蛋白激酶抑制剂调控木犀草素与葡萄糖醛酸结合的研究

Effect Protein Kinase Inhibitor on Luteolin Glucuronidation

目的探究蛋白激酶抑制剂对木犀草素与葡萄糖醛酸结合的影响。方法分别将不同浓度的蛋白激酶抑制剂(姜黄素和钙感光蛋白C)与LS174T细胞共孵育1 h后裂解细胞,获得的细胞S9成分与木犀草素进行体外孵育,用高效液相色谱法测定孵育液中葡萄糖醛酸结合产物。通过Real-time PCR和Western blot分别测定处理后的LS174T细胞中UGT1A在mRNA水平和蛋白水平的表达变化。结果木犀草素与经蛋白激酶抑制剂处理后的细胞共孵育,其葡萄糖醛酸结合受到抑制。而Real-time PCR和Western blot均表明,蛋白激酶抑制剂对UGT1A的表达无影响。结论蛋白激酶抑制剂可抑制木犀草素与葡萄糖醛酸的结合,而这种抑制作用是间接的。蛋白激酶抑制剂很可能通过调控UGTs磷酸化修饰而改变UGTs活性进而导致木犀草素与葡萄糖醛酸结合减少。

OBJECTIVE To evaluate the effect of protein kinase inhibitor on luteolin glucuronidation. METHODS LS174T cells were treated with either curcumin or calphostin C of various concentrations. The glucuronidation metabolites of luteolin, catalyzed by the $9 of treated LS174T cells, was measured by HPLC. The expression of UGT1A in treated LS174T cells was determined by real- time PCR and western blot. RESULTS A rapid down-regulation of luteolin glucuronidation catalyzed by LS174T cells following cur- cumin and calphostin C treatment was observed. However, there was no effect on the expression of UGT1A in treated LS174T cells. CONCLUSION The glueuronidation of luteolin can be suppressed by protein kinase inhibitor indirectly. The suppression may be caused by abnormal phosphorylation of UGTs, which are catalyzed by protein kinase.