Antioxidant properties of water-soluble polysaccharides from Antrodia cinnamomea in submerged culture

Antrodia cinnamomea, a well-known tradition Chinese medicine, possesses anti-tumor, anti-oxidation activities and stimulates the immune system. The aim of this study was to investigate the protective effect of water-soluble polysaccharides from the fermented filtrate and mycelia of Antrodia cinnamomea in submerged culture (ACSC) on hydrogen peroxide-induced cytotoxicity and DNA damage in Chang liver cells. Oxidative DNA damage was evaluated by single cell gel electrophoresis (Comet assay) or by the formation of 8-hydroxy-deoxyguanosine (8-OHdG) adducts. The polysaccharides isolated by ion-exchange chromatography contained glucose, xylose, galactose, arabinose, and mannose. The results showed that incubation of Chang liver cells with isolated polysaccharides at 200 μg/mL for 5 h prior to H2O2 treatment (50 μM, 30 min) significantly reduced oxidative DNA damage as detected by the formation of comet tail DNA and 8-OHdG adducts by 89% and 69%, respectively. Pre-treatment Chang liver cells with polysaccharides also reduced the levels of thiobarbituric acid reactive substances (TBARS) (p < 0.01) and intracellular reactive species (ROS) (p < 0.01) induced by H2O2. Moreover, glutathione S-transferase (GST) and the GSH/GSSG ratio were significantly increased in Chang liver cells pre-incubated with the polysaccharides (p < 0.01). These results demonstrate that polysaccharides in ASCS have antioxidant properties which may involve up-regulation of GST activity, maintenance of normal GSH/GSSG ratio, and scavenging of ROS.