Abstract:

This study was performed to investigae the antifatigue and antioxidant activities and monosaccharide composition
of a polysaccharide (PRK) extracted from roots of kiwifruit (Actinidia deliciosa). SPF mice were divided into control group
and three experimental groups (high-dose, moderate-dose and low-dose groups, which were established by oral administration
at 150, 75 mg/(kg·d) and 37.5 mg/(kg·d), respectively) with 10 mice in each group. All the mice were administered by gavage
with 20 mL/(kg·d) of normal saline or PRK solutions continuously for 15 d. At 30 min after the last administration, the loadedswimming
time, the contents of serum lactic acid and urea nitrogen, the contents of glycogen and MDA and the activity of SOD
in the liver were tested, and at 2 h, the survival time in hypoxic conditions under normal pressure was recorded. Compared with
the control group, PRK could prolong significantly the survival time in hypoxic conditions under normal pressure (P ＜ 0.01) and
the loaded-swimming time in low-dose group (P ＜ 0.05), moderate-dose and high-dose group (P ＜ 0.01), increase the content of
liver glycogen in moderate-dose group (P ＜ 0.05) and high-dose group (P ＜ 0.01), and enhance the activity of liver SOD in highdose
group (P ＜ 0.05). Moreover, PRK could decrease the contents of lactic acid and urea nitrogen in the serum after swimming
in high-dose group (P ＜ 0.01), decrease liver MDA content the after swimming in moderate-dose group (P ＜ 0.05) and highdose
group (P ＜ 0.01). These results showed that PRK had anti-fatigue and anti-oxidant activiteis in mice. PRK was hydrolyzed
and acetylated into acetylated monosaccharides. The acetylated monosaccharides were isolated and identified by gas chromatographymass
spectrometry. The result indicated that PRK was heteropolysaccharide and composed of ribose, arabinose, glucose and galactose.

Key words: polysaccharide extracted from kiwifruit roots, anti-fatigue activity, antioxidant activity, monosaccharide composition