仙人掌黄酮对活化巨噬细胞释放NO的抑制作用

Effects of Flavonoids from Opuntia dillenii on the NO Relaxation in Activated Macrophage

本研究采用LPS／IFN-γ诱导小鼠巨噬细胞RAW264．7释放NO，通过Griess法测定细胞培养上清液中NO的浓度，计算对小鼠巨噬细胞释放NO的抑制率，以MTT法评价细胞增殖程度，研究了从仙人掌中分离的12种黄酮化合物对活化巨噬细胞释放NO的抑制作用，并通过SDS／PAGE、Western Blot的方法检测仙人掌黄酮对iNOS表达的影响。结果表明，化合物2—7在12．5～100μmol／L的剂量范围内可明显抑制活化巨噬细胞释放NO，并呈现良好的剂量依赖关系。黄酮类化合物C环2，3位双键对NO抑制活性具有关键性作用，环上羟基的位置、数目对活性无显著影响。

In the present study,NO production was induced by a combination of lipopolysaccharide（LPS） and interferon- γ（ IFN-γ ） , and determined by Griess assay. Cytotoxieity was evaluated by MTF method. Inhibitory effects of 12 flavonoids from Opuntia dillenii on the NO production were evaluated, and the expression of iNOS was detected by using SDS/PAGE and Western blot. The results indicated that compounds 2-7 strongly inhibited LPS/IFN-3, induced NO production in a dose-dependant manner. The double bond between the second and third positions is responsible for the NO inhibitory activity. Position or amount of hydroxyl groups may be not necessary for inhibiting NO production.