Aim Baicalein is the major flavonoid obtained from the Scutellaria root. Our previous studies have dem- onstrated that baicalein has a clear positive effect on recovery in an experimental model of Parkinsonism. The pu...Aim Baicalein is the major flavonoid obtained from the Scutellaria root. Our previous studies have dem- onstrated that baicalein has a clear positive effect on recovery in an experimental model of Parkinsonism. The put- pose of this study was to investigate the role of baicalein in modulating dopamine （DA） metabolism in PC12 cells and to explore possible mechanisms of its actions. Methods The intracellular content and extracellular release of DA in both rotenone-treated and untreated PC12 cells were examined. Second, PC12 cells were first pretreated with baicalein （ 10 μmol · L^-1 ） for 10 rain, and then incubated with or without ionomycin （5 μmol · L^-1 ） for 10 rain to test whether short-term exposure to baicalein affected calcium-dependent or spontaneous DA release. Third, the intracellular and extracellular contents of DA and its related metabolites were examined. After treatment with baica- lein for 24 h, the The tyrosine hydroxylase （TH）, monoamine oxidase B （MAOB）, catechol-O-methyltransferase （COMT） and dopamine transporter （DAT） were detected by immunoblot analysis. Results The results showed that baicalein prevented rotenone-induced cytotoxicity and significantly increased the DA content in both rotenone- treated and untreated PC12 cells. Furthermore, it had no effect on ionomycin-induced or spontaneous DA release after short-term exposure but significantly increased DA content in a time- and dose-dependent manner after treat- ment for 6 h. Baicalein also significantly decreased the intracellular and extracellular homovanillic acid （HVA） content but increased the intracellular 3,4-dihydroxy phenylacetic acid （DOPAC） content. Finally, baicalein sig- nificantly decreased the expression of COMT and DAT, but it had no effect on the expression of TH and MAOB. Conclusion These data suggest that bacalein has the ability to increase DA content and modulate DA metabolism by inhibiting the expression of COMT and DAT. Our study provides evidence that baicalein may be a potential anti- PD drug that merits further study.展开更多
OBJECTIVE Mu-Xiang-You-Fang(MXYF)is a classic prescription of Hui medicine,composed of five herbs,which has been used to treat ischemic stroke for many years.However,the potential pharmacological mecha⁃nisms of MXYF r...OBJECTIVE Mu-Xiang-You-Fang(MXYF)is a classic prescription of Hui medicine,composed of five herbs,which has been used to treat ischemic stroke for many years.However,the potential pharmacological mecha⁃nisms of MXYF remain unclear.The present research is to investigate the neuroprotective effect of MXYF and its role in modulating autophagy via AMPK/mTOR signaling pathway in the PC12 oxygen-glucose deprivation and reperfusion(OGD/R)injury model.METHODS MXYF was extracted by supercritical CO2 fluid extraction apparatus.PC12 OGD/R injury model was established by oxygen-glucose deprivation for 2 h and reperfusion for 24 h.The effects of MXYF on the viability and cytotoxicity of PC12 cells were determined through cell counting kit(CCK-8)assay.Colorimetric method was performed to determine the LDH leakage rate.The calcium concentration was determined by chemical fluorescence method and the mitochondrial membrane potential was determined through flow cytometry.Monodansylcadaverine(MDC)staining was conducted to detect autophagosome formation.The expression of LC3,Beclin1,p62,p-AMPK,ULK1,p-mTOR and p-p70s6k proteins were determined by immunofluorescence and Western blotting analyses.RESULTS MXYF(1,2 and 4 mg·L^-1)could significantly increase the cell viability and mitochondrial membrane potential,while decreased the release of lactate dehydrogenase(LDH)and calcium concentration in PC12 cells.Mechanistic studies showed that MXYF reduced the LC3-II/LC3-I ratio and inhibited the expression of beclin1,p-AMPK and ULK1.In comparison,the expres⁃sion of p-mTOR,p-p70s6k and p62 were significantly enhanced.CONCLUSION MXYF inhibits autophagy after OGD/Rinduced PC12 cell injury through AMPK-mTOR pathway,thus MXYF might have therapeutic potential for treating the ischemic stroke.展开更多
文摘Aim Baicalein is the major flavonoid obtained from the Scutellaria root. Our previous studies have dem- onstrated that baicalein has a clear positive effect on recovery in an experimental model of Parkinsonism. The put- pose of this study was to investigate the role of baicalein in modulating dopamine （DA） metabolism in PC12 cells and to explore possible mechanisms of its actions. Methods The intracellular content and extracellular release of DA in both rotenone-treated and untreated PC12 cells were examined. Second, PC12 cells were first pretreated with baicalein （ 10 μmol · L^-1 ） for 10 rain, and then incubated with or without ionomycin （5 μmol · L^-1 ） for 10 rain to test whether short-term exposure to baicalein affected calcium-dependent or spontaneous DA release. Third, the intracellular and extracellular contents of DA and its related metabolites were examined. After treatment with baica- lein for 24 h, the The tyrosine hydroxylase （TH）, monoamine oxidase B （MAOB）, catechol-O-methyltransferase （COMT） and dopamine transporter （DAT） were detected by immunoblot analysis. Results The results showed that baicalein prevented rotenone-induced cytotoxicity and significantly increased the DA content in both rotenone- treated and untreated PC12 cells. Furthermore, it had no effect on ionomycin-induced or spontaneous DA release after short-term exposure but significantly increased DA content in a time- and dose-dependent manner after treat- ment for 6 h. Baicalein also significantly decreased the intracellular and extracellular homovanillic acid （HVA） content but increased the intracellular 3,4-dihydroxy phenylacetic acid （DOPAC） content. Finally, baicalein sig- nificantly decreased the expression of COMT and DAT, but it had no effect on the expression of TH and MAOB. Conclusion These data suggest that bacalein has the ability to increase DA content and modulate DA metabolism by inhibiting the expression of COMT and DAT. Our study provides evidence that baicalein may be a potential anti- PD drug that merits further study.
基金National Natural Science Foundation of China(8166070081260679)Ningxia College FirstClass Discipline Construction Project(Chinese Medicine)Funded Project(NXYLXK2017A06)
文摘OBJECTIVE Mu-Xiang-You-Fang(MXYF)is a classic prescription of Hui medicine,composed of five herbs,which has been used to treat ischemic stroke for many years.However,the potential pharmacological mecha⁃nisms of MXYF remain unclear.The present research is to investigate the neuroprotective effect of MXYF and its role in modulating autophagy via AMPK/mTOR signaling pathway in the PC12 oxygen-glucose deprivation and reperfusion(OGD/R)injury model.METHODS MXYF was extracted by supercritical CO2 fluid extraction apparatus.PC12 OGD/R injury model was established by oxygen-glucose deprivation for 2 h and reperfusion for 24 h.The effects of MXYF on the viability and cytotoxicity of PC12 cells were determined through cell counting kit(CCK-8)assay.Colorimetric method was performed to determine the LDH leakage rate.The calcium concentration was determined by chemical fluorescence method and the mitochondrial membrane potential was determined through flow cytometry.Monodansylcadaverine(MDC)staining was conducted to detect autophagosome formation.The expression of LC3,Beclin1,p62,p-AMPK,ULK1,p-mTOR and p-p70s6k proteins were determined by immunofluorescence and Western blotting analyses.RESULTS MXYF(1,2 and 4 mg·L^-1)could significantly increase the cell viability and mitochondrial membrane potential,while decreased the release of lactate dehydrogenase(LDH)and calcium concentration in PC12 cells.Mechanistic studies showed that MXYF reduced the LC3-II/LC3-I ratio and inhibited the expression of beclin1,p-AMPK and ULK1.In comparison,the expres⁃sion of p-mTOR,p-p70s6k and p62 were significantly enhanced.CONCLUSION MXYF inhibits autophagy after OGD/Rinduced PC12 cell injury through AMPK-mTOR pathway,thus MXYF might have therapeutic potential for treating the ischemic stroke.
