Antioxidative Properties of Crude Polysaccharides from <em>Inonotus obliquus</em>

Abstract

The mushroom <em>Inonotus obliquus</em><em> </em>has been widely used as a folk medicine in Russia, Poland and most of the Baltic countries. In this study, water-soluble and alkali-soluble crude polysaccharides (IOW and IOA) were isolated from <em>I. obliquus</em>, and the carbohydrate-rich fractions IOW-1 and IOA-1 were obtained respectively after deproteination and depigmentation. Their contents, such as neutral carbohydrate, uronic acid and protein, were measured. Their antioxidant properties against chemicals-induced reactive species (ROS) including 1,1'-Diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide anion radical, as well as their protective effects on H₂O₂-induced PC12 cell death were investigated. Results showed that <em>I. obliquus</em> polysaccharides can scavenge all ROS tested above in a dose-dependent manner. IOA and its product IOA-1 could rescue PC12 cell viability from 38.6% to 79.8% and 83.0% at a concentration of 20µg/mL. Similarly, IOW and its product IOW-1 at the same dose, can also increase cell viability to 84.9% and 88.6% respectively. The antioxidative activities of water-soluble and alkali-soluble polysaccharide constituents from <em>I. obliquus</em> might contribute to diverse medicinal and nutritional values of this mushroom.

Keywords

• &lt;em&gt;Inonotus obliquus&lt;/em&gt;
• polysaccharide
• antioxidant
• reactive oxygen species