Preparation of Lentinula edodes polysaccharide-calcium complex and its immunoactivity.

Polysaccharide is a major bioactive component of mushrooms. In this study, for the first time, starting from a new Lentinula edodes polysaccharide L2, we prepared a novel L2–calcium complex and the process was optimized. Scanning electron microscopy and Fourier Transform infrared spectrometry were used for characterization. The immunostimulating activities of L2 and L2–calcium complex were measured by enhancing the production of two cytokines TNF-α and IL-6 in RAW264.7 cells. While L2–calcium complex significantly stimulates the secretions of TNF-α and IL-6 compared with the control, complex with calcium ion decreased the secretion of them. These facts indicate that calcium ion can modulate immune stimulating activity of Lentinula edodes polysaccharide L2.