To investigate the association between esomeprazole pharmacokinetics and CYP2C19 gene polymorphisms in a cohort of 95 healthy Chinese participants. A cohort of 95 participants was assembled and stratified into 2 distinct groups, receiving either 20 or 40 mg of esomeprazole through oral administration. The subjects encompassed 17 poor metabolizers, 47 intermediate metabolizers, and 31 rapid metabolizers, and their genotypes were ascertained using the polymerase chain reaction-restriction fragment length polymorphism technique. Esomeprazole plasma concentrations were quantified employing a high-performance liquid chromatography-ultraviolet method. Pharmacokinetic parameters were computed via Phoenix WinNonlin 6.1 software, while SPSS 26.0 facilitated statistical analysis to contrast the pharmacokinetics and the CYP2C19 genotypes. In the aftermath of administering 20 or 40 mg esomeprazole, marked differences were discerned between terminal elimination half-life, maximum concentration/dose, and area under the plasma concentration-time curve from time zero to infinity/dose of esomeprazole (P < .05), with the exception of time to maximum concentration. The findings of this investigation signify a significant association between esomeprazole metabolism and CYP2C19 gene polymorphisms. There were no unprecedented adverse events documented subsequent to the administration of 20 and 40 mg esomeprazole dosages. Esomeprazole has manifested promising safety and tolerability profiles in pertinent clinical trials.

Aim: A prospective observational study was conducted to evaluate the feasibility of implementing clinical guidelines for warfarin dosing in black Zimbabwean patients. Methods: CYP2C9*5, CYP2C9*6, CYP2C9*8 and CYP2C9*11 and VKORC1 c. 1639 G>A variations were observed in 62 study patients. Results & Conclusion: Overall, 39/62 (62.90%) participants did not receive a warfarin starting dose as would have been recommended by Clinical Pharmacogenetics Implementation Consortium guidelines. US FDA and Dutch Pharmacogenetics Working Group guidelines are based on CYP2C9*2 and CYP2C9*3 only, hence, unlikely useful in this cohort, where such variants were not detected. Clinical Pharmacogenetics Implementation Consortium guidelines, on the other hand, have a specific recommendation on the African-specific variants CYP2C9*5, CYP2C9*6 and CYP2C9*11, and are hence suitable for implementation in Zimbabwe and would help optimize warfarin doses in patients in the study cohort.

Coptisine (COP) is the main active ingredient of Coptis chinensis. In Chinese veterinary clinics, Coptis chinensis is commonly used alongside florfenicol to treat intestinal infections. The goal of this study was to investigate the impact of COP co-administration on the pharmacokinetics of florfenicol in rats.Male Sprague-Dawley rats were orally administered COP (50 mg/kg BW) or sterile water for 7 consecutive days, followed by a single oral dose of florfenicol (25 mg/kg BW) on the 8th day. Pharmacokinetics of florfenicol were analysed using non-compartmental methods, while expression levels of cytochrome P450 (CYP) isoforms in the liver and P-glycoprotein (P-gp) in the jejunum were measured using real-time RT-PCR, Western blot and immunohistochemical analyses.Co-administration of COP and florfenicol significantly increased AUC(0-∞), MRT(0-∞), and Cmax of florfenicol, while CLz/F was significantly decreased. COP down-regulated the expression of CYP1A2, CYP2C11, and CYP3A1 in the liver, as well as P-gp in the jejunum.These findings suggest that co-administration of COP with florfenicol alters the pharmacokinetics of florfenicol in rats. The down-regulation of CYP and P-gp expression may contribute to this effect. Therefore, the co-administration of COP with florfenicol may enhance the prophylactic or therapeutic efficacy of florfenicol in veterinary practice.

Warfarin is extensively metabolized by cytochrome P450 2C9 (CYP2C9). Concomitant use with the potent CYP2C9 inducer, rifampin, requires close monitoring and dosage adjustments. Although, in theory, warfarin dose increase should overcome this interaction, most reported cases over the last 50 years have not responded even to high warfarin doses, but some have responded to modest doses. To investigate the genetic polymorphisms\' impact on this unexplained interpatient variability, we performed genotyping of CYP2C9, VKORC1, and CYP4F2 for warfarin and rifampin concomitant receivers from 2016 to 2022 at Hamad Medical Corporation, Doha, Qatar. We identified and included 36 patients: 22 responders and 14 nonresponders. Warfarin-responders were significantly more likely to have one or more warfarin-sensitizing CYP2C9/VKORC1 alleles than nonresponders (odds ratio = 23.2, 95% confidence interval = 3.2-195.6; P = 0.0001). The mean genetic-based pre-interaction calculated dose was significantly lower for responders than for nonresponders (P < 0.001); and was negatively correlated with warfarin sensitivity index (WSI) (r = -0.58; P = 0.0002). The median percentage time in therapeutic range and mean WSI were significantly higher in the warfarin-sensitizing CYP2C9/VKORC1 alleles carriers than noncarriers (P = 0.017 and 0.0004, respectively). Whereas the warfarin-sensitizing CYP2C9/VKORC1 genotypes were associated with modest on-rifampin warfarin dose requirements, the noncarriers would have required more than double these doses to respond. Warfarin-sensitizing CYP2C9/VKORC1 genotypes and low genetic-based warfarin calculated doses were associated with higher warfarin sensitivity and better anticoagulation quality in patients receiving rifampin concomitantly.

OBJECTIVE: Drug-drug interactions between warfarin and cytochrome P450 (CYP) 2C9 inhibitors and inducers are well known. Few studies have clarified the clinical impact of CYP2C9 inhibitors and inducers on warfarin therapy. Here, we evaluated the clinical impact of CYP2C9-mediated interactions on the pharmacodynamics of warfarin.
METHODS: This retrospective observational study enrolled patients who received warfarin between 2008 and 2020 at Mie University Hospital. We defined prothrombin time-international normalized ratio/daily warfarin dose (PT-INR/dose) as the primary outcome and conducted a multiple linear regression analysis to clarify the factors that affected the primary outcome. Additionally, we examined the clinical features of patients who received CYP2C9 inducers.
RESULTS: Out of 1,393 patients, 17 (1.2%) received carbamazepine, rifampicin, phenobarbital, or phenytoin as CYP2C9 inducers. Multiple linear regression analysis indicated that age, body mass index (BMI), serum albumin (Alb), estimated glomerular filtration rate (eGFR), and CYP2C9 inducers were associated with PT-INR/dose. The multiple regression equation was as follows: PT-INR/dose = 1.590 + 0.004 × age - 0.020 × BMI - 0.141 × Alb - 0.001 × eGFR - 0.149 × (if concomitant use of CYP2C9 inducers) (adjusted coefficient of determination = 0.106, Akaike information criterion = 267.3, p < 0.001). In patients receiving CYP2C9 inducers, lower PT-INR/dose values were observed regardless of co-administered CYP2C9 inhibitors.
CONCLUSIONS: In addition to age, BMI, Alb, and eGFR, concomitant use of CYP2C9 inducers should be considered when adjusting the warfarin dose and PT-INR.

CYP2C9 gene polymorphic variants can decrease the effects of losartan, reducing active metabolite (E-3174) formation. Study aims to determine the influence of *2 (+430C>T; rs799853) and *3 (+1075A>C; rs1057910) CYP2C9 gene polymorphic variants on the hypotensive and uricosuric effect of losartan on patients with arterial hypertension.
Eighty one patients with stage 1-2 arterial hypertension newly diagnosed with ABMP were enrolled in the study. Physicians started losartan treatment and then we measured urine concentration of E-3174/losartan to estimate CYP2C9 activity. After 3-month losartan treatment we compared effectiveness of the therapy with ABPM and plasma uric acid level between carriers of CYP2C9 *1/*1 and CYP2C9 gene polymorphic variants (*2 and *3).
Carriage of CYP2C9*2 and CYP2C9*3 alleles reduced the hypotensive effect of losartan (p<0.001, OR=8.13 (95% CI, 2.75-23.97)). Analysis of the ABPM data revealed that blood pressure was significantly higher in patients with polymorphic genotypes. There was no significant difference in uric acid level in plasma and losartan and its metabolite concentration in urine between genotypes.
Carriage of low function polymorphic variants of the CYP2C9 gene (*2 and *3) reduced the hypotensive effect of losartan according to ABPM and don\'t affect uric acid level in plasma and E-3174/losartan in urine.

Kuding tea (KT) is a traditional Chinese beverage rich in plant bioactives that may exhibit various health benefits. However, little is known about the safety of KT extract (KTE) when consumed long term at high doses as a dietary supplement. Therefore, in this study, we investigated aspects of the safety of KTE. Male C57BL/6 mice were fed a high-fat, high-fructose, Western-type diet (control) supplemented with either 12.88% γ-cyclodextrin (γCD), 7.12% KTE (comprising 0.15% ursolic acid, UA) encapsulated in 12.88% γCD (KTE-γCD), or 0.15% UA over a 6-week experimental period. The dietary treatments did not affect food intake, body weight or body composition. However, treatment with KTE-γCD, but not γCD and UA, increased liver weight and hepatic fat accumulation, which was accompanied by increased hepatic PPARγ and CD36 mRNA levels. KTE-γCD treatment elevated plasma cholesterol and CYP7A1 mRNA and protein levels compared to those in control mice. KTE-γCD substantially increased the mRNA and protein levels of hepatic CYP3A and GSTA1, which are central to the detoxification of drugs and xenobiotics. Furthermore, we observed a moderate elevation in hepatic CYP3A (5-fold change) and GSTA1 (1.7-fold change) mRNA levels in UA-fed mice. In vitro data collected in HepG2 cells indicated a dose-dependent increase in hepatic cytotoxicity in response to KTE treatment, which may have been partly mediated by UA. Overall, the present data may contribute to the safety assessment of KTE and suggest that KTE encapsulated in γCD affects liver fat storage and the hepatic phase I and phase II responses in mice.

Fufang Danshen Dripping Pill (FDDP) and Clopidogrel Bisulfate Tablet (CBT) are usually combined for treatment of coronary artery diseases in clinical. To investigate the pharmacokinetic interaction between FDDP and CBT after oral administration of FDDP, CBT and their combination in rats, a novel LC-MS method with segmented scan modes (multiple reaction monitoring and selected ion monitoring) and polarity (positive and negative ionization) was developed. Clopidogrel and the main active ingredients of FDDP, with different chemical and ionization properties, were simultaneously quantified in plasma in a single run. The method was validated in terms of specificity, linearity, precision, accuracy, recovery, matrix effect and stability. As a result, co-administration of FDDP and CBT significantly altered the pharmacokinetic parameters of danshensu, ginsenoside Rb1, dihydrotanshinone I, tanshinone I and tanshinone IIA of FDDP, as well as clopidogrel. Mechanism studies suggested that induction of liver cytochrome P450 isozymes CYP2C11 and CYP3A1 by co-administration, as well as inhibition of carboxyl esterase 1, was partly responsible for FDDP-CBT pharmacokinetic interactions. The developed LC-MS method could be used to simultaneously quantify different types of in vivo analytes in a single run, and the results could be used for clinical medication guidance of FDDP and CBT.

The anticancer drug ellipticine exerts its genotoxic effects after metabolic activation by cytochrome P450 (CYP) enzymes. The present study has examined the role of cytochrome P450 oxidoreductase (POR) and cytochrome b5 (Cyb5), electron donors to P450 enzymes, in the CYP-mediated metabolism and disposition of ellipticine in vivo. We used Hepatic Reductase Null (HRN) and Hepatic Cytochrome b5/P450 Reductase Null (HBRN) mice. HRN mice have POR deleted specifically in hepatocytes; HBRN mice also have Cyb5 deleted in the liver. Mice were treated once with 10 mg/kg body weight ellipticine (n = 4/group) for 24 h. Ellipticine-DNA adduct levels measured by 32P-postlabelling were significantly lower in HRN and HBRN livers than in wild-type (WT) livers; however no significant difference was observed between HRN and HBRN livers. Ellipticine-DNA adduct formation in WT, HRN and HBRN livers correlated with Cyp1a and Cyp3a enzyme activities measured in hepatic microsomes in the presence of NADPH confirming the importance of P450 enzymes in the bioactivation of ellipticine in vivo. Hepatic microsomal fractions were also utilised in incubations with ellipticine and DNA in the presence of NADPH, cofactor for POR, and NADH, cofactor for Cyb5 reductase (Cyb5R), to examine ellipticine-DNA adduct formation. With NADPH adduct formation decreased as electron donors were lost which correlated with the formation of the reactive metabolites 12- and 13-hydroxy-ellipticine in hepatic microsomes. No difference in adduct formation was observed in the presence of NADH. Our study demonstrates that Cyb5 contributes to the P450-mediated bioactivation of ellipticine in vitro, but not in vivo.

The interactions of the drugs amlodipine and paroxetine, which are prescribed respectively for treatment of hypertension and depression, with the metabolizing enzyme cytochrome CYP2B4 as the drug target, have been studied by molecular dynamics (MD) simulation. Poly ethylene glycol was used to control the drugs\' interactions with each other and with the target CYP2B4. Thirteen simulation systems were carefully designed, and the results obtained from MD simulations indicated that amlodipine in the PEGylated form prescribed with paroxetine in the nonPEGylated form promotes higher cytochrome stability and causes fewer fluctuations as the drugs approach the target CYP2B4 and interact with it. The simulation results led us to hypothesize that the combination of the drugs with a specific drug ratio, as proposed in this work, manifests more effective diffusivity and less instability while metabolizing with enzyme CYP2B4. Also, the active residues in the CYP2B4 enzyme that interact with the drugs were determined by MD simulation, which were consistent with the reported experimental results. Graphical Abstract Efficient drug-enzyme interactions, as a result of PEGylation.