N-Acetylcysteine Reduces Tissue Injury Induced by Oxygen–Glucose Deprivation in an Organotypic Culture of Mouse Cerebral Cortex Slices

Background/Objectives: Hypoxic–ischemic encephalopathy is the leading cause of infant mortality and disability. Hypothermic therapy is effective in hypoxic–ischemic encephalopathy, albeit in a limited number of cases. Hypothermia requires advanced technologies and significant financial resources, which are difficult to sustain in low-income countries, with devastating consequences. Valid alternatives to hypothermia therapy are therefore needed. Methods: In vitro organotypic cultures of mouse cerebral cortex slices were used to demonstrate the direct protective effect of N-acetylcysteine (NAC) against brain tissue damage induced by oxygen–glucose deprivation (OGD), and to identify the concentrations and time window that maximize the drug’s effectiveness. NAC’s effectiveness was measured by the incorporation of propidium iodide (PI), a marker of cell membrane integrity. Results: Adding 0.1 and 1 mM NAC to the incubation medium before OGD strongly reduced OGD-induced PI incorporation, by 80% (p 0.05). Exposure of slices to 0.1 and 1 mM NAC reduced PI incorporation in female cerebral cortex slices (p < 0.006), while only the higher concentration was effective in male slices (p < 0.05). Exposure to 0.1 mM NAC increased tissue levels of total glutathione (p = 0.0185), while no significant effect was observed with 1 mM NAC. Conclusions: This work highlights the direct effect of NAC in protecting cerebral cortex cells from OGD-induced damage and identifies the concentrations and time window that maximize the drug’s effect. The results underscore the need for further studies to verify the in vivo efficacy of NAC at concentrations found to be active in vitro, and for clinical trials to evaluate whether NAC can reduce hypoxia-induced brain damage in newborns.