| ObjectiveApplying intrahippocampal injection of Aβ25-35 to establish murine models of Alzheimer’s disease to study the effects of Danggui Shaoyao San (DSS), DCS and FBZ on behavior of the model mouse.MethodsKM mice randomly divided to one of seven groups:Sham group, Model group, DSS 3.2 g/kg group, DCSH 2.0 g/kg group, DCSL 1.0 g/kg group, FBZH 1.2 g/kg group and FBZL 0.6 g/kg group, three days after sterile saline or Aβ25-35 injection each group was administered with vehicle or DSS, DCS, and FBZ by oral gavage continuously for four weeks. The Morris water maze (MWM) task, object recognition task (ORT) and step-through test (STT) was used to evaluate the learning and memory functions in mice. Mice were sacrificed and cerebral coronal slices were used for Nissl’s staining, Fluoro-Jade B staining and immunostaining.ResultsDuring 5-day spatial learning in MWM, escape latency between each group was statistically significant (P<0.05); Escape latency between the sham group and the model group was statistically significant (P< 0.01), model group showed longer escape latency than sham group; Escape latency between the medicine treated group and the model group was statistically significant (P<0.05), model group showed longer escape latency than medicine treated group.There was no significant difference between the model and other groups in the probe trial.For ORT, compared with sham group (63.39±6.13), model group (43.79 ±14.70) showed less exploration time on the new object. All of the drug group showed more exploration time on the new object, compared with model group.There were no significant difference of Preference Index (PI) between each group.For STT, we found no difference between the model group and other groups in the step-through latency and the error times.Compared with sham group, the number of neurons in hippocampal CA1 region decreased in model group. Drug treatment inhibited neuronal loss in hippocampal CA1 region.Compared with sham group, the FJB-positive neurons were increased in the cerebral cortex of the model group. Drug treatment inhibited neuronal degeneration in the cerebral cortex, showing a decreased number FJB-positive neurons in the drug-treated groups.Compared with sham group, the model group had higher content level of Aβ 25-35 at hippocampus. Drug treatment showed a reducing Aβ25-35 content at hippocampus.ConclusionDanggui Shaoyao San and Optimized Danggui Shaoyao San(DCS and FBZ) could improve the cognition ability through decreasing content level of Aβ25-35 and inhibiting neuronal loss and degeneration. |
