Abstract: The present work was undertaken to investigate the in vitro antioxidant activity of crude polysaccharides extracted from Ganoderma lucidum spores with unbroken (UGS) cell wall, and those with cell wall broken mechanically (MGS) and biologically–mechanically (BGS) in terms of their scavenging activities against DPPH, hydroxyl and ABTS radicals and K3Fe(CN)6 reducing power and their ability to protect yeast cells from oxidative damage. The results showed that the three crude polysaccharides had different antioxidant activities in a dose-dependent manner. The scavenging capacities against DPPH, hydroxyl and ABTS radicals, and the reducing power of BGS polysaccharides were the highest among the three polysaccharides. At 5.0 mg/mL, the scavenging rates of DPPH, hydroxyl and ABTS radicals were 84.6%, 91.0%, and 99.9%, respectively, and the reducing power was 1.09. The protective effect of BGS polysaccharides on UV-induced oxidative damage was relatively strong. Therefore, the crude polysaccharide from Ganoderma lucidum spores with biologically and mechanically broken sporoderm has high antioxidant activity.

Key words: Ganoderma lucidum spore, biological sporoderm disruption, mechanical sporoderm disruption, crude polysaccharide, antioxidant activity