ABSTRACT
Objective::To study the mechanisms of action of four volatile oil components (safrole, myristicin, methyleugenol and asarone) and the reactive metabolites of safrole and myristicin with CYP1A2. Method::The inhibitory effects of the volatile oil components of Asari Radix et Rhizoma on the human liver microsomal enzymes CYP1A2, CYP2D6, CYP2E1, CYP3A4 and CYP2C19 were screened by the " Cocktail" probe substrate method. The ability of the volatile oil components and intermediates in binding to CYP1A2 enzyme was studied by means of semi-flexible molecular docking. Result::The screening results showed that the components had a strong inhibitory effect on CYP1A2.Molecular docking scores were 3.048 7 kcal·mol-1 (safrole), 6.016 4 kcal·mol-1 (myristicin), 16.969 2 kcal·mol-1 (methyleugenol), 16.013 8 kcal·mol-1 (asarone), 23.923 3 kcal·mol-1 (safrole reactive metabolites) and 25.594 3 kcal·mol-1 (myristicin reactive metabolites). Conclusion::Molecular docking results indicate that safrole metabolic intermediate and myristicin metabolic intermediate have the strongest ability in binding to CYP1A2 enzyme. This study further confirms that safrole and myristicin are the mechanism-based inhibitors of CYP1A2 enzyme, which is consistent with the results of previous IC50-shift and glutathione capture experiments.
ABSTRACT
<p><b>OBJECTIVE</b>E23K polymorphism in KCNJ11 gene is associated with cardiovascular disease and diabetes. In order to explore the mechanism of E23K correlation to related diseases, the effect of E23K polymorphism in KCNJ11 gene on membrane current was investigated.</p><p><b>METHODS</b>The exon of KCNJ11 was obtained by PCR amplification and the G-->A mutation was completed by overlap extension PCR. The sequences of KCNJ11 exon contained 23E or 23K was inserted into pcDNA3.1/CT-GFP vector respectively. The recombinant plasmid, pcDNA3.1-KCNJ11(E) and pcDNA3.1-KCNJ11(K), were transfected into HEK293T cells by lipofectamine and the membrane current density was determined by whole-cell patch clamp technique.</p><p><b>RESULTS</b>1,173 bp sequences of KCNJ11 gene's exon were amplified by PCR and the recombinant expression plasmid, pcDNA3.1-KCNJ11(E) and pcDNA3.1-KCNJ11(K), were constructed successful. Positive and negative currents were detected in HEK293T cells transfected with difference plasmid by whole-cell patch clamp technique. Results showed that the reversed voltage was 50mV. The current in HEK293T cells with pcDNA3.1-KCNJ11(E) was significantly greater than that with pcDNA3.1-KCNJ11(K) (P < 0.05, n = 10).</p><p><b>CONCLUSION</b>The polymorphism of E23K in exon of KCNJ11 gene changed the membrane currents in HEK293T cells. It could be an experiment support for the possible mechanism between the locus and related diseases.</p>