Black Currant Extract Protects against Oxidative Stress in SH-SY5Y Cells and High-Fat Diet-Induced Cognitive Impairment in C57BL/6 Mice

Black currant (Ribes nigrum L.) is rich in anthocyanins and other phenolic compounds with diverse health benefits. This study investigated the neuroprotective effects of black currant extract (BCE) using integrated in vitro and in vivo approaches. UHPLC-MS/MS analysis identified four major anthocyanins in BCE: delphinidin 3-O-glucoside, delphinidin 3-O-rutinoside, cyanidin 3-O-glucoside, and cyanidin 3-O-rutinoside. In vitro, BCE protected SH-SY5Y neuroblastoma cells against H2O2-induced oxidative stress in a dose-dependent manner, restoring cell viability to 77% of control levels at 50 mg/l. BCE also exhibited dose-dependent inhibition of acetylcholinesterase and butyrylcholinesterase, demonstrating cholinergic-enhancing properties. In vivo, C57BL/6 mice were fed a high-fat diet (HFD) for 4 weeks to induce obesity, followed by 4 weeks of oral BCE administration (50 or 200 mg/kg /day) with continued HFD feeding. Cognitive function was assessed using the Y-maze, passive avoidance, and Morris water maze tests. BCE treatment (50 mg/kg/day) significantly increased the time spent in the target quadrant compared with the HFD-only group (p < 0.05), suggesting that BCE mitigates HFD-induced cognitive impairment by enhancing spatial memory consolidation. BCE also showed trends toward improved performance in Y-maze and passive avoidance tests, though these did not reach statistical significance. These findings demonstrate that BCE exerts multi-target neuroprotective effects through antioxidant activity, cholinesterase inhibition, and amelioration of obesity-associated cognitive deficits, supporting its potential as a functional food ingredient for cognitive health in metabolic syndrome.