Park K Y, Lee S H, Min B K, Lee K S, Choi J S, Chung S R, Min K R, Kim Y
Planta Med. 1999 Jun;65(5):457-9. doi: 10.1055/s-2006-960812.
Interleukin (IL)-5 is a chemotactic factor of eosinophils, and promotes the growth and survival of eosinophils, which plays an important role in the eosinophilia-associated allergic inflammation. In this study, luteolin 4'-O-glucopyranoside was identified as the IL-5 inhibitor from Kummerowia striata Thunb. (Leguminosae) by activity-guided fractionation followed by structural analysis compared with reported spectral data. The flavone compound exhibited dose-dependent inhibitory effect on IL-5 bioactivity with 95% inhibition at 30 microM, 79% at 15 microM, 60% at 7.5 microM, 54% at 3.8 microM and 29% at 1.9 microM, where 50% of inhibition (IC50) value was shown at the concentration of 3.7 microM. Furthermore, the inhibitory effect on IL-5 bioactivity by other flavonoid compounds available was estimated. In view of the IC50 values, the inhibitory potency on IL-5 bioactivity was in order of luteolin 4'-O-glucopyranoside > cosmosiin (14.2 microM) approximately equal to apigenin (16.4 microM) approximately equal to luteolin (18.7 microM) > quercimeritrin (27.3 microM) approximately equal to kaempferol (30.0 microM).
白细胞介素（IL）-5是嗜酸性粒细胞的趋化因子，可促进嗜酸性粒细胞的生长和存活，在与嗜酸性粒细胞增多相关的过敏性炎症中起重要作用。在本研究中，通过活性导向分级分离，随后与报道的光谱数据进行结构分析，从鸡眼草（豆科）中鉴定出木犀草素4'-O-吡喃葡萄糖苷为IL-5抑制剂。该黄酮类化合物对IL-5生物活性表现出剂量依赖性抑制作用，在30μM时抑制率为95%，15μM时为79%，7.5μM时为60%，3.8μM时为54%，1.9μM时为29%，在3.7μM浓度时显示出50%的抑制（IC50）值。此外，还评估了其他可用黄酮类化合物对IL-5生物活性的抑制作用。鉴于IC50值，对IL-5生物活性的抑制效力顺序为木犀草素4'-O-吡喃葡萄糖苷>紫花前胡苷（14.2μM）约等于芹菜素（16.4μM）约等于木犀草素（18.7μM）>槲皮苷（27.3μM）约等于山奈酚（30.0μM）。
