Extraction And Phenylethanosides From Paraboea Martinii（Levl.） Burtt Protects PC12 Cells Against To H₂O₂-induced Neurotoxicity

Objective To investigate the protective effect of extraction and phenylethanosides from Paraboea martinii（Levl.）Burtt against H₂O₂-induced PC12 cells injury,their impact on the expression of Nrf2-regulated genes HO-1 and GCLC.Mothods The extracts of P.martinii and 3 phenylethanoid glycosides compounds will be preparated.PC12 cells damage model were established by H₂O₂,Real-time Cell Analysis（RTCA）was utilized for dynamic detection of cell index（CI）in living cells,to detect the protective effect as well as cytotoxicity of P.martinii.The activities of superoxide dismutase（SOD）and lactate dehydrogenase（LDH）in the PC12 cells were measured by biochemical method.Real-time PCR was used to determine m RNA expression of genes HO-1 and GCLC that regulated by Nrf2.Vanquish Flex was used to monitor the concentration of the compounds in the PC12cells culture medium.Results（1）Pre-treatment with different concentration of Caleolarioside B and Paraboside B showed represented protection on PC12 cells induced by H₂O₂.The antioxidant activity of Caleolarioside B showed in a dose-dependent manner within the scope of 3.125μmol·L-1-50μmol·L-1,the 50μmol·L-1 of it treatment showed the best protective effect.Paraboside B and Glutinoside B showed the best protective effect at the concentration 12.5μmol·L-1.（2）Caleolarioside B,Paraboside B and Glutinoside B could improve SOD activity and inhibit LDH activity after H₂O₂-induced injury in PC12cells.（3）Caleolarioside B,Paraboside B and Glutinoside B could obviously activate the expression of gene HO-1 that was Nrf2-regulated downstream gene,expression quantity was 1.5-6 times to control group.Caleolarioside B at 3.125μmol·L^-1 and 50μmol·L^-1could activate the expression of gene GCLC and expression quantity was merely 1.5 times to control group,but Paraboside B and Glutinoside B showed no obvious effect on expression of gene GCLC.Conclusion The n-butanol extract of P.martinii and phenylethanoid glycosides Caleolarioside B,Paraboside B and Glutinoside B showed protective effect on H₂O₂-induced PC12 cells injury,and the possible mechanism of may be the activation of Nrf2/ARE antioxidant signaling pathways.