM, Gaussian 09 and elemental analysis. The antifungal activities against the three fungi and the cytotoxicity were estimated in vitro. The results showed that the derivatives had better antifungal activities and water solubility than chitosan, and had good biocompatibility. They confirmed that these chitosan derivatives can be developed as antifungal agents for plant protection purposes.