Assessment of Biological Activity of Water-Soluble Polysaccharides Isolated From Cultivated Pleurotus pulmonarius and Pleurotus citrinopileatus

Anti-proliferative and antioxidant activities of Pleurotus pulmonarius and P. citrinopileatus water-soluble polysaccharides were examined using human colon adenocarcinoma (HT29) and human normal colonic epithelial (CCD841 CoTr) cell lines in vitro. Polysaccharides were prepared by cold and hot water extraction methods and chemically characterized. The monosaccharide analysis showed that all the preparations contained hexoses—mannose, glucose, galactose, and 3-O-methyl-hexose (identified as 3-O-methyl-galactose)—as well as trace amounts of pentose identified as arabinose. Linkage analysis, on the other hand, revealed a wide variety of monosaccharide linking bonds in the studied polysaccharides, depending on the polymer source and the method of isolation. Both fungal polysaccharide preparations with increasing concentrations showed lower DPPH free radical reducing activity. The degree of reduction depended on the origin of the compounds and the method of their preparation. Stimulation of nitric oxide (NOx) production by the tested cells was observed after their incubation with the polysaccharides. The tested compounds at lower concentrations (up to 500 µg/mL) did not significantly influence the metabolic activity of the tumor and normal cells after 24 h of incubation. The viability of the tumor and normal cells was limited after the impact of the polysaccharides in the concentration range of 25-1000 µg/mL. The hot and cold water isolated polysaccharides did not induce changes in the normal and tumor cell cytoskeleton organization. The paper presents newly prepared and characterized hot and cold isolated water-soluble polysaccharides with promising pro-health potential against tumor and normal human colon epithelium cells.