芫花主要黄酮成分对肝微粒体UGTs及UGT1A1活性的体外抑制作用

In Vitro Inhibitory Effect of Main Flavonoids Ingredients of Genkwa Flos on Liver Microsomal UGTs and UGT1A1 Activities

关键词:  芫花  芫花素  芹菜素  UGTs  UGT1A1  肝微粒体  抑制作用

Key words:  Genkwa Flos  genkwanin  apigenin  UGTs  UGT1A1  liver microsomes  inhibitory effect

摘要:

目的 考察芫花主要黄酮成分芫花素和芹菜素对尿苷二磷酸葡萄糖醛酸转移酶（UGTs）及UGT1A1活性的影响。方法 采用体外肝微粒体孵育模型，以4-硝基酚（4-nitrophenol，4-NP）为底物检测UGTs活性，胆红素为底物检测UGT1A1活性；利用UV及UPLC-MS/MS测定底物或代谢产物的含量。结果 对UGTs，在大鼠肝微粒体、小鼠肝微粒体以及人肝微粒体孵育体系中，芫花素和芹菜素均能不同程度地抑制UTGs活性；抑制强弱顺序：在大鼠肝微粒体温孵体系中，芫花素>芹菜素；在小鼠肝微粒体以及人肝微粒体温孵体系中，芹菜素>芫花素。对UGT1A1，在人肝微粒体孵育体系中，芫花素和芹菜素均表现为中等强度的竞争性抑制作用，抑制强弱顺序：芹菜素（IC₅₀=12.40 μmol·L^-1）>芫花素（IC₅₀=23.21 μmol·L^-1）。结论 芫花素和芹菜素对不同肝微粒体孵育体系中UGTs及UGT1A1均可产生显著抑制作用且存在种属差异。芫花素及芹菜素可能存在基于UGT酶的药物相互作用。

Abstract:

OBJECTIVE To investigate the inhibition of genkwanin and apigenin on UGTs and UGT1A1 activities of different liver microsomes. METHODS In the present study, in vitro liver microsornal incubation model was used. 4-nitrophenol (4-NP) and bilirubin were elected as substrates to determine activities of UGTs and UGT1A1 by UV and UPLC-MS/MS, respectively. RESULTS Genkwanin and apigenin significantly inhibited UGTs activity in rats, mice and human liver microsome. In rats liver microsome temperature hatch system, the inhibition strength suitable genkwanin was higher than apigenin. In mice and human liver microsome temperature hatch system, the inhibition strength suitable apigenin was higher than genkwanin. UGT1A1 activity was inhibited by genkwanin and apigenin with IC₅₀ about 23.21, 12.40 μmol·L^-1 in human liver microsome, respectively. The inhibition types were competitive inhibition. Inhibition of apigenin was better than genkwanin. CONCLUSION The results indicate that genkwanin and apigenin show different level of inhibition effects. This result may be caused drug interactions based on UGT1A1 enzyme.