Abelmoschus esculentus Ameliorates Cognitive Impairment in Hyperlipidemic ApoE−/− Mice via Modulation of Oxidative Stress and Neuronal Differentiation

Cardiovascular disease (CVD) and dementia may share common pathogenic factors such as atherosclerosis and hyperlipoproteinemia. Dyslipidemia-induced oxidative stress contributes to dementia comorbidity in CVD. <i>Abelmoschus esculentus</i> (AE, okra) potentiates in alleviating hyperlipidemia and diabetes-related cognitive impairment. This study evaluated the effects of AE in hyperlipidemic ApoE^-/- mice treated with streptozotocin (50 mg/kg) and fed a high-fat diet (17% lard oil, 1.2% cholesterol). AE fractions F1 or F2 (0.65 mg/kg) were administered for 8 weeks. AE significantly reduced serum LDL-C, HDL-C, triglycerides, and glucose, improved cognitive and memory function, and protected hippocampal neurons. AE also lowered oxidative stress markers (8-hydroxy-2'-deoxyguanosine, 8-OHdG) and modulated neuronal nuclei (NeuN) and doublecortin (DCX) expression. In vitro, AE promoted neurite outgrowth and neuronal differentiation in retinoic acid (RA)-differentiated human SH-SY5Y cells under metabolic stress (glucose and palmitate), alongside the upregulation of heme oxygenase-1 (HO-1), Nuclear factor-erythroid 2-related factor 2 (Nrf2), and brain-derived neurotrophic factor (BDNF). These findings suggest AE may counter cognitive decline via oxidative stress regulation and the enhancement of neuronal differentiation.