Visioli F, Bellosta S, Galli C
Institute of Pharmacological Sciences, Milan, Italy.
Life Sci. 1998;62(6):541-6. doi: 10.1016/s0024-3205(97)01150-8.
The Mediterranean diet, rich in fresh fruits and vegetables, has been associated with a lower incidence of cardiovascular disease and cancer, partly because of its high proportion of bioactive compounds such as vitamins, flavonoids and polyphenols. The major lipid component of such diet is the drupe-derived olive oil, that can be distinguished from other seed oils for the peculiar composition of its non-triglyceride fraction. In fact, several minor components, including polyphenols, grant the oil its particular taste and aroma. Oleuropein, the most abundant among these components, has been shown to be a potent antioxidant endowed with antiinflammatory properties. We investigated the effects of oleuropein on NO release in cell culture and its activity toward nitric oxide synthase (iNOS) expression. The results show that oleuropein dose-dependently enhance nitrite production in LPS-challenged mouse macrophages. This effect was blocked by the iNOS inhibitor L-NAME, indicating increased iNOS activity. Also, Western blot analysis of cell homogenates show that oleuropein increases iNOS expression in such cells. Taken together, our data suggest that, during endotoxin challenge, oleuropein potentiates the macrophage-mediated response, resulting in higher NO production, currently believed to be beneficial for cellular and organismal protection.
富含新鲜水果和蔬菜的地中海饮食与心血管疾病和癌症的较低发病率相关，部分原因在于其高比例的生物活性化合物，如维生素、类黄酮和多酚。这种饮食的主要脂质成分是源自核果的橄榄油，它因其非甘油三酯部分的特殊组成而与其他种子油不同。事实上，包括多酚在内的几种次要成分赋予了这种油独特的味道和香气。橄榄苦苷是这些成分中含量最丰富的，已被证明是一种具有抗炎特性的强效抗氧化剂。我们研究了橄榄苦苷对细胞培养中一氧化氮释放的影响及其对一氧化氮合酶（iNOS）表达的作用。结果表明，橄榄苦苷在脂多糖刺激的小鼠巨噬细胞中剂量依赖性地增强亚硝酸盐的产生。这种作用被iNOS抑制剂L-NAME阻断，表明iNOS活性增加。此外，细胞匀浆的蛋白质免疫印迹分析表明，橄榄苦苷增加了此类细胞中iNOS的表达。综上所述，我们的数据表明，在内毒素刺激期间，橄榄苦苷增强了巨噬细胞介导的反应，导致更高的一氧化氮产生，目前认为这对细胞和机体保护有益。
