Structural characterization and anti-melanoma activities of polysaccharides from the bamboo shoot shells of Pleioblastus amarus

Bamboo shoot shell biomass remains largely underexploited despite harboring valuable bioactive constituents. Herein, two homogeneous polysaccharides, purified Bamboo Shoot Shell Polysaccharide-1 (BSSP-1) and purified Bamboo Shoot Shell Polysaccharide-2 (BSSP-2), were purified from the bamboo shoot shells of Pleioblastus amarus Keng f. via sequential ion-exchange (DEAE cellulose-52) and gel filtration (Sephadex G-100) chromatographic fractionation. Their structural characteristics were analyzed using multiple complementary techniques: HPGPC for weight-average molecular weights at 16.6 kDa (BSSP-1) and 9.6 kDa (BSSP-2); HPLC-based sugar profiling identified constituent monosaccharides including mannose, ribose, rhamnose, glucose, galactose, xylose, arabinose, glucuronic acid, galacturonic acid, and fucose at varying molar proportions; FTIR spectroscopy confirmed pyranose ring configurations; Congo red complexation assays uniquely detected triple-helical architecture within BSSP-1. Antiproliferative screening against murine B16-F10 melanoma cells demonstrated dose-responsive growth suppression, achieving maximal inhibitory rates reaching 41.62 ± 2.92% (BSSP-1) and 48.78 ± 4.60% (BSSP-2). DNA content analysis via flow cytometry evidenced cellular accumulation within G1 phase boundaries. Global transcriptomic analysis identified 2033 differentially expressed genes following polysaccharide treatment. Bioinformatic pathway analysis using GO and KEGG databases identified significant enrichment in ribosomal assembly and TNF-mediated signaling pathways. Scratch wound closure experiments substantiated compromised migratory potential, while protein and transcript quantification linked these functional changes to attenuated MMP-2 and MMP-11 abundance. Collectively, these findings demonstrate that P. amarus shoot shell polysaccharides hold potential as natural anti-melanoma agents, supporting further development for pharmaceutical applications.