新藤黄酸对大鼠肝微粒体细胞色素P450亚型酶活性的影响

目的 采用“Cocktail”探针药物法考察新藤黄酸对大鼠肝微粒体细胞色素P450(cytochrome P450,CYP450)亚型酶活性的影响。 方法 将新藤黄酸与6种亚型酶(CYP1A2、CYP2C9、CYP2C19、CYP2D6、CYP2E1、CYP3A4)对应的特异性混合探针药茶碱、双氯芬酸钠、奥美拉唑、右美沙芬、氯唑沙宗和咪达唑仑与大鼠肝微粒体孵育,采用高效液相色谱法同时检测肝微粒体中6种探针底物的相对酶活性并计算其半抑制浓度（half maximal inhibitory concentration, IC50）。 结果 不同浓度新藤黄酸作用后大鼠肝微粒体CYP1A2、CYP2C9、CYP2C19、CYP2D6、CYP2E1和CYP3A4酶活性相比较,差异均具有统计学意义,且随着新藤黄酸的浓度增高,各种酶的活性呈现明显的降低趋势。通过抑制曲线计算得到新藤黄酸对CYP2C19、CYP2D6、CYP3A4的IC50值分别为4.18、45.61、10.02 μmol/L,对CYP1A2、CYP2C9、CYP2E1的IC50值均大于100 μmol/L。 结论 新藤黄酸对CYP2C19酶活性有中等抑制作用,对CYP3A4酶活性有弱抑制作用,但对CYP1A2、CYP2C9、CYP2D6、CYP2E1酶活性没有抑制作用。     

A preliminary assessment of the effect of PreCR™ DNA repair treatment on mixture ratios in two person mixtures

In this study, DNA extracted from known buccal samples was combined into two component mixture samples. These were subjected to UV exposure prior to their amplification with the Promega PowerPlex® 16HS amplification kit, and subsequent capillary electrophoresis on the ABI 3130xl instrument. Damaged samples were subjected to enzymatic repair treatment and retested to assess the amount of repair. Data showed that there is fidelity associated with the application with profile concordance after its use, and a corresponding increase in the amount of recovered alleles post damage. Results also showed changes in the stochastic relationship between mixture components that appear to be induced by the repair process itself. The mixture ratios of DNA samples were altered from an approximate original 1:3 ratio, to a ratio of 1:2 or greater. This variation can have a significant effect regarding the ability to reliably de-convolute DNA mixtures that have been subjected to the repair process.