Effects of Low Molecular Weight Yeast ß-Glucan on Antioxidant and Immunological Activities in Mice.

To evaluate the antioxidant and immune effects of low molecular yeast ß-glucan on mice, three sulfated glucans from Saccharomyces cerevisiae (sGSCs) with different molecular weight (MW) and degrees of sulfation (DS) were prepared. The structures of the sGSCs were analyzed through high performance liquid chromatography-gel permeation chromatography (HPLC-GPC) and Fourier transform infrared spectroscopy (FTIR). sGSC1, sGSC2, and sGSC3 had MW of 12.9, 16.5 and 19.2 kDa, respectively, and DS of 0.16, 0.24 and 0.27, respectively. In vitro and in vivo experiments were conducted to evaluate the antioxidant and immunological activities of the sGSCs. In vitro experiment, the reactive oxygen species (ROS) scavenging activities were determined. In vivo experiment, 50 male BALB/c mice were divided into five groups. The sGSC1, sGSC2 and sGSC3 treatment groups received the corresponding sGSCs at 50 mg/kg/day each. The GSC (glucans from Saccharomyces cerevisiae) treatment group received 50 mg/kg/day GSC. The normal control group received equal volume of physiological saline solution. All treatments were administered intragastrically for 14 day. Results showed that sGSC1, sGSC2 and sGSC3 can scavenge 1,1-diphenyl-2-picryl-hydrazyl (DPPH), superoxide, and hydroxyl radicals in vitro. The strength of the radical scavenging effects of the sGSCs was in the order of sGSC1 > sGSC2 > sGSC3. Oral administration of sGSC1 significantly improved serum catalase (CAT) and glutathione peroxidase (GSH-Px) activities and decreased malondialdehyde (MDA) level in mice. sGSC1 significantly improved the spleen and thymus indexes and the lymphocyte proliferation, effectively enhanced the percentage of CD4⁺ T cells, decreased the percentage of CD8⁺ T cells, and elevated the CD4⁺/CD8⁺ ratio. sGSC1 significantly promoted the secretion of IL-2 and IFN-γ. These results indicate that sGSC1 with low MW and DS has better antioxidant and immunological activities than the other sGSCs, and sGSC1 could be used as a new antioxidant and immune-enhancing agent.

Template-directed synthesis of pomegranate-shaped zinc oxide@zeolitic imidazolate framework for visible light photocatalytic degradation of tetracycline.

The development of photocatalysts for efficient tetracycline (TC) degradation under visible light is urgently needed yet remains a great challenge. Most semiconductor photocatalysts with low specific surface area are easy to agglomerate in solution and unfavorable for enriching pollutants. Herein, we present the preparation of pomegranate-shaped zinc oxide@zeolitic imidazolate framework (ZnO@ZIF-8) by in situ growth of ZIF-8 on a petal-shaped ZnO template that enhances the adsorption and photocatalytic degradation of TC. ZnO@ZIF-8 exhibits an excellent photostability and a TC photodegradation efficiency of 91% under visible light (λ > 420 nm) in 50 min at room temperature, which can be recycled over five times without any loss of activity. Moreover, the plausible photocatalysis reaction mechanism and the degradation intermediates are elucidated with the aid of three-dimensional excitation-emission matrix spectra and liquid chromatography-mass spectrometry system. This study offers new insights into the design of antibiotic degradation photocatalysts and the development of photocatalysts with broad-spectrum responses for efficient TC elimination.

Effect of sulfated yeast beta-glucan on cyclophosphamide-induced immunosuppression in chickens.

Immunosuppression is a condition that causes large economic losses in the poultry industry. To investigate the effect of sulfated yeast beta-glucan on immunosuppression, two hundred and fifty 11-day-old chickens were randomly assigned to five groups, and except for the normal control group, injected with cyclophosphamide once a day for 3 successive days. At 14 days of age, sulfated yeast beta-glucan from Saccharomyces cerevisiae(sGSC) was orally administered at three doses to the chickens in three experimental groups for 14 days. On days 7 and 14 after the first sGSC dose, serum cytokine concentrations and peripheral lymphocyte proliferation were measured. Gut microbiota, organ index, and histopathological changes in the bursa were investigated on day 14. The results demonstrated that at 4 mg/kg, sGSC could significantly enhance the bursa index and IFN-γ and IL-6 concentrations, decrease TGF-ß1 concentration, and promote lymphocyte proliferation; it could effectively decrease histopathological changes in the bursa and improve gut Bifidobacterium and Lactobacillus populations in cecal digesta of chickens compared with the model control group. This indicated that sGSC could effectively alleviate immunosuppression and regulate the beneficial microbiota in the gut.

Improvement of immune responses to influenza vaccine (H5N1) by sulfated yeast beta-glucan.

In this study, the adjuvant activity of sulfated glucan from saccharomyces cerevisiae (SGSC) was investigated. sGSC had molecular weight of 12.9kDa and degrees of sulfation of 0.16. The effects of SGSC on the splenic lymphocyte cells of mice were measured in vitro. The results showed that SGSC could significantly promote lymphocyte proliferation singly or synergistically with Con A and LPS, and stimulate the cells to secrete IL-2 and INF-γ. The adjuvant activity of SGSC was researched in BALB/c mice inoculated with inactivated H5N1vaccine in vivo. The results showed that SGSC could significantly enhance lymphocyte proliferation, effectively increase the percentage of CD4+ T cells, decrease the percentage of CD8+ T cells, and elevate the CD4+/CD8+ ratio; enhance the HI antibody titre, and promote the production of IL-2, INF-γ, IL-4 and IL-6 at medium level. These results indicated that sulfated glucan showed an excellent adjuvant effect on H5N1vaccine in a mouse model. Therefore, SGSC could be used as an effective immune adjuvant for an inactivated H5N1vaccine.

Sulfated glucan can improve the immune efficacy of Newcastle disease vaccine in chicken.

To evaluate the immune effect of sulfated glucan from saccharomyces cerevisiae (SGSC) on chickens, two experiments were researched. In vitro experiment, the effects of SGSC on chicken splenic lymphocyte proliferation were determined. The results displayed that SGSC could significantly stimulate chicken splenic lymphocyte proliferation. In vivo experiment, 200 14-day-old chickens were averagely divided into 5 groups. The chickens, except blank control (BC) group, were vaccinated with Newcastle disease (ND) vaccine, repeated vaccination at 28 days old. At the same time of the first vaccination, the chickens in three SGSC groups were injected, respectively, with the SGSC at low, medium and high concentrations, in vaccination control (VC) and BC group, with equal volume of physiological saline, once a day for three successive days. On days 7, 14, 21, 28, 35 and 42 after the first vaccination, the lymphocyte proliferation, serum antibody titer and interleukin-2 (IL-2) and interferon-gamma (IFN-γ) were measured. The results showed that SGSC at suitable dose could significantly promote lymphocyte proliferation, enhance serum antibody titer, and improve serum IL-2 and IFN-γ concentrations. It indicated that SGSC could significantly improve the immune efficacy of Newcastle disease vaccine, and would be as the candidate of a new-type immune adjuvant.

Cordyceps militaris polysaccharides can improve the immune efficacy of Newcastle disease vaccine in chicken.

Cordyceps militaris polysaccharide (CMP) was prepared by water decoction and ethanol precipitation. The fractional CMP40 and CMP50 were extracted from the CMP solution by stepwise precipitation with ethanol at 40% and 50% of working concentration, respectively. The immune-enhancing activities of two polysaccharides were researched. In vitro experiment, the effects of two polysaccharides on chicken peripheral lymphocyte proliferation were determined by MTT assay. The result displayed that two polysaccharides could significantly stimulate lymphocyte proliferation, the action of CMP40 was significantly or numerically stronger than those of CMP50. In vivo experiment, 320 14-day-old chickens were averagely divided into eight groups. The chickens, except blank control (BC) group, were vaccinated with Newcastle disease vaccine, repeated vaccination at 28 days old. At the same time of the first vaccination, the chickens in three CMP40 fraction groups and three CMP50 fraction groups were injected respectively with the polysaccharide at low, medium and high concentrations, in vaccination control (VC) and BC group, with equal volume of physiological saline, once a day for three successive days. On days 7, 14, 21, 28, 35 and 42 after the first vaccination, the lymphocyte proliferation, serum antibody titre and interferon-gamma and interleukin-4 were measured. The results showed that CMP40 and CMP50 at suitable dose could significantly promote lymphocyte proliferation, enhance serum antibody titre, and improve serum interferon-gamma and interleukin-4 concentrations. It indicated that CMP40 fraction and CMP50 fraction could significantly improve the immune efficacy of Newcastle disease vaccine, and would be as the candidate of a new-type immune adjuvant.