Objective: It was reported that Sipunculus nudus polysaccharide(SNP) had effects on fatigue in the early time in our laboratory

in the article we studied the anti-fatigue effects of purified SNP on the fatigue resistance. Method: The treatment groups were given various doses of SNP (50

100

200 mg·kg-1) for 7 consecutive days

respectively

and the longest swimming time was detected after loaded swimming test. the level of serum urea nitrogen (BUN)

muscle glycogen and the activity of hepatic antioxidase including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were detected. Result: After 7 days

the mouse swimming time in the blank control group was(115±40)s

and the swimming time with medium and high dose feeding of purified Sipunculus nudus polysaccharide was(206±93)

(203±74)s

respectively

longer than blank control groups(P<0.01). The serum urea nitrogen of the treated groups was(8.72±0.46)mmol·L-1

and that in medium and high dose group was(7.55±0.70)

(7.89±0.42)mmol·L-1

respectively

lower than blank control groups(P<0.01). Besides

the muscle glycogen in the blank control group was(0.41±0.04)mg·g-1

and that in medium and high dose groups was(1.01±0.18)

(1.06±0.22)mg·g-1

higher than blank control groups(P<0.01).Moreover

the activity of SOD and GSH-Px in high dose group in hepatic tissue was increased compared with blank control group(P<0.01). Conclusion: SNP has noticeable anti-fatigue effect on mice

especially in intermediate at dose group (100 mg·kg-1) and its strongest effect on most biomarkers is found when given an intermediate dose.