Dangkwisoo-San (DS) is an herbal extract that is widely used in traditional Korean medicine to treat traumatic
ecchymosis and
pain by promoting blood circulation and relieving blood stasis. However, the effect of DS in
cerebrovascular disease has not been examined experimentally. The protective effects of DS on focal ischemic brain were investigated in a mouse model. DS stimulated
nitric oxide (NO) production in human brain microvascular endothelial cells (HBMECs). DS (10-300 μg/mL) produced a concentration-dependent relaxation in mouse aorta, which was significantly attenuated by the
nitric oxide synthase (NOS) inhibitor
L-NAME, suggesting that DS causes vasodilation via a NO-dependent mechanism. DS increased resting cerebral blood flow (CBF), although it caused mild
hypotension. To investigate the effect of DS on the acute cerebral injury, C57/BL6J mice received 90 min of
middle cerebral artery occlusion followed by 22.5 h of reperfusion. DS administered 3 days before
arterial occlusion significantly reduced
cerebral infarct size by 53.7% compared with vehicle treatment. However, DS did not reduce
brain infarction in mice treated with the relatively specific endothelial NOS (eNOS) inhibitor, N(5)-(1-iminoethyl)-L-ornithine, suggesting that the
neuroprotective effect of DS is primarily endothelium-dependent. This correlated with increased phosphorylation of eNOS in the brains of DS-treated mice. DS acutely improves CBF in eNOS-dependent vasodilation and reduces
infarct size in focal
cerebral ischemia. These data provide causal evidence that DS is cerebroprotective via the eNOS-dependent production of NO, which ameliorates blood circulation.