PLEUROTUS OSTREATUS POLYSACCHARIDE INDUCES GO/G1 CELL CYCLE ARREST AND APOPTOSIS IN EHRLICH ASCITES CARCINOMA CELL LINE

In this study, Pleurotus ostreatus polysaccharide (POP) is isolated, refined, structurally analysed, and its anticancer properties are investigated. Polysaccharide yield was 6.27%, purified via DEAE-52 and Sephadex S-300 chromatography, with a molecular weight of 154649.8 Da. Structural analysis through FT-IR, HPLC, GC-MS, and NMR revealed POP as a homopolysaccharide composed of D-glucose units, featuring (1→6)-α-D-Glcp backbone with O-6 branches and T-α-D-Glcp terminations. These findings contribute to understanding the biological potential of POP. POP’s antitumor activity study showed that, with an IC₅₀ of 121.801 µg/mL, it was highly cytotoxic to EAC cell types, supported by LDH release analysis. POP inhibited cell migration, invasion, and colony formation, indicating its potential as an anti-cancer agent. Analysis using flow cytometry showed that POP induced apoptosis, which raised the expression of Bax and Caspase-9 while decreasing the expression of Bcl-2. DNA fragmentation assay showed characteristic laddering pattern, confirming apoptosis-mediated DNA degradation. Furthermore, alterations in the expression of the proteins p53, Cyclin D, and Cdk4 were linked with POP-induced cell cycle arrest in the G0/G1 phase. In conclusion, this study highlights the potential of Pleurotus ostreatus polysaccharides (POP) as an anti-cancer agent, demonstrating significant cytotoxicity against Ehrlich Ascites Carcinoma cells and elucidating its structural and apoptotic mechanisms of action. This study marks a breakthrough, suggesting Pleurotus ostreatus polysaccharides (POP) as potential health-food or medicinal agents, offering notable defense against human cancer.