Flavonoid glycoside scutellarin(SCU)has been widely applied in the treatment of cerebral ischemic diseases in China.In this article,we conducted research on the working mechanisms of SCU in hypoxia reoxygenation(HR)in...Flavonoid glycoside scutellarin(SCU)has been widely applied in the treatment of cerebral ischemic diseases in China.In this article,we conducted research on the working mechanisms of SCU in hypoxia reoxygenation(HR)injury of isolated cerebral basilar artery(BA)and erebral ischemia reperfusion(CIR)injury in rat models.In isolated rat BA rings,HR causes endothelial dysfunction(ED)and acetylcholine(ACh)induces endothelium-dependent vasodilation.The myography result showed that SCU(100μM)was able to significantly improve the endothelium-dependent vasodilation induced by Ach.However,SCU did not affect the ACh-induced relaxation in normal BA.Further studies suggested that SCU(10-1000μM)dose-dependently induced relaxation in isolated BA rings which were significantly blocked by the cGMP dependent protein kinase(PKG)inhibitor Rp-8-Br-cGMPs(PKGI-rp,4μM).Pre-incubation with SCU(500μM)reversed the impairment of endothelium-dependent vasodilation induced by HR,but the reversing effect was blocked if PKGI-rp(4μM)was added.The brain slice staining test in rats’model of middle cerebral artery occlusion(MCAO)induced CIR proved that the administration of SCU(45,90 mg/kg,iv)significantly reduced the area of cerebral infarction.The Western blot assay result showed that SCU(45 mg/kg,iv)increased brain PKG activity and PKG protein level after CIR surgery.In conclusion,our findings suggested that SCU possesses the ability of protecting brain cells against CIR injury through vascular endothelium protection and PKG signal.展开更多
基金the National Natural Science Foundation of China(Nos.81560589,30960450,81173110 and 81560072)Yunnan Provincial Science and Technology Department(Nos.202105AF150015,202102AA310030,2018FE001(-026),2017FE467(-019),2014BC012,and 2017IC041)Yunnan Provincial Educational Department(Nos.2018JS161).
文摘Flavonoid glycoside scutellarin(SCU)has been widely applied in the treatment of cerebral ischemic diseases in China.In this article,we conducted research on the working mechanisms of SCU in hypoxia reoxygenation(HR)injury of isolated cerebral basilar artery(BA)and erebral ischemia reperfusion(CIR)injury in rat models.In isolated rat BA rings,HR causes endothelial dysfunction(ED)and acetylcholine(ACh)induces endothelium-dependent vasodilation.The myography result showed that SCU(100μM)was able to significantly improve the endothelium-dependent vasodilation induced by Ach.However,SCU did not affect the ACh-induced relaxation in normal BA.Further studies suggested that SCU(10-1000μM)dose-dependently induced relaxation in isolated BA rings which were significantly blocked by the cGMP dependent protein kinase(PKG)inhibitor Rp-8-Br-cGMPs(PKGI-rp,4μM).Pre-incubation with SCU(500μM)reversed the impairment of endothelium-dependent vasodilation induced by HR,but the reversing effect was blocked if PKGI-rp(4μM)was added.The brain slice staining test in rats’model of middle cerebral artery occlusion(MCAO)induced CIR proved that the administration of SCU(45,90 mg/kg,iv)significantly reduced the area of cerebral infarction.The Western blot assay result showed that SCU(45 mg/kg,iv)increased brain PKG activity and PKG protein level after CIR surgery.In conclusion,our findings suggested that SCU possesses the ability of protecting brain cells against CIR injury through vascular endothelium protection and PKG signal.