Abstract:

Objective To discuss the protective effect of gingerone on the hippocampal neuron HT22 cells after oxygen-glucose deprivation/reoxygenation （OGD/R），and to clarify the related mechanism. Methods The HT22 cells were cultured， and the OGD/R cell injury model was established by setting the gradient of OGD/R time. The HT22 cells were divided into control group，OGD/R group， OGD/R+1 μmol·L^－1 gingerone group， OGD/R + 10 μmol·L^－1 gingerone group， OGD/R+100 μmol·L^－1 gingerone group，and OGD/R+0.2% dimethyl sulfoxide（DMSO） group.The viability of the cells in various groups was detected by CCK-8 assay； the survival rates of the cells in various groups were calculated to determine the optimal drug concentration of gingerone. The cells were divided into control， OGD/R group， OGD/R+ gingerone， and OGD/R+gingerone+nuclear factor erythroid-2-related factor 2（Nrf2） inhibitor（ML385） groups.The cells in OGD/R + gingerone group were treated with gingerone for 4 h before OGD treatment for 8 h followed by reoxygenation for 8 h， and the cells in OGD/R+gingerone+ML385 group were treated with 10 μmol·L^－1 ML385 for 6 h before gingerone treatment. The viability of the cells in various groups was detected by CCK-8 assay；the expression levels of Nrf2， heme oxygenase-1 （HO-1）， B-cell lymphoma-2 （Bcl-2）， and Bcl-2-associated X protein （Bax） proteins in the cells in various groups were detected by Western blotting method；the activity of superoxide dismutase （SOD） and the level of malondialdehyde （MDA） in the cell culture supernatant in various groups were detected by enzyme-linked immunosorbent assay （ELISA） method. Results Compared with control group， the survival rate of the HT22 cells was below 50% after treated with OGD for 8 h and reoxygenation for 8 h， so the HT22 cell OGD/R model was established by treated with OGD for 8 h and reoxygenation for 8 h. Compared with OGD/R group，the survival rates of the cells in OGD/R+different doses of gingerone groups were increased to various extents， and the survival rate of the cells in OGD/R+ 100 μmol·L^－1 gingerone group was significantly increased （P<0.01）； so 100 μmol·L^－1 gingerone was used for the subsequent experiment. Compared with control group， the viability of the cells in OGD/R group was significantly decreased （P<0.01）， and the expression levels of Nrf2， HO-1， and Bax proteins in the cells were significantly increased （P<0.01）， while the expression level of Bcl-2 protein in the cells was significantly decreased （P<0.05）， and the SOD activity in the cell culture supernatant was significantly decreased （P<0.01）， and the level of MDA was significantly increased （P<0.01）； compared with OGD/R group， the viability of the cells in OGD/R + gingerone group was significantly increased （P<0.01）， and the expression levels of Nrf2， HO-1， and Bcl-2 proteins in the cells were significantly increased （P<0.05 or P<0.01）， while the expression level of Bax protein in the cells was decreased（P<0.05）， the SOD activity in the cell culture supernatant was significantly increased （P<0.01）， and the level of MDA was significantly decreased （P<0.01）； compared with OGD/R + gingerone group， the viability of the cells in OGD/R + gingerone + ML385 group was significantly decreased （P<0.01）， and the expression levels of Nrf2， HO-1， and Bcl-2 proteins were significantly decreased （P<0.01）， while the expression level of Bax protein in the cells was significantly increased （P<0.01），the SOD activity in the cell culture supernatant was significantly decreased （P<0.01）， and the level of MDA was significantly increased （P<0.05）. Conclusion Gingerone alleviates the oxidative stress damage，and thereby plays an inhibiory effect on the apoptosis of the HT22 neurons by activating the Nrf2/HO-1 signaling pathway after OGD/R.

Key words: Gingerone, Oxygen-glucose deprivation, HT22 neuron, Nuclear factor erythroid-2-related factor 2, Heme oxygenase 1, Oxidative stress, Apoptosis