The neuroprotective effect of apigenin against OGD/R injury in rat hippocampal neurons

To investigate the effects of apigenin on the injury caused by oxygen and glucose deprivation in neurons and the underlying mechanisms, primary cultured rat hippocampal neurons were incubated with apigenin for 90 min before a 2-h oxygen and glucose deprivation followed by a 24-h reperfusion (OGD/R). Subsequently, cell viability, lactate dehydrogenase (LDH) leakage rate, apoptotic rate of neurons and activity of the sodium pump were assessed. In addition, activity of the sodium pump was also examined in the hippocampus of SD rats injected intraperitoneally with apigenin 90 min before a 10-min global cerebral ischemia/24-h reperfusion. The results showed that cell viability and activity of the sodium pump markedly decreased but LDH leakage rate and apoptotic rate significantly increased in OGD/R-treated neurons. However, pretreatment with apigenin (20-50μmol/L) reversed the changes dose-dependently. Compared to sham controls, activity of the sodium pump was significantly suppressed in global ischemia/reperfusion rats; application of apigenin (200mg/kg) restored the activity of the sodium pump. Furthermore, the neuroprotective effect of apigenin was blocked partly by the sodium pump inhibitor ouabain. Our findings provide the evidence that apigenin has a neuroprotective effect against OGD/R injury and the protective effect may be associated with its ability to improve sodium pump activity.