The Mediterranean diet (MD), characterized by olive oil, olives, fruits, vegetables, and wine intake, is associated with a reduced risk of dementia. These foods are rich in bioactives with neuroprotective and antioxidant properties, including hydroxytyrosol (HT), tyrosol (TYRS), serotonin (SER) and protocatechuic acid (PCA), a phenolic acid metabolite of anthocyanins. It remains to be established if these molecules cross the blood–brain barrier (BBB), a complex interface that strictly controls the entrance of molecules into the brain. We aimed to assess the ability of tyrosine (TYR), HT, TYRS, PCA and SER to pass through the BBB without disrupting its properties. Using Human Brain Microvascular Endothelial Cells as an in vitro model of the BBB, we assessed its integrity by transendothelial electrical resistance, paracellular permeability and immunocytochemical assays of the adherens junction protein β-catenin. The transport across the BBB was evaluated by ultra-high-performance liquid chromatography high resolution mass spectrometry. Results show that tested bioactives did not impair BBB integrity regardless of the concentration evaluated. Additionally, all of them cross the BBB, with the following percentages: HT (∼70%), TYR (∼50%), TYRS (∼30%), SER (∼30%) and PCA (∼9%). These results provide a basis for the MD neuroprotective role.

中文翻译：

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地中海食品生物活性物质血脑屏障转运的体外研究

地中海饮食 (MD) 的特点是摄入橄榄油、橄榄、水果、蔬菜和葡萄酒，可降低患痴呆症的风险。这些食物富含具有神经保护和抗氧化特性的生物活性物质，包括羟基酪醇（HT）、酪醇（TYRS）、血清素（SER）和原儿茶酸（PCA）（花青素的酚酸代谢物）。这些分子是否能穿过血脑屏障（BBB）还有待确定，血脑屏障是一个严格控制分子进入大脑的复杂界面。我们的目的是评估酪氨酸 (TYR)、HT、TYRS、PCA 和 SER 通过 BBB 而不破坏其特性的能力。使用人脑微血管内皮细胞作为BBB 的体外模型，我们通过跨内皮电阻、细胞旁通透性和粘附连接蛋白 β-连环蛋白的免疫细胞化学测定来评估其完整性。通过超高效液相色谱高分辨率质谱评估了穿过血脑屏障的运输。结果表明，无论评估的浓度如何，测试的生物活性物质都不会损害血脑屏障的完整性。此外，它们都穿过 BBB，比例如下：HT (∼70%)、TYR (∼50%)、TYRS (∼30%)、SER (∼30%) 和 PCA (∼9%)。这些结果为MD的神经保护作用提供了基础。