Chemical characterization of Pleurotus eryngii polysaccharide and its tumor-inhibitory effects against human hepatoblastoma HepG-2 cells

•PEP is the crude heteropolysaccharides isolated from Pleurotus eryngii.•PEP-1 and PEP-2 were purified from PEP by Cellulose DEAE-52 and Sephadex G-100.•High molecular mass PEP-2 exhibits more potent anticancer effect than PEP-1.•ROS was a critical mediator in PEP-2 induced HepG-2 cellular apoptosis.•PEP-2 is a good candidate for dietary supplement and therapeutic application in cancer.

This study was designed to investigate the chemical characterization and antitumor effects of Pleurotus eryngii polysaccharides (PEP). The crude PEP was fractionated into two fractions, namely PEP-1 and PEP-2. HPLC analysis showed that PEP-1 and PEP-2 were heteropolysaccharides mainly composed of glucose with the average molecular weights of 2.54 × 104 Da (PEP-1) and 4.63 × 105 Da (PEP-2), respectively. High molecular mass PEP-2 was shown to exhibit stronger growth inhibition against human hepatoblastoma HepG-2 cells in comparison with PEP-1. Flow cytometric analysis showed that PEP-2 exerted a stimulatory effect on apoptosis of HepG-2 cells, and induced the cell-cycle arrest at the S-phase, with the observation of intracellular ROS production. These findings suggest that the polysaccharides, especially PEP-2, are very important nutritional ingredients responsible for the anticancer health benefits of P. eryngii.

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