Effects and mechanism of Anemarrhenae Rhizoma-Phellodendri Chinensis Cortex medicine effective parts to improve cognitive impairment in type 2 diabetic rats / 中草药

ABSTRACT

Objective To study the effects of Anemarrhenae Rhizoma-Phellodendri Chinensis Cortex medicine effective parts on phosphatidyl inositol 3 kinase (PI3K)/protein kinase B (Akt) signaling pathway and explore its mechanism of action to improve brain cognitive of type 2 diabetes rats. Methods A total of 50 male SPF SD rats, divided into five groups with 10 for each group, named as control group, model group, high/low dosage of Anemarrhenae Rhizoma-Phellodendri Chinensis Cortex medicine effective parts (ZBH and ZBL) group, and Ebixa (MHT) treatment group; The rats were immunized with ip of streptozotocin (STZ) jointly fed high-fat diet for three weeks. Then the rats were continuously gavaged with ZBH, ZBL, and MHT for 20 weeks, the serum Aβ1-42 levels were determinated in 8th and 16th week respectively, the changes of the cognitive impairment were analyzed, combined with Barnes maze and Morris water maze to detects the cognitive ability of each group rats; At the end of 20 weeks of administration, dissecting and preservatting the rat pancreatic tissue, the hippocampus to made into routine pathological sections and brain tissue pathology morphology inspection and PI3K, Akt, and Bcl-2 mRNA expression by fluorescence quantitative PCR method detection. Results After treatment for 8 weeks and 16 weeks, compared with control group, Aβ1-42 levels of model group were significantly increased (P < 0.05, 0.01); Administration 20 weeks, compared with control group, pathological section results showed normal hippocampus cells arranged in neat rows, morphological rules, and color is very even. DM models of hippocampal tissue cells arranged scattered through the administration significantly after repair. Compared with model group, ZBH and ZBL could effectively improve the form of neurons and cell arrangement of rat's hippocampus, repairing nerve injury; Compared with control group, PI3K and Akt mRNA expression of hippocampal tissue of model group rats decreased, Bcl-2 mRNA expression was abate (P < 0.05). After delivery, MHT and ZBH group could significantly improve the level of PI3K, Akt, and Bcl-2 mRNA expression (P < 0.05, 0.01). Conclusion Anemarrhenae Rhizoma-Phellodendri Chinensis Cortex medicine effective parts can significantly reduce the accumulation of Aβ1-42 protein, and decreased the expression of PI3K and Akt, indicating that the effects of improvement of cognitive impairment in type 2 diabetic rats may be achieved through regulation of PI3K/Akt pathway.