Antifatigue effect of Rubus coreanus Miquel extract in mice.

The antifatigue properties of six Korean medicinal herb extracts were studied by evaluating forced swimming capacity and biochemical parameters in ICR mice. The treatment groups were orally administered 30% ethanolic extracts (500 mg/kg/day) of Rubus coreanus Miquel, Cyperus rotundus Linn., Acanthopanax sessiliflorus, Saururus chinensis Baili, Epimedium koreanumNakai, or Houttuynia cordata Thunb. for 4 weeks. Swimming time to exhaustion was found to be longer for the group fed R. coreanus than for the control group (P < .05). No significant differences were found in the plasma levels of either glucose or lactate between the control group and the group fed R. coreanus, which swam longer than the control. The plasma ammonia levels were significantly lower in the groups fed R. coreanus and A. sessiliflorus, when compared to the control group (P < .05). No significant differences were found in gastrocnemius muscle or liver glycogen content between the control group and any treatment group. These results suggest that R. coreanus extract, and none of the other herbs, has antifatigue effects in mice, as demonstrated by the increased forced swimming capacity and decreased plasma ammonia accumulation.