Objective:To investigate effect of polysaccharides extracting from Liuwei Dihuang decoction metabolized by photosynthetic bacteria (LW-PSB) on the antioxidative ability of Drosophila melanogaster. Method: Eight h eclosion unmated (D. melanegaster) were collected. Male and female were separated

cultivated in the artificial box with the culture medium at the temperature of (25±1) ℃

relative humidity for(60±5)%.D. melanogaster were randomly divided into 5 groups: negative control group

positive control group

LW-PSB polysaccharides groups(1

3

9 g·kg-1).Thirty-day old D. melanogaster were made into homogenate and the liveness of superoxide dismutase (SOD)

catalase (CAT)

glutathione peroxidase (GSH-Px)

total antioxidant capacity (TAOC) and the malonaldehyde (MDA) content were detected. Result: Compared with the negative group

the antioxidase activity such as SOD

CAT

GSH-Px

TAOC of 30-day old D. melanogaster were significantly increased(P<0.05

P<0.01 or P<0.001) and the MDA content was decreased(P<0.01 or P<0.001).Compared with the positive group

the antioxidase activity such as GSH-Px

TAOC of 30-day old D. melanogaster were significantly increased(P<0.05 or P<0.001) and the MDA content was decreased(P<0.01 or P<0.001). Conclusion: LW-PSB polysaccharides might have a satisfactory effect on anti-oxidant.