Antioxidant Activity and Oxidative Injury Rehabilitation of Chemically Modified Polysaccharide (TAPA1) from Tremella aurantialba

In our previous work, an acidic homogenous polysaccharide TAPA1 purified from Tremella aurantialba and its acetylated derivative TAPA1-ac, deacetylated derivative TAPA1-deac and sulfated fractions TAPA1-s were obtained by chemical modification and their partially chemical characterization were investigated. In present work, the antioxidant activities of various polysaccharides, including TAPA1, and its three derivative fractions, were determined in terms of scavenging of superoxide anion radicals and hydrogen peroxide (H2O2) by using chemiluminescence measurements, and their activities of oxidative injury rehabilitation were assessed by using PC12 oxidative injury model induced with H2O2. In general, compared with TAPA1, TAPA1-ac showed significant antioxidant activities and higher oxidative injury protection effects, whereas TAPA1-deac and TAPA1-s showed lower effects. These findings seemed to suggest that antioxidant effects and rehabilitation effect of oxidative injury, relate to not only different substituted group, but also the content and the degree of substitution (DS) of acetyl group, indicating that acetylation of TAPA1 was an effective means of enhancing its antioxidant activity and rehabilitation effect.