Neuroprotective effect of breviscapine on traumatic brain injury in rats associated with the inhibition of GSK3β signaling pathway

Breviscapine, a standardized Chinese herbal medicine extracted from Erigeron breviscapine, has been widely used to treat cerebrovascular diseases. However, there are no reports about the neuroprotective effects and underlying molecular mechanisms of breviscapine on traumatic brain injury (TBI). Therefore, this study was aimed to investigate the effects of breviscapine on rats with TBI insult and illuminate the underlying mechanism. We created a traumatic brain-injured model with breviscapine lateral ventricle injection and evaluated the expressional changes of glycogen synthase kinase 3 beta (GSK3β) as well as the GSK3β-involved signaling pathways including apoptosis and axonal growth. At 7, 14, 21 days after injection, we found a great reduction of motor disability in TBI rats following breviscapine treatment, which was accompanied with a notably increased expression of phospho-Ser9-GSK3β (p-Ser9-GSK3β) and decreased expression of phosphor-Try216-GSK3β (p-Try216-GSK3β) at 7 days after injection. Concomitantly, an enhanced expression of synaptic marker synaptophysin (SYP) together with a weakened expression of pro-apoptotic caspase3 was observed after TBI rats were treated with breviscapine. Terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling (TUNEL) immunohistochemical assay and SYP immunofluorescence staining also confirmed the result. This study suggests that breviscapine inhibits the GSK3β signaling pathway to promote neurobehavioral function following neurotrauma. These events may provide a new insight into the mechanism of breviscapine treating brain injury.