Cerebral ischemia-reperfusion injury(CI/RI)remains the main cause of disability and death in stroke patients due to lack of effective therapeutic strategies.One of the main issues related to CI/RI treatment is the pre...Cerebral ischemia-reperfusion injury(CI/RI)remains the main cause of disability and death in stroke patients due to lack of effective therapeutic strategies.One of the main issues related to CI/RI treatment is the presence of the blood-brain barrier(BBB),which affects the intracerebral delivery of drugs.Ginkgolide B(GB),a major bioactive component in commercially available products of Ginkgo biloba,has been shown significance in CI/RI treatment by regulating inflammatory pathways,oxidative damage,and metabolic disturbance,and seems to be a candidate for stroke recovery.However,limited by its poor hydrophilicity and lipophilicity,the development of GB preparations with good solubility,stability,and the ability to cross the BBB remains a challenge.Herein,we propose a combinatorial strategy by conjugating GB with highly lipophilic docosahexaenoic acid(DHA)to obtain a covalent complex GB-DHA,which can not only enhance the pharmacological effect of GB,but can also be encapsulated in liposomes stably.The amount of finally constructed Lipo@GB-DHA targeting to ischemic hemisphere was validated 2.2 times that of free solution in middle cerebral artery occlusion(MCAO)rats.Compared to the marketed ginkgolide injection,Lipo@GB-DHA significantly reduced infarct volume with better neurobehavioral recovery in MCAO rats after being intravenously administered both at 2 h and 6 h post-reperfusion.Low levels of reactive oxygen species(ROS)and high neuron survival in vitro was maintained via Lipo@GB-DHA treatment,while microglia in the ischemic brain were polarized from the pro-inflammatory M1 phenotype to the tissue-repairing M2 phenotype,which modulate neuroinflammatory and angiogenesis.In addition,Lipo@GB-DHA inhibited neuronal apoptosis via regulating the apoptotic pathway and maintained homeostasis by activating the autophagy pathway.Thus,transforming GB into a lipophilic complex and loading it into liposomes provides a promising nanomedicine strategy with excellent CI/RI therapeutic efficacy and industrialization prospects.展开更多
The effect of peripherally administered oxytocin(OT)on gastric ischemia-reperfusion injury(GI-RI)and its possible mechanism were investigated.The Sprague-Dawley(SD)rats were randomly divided into different treatment g...The effect of peripherally administered oxytocin(OT)on gastric ischemia-reperfusion injury(GI-RI)and its possible mechanism were investigated.The Sprague-Dawley(SD)rats were randomly divided into different treatment groups(n=6).The animal GI-RI model was established by clamping the celiac artery for 30 min to induce ischemia and then released to allow reperfusion for 1 h,and the degree of GI-RI was assessed by scoring the gastric mucosal damage index(GMDI),the gastric fluid output,gastric fluid output,gastric acidity were measured and the surgical preparations of vagotomy and sympathectomy were used to investigate the possible mechanism of OT on GI-RI.The results were as follows.Compared with the control group(NS plus GI-R only,GMDI 121.33P10.40,n=6),the intra peritoneal(ip)administration of oxytocin(20,100μg/0.5 mL)obviously attenuated GI-RI(P<0.05),GMDI were 82.33P14.26,53.5P5.58 respectively(n=6);the gastric fluid output and the gastric acidity(evaluated by pH)of the control group were(430.17P87.36)μL,1.55P0.25(n=6),and those of the OT group were(102.45P48.00)μL,2.65P0.40(n=6)res pectively;differences had statistical significance(P<0.01).The effect of oxytocin was reversed by atosiban,a selective oxytocin receptor antagonist.The GMDI of the group given atosiban 10 min before OT was 138.17P24.06(n=6),which had no significant difference with the control group.Oxytocin further attenuated GI-RI after vagotomy and sympathectomy(GMDI 6.83P8.89,29.67P5.54,n=6),compared with the GI-R group and the oxytocin group(P<0.01).These results indicated that the oxytocin could significantly protect gastric mucosal against injury induced by ischemia-reperfusion,and the oxytocin receptor was involved.This effect of oxytocin may be mediated through the vagus and sympathetic nerve,and then lead to the reduction of gastric juice output and the depression of gastric acidity.展开更多
基金This research was funded by the National Natural Science Foundation of China(No.81773911,81690263 and 81573616)the Development Project of Shanghai Peak Disciplines-Integrated Medicine(No.20180101).
文摘Cerebral ischemia-reperfusion injury(CI/RI)remains the main cause of disability and death in stroke patients due to lack of effective therapeutic strategies.One of the main issues related to CI/RI treatment is the presence of the blood-brain barrier(BBB),which affects the intracerebral delivery of drugs.Ginkgolide B(GB),a major bioactive component in commercially available products of Ginkgo biloba,has been shown significance in CI/RI treatment by regulating inflammatory pathways,oxidative damage,and metabolic disturbance,and seems to be a candidate for stroke recovery.However,limited by its poor hydrophilicity and lipophilicity,the development of GB preparations with good solubility,stability,and the ability to cross the BBB remains a challenge.Herein,we propose a combinatorial strategy by conjugating GB with highly lipophilic docosahexaenoic acid(DHA)to obtain a covalent complex GB-DHA,which can not only enhance the pharmacological effect of GB,but can also be encapsulated in liposomes stably.The amount of finally constructed Lipo@GB-DHA targeting to ischemic hemisphere was validated 2.2 times that of free solution in middle cerebral artery occlusion(MCAO)rats.Compared to the marketed ginkgolide injection,Lipo@GB-DHA significantly reduced infarct volume with better neurobehavioral recovery in MCAO rats after being intravenously administered both at 2 h and 6 h post-reperfusion.Low levels of reactive oxygen species(ROS)and high neuron survival in vitro was maintained via Lipo@GB-DHA treatment,while microglia in the ischemic brain were polarized from the pro-inflammatory M1 phenotype to the tissue-repairing M2 phenotype,which modulate neuroinflammatory and angiogenesis.In addition,Lipo@GB-DHA inhibited neuronal apoptosis via regulating the apoptotic pathway and maintained homeostasis by activating the autophagy pathway.Thus,transforming GB into a lipophilic complex and loading it into liposomes provides a promising nanomedicine strategy with excellent CI/RI therapeutic efficacy and industrialization prospects.
基金supported by the National Natural Science Foundation of China(Grant No.30370533,30570671)the Educational Department Science Research Foundation of Jiangsu Province(No.99KJB310005,05KJB310134)。
文摘The effect of peripherally administered oxytocin(OT)on gastric ischemia-reperfusion injury(GI-RI)and its possible mechanism were investigated.The Sprague-Dawley(SD)rats were randomly divided into different treatment groups(n=6).The animal GI-RI model was established by clamping the celiac artery for 30 min to induce ischemia and then released to allow reperfusion for 1 h,and the degree of GI-RI was assessed by scoring the gastric mucosal damage index(GMDI),the gastric fluid output,gastric fluid output,gastric acidity were measured and the surgical preparations of vagotomy and sympathectomy were used to investigate the possible mechanism of OT on GI-RI.The results were as follows.Compared with the control group(NS plus GI-R only,GMDI 121.33P10.40,n=6),the intra peritoneal(ip)administration of oxytocin(20,100μg/0.5 mL)obviously attenuated GI-RI(P<0.05),GMDI were 82.33P14.26,53.5P5.58 respectively(n=6);the gastric fluid output and the gastric acidity(evaluated by pH)of the control group were(430.17P87.36)μL,1.55P0.25(n=6),and those of the OT group were(102.45P48.00)μL,2.65P0.40(n=6)res pectively;differences had statistical significance(P<0.01).The effect of oxytocin was reversed by atosiban,a selective oxytocin receptor antagonist.The GMDI of the group given atosiban 10 min before OT was 138.17P24.06(n=6),which had no significant difference with the control group.Oxytocin further attenuated GI-RI after vagotomy and sympathectomy(GMDI 6.83P8.89,29.67P5.54,n=6),compared with the GI-R group and the oxytocin group(P<0.01).These results indicated that the oxytocin could significantly protect gastric mucosal against injury induced by ischemia-reperfusion,and the oxytocin receptor was involved.This effect of oxytocin may be mediated through the vagus and sympathetic nerve,and then lead to the reduction of gastric juice output and the depression of gastric acidity.
