Fungal polysaccharide boosts immune system
doi:10.1038/nindia.2013.64 Published online 16 May 2013
Researchers have isolated a glucan (a polysaccharide) from the fruit bodies of Ramaria botrytis, a fungus that grows in hilly forests. This polysaccharide is capable of activating various white blood cells that participate in the immune responses to various diseases.
The fungal fruit bodies are attractive as food. Recent studies have shown that they harbour polysaccharides with antitumour potential. However, no previous study had explored the therapeutic potential of the fruit bodies of R. botrytis.
To identify polysaccharides with therapeutic potential, the researchers boiled small pieces of R. botrytis fruit bodies and then cooled and filtered the extracts. They took the filtrate and processed it to yield water-soluble crude polysaccharide. Using chemical and spectroscopic analyses, they identified the polysaccharide as glucan.
The researchers then carried out experiments to probe glucan's potential to boost the immune system. For this, they used mouse macrophage, an immune cell that surrounds and destroys pathogens and cells in mouse spleen and thymus. The spleen is rich in splenocytes — cells that generate various white blood cells such as T and B cells, which stimulate immune responses; the thymus contains thymocytes that generate T cells.
At various concentrations, the glucan was found to enhance the production of splenocytes and thymocytes, suggesting that the glucan can boost the immune response. The study has shown that the glucan is nontoxic to healthy cells. Other studies have shown that glucans do not kill cancer cells; rather they exhibit antitumour activity by stimulating the host's immune system without injuring normal cells.
"Fungal glucan can be used as an immunostimulating agent for fighting different immunosuppressive diseases including cancers," says Syed S. Islam, a co-author of the study.
- Bhanja, S. K. et al. Structural studies of an immunoenhancing glucan of an ectomycorrhizal fungus Ramaria botrytis. Carbohydr. Res. 374, 59-66 (2013)