中文摘要：

探讨根皮素（phloretin）在体外对小鼠T淋巴细胞增殖、活化、周期和巨噬细胞NO释放、吞噬功能的影响。CFDA-SE标记技术结合流式细胞术检测根皮素对T淋巴细胞增殖的影响。荧光抗体染色结合流式细胞术分析根皮素对T淋巴细胞在ConA的刺激下CD69和CD25的表达水平的影响。碘化丙啶（PI）染色检测细胞周期的分布情况。Griess试剂盒和荧光微球分别用以检测巨噬细胞NO释放和吞噬功能。结果显示,根皮素（40、60和80μmol·L^-1明显抑制T淋巴细胞增殖,增殖指数（PI）从1.41±0.13分别下降到1.34±0.16、1.19±0.12和1.07±0.06。根皮素可明显抑制CD69和CD25的表达（P〈0.01）。细胞周期分析显示,根皮素可将细胞抑制在G0/G1期。巨噬细胞在LPS和IFN-γ的刺激下的NO释放量为（26.72±3.57）μmol·L^-1而在根皮素作用下NO释放量明显下降（P〈0.01）。巨噬细胞吞噬率在根皮素作用下也明显下降（P〈0.01）。以上结果表明,根皮素有望发展成为一种新的免疫抑制药物。

英文摘要：

This study investigated the effect of phloretin （Ph） on the proliferation, activation, and cell-cycle distribution of mouse T lymphocytes and NO production and phagocytosis of macrophages. Carboxyfluorescein diacetatesuccinimidyl ester （CFDA-SE） staining plus flow cytometry assay was employed to obtain the proliferation-related index （PI） of lymphocytes. The expression levels of CD69 and CD25 on T lymphocytes stimulated with Con A were evaluated with flow cytometry after staining with fluorescent monoclonal antibody. Cell-cycle distribution of T lymphocytes was analyzed by propidium iodide staining. Griess kit was used to evaluate the NO production and fluorescent microbeads were used to analyze the phagocytosis ability of macrophages. Our results showed that phloretin （40, 60, and 80 μmol·L^-1） significantly inhibited the proliferation of T lymphocytes and the PI reduced from 1.41 ±0.13 to 1.34 ± 0.16, 1.19 ± 0.12 and 1.07 ±0.06, respectively. Phloretin significantly inhibited the expression of CD69 and CD25 （P 〈 0.01）. The cell cycle distribution analysis showed that phloretin could induce a cell cycle arrest at G0/G1 phase. NO production of LPS ＋IFN-γ group of macrophages was （26.72 ±3.57） μmol·L^-1, and was significantly reduced by phloretin （P 〈 0.01）. And phagocytosis rate of macrophages was significantly reduced by phloretin （P 〈 0.01）. The results demonstrate that phloretin might be developed into a new immuosuppressive drug.