This study was designed to explore the therapeutic time window and mechanism of Buyang Huanwu Decoction on transient focal cerebral ischemia/reperfusion injury.
Middle cerebral artery occlusion was conducted in male Sprague-Dawley rats, and 40 g/kg of Buyang Huanwu Decoction was intragastrically infused at different time points, and the same dose was infused every 24 h for 3 days. The level of glutamate in cerebrospinal fluid and the expression of metabotropic glutamate receptor-1 RNA in striatum were detected before, during, and after ischemia/reperfusion. Neurological deficit scores and brain infarction volumes were measured at 72 h after reperfusion.
Cerebral ischemia/reperfusion resulted in significant neurological deficit and extensive cerebral infarct volume, associated with a large amount of glutamate in cerebrospinal fluid and elevation of metabotropic glutamate receptor-1 RNA expression. Buyang Huanwu Decoction significantly suppressed the release of glutamate, and reduced the expression of metabotropic glutamate receptor-1 RNA. The neurological defect score and infarction volume were significantly improved by administration of Buyang Huanwu Decoction, when compared with the Ischemia group.
Administration of Buyang Huanwu Decoction, within 4 h of post-transient focal stroke, reduced significant cerebral ischemia/reperfusion damage. The neuroprotective mechanism of Buyang Huanwu Decoction is, in part, associated with the down-regulation of metabotropic glutamate receptor-1 RNA and inhibition of glutamate release resulting from cerebral ischemia.