Effects of ODH on the Ach concentration and AChE activity in murine brains of scopolamine treated mice. Mice were orally preadministrated with tacrine (2 mg/kg), ursolic acid (2 mg/kg), ODH (100 or 200 mg/kg) for four weeks and injected with scopolamine (3 mg/kg) to induce amnesia. (a) evaluation of Ach concentration in brains of mice; (b) measurement of AChE activity in murine brains. Values are expressed as the means ± SD. * p < 0.05, ** p < 0.001 vs. scopolamine treated control group. N: normal group, C: control group, P: tacrine treated positive control groups, U: ursolic acid treated groups, O100: ODH 100 mg/kg treated group, O200: ODH 200 mg/kg treated group.