In vitro antioxidant activities of the polysaccharides from Pleurotus tuber-regium (Fr.) Sing.

The antioxidant activities of two homogeneous polysaccharides, water extraction of polysaccharide (W-PTR) and alkali extraction of polysaccharide (A-PTR) from Pleurotus tuber-regium (Fr.) Sing, were evaluated. Results showed that W-PTR was stronger than A-PTR in O-2(-center dot) scavenging activity, while A-PTR was stronger than W-PTR in the scavenging activities to (OH)-O-center dot, DPPH center dot, inhibition effects on liver lipid peroxidation, liver mitochondria swelling, and red blood cell (RBC) hemolysis. At concentration of 0.3 g/L, the O-2(-center dot) scavenging activity of W-PTR and A-PTR were 85.7% and 71.7%. At concentration of 0.25 g/L, the (OH)-O-center dot scavenging activity of W-PTR and A-PTR were 64.20% and 74.97%. At the concentration of 0.3 g/L, the lipid peroxidation inhibition effects of A-PTR were 79.37%. At concentration of 0.8 g/L, the hemolysis inhibition rate of A-PTR was 77.16%. The polysaccharides of P. tuber-regium had strong antioxidant potency and might be exploited as effective natural antioxidant to alleviate oxidative stress. (C) 2013 Elsevier Ltd. All rights reserved.