Compare activities on regulating lipid-metabolism and reducing oxidative stress of diabetic rats of Tremella aurantialba broth's extract (TBE) with its mycelia polysaccharides (TMP)

Abnormal lipid-metabolism and elevated oxidative stress are the familiar complications of diabetic mellitus. Regulated lipid-metabolism and decreased oxidative stress have become the key indices to cure diabetic complications. The activities of broth extract (TBE) and mycelia polysaccharides (TMP) of Tremella aurantialba, which is one of the best-known multipurpose medicinal fungi in China, were studied using alloxan-induced diabetic rats. TBE contains saponins, while TMP contains polysaccharides. Both TBE and TMP could reduce the blood glucose levels of diabetic rats; TBE had stronger abilities to reduce the levels of total cholesterol and total triglyceride in serum, those of malondialdehyde, and enhance the activities of superoxide dismutase and glutathione reductase in different tissues of diabetic rats (P < 0.01). TBE had slightly stronger abilities to enhance the total antioxidant capability, catalase, and glutathione peroxidase in different tissues of diabetic rats, but no significant difference was found between TBE and TMP groups. All these results indicated that TBE was more capable of regulating lipid-metabolism and decreasing oxidative stress.

Structural analysis of anti-tumor heteropolysaccharide GFPS1b from the cultured mycelia of Grifola frondosa GF9801

A 21-kDa heteropolysaccharide, coded as GFPS1b, was obtained from the cultured mycelia of Grifola frondosa GF9801 by hot-water extraction, ethanol precipitation, and fractioned by DEAE Sepharose Fast-flow, followed by the purification with Sephadex G-100 column chromatography using an AKTA purifier. It exhibited more potent anti-proliferative activity on MCF-7 cells than other polysaccharide fractions. GFPS1b was an acidic polysaccharide with approximately 16.60% protein and 4.3% uronic acid. Gas chromatography of absolute acid hydrolysate of GFPS1b suggested that it was composed of D-glucose, D-galactose, and L-arabinose with a molar ratio of 4:2:1. Periodate oxidation, Smith degradation, partial acid hydrolyzation, methylation analysis, FT-IR, and (1)H, (13)C NMR spectroscopy analysis revealed that GFPS1b had a backbone consisting of alpha-(1-->4)-linked D-galacopyranosyl and alpha-(1-->3)-linked D-glucopyranosyl residues substituted at O-6 with glycosyl residues composed of alpha-L-arabinose-(1-->4)-alpha-D-glucose (1--> linked residues.

Optimization of the medium composition for production of mycelial biomass and exo-polymer by Grifola frondosa GF9801 using response surface methodology

In this work, a three-level Box-Behnken factorial design was employed combining with response surface methodology (RSM) to optimize the medium composition for the production of the mycelial biomass and exo-polymer in submerged cultures by Grifola frondosa GF9801. A mathematical model was then developed to show the effect of each medium composition and their interactions on the production of mycelial biomass and exo-polymer. The model estimated that, a maximal yield of mycelial biomass (17.61 g/l) could be obtained when the concentrations of glucose, KH2PO4, peptone were set at 45.2 g/l, 2.97 g/l, 6.58 g/l, respectively; while a maximal exo-polymer yield (1.326 g/l) could be achieved when setting concentrations of glucose, KH2PO4, peptone at 58.6 g/l, 4.06 g/l and 3.79 g/l, respectively. These predicted values were also verified by validation experiments. Compared with the values obtained by other runs in the experimental design, the optimized medium resulted in a significant increase in the yields of mycelial biomass and exo-polymer. Maximum mycelial biomass yield of 22.50 g/l was achieved in a 15-l fermenter using the optimized medium.