Neuroprotective effect of the stearic acid against oxidative stress via phosphatidylinositol 3-kinase pathway

Stearic acid is a long-chain saturated fatty acid consisting of 18 carbon atoms without double bonds. In the present study, we reported the neuroprotective effects and mechanism of stearic acid on cortical or hippocampal slices insulted by oxygen–glucose deprivation, NMDA or hydrogen peroxide (H2O2) in vitro. Different types of models of brain slice injury in vitro were developed by 10 min of oxygen/glucose deprivation, 0.5 mM NMDA or 2 mM H2O2, respectively. After 30 min of preincubation with stearic acid (3–30 μM), cortical or hippocampal slices were subjected to oxygen–glucose deprivation, NMDA or H2O2. Then the tissue activities were evaluated by using the 2,3,5-triphenyltetrazolium chloride (TTC) method. Population spikes were recorded in randomly selected hippocampal slices. Stearic acid (3–30 μM) dose-dependently protected brain slices from oxygen–glucose deprivation, NMDA and H2O2 insults. Its neuroprotective effect against H2O2 insults can be completely blocked by wortmannin (inhibitor of PI3K) and partially blocked by H7 (inhibitor of PKC) or genistein (inhibitor of TPK). Treatment of cortical or hippocampal slices with 30 μM stearic acid resulted in a significant increase in PI3K activity at 5, 10, 30 and 60 min. These observations reveal that stearic acid can protect cortical or hippocampal slices against injury induced by oxygen–glucose deprivation, NMDA or H2O2, and its neuroprotective effects are via phosphatidylinositol 3-kinase dependent mechanism.