Isolation and characterization of exopolysaccharide with immunomodulatory activity from fermentation broth of Morchella conica

Background and the purpose of this study: Mushroom polysaccharides have traditionally been used for the prevention and treatment of a multitude of disorders like infectious illnesses, cancers and various autoimmune diseases. In vitro and in vivo studies suggest that certain polysaccharides affect immune system function. Morchella conica (M. conica) is a species of rare edible mushroom whose multiple medicinal functions have been proven. Thus, the objective of this study is to isolate and characterize of exopolysaccharide from submerged mycelial culture of M. conica, and to evaluate its immunomodulatory activity. Methods: A water-soluble Morchella conica Polysaccharides (MCP) were extracted and isolated from the fermentation broth of M. conica through a combination of DEAE-cellulose and Sephacryl S-300 HR chromatograph. NMR and IR spectroscopy has played a developing role in identification of polysaccharide with different structure and composition from fungal and plant sources, as well as complex glycosaminoglycans of animal origin. Thus, NMR and IR spectroscopy were used to analyze the chemical structure and composition of the isolated polysaccharide. Moreover, the polysaccharide was tested for its immunomodulatory activity at different concentrations using in vitro model. Results: The results showed that MCP may significantly modulate nitric oxide production in macrophages, and promote splenocytes proliferation. Analysis from HPLC, infrared spectra and nuclear magnetic resonance spectroscopy showed that MCP was a homogeneous mannan with an average molecular weight of approximately 81.2 kDa. The glycosidic bond links is →6)-α-D-Man p-(1→. Conclusion: The results suggested that the extracted MCP may modulate nitric oxide production in macrophages and promote splenocytes proliferation, and it may act as a potent immunomodulatory agent.