The Combined Effect of Green Tea, Saffron, Resveratrol, and Citicoline against Neurodegeneration Induced by Oxidative Stress in an In Vitro Model of Cognitive Decline.

During ageing, the brain is vulnerable to a growing imbalance of the antioxidant defence system, resulting in increased oxidative stress. This condition may be mainly responsible for cognitive decline, resulting in synaptic transmission disruptions and the onset of neuronal dysfunction. In this context, developing efficient preventive and therapeutic strategies against increased oxidative stress and decreased antioxidant defence mechanisms should be considered a public health priority to promote healthy ageing. Therefore, the current study explored the benefits of a novel combination of green tea, saffron, trans-Reveratrol, and citicoline, called MIX, on improving intracellular processes to ameliorate the mechanisms linked to cognitive decline under oxidative stress conditions. First, the ability of MIX to cross the blood-brain barrier (BBB) was evaluated in an in vitro model, analysing TEER value and the specific tight junctions; second, the CCF-STTG1 cell line was pretreated with 200 µM H₂O₂ for 30 min to explore the effects of the single active compounds and their combination under oxidative stress conditions. Our results demonstrated for the first time the synergistic effects of the new combination to improve the absorption rate of individual agents through the BBB and maintain its integrity. Subsequently, further research was done to assess the positive role of the combination to counteract oxidative damage; as expected, MIX restored the neurodegenerative state activated by 200 µM H₂O₂, reducing mitochondrial damage, and improving survival pathways. Additionally, MIX acted as a regulator of both cellular energy metabolism and apoptosis, reducing the inflammatory state activated by oxidative stress. Finally, MIX can balance neurotrophin production to prevent mitochondrial disruption. In conclusion, MIX counteracted the adverse effects of brain oxidative stress, suggesting that this new proposed formulation prevents the molecular mechanisms underlying the onset of cognitive decline, even in support of conventional therapy.