Effects of oroxylin A in cerebral vascular tone regulation (841.3)

Oroxylin A, a flavonoid and an active component isolated from Scutellariae baicalensis, has been considered beneficial in preventing inflammation-induced microglia-mediated neurodegeneration. Its role in regulation of cerebral vascular smooth muscle tone and blood flow, however, remains unclear. This study was designed to assess possible beneficial effects of oroxylin A in cerebral blood flow and cerebral vascular smooth muscle tone regulation in vitro and in vivo. The results indicated that oroxylin A (10 mg/Kg, iv), which did not affect the systemic blood pressure, significantly increased regional cerebral blood flow in the striatum of the rat in vivo, using laser Doppler flowmetry. Results from tissue bath myography studies indicated that oroxylin A (100 nM - 30 μM) in a concentration-dependent manner relaxed U46619-precontracted porcine isolated basilar arteries. The vasorelaxation was not affected by denudation of the endothelium, cold storage for 5 days, tetrodotoxin (0.3 μM), ODQ (10 μM, a soluble ...