Establishment of In Silico Prediction Models for CYP3A4 and CYP2B6 Induction in Human Hepatocytes by Multiple Regression Analysis Using Azole Compounds

Abstract

Drug-drug interactions (DDIs) via cytochrome P450 (P450) induction are one clinical problem leading to increased risk of adverse effects and the need for dosage adjustments and additional therapeutic monitoring. In silico models for predicting P450 induction are useful for avoiding DDI risk. In this study, we have established regression models for CYP3A4 and CYP2B6 induction in human hepatocytes using several physicochemical parameters for a set of azole compounds with different P450 induction as characteristics as model compounds. To obtain a well-correlated regression model, the compounds for CYP3A4 or CYP2B6 induction were independently selected from the tested azole compounds using principal component analysis with fold-induction data. Both of the multiple linear regression models obtained for CYP3A4 and CYP2B6 induction are represented by different sets of physicochemical parameters. The adjusted coefficients of determination for these models were of 0.8 and 0.9, respectively. The fold-induction of the validation compounds, another set of 12 azole-containing compounds, were predicted within twofold limits for both CYP3A4 and CYP2B6. The concordance for the prediction of CYP3A4 induction was 87% with another validation set, 23 marketed drugs. However, the prediction of CYP2B6 induction tended to be overestimated for these marketed drugs. The regression models show that lipophilicity mostly contributes to CYP3A4 induction, whereas not only the lipophilicity but also the molecular polarity is important for CYP2B6 induction. Our regression models, especially that for CYP3A4 induction, might provide useful methods to avoid potent CYP3A4 or CYP2B6 inducers during the lead optimization stage without performing induction assays in human hepatocytes.

The Connection of Azole Fungicides with Xeno-Sensing Nuclear Receptors, Drug Metabolism and Hepatotoxicity

“…This conclusion is supported also by in vitro reporter gene data including CAR binding site-deficient mutant constructs [32,33], and by the fact that CAR target gene induction was abolished in a CAR-deficient knockout mouse model [20]. Propiconazole agonism at CAR appears not to be limited to murine systems, as in vitro FRET, reporter gene and target mRNA data as well as molecular docking show that CAR and its target genes are activated by the compound also in human cells [16,[31][32][33]38]. Activation of CAR appears to occur with rather moderate potency, as suggested by in vitro assays and computationally derived binding energy [32].…”

“…Specificity of this type of information is, of course, questionable because the target gene batteries of CAR and PXR show substantial overlap. In human cells, however, direct evidence at the reporter gene and mRNA level is available supporting the notion that propiconazole is a moderately potent agonist of human PXR [12,16,28,31,32,38]. This is substantiated by experiments in a CAR-deficient, PXR-expressing cell line [32].…”

“…Data for mouse and rat are mainly derived from in vivo studies that yielded indirect evidence for AHR activation via target gene and enzyme activity regulation [4,6,31,36]. For human liver cells, in vitro evidence at the reporter gene, target mRNA, protein, and enzyme activity level suggests weak agonism of propiconazole at the AHR, substantiated by in silico molecular docking study results [16,26,27,31,35,37,38]. Additionally, in vitro experiments using a human AHR antagonist, AHR binding site-mutated reporter variants or AHR knockout cells mechanistically strengthen the evidence for AHR activation by propiconazole [31].…”

“…Again, target enzyme activity inhibition is presumably a consequence of direct CYP inhibition [32,35]. [12,16,28,32] Target mRNA [31,32,38] Target enzyme activity [32,35] In vivo studies Target mRNA [6,33,36] [4,5,36] Propiconazole has been assessed for its toxicity after short-and long-term exposure as well as for its carcinogenic potential in vivo in a number of studies conducted according to harmonized OECD test guidelines within the regulatory approval procedure. Study results are summarized in the assessment report [41], JMPR [42], as well as in the respective EFSA conclusion [43].…”

“…AHR activity of tebuconazole is an interesting case: on the one hand, reporter gene assays in human cell lines failed to reveal increased AHR activity [26,37,63]. On the other hand, analyses at the target mRNA, protein, and enzyme activity levels showed a clear increase [26,35,37,38,63]. This induction was abolished in AHR-KO cells or after pharmacological inhibition of AHR, demonstrating that the process of target gene induction is AHR-dependent [37].…”