Combination of Paeoniflorin and Calycosin-7-glucoside Promotes Ischemic Stroke Recovery via the PI3K/AKT Signaling Pathway

Abstract Background Paeoniflorin (PF) and calycosin-7-glucoside (CG) play a role in protecting against brain damage following cerebral ischemia. However, the mechanism of action of PF in combination with CG (PF + CG) against ischemia/reperfusion injury remains unclear. Methods The aim of this study was to investigate the protective role of PF + CG on ischemia/reperfusion injury in vivo and in vitro, as well as its potential mechanism of action indicating that PF + CG attenuates middle cerebral artery occlusion (MCAO) /oxygen-glucose deprivation reperfusion (OGD/R) injury via the PI3K/AKT pathway. MCAO rat model was prepared by modified suture method, and behavioral scoring, cerebral infarction area, brain tissue water content measurement, using PI3K, p-PI3K, AKT, p-AKT, Bcl-2, Bax, GSK-3β protein expression as indicators, observe the effect of PI3K / AKT signaling pathway inhibitor LY294002 on the anti-ischemia-reperfusion effect of PF + CG. Oxygen deprivation method was used to prepare the OGD/R model, CCK-8 was used to determine the survival rate of HT22 cells, the contents of SOR, ROS, MDA, and LHD were determined, and apoptosis was detected by flow cytometry and mitochondrial membrane potential, using PI3K, p-PI3K, AKT, p-AKT, Bcl-2, Bax, GSK-3β protein expression as indicators, observe the effect of PI3K/AKT signaling pathway inhibitor LY294002 on the anti- oxidative and glucose deprivation effect of PF + CG. Results The animal studies showed that PF + CG significantly decreased neurobehavioral deficits, cerebral infarct volume, and brain edema; ameliorated histopathological damage in model rats; increased levels of PI3K, AKT, p-PI3K, p-AKT, and Bcl-2; and reduced BAX and GSK-3β expression. After treatment with PF + CG, the morphology and number of cells in brain tissue were restored to normal, demonstrating a therapeutic effect in cerebral ischemia-reperfusion injury. Results of further studies revealed that, in vitro, PF + CG has a therapeutic effect to enhance cell vitality; elevate levels of superoxide dismutase (SOD); reduce levels of reactive oxygen species (ROS), lactate dehydrogenase (LDH), and malondialdehyde (MDA); decrease apoptosis rate; increase levels of PI3K, AKT, p-PI3K, p-AKT, and Bcl-2; and reduce BAX and GSK-3β expression. Conclusion These results demonstrate that PF + CG has a positive therapeutic effect on ischemia/reperfusion and OGD/R injury, and the mechanism is attributed to activation of the PI3K/AKT signaling pathway.