Cerebral protection of salvianolic acid A by the inhibition of granulocyte adherence.

Ischemic stroke is one of the most common causes of death and disability that is induced by ischemia reperfusion (IR). Granulocyte adherence has been proven to be a principal cause of IR. Salvianolic acid A (Sal A) is one of the major active components of Danshen, a Chinese herbal medicine used for the treatment of cardiovascular and cerebrovascular diseases, such as ischemic stroke. Some experimental studies have shown the strong cerebral protection effect of Sal A. However, little information is available about the effect of Sal A on granulocyte adherence to brain micro-vascular endothelial cells (BMEC). Therefore, the aim of the present study was to investigate the effect of Sal A on the leukocyte adhesion rate and the intercellular cell adhesion molecule-1 (ICAM-1) expression in BMEC injured by hypoxia/reoxygenation (H/R), using a rheometer, qRT-PCR, and flow cytometry (FCM). The results of the adhesion rate gathered by the rheometer showed that Sal A could remarkably inhibit the adherence of granulocytes on BMEC in the case of H/R injury. Moreover, PCR and FCM results showed that Sal A could decrease the expression of ICAM-1 on BMEC on the gene and protein levels. In conclusion, the study demonstrated that the inhibition of granulocyte adherence is one of the targets of Sal A in the treatment of ischemic stroke. Meanwhile, Sal A inhibits of granulocyte adherence by decreasing the expression of ICAM-1 in BMEC.