Culture conditions and medium components for the production of mycelial biomass and exo-polysaccharides with Paecilomyces japonica in liquid culture.

In this study, the liquid culture conditions were optimized for maximal production of mycelial biomass and exo-polysaccharide by Paecilomyces japonica. The effects of medium composition, C/N ratio and physical parameters were investigated. From these experiments, 30 g glucose, 20 g yeast extract, 0.5 g KH2PO4, and 0.1 g CuCl2 2H2O in 1-l distilled water were found to be the most suitable carbon, nitrogen, and mineral sources, respectively. The optimal temperature, initial pH, agitation, and aeration were determined to be 27°C, uncontrolled pH, 400 rpm, and 1.0 vvm, respectively. Under these optimal conditions, the maximum mycelial growth and polysaccharides production were 23.1 g/l and 2.5 g/l, respectively.

Hispidin isolated from Phellinus linteus protects against hydrogen peroxide-induced oxidative stress in pancreatic MIN6N ß-cells.

Reactive oxygen species (ROS) have been shown to cause DNA damage, protein denaturation, loss of antioxidative enzyme activity, and lipid peroxidation. Thus, ROS are associated with tissue damage and are considered to be prime contributing factors in inflammation, diabetes, aging, and cancer. In this study, we investigated whether or not hispidin protects pancreatic MIN6N ß-cells from oxidative stress caused by hydrogen peroxide. Treatment of MIN6N ß-cells with 0.5 mM hydrogen peroxide for 4 hours caused significant loss of cell viability and an increase in the number of apoptotic cells. However, pretreatment of MIN6N ß-cells with hispidin for 24 hours reduced loss of cell viability and decreased the number of apoptotic cells. In addition, 70 µM hispidin significantly scavenged intracellular ROS and inhibited apoptosis and caspase-3 induced by hydrogen peroxide. Furthermore, the generation of thiobarbituric acid-reactive substances was inhibited in the presence of hispidin in a dose-dependent manner. Also, 70 µM hispidin significantly increased insulin secretion in hydrogen peroxide-treated MIN6N ß-cells. These results suggest that hispidin may be effective for protecting MIN6N ß-cells from ROS toxicity in diabetes.

Immunostimulating activity by polysaccharides isolated from fruiting body of Inonotus obliquus.

In this study, we investigated the immunostimulating activity of polysaccharides isolated from fruiting body of Inonotus obliquus (PFIO). Additionally, the signaling pathway of PFIO-mediated macrophage activation was investigated in RAW264.7 macrophage cells. We found that PFIO was capable of promoting NO/ROS production, TNF-α secretion and phagocytic uptake in macrophages, as well as cell proliferation, comitogenic effect and IFN-γ/IL-4 secretion in mouse splenocytes. PFIO was able to induce the phosphorylation of three MAPKs as well as the nuclear translocation of NF-κB, resulting in activation of RAW264.7 macrophages. PFIO also induced the inhibition of TNF-α secretion by anti-TLR2 mAb, consequently, PFIO might be involved in TNF-α secretion via the TLR2 receptor. In addition, our results showed that oral administration of PFIO suppressed in vivo growth of melanoma tumor in tumorbearing mice. In conclusion, our experiments presented that PFIO effectively promotes macrophage activation through the MAPK and NF-κB signaling pathways, suggesting that PFIO may potentially regulate the immune response.

Study of macrophage activation and structural characteristics of purified polysaccharide from the fruiting body of Cordyceps militaris.

Cordyceps militaris, an entomophathogenic fungus belonging to the class Ascomycetes, has been reported to have beneficial biological activities such as hypoglycemic, anti-inflammatory, anti-tumor, anti-metastatic, hypolipidemic, immunomodulatory, and antioxidant effect. In this study, the crude water-soluble polysaccharides CMP, which was obtained from the fruiting body of C. militaris by hot water extraction and ethanol precipitation, was fractionated by DEAE cellulose and Sepharose CL-6B column chromatography. This process resulted in three polysaccharide fractions, termed CMP Fr I, CMP Fr II, and CMP Fr III. Of these fractions, CMP Fr II, with an average molecular weight of 127 kDa, was able to upregulate effectively the phenotypic functions of macrophages such as NO production and cytokine expression. The chemical property of the stimulatory polysaccharide, CMP Fr II, was determined based on monosaccharide composition, which consisted of glucose (56.4 %), galactose (26.4 %), and mannose (17.2%). Its structural characteristics were investigated by a combination of chemical and instrumental analyses, including methylation, reductive cleavage, acetylation, Fourier transform infrared spectroscopy (FT-IR), and gas chromatography-mass spectrometry (GC-MS). Results indicated that CMP Fr II consisted of the (1-->4) or (1-->2) linked glucopyranosyl or galactopyranosyl residue with a (1-->2) or (1-->6) linked mannopyranosyl, glucopyranosyl or galactopyranosyl residue as a side chain. The configuration of the beta-linkage and random coil conformation of CMP Fr II were confirmed using a Fungi Fluor kit and Congo Red reagent, respectively.

Hispidin produced from Phellinus linteus protects pancreatic beta-cells from damage by hydrogen peroxide.

Phellinus linteus, which is a traditional medicinal mushroom used in Asian countries for the treatment of various diseases, has attracted a lot of attention due to its antioxidant, anti-inflammatory, anti-mutagenicity, and cell-mediated immunity properties in addition to its ability to inhibit tumor growth and metastasis. However, the antidiabetic efficacy of P. linteus has not yet been examined. In this study, hispidin from P. linteus exhibited quenching effects against DPPH radicals, superoxide radicals, and hydrogen peroxide in a dose-dependent manner. Intracellular reactive oxygen species scavenging activity of hispidin was approximately 55% at a concentration of 30 microM. In addition, hispidin was shown to inhibit hydrogen peroxide-induced apoptosis and increased insulin secretion in hydrogen peroxide-treated cells. These combined results indicate that hispidin may act as an antidiabetic and that this property occurs through preventing beta-cells from the toxic action of reactive oxygen species in diabetes.