OBJECTIVE To explore the effects and mechanism of icariside Ⅱ(ICS Ⅱ),a pharmacologically active compound derived from herbal Epimedii with previous study-proved phosphodiesterase 5(PDE5) inhibitors,was investigated ...OBJECTIVE To explore the effects and mechanism of icariside Ⅱ(ICS Ⅱ),a pharmacologically active compound derived from herbal Epimedii with previous study-proved phosphodiesterase 5(PDE5) inhibitors,was investigated in vivo using a middle cerebral artery occlusion/reperfusion(MCAO/R) model in rats and in vitro using an oxygen-glucose deprivation/reperfusion(OGD/R) model in primary hippocampal neurons.METHODS Laser Doppler flowmeter was introduced to examine the cerebral blood flow of MCAO/R rats.The neurological deficits scores,brain water content and infarction volume were assessed after MCAO/R.OGD/R-induced primary hippocampal neuronal injury and apoptosis were examined by MTT,lactate dehydrogenase(LDH) release,TUNEL staining and flow cytometry,respectively.Expressions of PDE5 A and memory-related signaling pathways were measured using Western blotting analysis.The direct interaction between ICS Ⅱand PDE5 was further evaluated by molecular docking.RESULTS ICS Ⅱ significantly decreased the infraction volume in MCAO/R rats.Furthermore,ICS Ⅱ significantly abrogated OGD/R-induced hippocampal neuronal death.Moreover,ICSⅡ not only effectively restored the 3′ 5′-cyclic guanosine monophosphate(cGMP) level and protein kinase G(PKG) activity both in vivo and in vitro,but also increased brain-derived neurotrophic factor(BDNF),tyrosine protein kinase B(TrkB) and cAMP response element-binding protein(CREB) expressions,thereby inhibited hippocampal neuronal apoptosis.Mechanistically,the beneficial effects of ICS Ⅱ was attributed to its activation of the PKG/TrkB/BDNF via increasing BDNF expression,evidenced by that the inhibition effects of ICSⅡ was abrogated by Rp-8-BrcGMPS,a PKG inhibitor,or ANA-12,a TrkB inhibitor.ICSⅡ also decreased both protein level and activity of PDE5.Notably,ICSⅡ might effectively bind and inhibite PDE5 as demonstrated by relatively high binding score.CONCLUSION ICSⅡ significantly protect against cerebral ischemia/reperfusion injury in rats and rescues OGD/Rinduced hippocampal neuronal injury,and the underling mechanisms are,at least partly,due to inhibition of PDE5 and activation of BDNF/TrkB/CREB signaling pathway.Hence ICS Ⅱ may be an effective agent for combating cerebral ischemia/reperfusion injury.展开更多
基金National Natural Science Foundation of China(81560585)Program for Excellent Young Talentsof Zunyi Medical University(15zy-002)+2 种基金Scienceand Technology Innovation Talent Team of GuizhouProvince(20154023)the hundred”Level of High—level Innovative Talents in Guizhou Province(QKHRCPT 20165684):Education Department of Guizhou Province of China[GNYL(2017)006,YLXKJS—YS一06]Program for Changjiang Scholars and lnnovative Research Team in University,China(IRT-17R113).
文摘OBJECTIVE To explore the effects and mechanism of icariside Ⅱ(ICS Ⅱ),a pharmacologically active compound derived from herbal Epimedii with previous study-proved phosphodiesterase 5(PDE5) inhibitors,was investigated in vivo using a middle cerebral artery occlusion/reperfusion(MCAO/R) model in rats and in vitro using an oxygen-glucose deprivation/reperfusion(OGD/R) model in primary hippocampal neurons.METHODS Laser Doppler flowmeter was introduced to examine the cerebral blood flow of MCAO/R rats.The neurological deficits scores,brain water content and infarction volume were assessed after MCAO/R.OGD/R-induced primary hippocampal neuronal injury and apoptosis were examined by MTT,lactate dehydrogenase(LDH) release,TUNEL staining and flow cytometry,respectively.Expressions of PDE5 A and memory-related signaling pathways were measured using Western blotting analysis.The direct interaction between ICS Ⅱand PDE5 was further evaluated by molecular docking.RESULTS ICS Ⅱ significantly decreased the infraction volume in MCAO/R rats.Furthermore,ICS Ⅱ significantly abrogated OGD/R-induced hippocampal neuronal death.Moreover,ICSⅡ not only effectively restored the 3′ 5′-cyclic guanosine monophosphate(cGMP) level and protein kinase G(PKG) activity both in vivo and in vitro,but also increased brain-derived neurotrophic factor(BDNF),tyrosine protein kinase B(TrkB) and cAMP response element-binding protein(CREB) expressions,thereby inhibited hippocampal neuronal apoptosis.Mechanistically,the beneficial effects of ICS Ⅱ was attributed to its activation of the PKG/TrkB/BDNF via increasing BDNF expression,evidenced by that the inhibition effects of ICSⅡ was abrogated by Rp-8-BrcGMPS,a PKG inhibitor,or ANA-12,a TrkB inhibitor.ICSⅡ also decreased both protein level and activity of PDE5.Notably,ICSⅡ might effectively bind and inhibite PDE5 as demonstrated by relatively high binding score.CONCLUSION ICSⅡ significantly protect against cerebral ischemia/reperfusion injury in rats and rescues OGD/Rinduced hippocampal neuronal injury,and the underling mechanisms are,at least partly,due to inhibition of PDE5 and activation of BDNF/TrkB/CREB signaling pathway.Hence ICS Ⅱ may be an effective agent for combating cerebral ischemia/reperfusion injury.
