Objective: To observe the effect of electroacupuncture (EA) of "Xiusanzhen" [3 acupoints, i.e., bilateral "Yingxiang" (LI 20) and "Yintang" (EX-HN 3)] on expression of B-cell lymphoma/leukemia-2 (Bcl-2, an antiapoptosis protein) and Bax (a protein for promoting apoptosis) in the hippocampus in Alzheimer disease (AD) rats, so as to explore its clinical mechanisms underlying relieving AD.
Methods: A total of 40 Sprague Dawley rats were randomly divided into normal control, AD model, EA and olfactory nerve transaction(ONT) + EA groups, with 10 rats in each. AD model was established by injection of beta-amyloid (Abeta)(1-40) (2 microL containing 10 microg) into the hippocampus (Bregma: 3.5 mm, L: 2.0 mm, H: -2.8 mm below dura), and the ON was sectioned by using a fine needle. EA (80-100 Hz, 1-3 mA) was applied to bilateral LI 20 and EX-HN 3 for 10 min, once daily (except Saturdays and Sundays) for 6 weeks. The expression of Bcl-2 and Bax of hippocampus was measured by immunohisto-chemistry.
Results: Compared with the normal control group, the expression of Bcl-2 of hippocampus was significantly lower in the AD model group (P<0.05), and that of Bax in AD model group was much higher (P<0.01). In comparison with the model group, the expression of hippocampal Bcl-2 was up-regulated significantly (P<0.01), and that of hippocampal Bax protein downregulated considerably in the EA group (P<0.01). No significant differences were found between AD model and ONT + EA groups in the expression of hippocampal Bcl-2 and Bax proteins (P>0.05), suggesting a necessary premise condition for EA in regulating hippocampal Bcl-2 and Bax expression.
Conclusion: "Xiusanzhen" can regulate the expression of hippocampal Bcl-2 and Bax proteins in AD rats, which may contribute to its clinical effect in relieving AD, and the therapeutic effect depends on the integrity of the olfactory nerve pathway.