[Effect of Laportea bulbifera extract on CYP450 enzyme activities in rats by Cocktail probe drug method].

The Cocktail probe drug method was used to evaluate the effect of Laportea bulbifera extract on the different subtypes of CYP450 enzyme activities in rats, and to provide references for its clinical rational drug use. The rats were randomly divided into a high-dose L. bulbifera group(0.45 g·kg~(-1)·d~(-1)) and a low-dose L. bulbifera group(0.09 g·kg~(-1)·d~(-1)). After continuous gavage for 7 and 14 days, the Cocktail probe mixing solution, including caffeine, midazolam, tolbutamide, omeprazole, metoprolol, and chlorzoxazone, was injected into the tail vein, and the blood sample was obtained from the tail vein at different time points. Ultra-high performance liquid chromatography-mass spectrometry(UPLC-MS) was established to determine the concentration of six probe drugs in rat plasma. DAS 2.0 was used to calculate its pharmacokinetic parameters, and the effect of L. bulbifera extract on CYP1 A2, CYP2 C9, CYP2 C19, CYP2 D6, CYP2 E1, and CYP3 A4 in rats was investigated. As compared with the blank control group, under the omeprazole index, the AUC_(0-t) and AUC_(0-∞) of the 7-day administration groups and the 14-day high-dose group were significantly decreased, and the CLz and Vz were significantly increased. Under the midazolam index, the AUC_(0-t) and AUC_(0-∞) of the 7-day low-dose group and the 14-day administration group were significantly decreased, and the CLz was significantly increased. In addition, the AUC_(0-∞) of the 7-day high-dose group was also significantly decreased. Under the index of metoprolol, the AUC_(0-t) and AUC_(0-∞) of each experimental group were decreased significantly, and the CLz and Vz of the 7-day low-dose group and the 14-day low-dose group were increased significantly. Under the caffeine index, the AUC_(0-t) and AUC_(0-∞) of the 7-day administration groups were increased significantly, the CLz was decreased significantly, and the t_(1/2 z) of the 14-day high-dose group was increased significantly. Under the chlorzoxazone index, the AUC_(0-t) and AUC_(0-∞) of the 7-day low-dose group were increased significantly, and the CLz was decreased significantly. Under the tolbutamide index, there was no statistical difference in the pharmacokinetic parameters. In conclusion, L. bulbifera extract induces the activities of CYP2 C19, CYP3 A4, and CYP2 D6, inhibits the activities of CYP1 A2 and CYP2 E1, and does not affect the activity of CYP2 C9.

Effects of Valeriana amurensis Roots and Rhizomes Extract and Its Active Constituents on Activities of Drug Metabolism Enzymes in Liver / 中国实验方剂学杂志

Objective::To evaluate the effects of Valeriana amurensis roots and rhizomes extract and its active constituents on the activities of six major cytochrome P450 (CYP450) enzymes in human liver microsomes. Method::Coumarin, bupropion, tolbutamide, omeprazole, dextromethorphan and testosterone were used as probe substrates for CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6 and CYP3A4, respectively. Taking their specific metabolites of hydroxylation or demethylation (7-hydroxycoumarin, hydroxybupropion, 4-hydroxytolbutamide, 5-hydroxyomeprazole, dextromethorphan, 6β-hydroxytestosterone) as indicators of enzyme activities. The analytical indexes were used to establish an in vitro model of human liver microsomes of Cocktail probe substrates. This method was applied to evaluate the effects of V. amurensis roots and rhizomes extract and its active constituents on human liver microsomal enzymes. Result::The V. amurensis roots and rhizomes extract had different inhibitory effects on CYP2B6, CYP2C9, CYP2D6 and CYP3A4, their half-inhibitory concentration (IC50) values were 87.49, 1.73, 68.29, 2.80 mg·L-1, respectively. Among the 9 lignans, (-)-massoniresinol-3α-O-β-D-glucopyranoside had a moderate inhibitory effect on CYP2A6 with an IC50 value of 8.51 μmol·L-1, 8, 8′-dihydroxypinoresinol-4, 4′-di-O-β-D-glucopyranoside had a moderate inhibitory effect on CYP2D6 with an IC50 value of 8.73 μmol·L-1, (+)-medioresinol-4, 4′-O-di-β-D-glucopyranoside had a moderate inhibitory effect on CYP2B6 and CYP2C9 with IC50 values of 5.41 μmol·L-1 and 8.20 μmol·L-1. Conclusion::The V. amurensis roots and rhizomes extract and its active constituents have inhibitory effects on liver CYP450 enzymes. Therefore, in the clinical study of new drugs, it is necessary to fully evaluate the risk of drug interactions caused by combination therapy.

Effect of Inula cappa on CYP450 Enzyme in Rats by Cocktail Probe Drugs / 中国实验方剂学杂志

Objective:To study on the effect of Inula cappa extract on the activities of six cytochrome P450(CYP450) enzymes in rats by Cocktail probe method. Method:Rats in the I. cappa high and low dose groups were given oral administration of active fractions of I. cappa at a dose of 8.127,2.709 g·kg-1·d-1 of the material for 7,14 d,repectively.Probe drugs(caffeine,midazolam,tolbutamide,omeprazole,metoprolol,chlorzoxazone) were simultaneously injected to rats after administration.Plasma was collected at different time after the administration of probe drugs.The plasma concentrations of these six probes were measured by UPLC-MS and their corresponding pharmacokinetic parameters were calculated with DAS 2.0. Result:Compared with the control group,only the apparent volume of distribution(V) of midazolam was increased;area under the curve(AUC0-t and AUC0-∞)and half-life period(T1/2) of caffeine,midazolam,tolbutamide and omeprazole were increased and the clearance rate(CL) of them was decreased in rats of I. cappa groups.But there were no differences in pharmacokinetic parameters of chlorzoxazone and metoprolol. Conclusion:I. cappa can reduce the enzymatic activities of CYP3A,CYP1A2,CYP2C9 and CYP2C19 in rats at different degree,among which CYP3A is the strongest.