Characterization of a polysaccharide from Sanghuangporus vaninii and its antitumor regulation via activation of the p53 signaling pathway in breast cancer MCF-7 cells

Sanghuangporus is a traditional medicine that has been used for nearly 2000 years in Asia. It has been found to enhance immunity and have anticancer properties. Some studies determined that Sanghuangporus polysaccharide can inhibit tumors in vitro, although the underlying mechanisms remain unknown. Therefore, the present study investigated the antitumor effects of polysaccharides from the fruiting body of S. vaninii and their associated mechanisms. Water-soluble S. vaninii polysaccharide (SVP) with a molecular weight of 3.156 × 104 Da was isolated and found to be mainly composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucosamine, glucose, galactosamine, galactose, xylose, arabinose, and fucose in molar ratios of 1.63:0.04:0.36:0.03:0.13:8.39:0.08:1.08:0.25:1.07:0.40. SVP showed modest anti-proliferative activity against HeLa, SHG-44, SMMC-7721, and MCF-7 cells. Furthermore, it effectively regulated cell cycle, promoted apoptosis, and reduced the migratory and invasive capacities of MCF-7 cells. Mechanistically, SVP enhanced activation of p53-related genes and down-regulated MMP expression. These findings describe a potential natural polysaccharide for tumor therapy and a basis for the development of fungal polysaccharides as a type of health food.