Fig. 1

Inhibition of abdominal writhing induced by acetic-acid as described in “Materials and methods”. The total numbers of writhing were evaluated over the period of 30 min. Each column represents the mean ± SEM of 6–7 mice per group. *p < 0.05, **p < 0.01 and ***p < 0.001 denote the significant differences from the negative control group