Targeted Delivery of Intranasally Administered Cyclovirobuxine D Liposomes to Brain for Treatment Cerebral Ischemia-Reperfusion Injury via Anti-oxidative Stress and Activating Autophagy

Abstract

The lack of effective therapy mandates development of treatment for cerebral ischemia-reperfusion injury (CIRI. The previous study suggested that Cyclovirobuxine D (CVBD) encapsulated in Angiopep-conjugated Polysorbate 80-Coated Liposomes showed a better brain targeting by intranasal administration. Therefore, this study focused on the protection and mechanism of CVBD brain-targeted liposomes in treating CIRI. In order to evaluate these, the CIRI rat model was induced by middle cerebral artery occlusion (MCAO)-reperfusion. Pharmacological evaluation was assessed in vivo by general indexs, neurobehavioral scores, triphenyl tetrazolium chloride (TTC) staining, histopathological staining (HE staining and Nissl staining), small animal magnetic resonance imaging, biochemical assay and Western blot. The results show that CVBD liposomes alleviated pathological damage of brain. Futhermore, the protective effect of CVBD liposomes on OGD/R-injured HT22 cell was investigated by cell fusion degree, cell proliferation curve and cell viability. OGD/R-injured HT22 cell was infected by mRFP-GFP-LC3 adenovirus. The autophagosome and autophagy flow were observed by laser confocal microscopy, and autophagy-related protein expressions (LC3, p62 and Beclin 1) were analyzed by Western blot. Meanwhile, the classic autophagy inhibitor, chloroquine, was used to explore the autophagy-regulated mechanism of CVBD brain-targeted liposomes in treating CIRI. In cell model of oxygen and glucose deprivation/re-oxygenation, CVBD liposomes increased cell viability and decreased ROS level. CVBD liposomes improved oxidative stress protein expressions and activated autophagy in vitro. Furthermore, CVBD liposomes reversed the decrease of cell viability, increase of ROS level, and reduction of protein expressions associated to anti-oxidative stress and autophagy induced by chloroquine. Collectively, CVBD liposomes inhibited CIRI via regulating oxidative stress and enhancing autophagy level in vivo and in vitro, showing a great potential in treating CIRI in clinic.