Molecular properties, structure, and antioxidant activities of the oligosaccharide Hep-2 isolated from cultured mycelium of Hericium erinaceus.

The oligosaccharide Hep-2 from cultured mycelium of Hericium erinaceus was obtained with a hollow-fiber ultrafiltration cartridge and purified with a DEAE Sephadex A-50 column followed by a Bio-Gel P-30 column. The properties, structure, and antioxidant activities of Hep-2 were studied. Hep-2 had the molecular weight of 1,080 Da and consists of Glc and Gal in a molar ratio of 1.0:0.4. Fragmentation analysis by GC-MS suggests that the structure of Hep-2 consists of three linear sugar residues. Furthermore, we used the LC-MSn combined methylation method to determine the types of bonds between sugar residues. We found that the structure of Hep-2 is based on 2-7 sugars. Among these, the trisaccharides and pentasaccharides consist of 1 â†’ 6-Gal, whereas the tetrasaccharides, hexasaccharides, and heptasaccharides consist of 1 â†’ 4-Glc and 1 â†’ 6-Gal. The activity tests indicated that Hep-2 significantly reduced the damage caused by H2 O2 in GES-1 cells, and could induce expression of T-SOD and GSH-px, scavengers of oxygen free radicals, in a concentration-response manner. Hep-2 also reduced cell apoptosis as assessed by changes in the ratio of Bcl-2/Bax proteins by western blot. Both sets of results suggest that Hep-2 might possess significant antioxidant activity. PRACTICAL APPLICATIONS: This paper reports the physical and the chemical parameters, structure and biological potential of oligosaccharides from Hericium erinaceus, a common edible fungus. Hericium erinaceus has been used as an anti-atrophic gastritis drug in China with good effect. Oligosaccharides are more easily digested and utilized by human body, and have strong antioxidant activity. These results can increase people's interest in the product, and thus have a positive impact on the oligosaccharides of Hericium erinaceus as health food.

A unique polysaccharide purified from Hericium erinaceus mycelium prevents oxidative stress induced by H2O2 in human gastric mucosa epithelium cell.

Hericium erinaceus (HE) has been used both as a traditional Chinese medicine and home remedy for treatment of gastric and duodenal ulcers and gastritis. EP-1, a purified polysaccharide isolated from HE mycelium, has recently been identified as the active component responsible for HE anti-gastritis activity. Because oxidative stress has been implicated as a pathogenic cause of gastritis and gastric ulcers, EP-1 antioxidant properties were systematically examined in vitro using the human gastric mucosal epithelial cell line, GES-1. Results showed that EP-1 possessed higher oxygen radical absorbance capacity (ORAC) and 2-3 times higher ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals than a hot water extract of commercially available HE fruiting body. A crude mycelial polysaccharide (CMPS) extract of HE, from which EP-1 was purified, showed slightly stronger radical scavenging activity and ORAC than EP-1, with the exception of DPPH-scavenging activity. Antioxidant activities of these extracts were further studied using hydrogen peroxide (H2O2)-abused GES-1 cells; EP-1 dose-dependently preserved cell viability of abused cells as assessed via MTT assay. Moreover, FACS analysis revealed that EP-1 prevented H2O2-induced apoptotic cell death by inhibiting activation of apoptotic cellular signals within mitochondria-dependent apoptotic pathways. CMPS also prevented H2O2-induced oxidative stress, but to a lesser degree than did EP-1, even though CMPS exhibited comparable or stronger in vitro antioxidant activity than did EP-1.

A Polysaccharide Isolated from Mycelia of the Lion's Mane Medicinal Mushroom Hericium erinaceus (Agaricomycetes) Induced Apoptosis in Precancerous Human Gastric Cells.

Hericium erinaceus is typically used in traditional Chinese medicine for mucosal protection, healing of gastric ulcers, and treatment of gastritis. We purified from the cultured mycelia of H. erinaceus a polysaccharide with anti-gastric ulcer and antigastritis activity, but its effects on gastric malignancy have not been elucidated. We examined the differential effects of this purified polysaccharide, named EP-1, on the human gastric (GES-1) cell line and a precancerous cell line (MC) that was transformed from GES-1 using N-methyl-N'-nitro-N-nitrosoguanidine. We observed that the polysaccharide potently induced cell apoptosis and cell cycle arrest at the G0/G1 phase in the MC cell line but did not have any effect on the GES-1 cell line at the same doses. Further mechanistic studies revealed that the polysaccharide exerted its activity through an apoptosis-associated pathway by modulating the expression of Bax, Bcl-2, and caspase-3. Differential effects of the polysaccharide on the GES-1 and MC cell lines indicate that the polysaccharide was effective in preventing gastric cancer progression.