Artemisinin alleviates hippocampal neuronal apoptosis and cognitive impairment in rats after cardiac arrest resuscitation: Association with the PI3K/Akt pathway

Abstract: Background: Cardiac arrest (CA) is associated with high mortality and severe neurological sequelae. Artemisinin (ARS), a natural product from Artemisia annua, has potential neuroprotective effects, but its role in brain injury after CA resuscitation remains unclear. Objectives: This study investigated the effects of ARS on hippocampal neuronal apoptosis and cognitive dysfunction in rats after CA resuscitation and explored whether these effects are associated with the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. Methods: Sixty male rats were randomly assigned to six groups: sham, model, artemisinin (40 mg/kg), dimethyl sulfoxide ((DMSO, 100 mg/kg), LY294002 (a phosphatidylinositol 3-kinase inhibitor, 25 mg/kg) and artemisinin plus LY294002. Cardiac arrest was induced by transcutaneous electrical stimulation. Outcome assessors were blinded. Neurological function was evaluated using the Neurological Deficit Scale. Hippocampal damage and apoptosis were assessed by hematoxylin and eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Learning and memory were tested using novel object recognition and the Morris water maze. Protein expression was measured by Western blot. Results: Artemisinin significantly improved Neurological Deficit Scale scores, reduced terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells and alleviated hippocampal damage. Artemisinin also prolonged novel object exploration time, shortened escape latency, increased target quadrant time and upregulated phosphatidylinositol 3-kinase expression and the ratio of phosphorylated protein kinase B to protein kinase B. Co-administration of LY294002 partially reversed these effects. Conclusion: Artemisinin alleviates hippocampal neuronal apoptosis and improves neurological deficits and cognitive dysfunction in rats after cardiac arrest resuscitation, suggesting a possible association with activation of the phosphatidylinositol 3-kinase/protein kinase B pathway. Limitations include use of a single pharmacological inhibitor and lack of genetic validation.