Purified Auricularia auricular-judae polysaccharide (AAP I-a) prevents oxidative stress in an ageing mouse model

This paper reports on a water-soluble polysaccharide (AAP I-a) extracted from Auricularia auricular with assistance from ultrasonics, and purified by anion-exchange and gel-permeation chromatography. Additional further structural characteristics were determined from high-performance liquid chromatography/gel permeation chromatograph (HPLC/GPC), Fourier transform infrared (FT-IR) spectrometer and gas chromatography–mass spectrophotometer (GC–MS). AAP I-a is composed of l-rhamnose, l-arabinose, d-xylose, d-mannose, d-glucose, and d-galactose in a molar ratio of 0.2:2.6:0.4:3.6:1.0:0.4. After 35 days of AAP I-a oral administration (50, 100 and 200 mg/kg once a day), the AAP I-a significantly decreased the level of malondialdehyde (MDA) and increased superoxide dismutase (SOD) and glutathione (GSH) activities in mice where ageing is induced by d-galactose (p < 0.05). In conclusion, our results indicated that AAP I-a possessed potent antioxidant activity.