Minonzio F, Venegoni E, Ongari A M, Ciani D, Capsoni F
Institute of Clinica Medica I, University of Milan, Italy.
Int J Tissue React. 1988;10(4):223-31.
The effect in vitro of the naturally occurring flavonoid silybin on human polymorphonuclear leukocyte (PMN) functions has been studied. Preincubation of PMNs for 10 min at 37 degrees C with silybin inhibited, in a dose-dependent way, the luminol-enhanced chemiluminescence (CL) generated by stimulated cells without affecting the non-enhanced CL or superoxide anion production evaluated by the cytochrome C reduction assay. No significant effect of silybin on PMN phagocytic or chemotactic activities were found. Silybin did not absorb light at the wavelength of luminol-enhanced CL and was not toxic to PMNs at the concentrations used. Catalase, a scavenger of H2O2, inhibited luminol-enhanced CL to a similar degree as silybin; moreover, when incubated together with PMNs, silybin and catalase did not produce an additive inhibition of CL. On the contrary, the simultaneous addition of silybin and sodium azide, an inhibitor of myeloperoxidase, further increased inhibition over that seen with azide alone. These results suggest that inhibition of H2O2 may be the mechanism by which silybin inhibits the luminol-enhanced CL generated by stimulated PMNs. Such results indicate a possible anti-inflammatory activity for silybin even if their clinical relevance remains to be elucidated.
已对天然存在的类黄酮水飞蓟宾对人多形核白细胞（PMN）功能的体外作用进行了研究。将PMN在37℃下与水飞蓟宾预孵育10分钟，可剂量依赖性地抑制受刺激细胞产生的鲁米诺增强化学发光（CL），而不影响通过细胞色素C还原试验评估的非增强CL或超氧阴离子产生。未发现水飞蓟宾对PMN吞噬或趋化活性有显著影响。水飞蓟宾在鲁米诺增强CL的波长处不吸收光，在所使用的浓度下对PMN无毒。过氧化氢酶（一种H2O2清除剂）对鲁米诺增强CL的抑制程度与水飞蓟宾相似；此外，当与PMN一起孵育时，水飞蓟宾和过氧化氢酶对CL没有产生相加抑制作用。相反，同时添加水飞蓟宾和叠氮化钠（一种髓过氧化物酶抑制剂），其对CL的抑制作用比单独使用叠氮化钠时进一步增强。这些结果表明，抑制H2O2可能是水飞蓟宾抑制受刺激PMN产生的鲁米诺增强CL的机制。这些结果表明水飞蓟宾可能具有抗炎活性，尽管其临床相关性仍有待阐明。
