Buqi Huoxue Tongnao prescription protects against chronic cerebral hypoperfusion via regulating PI3K/AKT and LXRα/CYP7A1 signaling pathways

Background Chronic cerebral hypoperfusion (CCH) has been confirmed as one of the pathogenesis underlying vascular cognitive impairment. A series of pathological changes, including inflammation, oxidative stress, and apoptosis, are involved in this pathophysiology and contribute to cognitive impairment and neuropathological alterations. The traditional Chinese medicine (TCM) of Buqi Huoxue Tongnao (BQHXTN) prescription possesses a remarkable clinical efficacy for treating patients with CCH, but still lacks a scientific foundation for its pharmacological mechanisms. Purpose To investigate the role and underlying mechanism of the effects of BQHXTN on CCH both in vitro and in vivo . Methods In this study, we established a two-vessel occlusion (2-VO) induced CCH model in Sprague-Dawley rats, an oxygen-glucose deprivation model in BV2 cells, and a steatosis cell model in L02 cells to reveal the underlying mechanisms of BQHXTN by behavioral test, histopathological analysis and the detection of pro-inflammatory cytokine, apoptotic factors and reactive oxide species. Donepezil hydrochloride and Buyang Huanwu decoction were used as positive drugs. Results Compared with the 2-VO group, BQHXTN treatment at three doses significantly enhanced the memory and learning abilities in the Y-maze and novel object recognition tests. The hematoxylin-eosin staining indicated that BQHXTN protected against hippocampal injury induced by CCH. Of note, in both in vivo and in vitro experiments, BQHXTN prominently inhibited the production of IL-1β, TNF-α, cleaved-caspase 3, and iNOS by regulating the PI3K/AKT pathway, consequently exerting anti-inflammatory, anti-apoptotic, and antioxidant effects. Moreover, it provided the first initial evidence that BQHXTN treatment mitigated dyslipidemia by increasing the LXRα/CYP7A1 expression, thereby delaying the neuropathological process. Conclusion In summary, these findings firstly revealed the pharmacodynamics and mechanism of BQHXTN, that is, BQHXTN could alleviate cognitive impairment, neuropathological alterations and dyslipidemia in CCH rats by activating PI3K/AKT and LXRα/CYP7A1 signaling pathways, as well as providing a TCM treatment strategy for CCH.