BACKGROUND： Previous studies have demonstrated that intracellular Ca^2＋ （[Ca^2＋]） overload, excitotoxicity, free radical injury, and nitric oxide toxicity are involved in mechanisms of neuronal death in the ische...BACKGROUND： Previous studies have demonstrated that intracellular Ca^2＋ （[Ca^2＋]） overload, excitotoxicity, free radical injury, and nitric oxide toxicity are involved in mechanisms of neuronal death in the ischemic brain. OBJECTIVE： To investigate the influence of Panax quinquefo/ium saponins （PQS） on multiple factors-induced Ca^2＋ overload in the rat pheochromocytoma （PC12） cell line. DESIGN, TIME AND SETTING： Intergroup comparison, in vitro study. The experiment was performed at the Heilongjiang Key Laboratory of Anti-fibrosis Biotherapy, Mudanjiang Medical University between November 2007 and April 2008. MATERIALS- In vitro cultured PC12 cells in the logarithmic phase were assigned into blank control, model, and drug treatment groups （10 μmol/L nimodipine; 40 μg/L, 100 μg/L, and 250 μg/L PQS）. Nimodipine was purchased from Jiangsu Yangtze River Pharmacy Group Co., China; PQS （purity 〉 95%, HLPC grade） was provided by School of Basic Medical Sciences, Jilin University. Caffeine, Na2S2O4, L-glutamic acid （Glu）, Fura-2/AM, and calcium ionophore A23187 were purchased from Sigma, USA. METHODS： PC12 cells in the model and drug treatment groups were separately incubated in glucose-free Hank＇s buffered saline solution ＋ Na2S2O4 （2 mmol/L） for 6 hours, Glu （200 μmot/L） plus A23187 （0.05 μmol/L） for 6 hours, KCI （50 mmol/L） for 1 hour, and caffeine （5 mmol/L） for 3 hours to establish models of intracellular Ca^2＋ overload induced by oxygen and glucose deprivation, Glu, A23187, high K＋, or caffeine. In addition, control cells were incubated in high-glucose DMEM culture medium. MAIN OUTCOME MEASURES： [Ca^2＋]i changes in PC12 cells exposed to oxygen-glucose deprivation, Glu, A23187, high K^＋, or caffeine were detected using spectrofluorometer. RESULTS： PQS blocked the [Ca^2＋]i increase induced by oxygen-glucose deprivation, Glu, A23187, high K＋, or caffeine. In particular, high-dose PQS was most effective （P 〈 0.01）. PQS significantly inhibited Glu- or caffeine-induced [Ca^2＋]i increases in the absence of extracellular Ca^2＋, but nimodipine did not. CONCLUSION： PQS blocked intracellular Ca^2＋ overload induced by oxygen-glucose deprivation, Glu, A23187, high K^＋, or caffeine. This mechanism might be involved in the attenuation of neuronal apoptosis following ischemic brain injury.展开更多
Objective To investigate the effects and underlying mechanisms of Panax quinquefolium saponin(PQS)on energy deficiency in hypoxia-reperfusion(H/R)induced cardiomyocytes.Methods The H/R injury involved hypoxia for 3 h ...Objective To investigate the effects and underlying mechanisms of Panax quinquefolium saponin(PQS)on energy deficiency in hypoxia-reperfusion(H/R)induced cardiomyocytes.Methods The H/R injury involved hypoxia for 3 h and then reperfusion for 2 h.Cardiomyocytes recruited from neonatal rat ventricular myocytes(NRVMs)were randomly divided into control,H/R,H/R+compound C(C.C),H/R+PQS,and H/R+C.C+PQS groups.BrdU assay,lactase dehydrogenase(LDH)leakage and early apoptosis rate were evaluated to assess cell damages.Contents of high energy phosphate compounds were conducted to detect the energy production.Protein expression levels of adenosine monophosphate-activated protein kinase a(AMPKα),glucose transporter 4(GLUT4),phosphate fructose kinase 2(PFK2),fatty acid translocase/cluster of differentiation 36(FAT/CD36),and acetyl CoA carboxylase 2(ACC2)in the regulatory pathways were measured by Western blotting.Immunofluorescence staining of GLUT4 and FAT/CD36 was used to observe the mobilization of metabolic transporters.Results PQS(50 mg/L)pretreatment significantly alleviated H/R-induced inhibition of NRVMs viability,up-regulation of LDH leakage,acceleration of early apoptosis,and reduction of energy production(P<0.05).Compared with the H/R group,up-regulated expression of AMPKα,GLUT4,PFK2,FAT/CD36 and ACC2 were observed,and more GLUT4 and FAT/CD36 expressions were detected on the membrane in the H/R+PQS group(P<0.05).These effects of PQS on H/R-induced NRVMs were eliminated in the H/R+C.C+PQS group(P<0.05).Conclusion PQS has prominent advantages in protecting NRVMs from H/R-induced cell damages and energy metabolic disorders,by activation of AMPKα-mediated GLUT4-PFK2 and FAT/CD36-ACC2 pathways.展开更多
Objective： To explore the effects of Panax Quinquefolium Saponin （PQS） on phosphatidylinositol 3-kinase/serine threonine kinase （P13/Akt） pathway of neonatal rat myocardial cells subjected to hypoxia. Methods： N...Objective： To explore the effects of Panax Quinquefolium Saponin （PQS） on phosphatidylinositol 3-kinase/serine threonine kinase （P13/Akt） pathway of neonatal rat myocardial cells subjected to hypoxia. Methods： Neonatal rat myocardial cells were cultured in vitro. After the myocardial cell injury was induced by hypoxia, the cells were randomized into 5 groups： the normal group, the model group, the positive control group （Ciclosporin A, 2 p, mol/L）, the low-dose PQS group （PQSL, 25mg/L）, and the high-dose PQS group （PQSH, 50 mg/L）. Morphology and behavior of myocardial cells were observed under an inverted microscope. Apoptosis rate and lactate dehydrogenase （LDH） leakage rate of myocardial cells were determined by colorimetry. Mitochondrial transmembrane potential was assessed using a fluorexon laser. Phospho-glycogen synthase kinase （GSK）-3β and phospho-Akt as well as cytochrome C were determined by Western blot. Results： LDH leakage in the Ciclosporin A group, PQSH group and PQSL group reduced progressively compared with the model group （P〈0.05）. Akt and GSK-3β was strongly phosphorylated after treatment with Ciclosporin A and PQS compared with the model group （P〈0.05, P〈0.01）. Compared with the model group （16.41 ± 1.74; 35.28 ± 6.30）, both the integrated optical density of mitochondrial permeability transition pore （MPTP） and the mitochondrial transmembrane potential significantly increased in the PQSH group （42.74± 2.12; 71.36 ± 6.54） and the PQSL group （39.58± 1.49; 66.99± 5.45; P〈0.05, P〈0.01）. However, the protein of cytochrome C outside the mitochonddon decreased in the PQSH group （273.66 ± 14.61） and the PQSL group （259.62 ± 17.31） compared with the model group （502.41 ± 17.76; P〈0.05）. Conclusion： Through activation of the P13K/Akt pathway and inhibition of the MPTP, PQS might protect the heart against ischemia injury and apoptosis of myocardial cells.展开更多
One new triterpcnoid saponin, quinquenoside L17 （1）, was isolated from the leaves and stems of Panax quinquefolium L., and its structure was elucidated as 20-O-[（β-D-xylopyranosyl-（1-6）-O-β-D-glucopyranosy）]-6...One new triterpcnoid saponin, quinquenoside L17 （1）, was isolated from the leaves and stems of Panax quinquefolium L., and its structure was elucidated as 20-O-[（β-D-xylopyranosyl-（1-6）-O-β-D-glucopyranosy）]-6-O-β-D-glucopyranosy1-dammar-24-ene- 3,6,12,20-tetraol, by the combination analysis of one-dimensional NMR and two-dimensional NMR, mass spectrometry, CD spectrum and chemical evidences.展开更多
基金Supported by:the Natural Science Foundation of Heilongjiang Province,No ZA2006-07
文摘BACKGROUND： Previous studies have demonstrated that intracellular Ca^2＋ （[Ca^2＋]） overload, excitotoxicity, free radical injury, and nitric oxide toxicity are involved in mechanisms of neuronal death in the ischemic brain. OBJECTIVE： To investigate the influence of Panax quinquefo/ium saponins （PQS） on multiple factors-induced Ca^2＋ overload in the rat pheochromocytoma （PC12） cell line. DESIGN, TIME AND SETTING： Intergroup comparison, in vitro study. The experiment was performed at the Heilongjiang Key Laboratory of Anti-fibrosis Biotherapy, Mudanjiang Medical University between November 2007 and April 2008. MATERIALS- In vitro cultured PC12 cells in the logarithmic phase were assigned into blank control, model, and drug treatment groups （10 μmol/L nimodipine; 40 μg/L, 100 μg/L, and 250 μg/L PQS）. Nimodipine was purchased from Jiangsu Yangtze River Pharmacy Group Co., China; PQS （purity 〉 95%, HLPC grade） was provided by School of Basic Medical Sciences, Jilin University. Caffeine, Na2S2O4, L-glutamic acid （Glu）, Fura-2/AM, and calcium ionophore A23187 were purchased from Sigma, USA. METHODS： PC12 cells in the model and drug treatment groups were separately incubated in glucose-free Hank＇s buffered saline solution ＋ Na2S2O4 （2 mmol/L） for 6 hours, Glu （200 μmot/L） plus A23187 （0.05 μmol/L） for 6 hours, KCI （50 mmol/L） for 1 hour, and caffeine （5 mmol/L） for 3 hours to establish models of intracellular Ca^2＋ overload induced by oxygen and glucose deprivation, Glu, A23187, high K＋, or caffeine. In addition, control cells were incubated in high-glucose DMEM culture medium. MAIN OUTCOME MEASURES： [Ca^2＋]i changes in PC12 cells exposed to oxygen-glucose deprivation, Glu, A23187, high K^＋, or caffeine were detected using spectrofluorometer. RESULTS： PQS blocked the [Ca^2＋]i increase induced by oxygen-glucose deprivation, Glu, A23187, high K＋, or caffeine. In particular, high-dose PQS was most effective （P 〈 0.01）. PQS significantly inhibited Glu- or caffeine-induced [Ca^2＋]i increases in the absence of extracellular Ca^2＋, but nimodipine did not. CONCLUSION： PQS blocked intracellular Ca^2＋ overload induced by oxygen-glucose deprivation, Glu, A23187, high K^＋, or caffeine. This mechanism might be involved in the attenuation of neuronal apoptosis following ischemic brain injury.
基金Supported by the National Natural Science Foundation of China(No.81273934 and No.81874410)。
文摘Objective To investigate the effects and underlying mechanisms of Panax quinquefolium saponin(PQS)on energy deficiency in hypoxia-reperfusion(H/R)induced cardiomyocytes.Methods The H/R injury involved hypoxia for 3 h and then reperfusion for 2 h.Cardiomyocytes recruited from neonatal rat ventricular myocytes(NRVMs)were randomly divided into control,H/R,H/R+compound C(C.C),H/R+PQS,and H/R+C.C+PQS groups.BrdU assay,lactase dehydrogenase(LDH)leakage and early apoptosis rate were evaluated to assess cell damages.Contents of high energy phosphate compounds were conducted to detect the energy production.Protein expression levels of adenosine monophosphate-activated protein kinase a(AMPKα),glucose transporter 4(GLUT4),phosphate fructose kinase 2(PFK2),fatty acid translocase/cluster of differentiation 36(FAT/CD36),and acetyl CoA carboxylase 2(ACC2)in the regulatory pathways were measured by Western blotting.Immunofluorescence staining of GLUT4 and FAT/CD36 was used to observe the mobilization of metabolic transporters.Results PQS(50 mg/L)pretreatment significantly alleviated H/R-induced inhibition of NRVMs viability,up-regulation of LDH leakage,acceleration of early apoptosis,and reduction of energy production(P<0.05).Compared with the H/R group,up-regulated expression of AMPKα,GLUT4,PFK2,FAT/CD36 and ACC2 were observed,and more GLUT4 and FAT/CD36 expressions were detected on the membrane in the H/R+PQS group(P<0.05).These effects of PQS on H/R-induced NRVMs were eliminated in the H/R+C.C+PQS group(P<0.05).Conclusion PQS has prominent advantages in protecting NRVMs from H/R-induced cell damages and energy metabolic disorders,by activation of AMPKα-mediated GLUT4-PFK2 and FAT/CD36-ACC2 pathways.
基金Supported by the China Postdoctoral Science Fondation(No.20100480427)the National Natural Science Fondation of China(No.81041038)
文摘Objective： To explore the effects of Panax Quinquefolium Saponin （PQS） on phosphatidylinositol 3-kinase/serine threonine kinase （P13/Akt） pathway of neonatal rat myocardial cells subjected to hypoxia. Methods： Neonatal rat myocardial cells were cultured in vitro. After the myocardial cell injury was induced by hypoxia, the cells were randomized into 5 groups： the normal group, the model group, the positive control group （Ciclosporin A, 2 p, mol/L）, the low-dose PQS group （PQSL, 25mg/L）, and the high-dose PQS group （PQSH, 50 mg/L）. Morphology and behavior of myocardial cells were observed under an inverted microscope. Apoptosis rate and lactate dehydrogenase （LDH） leakage rate of myocardial cells were determined by colorimetry. Mitochondrial transmembrane potential was assessed using a fluorexon laser. Phospho-glycogen synthase kinase （GSK）-3β and phospho-Akt as well as cytochrome C were determined by Western blot. Results： LDH leakage in the Ciclosporin A group, PQSH group and PQSL group reduced progressively compared with the model group （P〈0.05）. Akt and GSK-3β was strongly phosphorylated after treatment with Ciclosporin A and PQS compared with the model group （P〈0.05, P〈0.01）. Compared with the model group （16.41 ± 1.74; 35.28 ± 6.30）, both the integrated optical density of mitochondrial permeability transition pore （MPTP） and the mitochondrial transmembrane potential significantly increased in the PQSH group （42.74± 2.12; 71.36 ± 6.54） and the PQSL group （39.58± 1.49; 66.99± 5.45; P〈0.05, P〈0.01）. However, the protein of cytochrome C outside the mitochonddon decreased in the PQSH group （273.66 ± 14.61） and the PQSL group （259.62 ± 17.31） compared with the model group （502.41 ± 17.76; P〈0.05）. Conclusion： Through activation of the P13K/Akt pathway and inhibition of the MPTP, PQS might protect the heart against ischemia injury and apoptosis of myocardial cells.
基金supported by 973 Program(No.2006CB708517)Program for New Century Excellent Talents in University of Peoples Republic of China(No.NCET-04-0289)
文摘One new triterpcnoid saponin, quinquenoside L17 （1）, was isolated from the leaves and stems of Panax quinquefolium L., and its structure was elucidated as 20-O-[（β-D-xylopyranosyl-（1-6）-O-β-D-glucopyranosy）]-6-O-β-D-glucopyranosy1-dammar-24-ene- 3,6,12,20-tetraol, by the combination analysis of one-dimensional NMR and two-dimensional NMR, mass spectrometry, CD spectrum and chemical evidences.
