Objective: To investigate the antagonistic cell injury effect and molecular mechanism of scutellarin(SCU)in hypoxia reoxygenation(HR) treated human cardiac microvascular endothelial cells(HCMECs).Methods: The method of 12 h hypoxia following by 12 h reoxygenation was used to culture HCMECs in vitro to built cell injury model. The groups were divided into control group, model(HR) group, and HR + SCU(0.1 μmol/L, 1 μmol/L, and 10 μmol/L) group. The cell viability was determined by MTT, and oxidative stress was detected by malondialdehyde(MDA) levels by biochemical assay kit. Protein expression of JAK2/p-JAK2 and STAT3/p-STAT3 were evaluated by Western blot.Results: The results of MTT and MDA showed that HR decreased the cell viability(P < 0.05) and increased MDA level significantly(P < 0.05), SCU played a contrary role in these processes. Western blot analysis indicates that, the expression of JAK2 and p-JAK2, STAT3, and p-STAT3 were increased in model group when compared with control group(P < 0.05); Compared with model group, their expression were reduced by SCU(P < 0.05).Conclusion: SCU took a protective effect on HR-treated HCMECs, and the molecular mechanism may be associated with the inhibition of JAK2/STAT3 signal transduction pathway.
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.
OBJECTIVE This study discusses the effects of scutellarin(SCU),which is one of effective component of Erigeron breviscapus(Vant.)Hand-Mazz,on cGMP dependent protein kinase(PKG)in human cardiac microvascular endothelial cells(HCMECs)after hypoxia roxygenation(HR).METHODS Based on a model of HCMECs cells with HR injury,cell viability is examined by MTT assay.Protein expression of PKG is analyzed by Western blotting and its enzyme activity is investigated by ELISA technology.RESULTS The results of MTT assay- indicate that SCU(1,10μmol·L1)could protect HCMECs against HR injury.SCU(0.1,1 and 10μmol·L-1)canenhance PKG-I expression in control and HR injury cells.Furthermore,SCU(1,10μmol·L-1 significantly increase PKG activity in control cells(P<0.01),and also SCU(100μmol·L-1)appears similar on enzyme activity in HR injury cells(P <0.05).CONCLUSION SCU appears protective effects on endothelial cells against HR damage.While its mechanisms may be related to the influence of SCU on PKG activity in HCMECs.
