Polysaccharides isolated from Ganoderma bambusicola: Structural characterization and in vitro bioactivities

The potential role of Ganoderma polysaccharides in adjuvant cancer therapy have been extensively studied; however, many species remain insufficiently explored. In this study, three novel polysaccharides were isolated from Ganoderma bambusicola: GBP-1 (23.53 kDa), GBP-2 (14.63 kDa), and GBP-3 (11.36 kDa). Structural characterization using Fourier-transform infrared spectroscopy, methylation analysis, and nuclear magnetic resonance spectroscopy revealed that GBP-1 and GBP-2 are galactoglycans with α-(1,6)-Galp backbones, whereas GBP-3 is a glucan exhibiting a triple-helix conformation. Cytotoxicity in HepG2, A549, HT-29, and SGC-7901/DDP cell lines was assessed using the cell-counting kit-8 assay, revealing concentration-dependent cytotoxic effects were concentration-dependent. Among the three polysaccharides, GBP-3 exhibited the most potent antitumor activity, reducing cell viability by 75 % at 400 μg/mL, compared to 45 % for both GBP-1 and GBP-2. These findings highlight the potential of G. bambusicola polysaccharides in cancer therapy, possibly through modulation of the tumor micro-environment.