Danhong injection (DHI), a Chinese
Materia Medica standardized product extracted from Radix Salviae miltiorrhizae and
Flos Carthami tinctorii, is widely used in China for treating
acute ischemic stroke. In the present study, we explored the neuroprotective efficacy of DHI in a rat model of temporary
middle cerebral artery occlusion, and evaluated the potential mechanisms underlying its effects. Pretreatment with DHI (0.9 and 1.8 mL/kg) resulted in a significantly smaller
infarct volume and better neurological scores than pretreatment with saline. Furthermore, DHI significantly reduced the permeability of the blood-brain barrier, increased
occludin protein expression and decreased neutrophil infiltration, as well as profoundly suppressing the upregulation of matrix metallopeptidase-9 expression seen in rats that had received vehicle. Matrix metallopeptidase-2 expression was not affected by
ischemia or DHI. Moreover, DHI (1.8 mL/kg) administered 3 hours after the onset of
ischemia also improved neurological scores and reduced
infarct size. Our results indicate that the neuroprotective efficacy of DHI in a rat model of
cerebral ischemia-
reperfusion injury is mediated by a protective effect on the blood-brain barrier and the reversal of neutrophil infiltration.