Mechanism of ginsenoside Rb₃ against OGD/R damage based on metabonomic and PCR array analyses

In order to study the mechanisms of ginsenoside Rb₃ (G-Rb₃) against oxygen-glucose deprivation/reoxygenation (OGD/R) injury in HT22 cells based on metabolomics and PCR array, HT22 cells were randomly divided into control group, model group, G-Rb₃ high-dose group (10 µmol/l) and G-Rb₃ low-dose group (5 µmol/l). Except for the control group, which was left untreated, the remaining groups were incubated with 10 mmol/l Na₂S₂O₄ in sugar-free DMEM medium for 2 h and then replaced with serum-free high-sugar DMEM medium for 2 h in order to replicate in vitro OGD/R model. Trypan blue staining was used to detect the cell viability; flow cytometry was used to detect apoptosis; western blotting was used to detect the protein expression levels of Bax, Bcl-2 and caspase-3. The metabolomics were used to analyze the differential metabolites of G-Rb₃ affecting OGD/R in order to find the relevant metabolic pathways. PCR array assay was performed to identify the expression of the differential genes. G-Rb₃ could inhibit HT22 apoptosis according to the result of cell morphology, trypan blue staining and flow cytometry. The levels of Bax and caspase-3 protein expression were decreased, whereas the level of Bcl-2 protein expression was increased after the treatment of G-Rb₃. Metabolomics results showed that a total of 31 differential metabolites between OGD/R group and G-Rb₃ group, such as guanosine level, was downregulated, the levels of enalaprilat and sorbitol were upregulated, affecting ABC transporters, galactose metabolism, citrate cycle and other related metabolic pathways; according to the result of PCR array, it was observed that G-Rb₃ significantly downregulated Trp63, Trp73, Dapk1, Casp14 and Cd70 pro-apoptotic genes. In conclusion, G-Rb₃ has a significant protective effect on the OGD/R model simulated in vitro, and the mechanism may be related to the inhibition of apoptosis by affecting metabolites.