To evaluate the antioxidant and immune effects of low molecular yeast β-glucan on mice, three sulfated glucans from Saccharomyces cerevisiae (sGSCs) with different molecular weight (M_W) 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 M_W 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 M_W 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.

A novel water-soluble acidic heteropolysaccharide, called PPL-1, was purified from Pueraria lobata. PPL-1 had an average molecular weight of 35 Kad, and it was composed of glucose, arabinose, galactose and galacturonic acid (6.3:0.8:0.8:2.1). In accordance with methylation and nuclear magnetic resonance analyses, PPL-1 primarily consisted of (1→2)-linked α-Araf, (1→4)-linked α-Glcp, (1→)-linked β-Glcp, (1→6)-linked α-Glcp, (1→3,6)-linked α-Galp, (1→)-linked β-GalpA and (1→4)-linked α-GalpA. In terms of bioactivities, PPL-1 exhibited remarkable scavenging ability towards DPPH (1,1-Diphenyl-2-picrylhydrazyl) radicals and moderate activity by enhancing the proliferation rate of RAW 264.7 cells by approximately 30% along with the secretion of NO. This work demonstrates that PPL-1 can be a potential source of immunoenhancers and antioxidants.