Effects of Buyang Huanwu decoction on the expression of Cyclin D1 and Cdk2 in rats with post-stroke depression

Abstract

Objective To observe the effects of Buyang Huanwu decoction(BYHW) on the expression of Cyclin D1 and Cdk2 in rats with post-stroke depression(PSD). Methods The rats model of focal cerebral ischemia was established by means of middle cerebral artery occlusion(MCAO). Then three weeks of salute-living and chronic unpredictable mild stress(CUMS) was given to the animal after cerebral stroke to induce the post-stoke depression animal model.The rats were divided into 5 groups: the sham operated group, the midge cerebral artery occlusion(MCAO) group, the PSD group, the fluoxetine group and the BYHWD group.The rats were subjected to left MCAO rebuilding in consistent focal cerebral ischemia, followed by an 21-day exposure to chronic mild stress(CMS)and single housing to induce PSD animal model. All rats were killed in 7, 14 and 21 day after operation. The expressions of Cyclin D1 and Cdk2 were measured by immunohistochemical staining. Results Pathological changes such as hippocampal nerve cell regression, degeneration and necrosis were observed in the model rats compare with the sham operated group. The expression of Cyclin D1 in normal hippocampus in 7, 14 or 21 day after operation was (1.16±0.34)%, (1.62±0.29)% and (1.60±0.24)% respectively, and Cdk2 was (1.52±0.26)%, (1.85±0.23)% and (1.97±0.10)%.After PSD the expression of Cyclin D1 was (49.69±5.68)%, (58.17±2.89)% and (50.87±2.48)% respectively, and Cdk2 was (50.63±2.93)%, (70.34±1.47)% and (61.35±3.04)%.Compared with model group, Fluoxetine and BYHW significantly reduced the numbers of Cyclin D1 and Cdk2 positive cells, the expression of Cyclin D1 was (16.62±4.27)%, (29.66±5.24)% and (26.71±1.32)% at fluoxetine group, and Cdk2 was (18.05±2.26)%, (33.84±3.12)% and (24.51±2.66)%.The expression of Cyclin D1 was (14.62±2.06)%, (26.89±3.41)% and(23.68±2.01)% at BYHWD group, and Cdk2 was (16.60±2.42)%, (20.09±3.45)% and (22.19±1.70)%. Conclusion The abnormal expression of Cyclin D1 and Cdk2 at the PSD rats indicate that they may be involved in the mechanism of neuronal death. Buyang Huanwu decoction may reduce the neuronal apoptosis through down-regulating the expression of Cyclin D1 and Cdk2. Key words: Post stroke depression; Buyang Huanwu decoction; Cyclin D1; Cdk2; Rats