BackgroundCYP/CYP450 2C19 (CYP2C19) is a highly polymorphic enzyme and exhibits individual differences in metabolic activity. The purpose of this research was mainly to explore the catalytic activities of 30 CYP2C19 variants on the substrate voriconazole in vitro, including 24 novel CYP2C19 variants (2C19.2E-.2H, .2J, .3C, .29-.33, L16F, 35FS, R124Q, R125G, T130M, N231T, M255T, R261W, N277K, S303N, I327T, N403I, and A430V) found in Chinese Han population for the first time.MethodsThese CYP2C19 variants were expressed in Spodoptera frugiperda (Sf) 21 insect cells using the baculovirus-mediated expression system. The substrate voriconazole was incubated with the abovementioned proteins at 37°C for 30 minutes in an appropriate designed system. Then through detecting its major metabolite voriconazole N-oxide by ultra-performance liquid chromatography tandem mass spectrometry, available data were obtained to explain the influence of CYP2C19 polymorphisms on voriconazole.ResultsFrom the results, when compared to CYP2C19.1, most variants exhibited either reduced Vmax and/or increased Km value, indicating that the intrinsic clearance (Vmax/Km) values of most variants were significantly altered. The catalytic activities of 20 novel variants exhibited decreases in different degrees compared to CYP2C19.1, with relative clearance values ranging from 1.11% to 83.78%. However, L16F exhibited the increased catalytic activity for 135.68%. In addition, the kinetic parameters of four variants (2C19.2H, .3, 35FS, and R124Q) could not be detected, due to the defective gene.ConclusionThis is the first study to report the effects of CYP2C19 polymorphisms on vori-conazole metabolism in vitro, and we hope these data could lay the foundation for the early clinical research and individualized treatment.

Background: Lidocaine has cardiovascular and neurologic toxicity, which is dosedependent. Due to CYP3A4-involved metabolism, lidocaine may be prone to drug-drug interactions. Materials and Methods: Given statins have the possibility of combination with lidocaine in the clinic, we established in vitro models to assess the effect of statins on the metabolism of lidocaine. Further pharmacokinetic alterations of lidocaine and its main metabolite, monoethylglycinexylidide in rats influenced by simvastatin, were investigated. Results: In vitro study revealed that simvastatin, among the statins, had the most significant inhibitory effect on lidocaine metabolism with IC 50 of 39.31 µM, 50 µM and 15.77 µM for RLM, HLM and CYP3A4.1, respectively. Consistent with in vitro results, lidocaine concomitantly used with simvastatin in rats was associated with 1.2-fold AUC (0-t) , 1.2-fold AUC (0-∞) , and 20%-decreased clearance for lidocaine, and 1.4-fold C max for MEGX compared with lidocaine alone. Conclusion: Collectively, these results implied that simvastatin could evidently inhibit the metabolism of lidocaine both in vivo and in vitro. Accordingly, more attention and necessary therapeutic drug monitoring should be paid to patients with the concomitant coadministration of lidocaine and simvastatin so as to avoid unexpected toxicity.

Background MTH1 and NUDT5 effectively degrade nucleotides containing 8-oxoguanine. MTH1 and NUDT5 have been linked to the malignancy of multiple cancers. However, their functions in tumor growth and metastasis in esophageal squamous carcinoma (ESCC) remain obscure. Our present study aims to explore their prognostic value in ESCC and investigate their function in MTH1 or NUDT5-knockout tumor cells. Methods MTH1 and NUDT5 protein expression in ESCC adjacent normal tissues and tumor tissues was examined by immunohistochemistry staining. Kaplan–Meier curves were used to assess the association between their expression and overall survival (OS) in ESCC patients. Univariate and Multivariate Cox regression analyses were generated to determine the correlation between these protein expression and OS of ESCC patients. Protein expression in ESCC cell lines were measured by Western blotting. To explore the potential effects of the MTH1 and NUDT5 protein in ESCC, cell models with MTH1 or NUDT5 depletion were established. CCK-8, cell cycle, Western blotting, migration and invasion assays were performed. Results Our present study demonstrated that the levels of MTH1 and NUDT5 were upregulated in ESCC cell lines and ESCC tissues, the expression of MTH1 and NUDT5 in ESCC tissues was significantly higher than in adjacent non-tumorous, and higher levels of MTH1 and NUDT5 predicted a worse prognosis in patients with ESCC. MTH1 and NUDT5 are novel biomarkers of the progression of ESCC and a poor prognosis. We also found for the first time that the high expression of NUDT5 independently predicted lower OS in patients with ESCC (hazard ratio (HR) 1.751; 95% confidence interval (CI) [1.056–2.903]; p = 0.030). In addition, the depletion of MTH1 and NUDT5 strongly suppressed the proliferation of ESCC cells and significantly delayed the G1 phase of the cell cycle. Furthermore, we found that MTH1 and NUDT5 silencing inhibited epithelial–mesenchymal transition mainly by the MAPK/MEK/ERK dependent pathway, which in turn significantly decreased the cell migration and invasion of ESCC cells. Our results suggested that the overexpression of MTH1 and NUDT5 is probably involved in the tumor development and poor prognosis of ESCC.

Saxagliptin is a dipeptidyl peptidase 4 (DPP‐4) inhibitor widely used in patients with type 2 diabetes. It can increase the amount of insulin after meals and lower blood sugar. CYP450 3A4 (CYP3A4) can metabolize about 30%–40% of therapeutic drugs. Individual differences caused by CYP3A4 genetic polymorphisms can lead to treatment failure, unpredictable side effects, or severe drug toxicity. The aim of this study was to evaluate the catalytic activities of 27 CYP3A4 variants on saxagliptin metabolism in vitro, which were identified in human CYP alleles. We successfully constructed 27 kinds of wild‐type and variant vectors of pFast‐dual‐OR‐3A4 by overlap extension PCR and prepared 27 kinds of CYP3A4 highly expressed cell microsomes by baculovirus insect cell expression system. The ultra‐performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) was used to detect the concentrations of the metabolite of saxagliptin (5‐hydroxysaxagliptin) and the internal standard. Compared with the wild‐type CYP3A4.1, the intrinsic clearance values of most varieties decreased to 1.91%–77.08%. Most of these varieties showed a decrease in Vmax and an increase in Km values compared with wild type. We are the first to report the vitro metabolic data of 27 CYP3A4 variants of the metabolism of saxagliptin which can deepen our understanding of individualized drug use by combining previous studies about the effects of CYP3A4 variants of drug metabolism. With further in vivo studies, we hope it can guide individualized drug use in the clinic when the variants with low metabolic activity to saxagliptin were sequenced in the human body.

Objective To discuss the effects of genistein on the metabolism of celecoxib in vitro and in vivo. Method In vitro, the effects of genistein on the metabolism of celecoxib were studied using rat and human liver microsomes. In vivo, pharmacokinetics of celecoxib was evaluated in rats with or without genistein. Fifteen Sprague-Dawley (SD) rats were randomized into three groups: celecoxib (A group), celecoxib and 50 mg/kg genistein (B group), and celecoxib and 100 mg/kg genistein (C group). Single dose of 33.3 mg/kg celecoxib was orally administered 30 min after genistein ig. At 0.5, 1, 2, 3, 4, 6, 8, 10, 12, and 24 h after celecoxib administration, 300–400 µl blood samples were collected and the concentration of celecoxib was analyzed by ultrahigh-performance liquid chromatography-tandem mass spectrometry system. Result Genistein showed notable inhibitory effects on three microsomes. It affected pharmacokinetics of celecoxib in vivo experiments. Genistein had dramatically ability to suppress CYP2C9∗1 and ∗3. After pretreatment with genistein, AUC and Cmax of the C group were higher than B group. CLz/F of C group was lower than the B group. Conclusion Genistein inhibits the conversion of celecoxib in vitro and in vivo. So, the dosage of celecoxib should be adjusted if it was used associated with genistein.