Ameliorating effect of Alpinia oxyphylla-Schisandra chinensis herb pair on cognitive impairment in a mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is the most common cause of dementia. In our previous study, we found both Alpinia oxyphylla and Schisandra chinensis can improve the cognitive function of AD. To investigate whether the Alpinia oxyphylla - Schisandra chinensis herb pair (ASHP) has ameliorating effect on cognitive impairment, we used scopolamine to induce learning and memory impairments, as a mouse model of AD. Subsequently, we carried out Y-maze test and Morris water maze test to observe the behavior of mice. Finally, the level of Acetylcholine (Ach) and muscarinic receptor (M1) receptors, the activity of choline acetyltransferase (ChAT) and acetyl cholinesterase (AChE) were measured by commercial assay kits and ELISA kit. And we used hematoxylin-eosin (HE) staining to check the changes in cortex and the CA1 region of hippocampus. ASHP significantly protected against learning and memory impairments induced by scopolamine in Y-maze test and Morris water maze test. Besides, ASHP was able to increase the level of ACh and M1 receptors, and decrease the activity of AChE, but did not significantly affect the activity of ChAT. In addition, from the results of histopathological examination, we speculated ASHP may have neuroprotective effects. This study provided an experimental basis for further study of Alpinia oxyphylla - Schisandra chinensis herb pair in AD therapy.