Effect of Hochu-ekki-to (TJ-41), a Japanese Herbal Medicine, on Daily Activity in a Murine Model of Chronic Fatigue Syndrome

We aimed to evaluate the effect of a Japanese herbal medicine,Hochu-ekki-to (TJ-41), on daily activity in a murine model ofchronic fatigue syndrome (CFS). CFS was induced by repeatedinjection of Brucella abortus (BA) antigen every 2 weeks. TJ-41was orally administered to mice in a dose of 500 mg/kg/day for1 week before injecting BA and for 4 weeks thereafter. We evaluateddaily running activity in mice receiving TJ-41 as compared withthat in untreated mice. Survival of both mouse groups was alsomonitored during the observation period. Body weight (BW), spleenweight (SW), SW/ BW ratio and expression levels of interleukin-10(IL-10) mRNA in spleen were determined in both groups at thetime of sacrifice. The daily activity was significantly higherin the treated group than in the control. Two mice in the untreatedgroup died 2 days after the second injection of BA, whereasno mice in the group treated with TJ-41 died. The SW and SW/BWratio were significantly lower in the treated mice than in thecontrol. Suppressed IL-10 mRNA levels were observed in the spleensof the mice treated with TJ-41. Our data suggest that Hochu-ekki-tomight possess an inhibitory effect on the marked decrease inrunning activity following BA injection.