Abstract: Objective To study the antioxidant effect of polysaccharides from Dendrobium devoninum on mice with oxidative damage induced by D-galactose. Methods Seventy-two mice were randomly divided into six groups: the control group, model group,vitamin C group, and high, medium, low dose groups of Dendrobium devonianum polysaccharides. Except the control group,mice in the other groups were injected with D-galactose 120 mg·kg^-1·d^-1 to establish a model of oxidative damage. For six weeks, the control group and model group were given normal saline of the equal volume by gavage, while the vitamin C group, high, medium and low dose groups of Dendrobium devonianum polysaccharides were treated with 100 mg·kg^-1·d^-1, 400 mg·kg^-1·d^-1, 200 mg·kg^-1·d^-1 and 100 mg·kg^-1·d^-1, respectively. One hour after the last administration,the activity of superoxide dismutase(SOD) and the contents of malondialdehyde (MDA),glutathione(GSH), and protein carbonyl in the serum and liver were detected. Results Compared with the model group, Dendrobium devonianum polysaccharides could significantly improve the activity of SOD and content of GSH, but decrease the contents of MDA and protein carbonyl in the serum and liver of mice with oxidative damage induced by D-galactose. Conclusion Dendrobium devonianum polysaccharides have antioxidant effect.

Key words: Dendrobium devonianum polysaccharides, D-galactose, mice, antioxidant