Effect of hippocampal L‑NBP on BDNF and TrkB expression and neurological function of vascular dementia rats.

The pathogenesis of vascular dementia (VD) is associated with neuronal degeneration, apoptosis or necrosis following ischemic brain injury. L‑butylphthalide (L‑NBP), has been demonstrated to exhibit potent anti‑ischemic and anti‑VD effects, however the associated specific mechanism remains to be elucidated. The present study generated a VD rat model, in which the effect of L‑NBP on neurological function and expression levels of brain‑derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) were observed. A total of 90 male Sprague Dawley rats were randomly divided into sham, model and L‑NBP groups (n=30). The VD model was generated by ligation of bilateral common carotid artery. A Morris water maze was used to test learning and memory functions. Animals were then sacrificed and cortical and hippocampal tissues were extracted. Hematoxylin and Eosin staining was used to observe brain tissue injury, and reverse transcription‑quantitative polymerase chain reaction was employed to measure BDNF and TrkB mRNA levels. Western blotting was employed to measure BDNF, TrkB and serine‑threonine protein kinase (Akt) protein levels. Immunohistochemistry staining was used to detect the N‑methyl‑D‑aspartate receptor (NMDAR) levels. VD rats exhibited elongated escape latency and lower crossing times, with significant neuronal damage. L‑NBP treatment shortened escape latency, increased crossing times and improved cortical and hippocampal injury. BDNF, TrkB, Akt and NMDAR expressions in the treatment group were significantly increased compared with the model group (P<0.05). L‑NBP may therefore enhance hippocampal expression of BDNF, TrkB, Akt and NMDAR, decrease ischemic injury of VD rats, and improve learning and memory.