Structural characterization and immunomodulatory activity of a mannan from Helvella leucopus

A new polysaccharide fraction HLP-1 (2.55 x 10(5) Da) was obtained from the fruiting bodies of Helvella leucopus. Structural characterization of HLP-1 was elucidated by infrared spectroscopy, monosaccharide composition analysis, methylation analysis, nuclear magnetic resonance spectroscopy, scanning electron microscopy and Congo red assay. HLP-1 was a mannan with a backbone of -> 6)-alpha-D-Manp(1 -> 4)- alpha-D-Manp(1 -> 6)-alpha-D-Manp(1 -> 3)-alpha-D-Manp(1 -> 4)-alpha-D-Manp(1 -> 3)-alpha-D-Manp(1 -> , which branched at the O-6 position and terminated with T-ss-D-Manp. Moreover, HLP-1 could significantly improve the proliferation and neutral red phagocytosis of RAW264.7. Besides, HLP-1 could stimulate the production of nitric oxide (NO), ROS, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 ss) and interleukin-6 (IL-6). HLP-1 induced macrophage activation via NF-kappa B signal pathway. These findings indicated that HLP-1 was a potential immune enhancement agent applied in functional foods.

Automated summary

In this study, a new polysaccharide fraction HLP-1 was extracted from the fruiting bodies of Helvella leucopus and its structure and functions were investigated. The results indicated that HLP-1 had the potential to enhance immunity and could be applied in functional foods.