Effect of berberine chloride on expression of insulin degrading enzyme in rat models with AD

Objective To explore the effect of berberine chloride on the expression of insulin degrading enzyme (IDE) in the rat models with Alzheimer's disease (AD). Methods Eighteen adult male SD rats, weighting 220-250 g, were randomly divided into normal control group, Aβ1-40 group and Aβ40+berberine chloride group (n=6). The rat models with AD were established by stereotactically injecting condensed Aβ1-40 (5 μg) into the bilateral hippocampus of rats. The rats in the Aβ1-40+berberine chloride group were given berberine chloride (50 mg/kg) by intragastric administration once daily for 14 d. The expressions of IDE were assayed by real time polymerase chain reaction (real-time PCR) and Western blotting. Results The relative quantity of mRNA expression of IDE was (34.2±6.7) in the Aβ1-40+berberine group, which was significantly increased as compared with that in the Aβ1-40 group (45.7±12.8) and normal control group (23.4±11.3, P＜0.05). The relative quantity of protein expression of IDE was (0.61 ±0.05) in the Aββ1-40+berberine group, which was significantly increased as compared with that in the Aβ1-40group (0.46±0.07) and the normal control group (0.23±0.03, P＜0.05). Conclusion The injection of Aβ1-40 (5 μg) in the hippocampus can highly increase the expressions of IDE, thus resulting in the increase effect of Aβ clearance. Key words: Alzheimer's disease; Berberine chloride; Insulin degrading enzyme