Protective Effect Of Quercetin On The Oxidative Damage Induced By Hydrogen Peroxide And Mechanism In PC12Cells

AimOur purpose is to understand the effects of quercetin on cell proliferation and its protective role on cellular oxidate injury induced by hydrogen peroxide in PC12cell line.MethodsMTT assay was used to evaluate the effects of quercetin on cell proliferation and measure its protective role on the oxidative injury model by H2O2induced. Lactate dehydrogenase(LDH) assay was used to detect the protective effect by quercetin on PC12cells oxidative injury by H2O2induced as well. In the meantime, the morphological changes of PC12cells and hippocampal neuron were observed under reversal phase microscope by Hoechst-33342stain, PI stain and TUNEL method. The apoptosis of cell was detected by FCM to conform whether quercetin would prevent PC12cells from H2O2induced oxidative damage. We also discussed mechanism of potential antioxidant on quercetin. Firstly, level of ROS and malondialdelyde (MDA) were measure respectively with HCS and ultraviolet spectral photometer. Furthermore, the activity of superoxide dismutase(SOD), CAT and GSH-PX in cells were measured by spectroscopy respectively. The purpose is to know that whether quercetin could rescued the balance of oxidant and antioxidant on intracellular. Finally, we mainly analyzed expression of caspase-3, bcl-2, bax and p53et.al regulating apoptosis associated factor by western-blotting method, to probe effect of quercetin in apoptotic signaling.Results(1) Quercetin had no toxicity to cultured PC12cells under the tested concentrations.(2) This study was demonstrated that quercetin could obviously inhibited oxidative damage by H2O2induced PC12cell with MTT and LDH methods.(3) Quercetin remitted the morphological changes of PC12cells since H2O2induced production, and reduced apoptosis body development, inhibited nuclear enrichment and marginalization. In the meanwhile, it could reduce hippocampal neuron apoptosis.(4) Our data suggested that quercetin reduced the cellular active oxygen by up-regulation of SOD, CAT and GSH-PX. Quercetin also reduced the MDA and thereby prevented the ROS injury induced by H2O2. (5) We fund the expression of Bax and P53was lower and litter level of procaspase-3cracked into cleave-caspase-3than before quercetin treated PC12cell. While the expression of anti-apoptoic protein-Bcl-2was higher than only H2O2treat PC12cells.ConclusionFirstly, this study demonstrated that quercetin can functions as an antioxidant to prevent the cellular injury induced by H2O2in cultured PC12cells and hippocampal neuron, and without toxic to the cell viability. Secondly, the mechanism is likely that quercetin increases activity of SOD, CAT, GSH-PX etc. antioxidant system, and then reduced induced produce ROS and liqid peroxidation produce MDA by H2O2. Finally, maybe quercetin increase express of anti-apoptosis associated factor (likely Bcl-2), while inhibited trigger apoptosis factor (likely ROS) initiated apoptosis factor (likely caspase-3, Bax and P53) mediated signaling pathway. According to these results account for protective effect of quercetin on induced oxidative injury by H2O2in PC12cells.