Search

In this study, we report the synthesis of platinum nanoparticles (Cs-PtNPs) using an aqueous extract of Caulerpa sertularioides as a reducing agent. Cs-PtNPs were characterized by UV-Vis spectroscopy, fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDAX), high-resolution transmission electron microscopy (HR-TEM) and dynamic light scattering (DLS) analysis. Cs-PtNPs are spherical with a particle size of 6-22 nm. Cs-PtNPs have been shown to have highly effective antioxidant activities with 74% for DPPH, 63% for reducing power, and 59% for total antioxidant at 1 mg/ml, and results were compared with standard L-ascorbic acid. Furthermore, the Cs-PtNPs demonstrated excellent antibacterial activity against the Gram-negative bacteria, Vibrio parahaemolyticus with the highest zone of inhibition (18 mm) at 50 µg/ml. Moreover, Artemia nauplii showed less toxicity when treated with Cs-PtNPs at 150 µg/ml, indicating that the Cs-PtNPs are less toxic and environment friendly.

Polysaccharides from Pimpinella anisum were isolated using water at elevated temperature and DEAE Sepharose FF chromatography to examine their chemical structure and activation capacity on immune cells. P. anisum fractions (PAF1, PAF2 and PAF3) were mainly composed of neutral sugars (84.0-98.2%) and uronic acids (2.1-11.8%) with weight average molecular weight (M

The electrospinning of nanofibers (NFs) from 2-hydroxypropyl β-cyclodextrin supramolecular inclusion complexes (150% HPβ-CD, w/v) with vitamin B5 (pantothenic acid [PA]) was achieved without using any carrier polymeric matrix. The presence of PA and the formation of the HPβ-CD/PA inclusion complex within the NFs structure were confirmed by SEM, FTIR, XRD, and TGA analysis. SEM images depicted the bead-free uniform NFs and confirmed the incorporation of HPβ-CD/PA NFs did not alter the fiber morphology having an average fiber diameter of 512 ± 24 nm, 328 ± 18 nm, and 150 ± 19 nm, respectively. Fourier transform infrared (FTIR) spectrum indicated inclusion complex from the shifting of the peaks of each component in HPβ-CD/PA NFs, whereas XRD pattern revealed that HPβ-CD/PA NFs was achieved due to the formation of a new amorphous structure. TGA studies showed that the stability of PA after HPβ-CD encapsulation was improved. Molecular docking was used to simulate the positions and interactions of the binding sites of the HPβ-CD/PA inclusion complex. The phase solubility test showed enhanced solubility of PA due to the inclusion complexation; in addition, the stoichiometry of HPβ-CD/PA was determined to be 1:1. The release of PA from HPβ-CD/PA NFs prevented the colonization of Escherichia coli (5.0 ± 0.3%) and Staphylococcus aureus (2.0 ± 0.5%) bacteria to a great extent, as observed in the antibacterial activity results. The cell viability of HCT-116 cells treated with 100 μg/mL of HPβ-CD/PA NFs was registered at 97.5 ± 2.1%. It was observed that HPβ-CD/PA NFs had higher anticancer activity compared to pure PA and HPβ-CD due to the solubility increase. In brief, our results suggested that polymer-free HPβ-CD/PA inclusion complex NFs could have potential applications in food, pharmaceuticals, and healthcare thanks to its efficient antibacterial and anticancer activities.

Preparation of multiple heteroatom-doped photoluminescent carbon dots and their applications in ratiometric detection of Hg2+, multicolor imaging and real samples are described.

In this study, we synthesized zinc oxide nanoparticles (ZnONPs) using aqueous leaf extract from Rivina humilis and its functions such as antioxidant, antibacterial and anticancer activities were investigated. ZnONPs were further characterized by UV–vis spectrophotometric analysis (UV–vis), Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Transmission electron microscope and Energy dispersive X-ray spectroscopy (EDX).The synthesized ZnONPs exhibited a strong SPR peak at 370 nm.The XRD results confirming that the ZnONPs were crystalline in nature. Electron microscopic data depicted that these nanoparticles were irregular and circular in appearance with a size of 14.4 nm. The ZnONPs exhibited remarkable antioxidant activities than the extract of R. humilis. The antibacterial effect of ZnONPs against bacterial species was determined by agar diffusion assay. Further, Neuro 2a neuroblastoma cells indicated a dose-dependent decrease of viable cells when exposed to ZnONPs (5–100 µg/ml). ZnONPs induces a huge amount of lipid peroxidation end product malondialdehyde thus driving the cancer cells to apoptosis. Moreover, treatment of Neuro 2a cells with ZnONPs brings about activation of apoptotic cell death through the intrinsic mitochondrial pathway by overexpressing caspases 3 and 9 while the reduction in Bcl-2and upregulation of Bax protein.

The structural elucidation and investigation of the immunostimulatory effects of crude polysaccharides (ECPs), non-starch polysaccharides (ECPs-I), and deproteinated non-starch polysaccharides (ECPs-II) derived from finger millet (Eleusine coracana) were performed. The extracted ECPs, ECPs-I, and ECPs-II primarily comprised different levels of carbohydrate (82.9, 41.9 and 62.0%), protein (5.3, 38.4 and 22.0%) and uronic acid (0.5, 2.4 and 0.7%). Monosaccharide composition analysis showed that glucose (88.2 and 40.6) was the main sugar unit present in ECPs and ECPs-I, followed by galactose, arabinose, xylose, rhamnose, and mannose; however, ECPs-II contained galactose (42.2%) as a major unit. The average molecular weights of ECPs, ECPs-I, and ECPs-II were found to be 120, 78 and 43 kDa, respectively. The polysaccharides as well as non-starch polysaccharides did not show any toxic effects on RAW 264.7 cells. ECPs-II treatment significantly enhanced the activation of RAW 264.7 cells by inducing nitric oxide (NO) production, upregulating inducible nitric oxide synthase (iNOS) and various pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor alpha (TNF-α). Furthermore, the RAW 264.7 cells were activated after ECPs-II treatment via the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and mitogen-activated protein kinase signaling (MAPK) pathways induced by a cluster of differentiation 40 (CD40) expression. The structure of ECPs-II mainly consists of (1→3,4)-linked galactopyranosyl and (1→3,5) arabinopyranosyl.

Recently, in India, the marine finfish culture is expanding rapidly without adequate knowledge and research information on the coastal and marine finfish disease epidemics. Therefore, for the benefit of farmers, this study was designed to find the prevalence of Vibriosis outbreaks in marine finfish farms. In this study, 167 moribund fishes that show outward symptoms of lethargy, popeye, pale gills, skin erosions, abdominal edema, and hemorrhagic spots on different parts of the body were collected from 26 marine finfish farms (Lates calcarifer, Rachycentron canadum, and Trachinotus blochii) located in the states of Tamil Nadu, Andhra Pradesh, and Kerala, India. A total of 173 bacterial isolates were retrieved from all the fish samples, of which 144 isolates demonstrated a Vibrio-like character during biochemical and Vibriostatic 0/129 examinations. The phenotypic, 16s RNA gene sequencing and histopathological analysis confirm that the isolated bacterial strains were Vibriospecies. In the collected fish samples, the total prevalence of Vibrio species was 83.2% and the remaining 16.8% were other bacterial species. Among these bacteria, V. harveyi was the most predominant bacterium (34.1%) that cause infection in all the three fish species whereas Photobacterium damselae was found to be the least (2.9%) one. In the pathogenicity study, the highest mortality of 83% was observed after 168 h, when the seabass fingerling exposure to V. harveyi at 106 CFU/ml, and established similar clinical signs to the disease specimens of farmed fish. The in vitro antibacterial study confirms that the tested probiotic effectively inhibits the V. harveyi at 125 µl (108 CFU/ml). The above results inspire further in-depth studies on the probiotic efficacy to control the V. harveyi in finfish farms.

Graphical Abstract Non-starch polysaccharides derived from natural resources play a significant role in the field of food science and human health due to their extensive distribution in nature and less toxicity. In this order, the immunostimulatory activity of a non-starch polysaccharide (CQNP) from Chenopodium quinoa was examined before and after deproteination in murine macrophage RAW 264.7 cells. The chemical composition of CQNP and deproteinated-CQNP (D-CQNP) were spectrometrically analysed that revealed the presence of carbohydrate (22.7 ± 0.8% and 39.5 ± 0.8%), protein (41.4 ± 0.5% and 20.8 ± 0.5%) and uronic acid (8.7 ± 0.3% and 6.7 ± 0.2%). The monosaccharide composition results exposed that CQNP possesses a high amount of arabinose (34.5 ± 0.3) followed by galactose (26.5 ± 0.2), glucose (21.9 ± 0.3), rhamnose (7.0 ± 0.1), mannose (6.0 ± 0.1) and xylose (4.2 ± 0.2). However, after deproteination, a difference was found in the order of the monosaccharide components, with galactose (41.1 ± 0.5) as a major unit followed by arabinose (34.7 ± 0.5), rhamnose (10.9 ± 0.2), glucose (6.6 ± 0.2), mannose (3.4 ± 0.2) and xylose (3.2 ± 0.2). Further, D-CQNP potentially stimulate the RAW 264.7 cells through the production of nitric oxide (NO), upregulating inducible nitric oxide synthase (iNOS) and various pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor-alpha (TNF-α). Moreover, stimulation of RAW 264.7 cells by D-CQNP takes place along the NF-κB and the MAPKs signaling pathways through the expression of cluster of differentiation 40 (CD40). This results demonstrate that RAW 264.7 cells are effectively stimulated after removal of the protein content in C. quinoa non-starch polysaccharides, which could be useful for develop a new immunostimulant agent.

Heteroatom-doped photoluminescent (PL) carbon dots (CDs) have recently gained attention as optical sensors due to their excellent tunable properties. In this work, we propose a one-pot hydrothermal synthesis of PL nitrogen (N), sulfur (S), and phosphorus (P) co-doped carbon dots (NSP-CDs) using glutathione and phosphoric acid (H

Heavy metal ion pollution harms human health and the environment and continues to worsen. Here, we report the synthesis of boron (B), phosphorous (P), nitrogen (N), and sulfur (S) co-doped carbon dots (BP/NS-CDs) by a one-step facile hydrothermal process. The optimum synthetic parameters are of 180 °C temperature, 12 h reaction time and 15% of PBA mass. The as-synthesized BP/NS-CDs exhibits excellent water solubility, strong green photoluminescence (PL) at 510 nm, and a high quantum yield of 22.4%. Moreover, BP/NS-CDs presented high monodispersity (7.2 ± 0.45 nm), excitation-dependent emission, PL stability over large pH, and high ionic strength. FTIR, XRD, and XPS are used to confirm the successful B and P doping of BP/NS-CDs. BP/NS-CD photoluminescent probes are selectively quenched by Cu

Astragalus membranaceus (A. membranaceus) is commonly used in various herbal formulations to treat several human and animal diseases. Polysaccharides, which are the major bioactive components in the A. membranaceus, exhibit various bioactive properties. However, the ability of A. membranaceus polysaccharides (APS) to activate the mucosal immune response has not been examined. We examined the effect of intranasal administration of APS on mucosal immune cell activation and the growth-inhibitory activity against pulmonary metastatic melanoma in mice by combination treatment with immune checkpoint blockade. The intranasal treatment of APS increased the number of lineage-CD11c+ dendritic cell (DCs) in the mesenteric lymph nodes (mLN) through the upregulation of CC-chemokine receptor 7 expression. Moreover, intranasal treatment of APS activated DCs, which further stimulated natural killer (NK) and T cells in the mLN. The APS/anti-PD-L1 antibody combination inhibited the pulmonary infiltration of B16 melanoma cells. The depletion of NK cells and CD8 T cells in mice mitigated the anti-cancer effect of this combination, thereby highlighting the critical role of NK cells and CD8 T cells in mediating anti-cancer immunity. These findings demonstrated that APS could be used as a topical mucosal adjuvant to enhance the immune check point inhibitor anti-cancer effect.

The crude polysaccharide was extracted from A. asphodeloides rhizomes and further purified to produce two fractions F1 (50.0%) and F2 (19.6%). The chemical constitutions of the polysaccharides were neutral sugars (51.4%–89.7%), uronic acids (1.0%–30.2%) and sulfate esters (3.4%–8.1%), with various ratios of monosaccharides including rhamnose (1.4%–6.1%), arabinose (7.1%–21.2%), xylose (0.2%–4.8%), mannose (39.9%–79.0%), glucose (6.0%–11.1%) and galactose (2.6%–22.0%). The molecular properties of the polysaccharides were investigated by the HPSEC-UV-MALLS-RI system, revealing the Mw 130.0 × 103–576.5 × 103 g/moL, Rg 87.6–382.6 nm and SVg 0.3–54.3 cm3/g. The polysaccharides stimulated RAW264.7 cells to produce considerable amounts of NO and up-regulate the expression of TNF-α, IL-1 and COX-2 genes. Polysaccharides exhibited the growth inhibitory effects on cancer cells lines of AGS, MKN-28 and MKN-45, in which F2 fraction exhibited prominent bioactivities. The AGS cells treated with F2 experienced condensed cytoplasm, shrinkage of nucleus and chromatin marginalization with the highest number of cells at early-stage apoptosis reaching 54.6%. The inhibitory effect of F2 polysaccharide on AGS cells was through MAPKs and STAT3 signaling pathways. The backbone of the F2 was mainly linked by (1 → 4)-linked mannopyranosyl and (1 → 3)-linked galactopyranosyl. Taken together, the polysaccharide from A. asphodeloides rhizomes could be utilized as medicinal, pharmacological and functional food ingredients.

A convenient and an efficient protocol for the assembly of diverse xanthenes bearing a biologically interesting oxindole nucleus is developed by utilizing the In(III)-catalyzed spiro coupling of 1,4-benzoquinones or 1,4-naphthoquinones with oxindoles. This novel protocol proceeds via a cascade of double Michael additions and intramolecular cyclization. The synthesized compounds have potential use as fluorophores for the selective imaging of heavy metals in living cells.

Photoluminescent nitrogen and sulfur co-doped carbon nanodots (N,S-CNDs) were prepared via single-step hydrothermal carbonization using 2,4-diaminobenzenesulfonic acid (2,4-DABSA) as the sole precursor. The synthesized N,S-CNDs are easily dispersed in aqueous solution and have an average particle size of 5.0 ± 0.2 nm, showing a high quantum yield of 23.1% with excellent stability. The surface states of the N,S-CNDs were confirmed by Fourier-transform infrared spectroscopy, powder X-ray diffractometry, Raman spectroscopy, and X-ray photoelectron spectroscopy techniques. These N,S-CNDs were applied for the rapid visual sensing detection of Ag+ ions, which can be identified by their photoluminescent color change under ultraviolet (UV) light illumination at 365 nm within 5 s. Furthermore, a linear correlation coefficient between P0/P and Ag+ ions was observed in the linear range of 0-1.2 μM with a detection limit of 7.88 nM. The proposed method was successfully used for the sensitive detection of Ag+ ions in real samples with satisfactory recoveries and relative standard deviation. The photoluminescence properties of N,S-CND and N,S-CNDs/Ag+ aqueous solutions were demonstrated by their invisible inks that can only be seen when irradiated with UV light. The RGB values of N,S-CND and N,S-CNDs/Ag+ aqueous solutions were measured using a color selector smartphone application. In addition, N,S-CND and N,S-CNDs/Ag+ aqueous solutions were further used for the multicolor imaging of HCT-116 cancer cells due to the low toxicity of N,S-CNDs.

Tunicates are known to contain biologically active materials and one species in particular, the sea peach (Halocynthia aurantium), has not been thoroughly studied. In this study we aimed to analyze the fatty acids profile of the H. aurantium body wall and its immunomodulatory effects on RAW264.7 macrophage-like cells. The fatty acids were classified into three categories: saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs). Omega-3 fatty acid content, including EPA and DHA, was higher than omega-6 fatty acids. H. aurantium body wall fatty acids exhibited enhanced immune response and anti-inflammatory effects on RAW264.7 macrophage-like cells. Under normal conditions, fatty acids significantly increase nitric oxide (NO) and PGE2 production in a dose-dependent manner, thereby improving the immune response. On the other hand, in LPS-treated RAW264.7 cells, fatty acids significantly decreased nitric oxide (NO) and PGE2 production in a dose-dependent manner, thereby enhancing anti-inflammatory effects. Fatty acids transcriptionally control the expression of the immune-associated genes, iNOS, IL-1β, IL-6, COX-2, and TNF-α, via the MAPK and NF-κB signaling cascades in RAW264.7 cells. However, in LPSstimulated RAW264.7 cells, H. aurantium body wall fatty acids significantly inhibited expression of inflammatory cytokine; similarly, production of COX-2 and PGE2 was inhibited. The results of our present study provide insight into the immune-improving and anti-inflammatory effects of H. aurantium body wall fatty acids on macrophages. In addition, our study demonstrates that H. aurantium body wall is a potential source of immune regulatory components.

This study aims to synthesis pharmaceutical potential platinum nanoparticles from Tragia involucrata leaf extract (Ti-PtNPs) for biomedical applications. The colour development in the reaction mixture confirms the integration of Ti-PtNPs and its surface plasmon resonance (SPR) peak observed at 252 nm. The crystalline nature of Ti-PtNPs was authenticated by X-ray diffraction (XRD) analysis. The functional groups present in the T. involucrata (AE-Ti) aqueous extract, notably polyphenols, alkaloids, flavonoids, and proteins, participated in the synthesis of Ti-PtNPs, established in the Fourier-transform infrared spectroscopy (FT-IR) analysis. The synthesized Ti-PtNPs demonstrate spherical like particles with an average size of 10 nm. Ti-PtNPs exhibited dose depended on antioxidant activities and the activities were higher than the AE-Ti. The antibacterial activity of Ti-PtNPs was tested against Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) and displays admirable inhibitory activity in agar bioassay, disc diffusion, killing kinetics. Also, the synthesized Ti-PtNPs have attached the outer cell wall of bacteria and increased the protein leakage activity. The Ti-PtNPs exhibited potent cytotoxicity against HeLa cells with an IC50 value of 27.72 μg/ml. Moreover, the Ti-PtNPs enhance the intracellular ROS production, which induces the mitochondria-mediated apoptosis. Thus, the synthesis Ti-PtNPs can be used as a broad spectrum of pharmaceutical applications.

The aim of the present study to isolate the water-soluble polysaccharide from Astragalus membranaceus roots (AMP) and investigate the structural effects on RAW 264.7 murine macrophage and natural killer (NK) cells. AMP mainly consists of carbohydrates (66.2%), proteins (11.8%), and sulfates (18.0%) with minor level of uronic acid (2.0%). The structural modification was carried out by removal of protein and sulfate from AMP through deproteination and desulfation. After deproteination (DP), the protein content was decreased from 11.8% to 5.4%. Similarly, the sulfate content was decreased from 18.0% to 8.1% in desulfated AMP (DS). AMP and DP could stimulate RAW264.7 cells to produce nitric oxide (NO) and up-regulate mRNA expression through NF-κB and MAPKs pathways. However, DS showed a considerably lower level of NO production than AMP and DP, suggesting that DS could not stimulate RAW264.7 cells. AMP and its derivatives significantly increased the natural killer cells (NK cell) proliferation (113.1% to 128.7%) and cytotoxicity against HeLa cells (37.4% to 55.5%). However, DS exhibited the lowest level of NK cells activation through the expression of IFN-γ, TNF-α, Granzyme-B, and NKp44. These results suggest that sulfate groups of AMP might play a crucial role in the RAW264.7 cells and NK cells activation.

In this study, the potential of infrared assisted freeze-drying (IRAFD) was tested for the production of shelf-stable edible insects: Protaetia brevitarsis larva (larva of white-spotted flower chafer). The IRAFD system was customized using an infrared lamp, K-type thermocouple, controller, and data acquisition system. The infrared lamp provided the sublimation energy for rapid freeze-drying (FD). The IRAFD conditions were continuous IRAFD-5.0 kW/m2 and IRAFD-5.0 kW/m2 at different weight reduction (WR) (10%, 20%, and 30%). The continuous IRAFD reduced the drying time to 247 min compared to the 2,833 min duration of FD (p

In this study, we report a green synthesis of pharmaceutically active gold nanoparticles from marine red alga Acanthophora spicifera by the reduction of chloroauric acid. The formation of A. spicifera-mediated gold nanoparticles (As-AuNPs) was characterized by several analytical techniques. The crystalline and face-centered cubic (fcc) structure were confirmed by X-ray diffraction (XRD) analysis. Electron microscopy results confirmed that As-AuNPs were spherical and the average size of particles was

When Bacillus subtilis NB-NUC1 associated with Cheonggukjang fermentation was aerobically grown in a synthetic medium containing 1 to 2% glycine (w/v), cell growth was inhibited in a dose-dependent manner. Subsequently, different concentrations of glycine (0, 1, and 2%) were used in Cheonggukjang fermentation for 96 h at 40 °C. Supplementation of 1% glycine increased extracellular γ-glutamyl transpeptidase (γ-GTPase), responsible for the production of viscous substance. Based on correlation studies, we conclude that the production of viscous substance is correlated with viscous extension (r = 0.867), extracellular proteins contents (r = 0.821), and γ-GTPase activity (r = 0.807). The molecular weight of the viscous substance obtained during Cheonggukjang fermentation by B. subtilis NB-NUC1 was also affected by glycine supplementation. Our results demonstrate that glycine supplementation before solid-state fermentation may increase the mass production of mucilage in food industry.

In this study we investigated the immune effects of oral administration of anionic macromolecules extracted from Codium fragile (CFAM) and red ginseng extract mixture on the peritoneal macrophage cells in immune-suppressed mice. Cyclophosphamide (CY) induces the immune-suppressed condition. CY-treated mice were orally fed with different concentrations of CFAM supplemented with red ginseng extract and the peritoneal macrophages collected. CY treatment significantly decreased the immune activities of peritoneal macrophages, compared to the normal mice. The administration of CFAM mixed with red ginseng extract significantly boosted the viability of macrophage cells and nitric oxide production of peritoneal macrophages. Further, the oral administration of CFAM mixed with red ginseng extract up-regulated the expression of iNOS, COX-2, and TLR-4 as well as cytokines such as IL-1β, IL-6, TNF-α, and IFN-γ more than the red ginseng-treated group. This study showed that CFAM enhanced the immune activity of red ginseng extract in the peritoneal macrophage cells of immune-suppressed mice. Furthermore, CFAM might be used as a co-stimulant of red ginseng extract through the regulation of macrophage cells for the enhancement of human health and immunity.

An effective method for reducing silver ions using gelatin (Gel) and 2-hydroxypropyl-β-cyclodextrin (HPCD) hydrogels, which stabilize silver at various concentrations is described. The formation of AgNPs in solution, as well as Gel-HPCD nanogels, is confirmed by the surface plasmon resonance (SPR) band at 420-440 nm in the UV-Vis spectrum. The resulting Gel-HPCD and Gel-HPCD/AgNPs composites are characterized using various techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). SEM images showed that the porous structure and the AgNPs are homogeneously dispersed throughout the Gel-HPCD/AgNP composites network. The AgNPs in the Gel-HPCD/AgNPs composite is crystalline, with spherical particles having an average size of 7.0 ± 2.5 nm, as determined by TEM. The Gel-HPCD/AgNPs composites are strongly effective against both gram-positive (

Laminaria japonica is a brown alga and is composed primarily of polysaccharides. Fucoidan and laminarin are the major polysaccharides of L. japonica and exhibit biological activities, including immune modulation and anti-coagulant and antioxidant effects in animals and humans. In this study, we evaluated the ability of fucoidan and laminarin from L. japonica to induce immune cell activation and anti-cancer immunity, which has not yet been studied. The injection of fucoidan to mice promoted the upregulation of major histocompatibility complex and surface activation molecules in splenic dendritic cell subsets, whereas laminarin showed a weaker immune activation ability. In addition, fucoidan treatment elicited inflammatory cytokine production; however, laminarin did not induce the production of these cytokines. Regarding cytotoxic cell activities, fucoidan induced the activation of lymphocytes, including natural killer and T cells, whereas laminarin did not induce cell activation. Finally, fucoidan enhanced the anticancer efficacy of anti-programmed Death-Ligand 1 (PD-L1) antibody against Lewis lung carcinoma, whereas laminarin did not promote the cancer inhibition effect of anti-PD-L1 antibody. Thus, these data suggest that fucoidan from L. japonica can be used as an immune stimulatory molecule to enhance the anticancer activities of immune checkpoint inhibitors.

In this study, the mucilage polysaccharide (MP) from Amanita hemibapha subspecies javanica was prepared by hot water extraction and ethanol precipitation and then fractionated using anion-exchange chromatography equipped with a DEAE Sepharose fast flow column. The most immune-enhancing polysaccharide fraction 2 (MPF2) was subjected to a structural modification such as hydrolysis or over-sulphation. The sulphate and molecular weight (Mw) of over-sulphated (OS1-3) and hydrolysed (HS1-3) derivatives of MPF2 differed between 9.85% and 14.2% and 32.8 and 88.1 × 103 g/mol, respectively. Further, the immune-enhancing properties of MPF2 and its derivatives were tested on RAW264.7 and NK cells through various in vitro assays. Interestingly, a low molecular weight of HS1-3 significantly increased the nitric oxide (NO) production (p &lt, 0.05) more than MPF2, indicating that Mw is a major factor in RAW264.7 cell stimulation. In addition, RAW264.7 cells produced various cytokines by up-regulating mRNA expression levels and the activation of nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. On the other hand, OS1-3-treated natural killer (NK) cells induced cytotoxicity in HepG2 cells through the expression of IFN-γ, Grandzyme-B, perforin, NKp30, and FasL. These results demonstrated that sulphate derivatives play an important role in NK cell activation. Further, this study also explores how polysaccharide binds to RAW264.7 and NK cells. MPF2 and HS3 may activate RAW264.7 cells via binding to TLR4 receptors, and OS2 could be activated through the CR3 signalling pathways.

Natural polysaccharides have shown promising effects on the regulation of immunity in animals. In this study, we examined the immune stimulatory effect of intranasally administered Codium fragile polysaccharides (CFPs) in mice. Intranasal administration of CFPs in C57BL/6 mice induced the upregulation of surface activation marker expression in macrophages and dendritic cells (DCs) in the mediastinal lymph node (mLN) and the production of interleukin-6 (IL-6), IL-12p70, and tumor necrosis factor-α in bronchoalveolar lavage fluid. Moreover, the number of conventional DCs (cDCs) was increased in the mLNs by the upregulation of C-C motif chemokine receptor 7 expression, and subsets of cDCs were also activated following the intranasal administration of CFP. In addition, the intranasal administration of CFPs promoted the activation of natural killer (NK) and T cells in the mLNs, which produce pro-inflammatory cytokines and cytotoxic mediators. Finally, daily administration of CFPs inhibited the infiltration of Lewis lung carcinoma cells into the lungs, and the preventive effect of CFPs on tumor growth required NK and CD8 T cells. Furthermore, CFPs combined with anti-programmed cell death-ligand 1 (PD-L1) antibody (Ab) improved the therapeutic effect of anti-PD-L1 Ab against lung cancer. Therefore, these data demonstrated that the intranasal administration of CFP induced mucosal immunity against lung cancer.