淫羊藿苷对不同月龄大鼠肝微粒体细胞色素P450的影响

目的 揭示淫羊藿苷(Ica)对大鼠肝微粒体细胞色素P450的含量及部分亚型的影响,并比较月龄的差异.方法 ig给予6月龄和18月龄的♂SD大鼠Ica( 60 mg· kg -1),4周后取肝脏,用钙沉淀法提取肝微粒体,BCA法测定微粒体蛋白浓度；用一氧化碳还原差示光谱法测定CYP450的含量；用ELISA法测定CYP1 A1、CYPb5的含量；用比色法测定苯胺羟化酶(反映CYP2E1活性)和红霉素-N-脱甲基酶(反映CYP3A活性)的活性；用real - time RT - PCR检测CYP1 A1、CYP2A3、CYP2E1、CYP3A1、CYP3A2和CYP4B1 mRNA的表达.结果 60 mg· kg-1 Ica明显增加了CYP450的总酶和CYP1 A1的含量、CYP3A的活性及CYP1 A1、CYP3A1、CYP3A2 mRNA的表达,降低了CYP2E1的活性及其mRNA的表达；但Ica对上述各指标的诱导或抑制作用在大鼠月龄方面差异不明显；Ica对CYPb5的含量及CYP2A3、CYP4B1 mRNA的表达未见明显影响.结论 Ica对大鼠肝微粒体CYP450总酶、CYPI A1和CYP3A具有诱导作用,对CYP2E1具有抑制作用,该作用未见明显月龄差异.

Effects of icariin on liver microsomal cytochrome P450 in rats with different ages

OBJECTIVE To compare the effects of icariin on liver microsomal cytochrome P450 in the rats with different ages.METHODS After intragastric administration of icariin（60 mg·kg^-1） for 4 weeks,Liver microsomes of six-month-old and eighteen-month-old SD male rats were extracted by calcium precipitation method.The cytochrome P450 content was measured through carbon monoxide reductive difference spectrometry assay.The activities of aniline hydroxylase（CYP2E1） and erythromycin-N-demethylase（CYP3A） were detected colorimetrically.ELISA was used to determined the content of CYP1A1,CYPb₅.Expression of CYP1A1,CYP2A3,CYP2E1,CYP3A1,CYP3A2 and CYP4B1 mRNA were detected by real-time RT-PCR.RESULTS Compared with controls,contents of CYP450 and CYP1A1,activities of Erythromycin-N-demethylase and the expression of CYP1A1,CYP3A1 and CYP3A2 mRNA were increased remarkably by icariin.In contrast,the activity of aniline hydroxylase and CYP2E1 mRNA expression were decreased.There was no significant diference of above-mentioned changes between six-month-old and eighteen-month-old rats.The content of CYPb5 and expression of CYP2A3,CYP4B1 mRNA were unchanged.CONCLUSION 60 mg·kg^-1 icariin can induce CYP450,CYP1A1 and CYP3A,inhibit CYP2E1,but age-difference has no effect.