Effects of Chinese herbal medicine of tonifying spleen and stomach on learning and memory ability and PKA/ERK/p-CREB pathway in hippocampus of SAMP8 mice / 中草药

ABSTRACT

Objective: To study the effects of prescriptions including Ginseng Decoction, Xixin Decoction, and Dabuyuan Decoction for tonifying spleen and stomach on learning and memory ability and PKA/ERK/p-CREB pathway in hippocampus of SAMP8 mice, and explore the mechanism in the prevention and treatment of Alzheimer's disease (AD). Methods: Three-month-old SAMP8 mice were randomly divided into model group, Donepezil Hydrochloride group, prescription group of Tonifying Spleen and Stomach Yuanqi Prescription (Ginseng, Xixin Decoction, and Dabuyuan Decoction). Moreover, three-month-old SAMR1 mice were recruited as a normal control group, six groups in total. Related indices were detected after 10 weeks continuous gastrogavage. The spatial learning-memory deficit of mice was detected by Morris water maze test. The expression levels of PKA protein in hippocampal region of mice were detected by immunohistochemistry, and the expression levels of ERK and p-CREB protein in hippocampal region of mice were detected by immunofluorescence. The protein expression levels of PKA, ERK, and p-CREB in hippocampus were detected by Western blotting. Results: Compared with the model group, the escape latency of the prescription group of tonifying spleen and stomach was decreased (P < 0.05, P < 0.01), while the swimming time and the times of crossing the platform in the target quadrant were increased (P < 0.01). Results of immunohistochemistry showed that the protein expression of PKA was significantly increased and the expression of ERK and p-CREB in hippocampal region was significantly increased (P < 0.05, P < 0.01). The results of Western blotting were consistent with those of immunohistochemistry and immunofluorescence (P < 0.05, P < 0.01). Conclusion: The Tonifying Spleen and Stomach Yuanqi Prescription showed obvious improvement on the spatial learning-memory deficit in SAMP8 mice, which might be associated with affecting the PKA/ERK/p-CREB pathway in hippocampal region.