CYP3A4 Research Articles

Insights into CYP 1A2 dynamics in acute lymphocytic leukemia: Gene regulation, promoter methylation, and pesticide exposure in the Kashmiri population

Insights into CYP 1A2 dynamics in acute lymphocytic leukemia: Gene regulation, promoter methylation, and pesticide exposure in the Kashmiri population

Triterpenoids from Ganoderma lucidum inhibit cytochrome P450 enzymes interfering with the metabolic process of specific clinical drugs.

Ganoderma lucidum (G. lucidum), which possesses various biological effects, has been widely used as traditional medicine and functional food in Asian countries, especially China. In consideration of its various biological effects on human healthcare, G. lucidum was usually used in combination with other drugs. However, the potential drug-drug interaction induced by G. lucidum through cytochrome P450 enzymes (CYPs) remain unknown. Using the in vivo activity assay of CYPs, the inhibitory effects of G. lucidum and its constituents could be evaluated. The interference of G. lucidum on the metabolic processes of clinical drugs could be investigated. The chemical constituents of G. lucidum could be identified using LC-MS. The interaction between bioactive compounds and CYPs could be proposed through in silico docking analysis and molecular dynamics. The dichloromethane extract of G. lucidum could inhibit various CYP450 subtypes in vitro and interfere with the pharmacokinetics of four drugs in rats. Triterpenoids were identified as the main constituents of the dichloromethane extract by Q-TOF-MSn in preliminary analyses. Then, a triterpenoid library containing 66 compounds was established to evaluate their inhibitory effects against CYP 1A2, 2D6, 3A4, 2A6, 2B6, 2C9, and 2C19. CYP 1A2 was inhibited by most lanostane triterpenoids, indicating a strong affinity for these compounds. Among triterpenoids, compound 25 displayed a broad inhibitory effect against CYPs, except for CYP 3A4, 2D6, 2C9, and 2C19. Finally, compounds 6 and 25 exhibited interference with the metabolism of 16 drugs through the inhibition of CYPs in vitro. In silico molecular docking analyses for assaying the interaction between compound 25 and CYPs indicated that the hydrogen bonds formed between the hydroxyl groups and amino acid residues. G. lucidum displayed broad inhibitory effects on CYPs, with triterpenoids as the main bioactive constituents, which may induce potential drug-drug interaction. This information should be helpful for the rational use of G. lucidum in promoting human health.

Clozapine Toxicity Predictor: Deep neural network model predicting clozapine toxicity and its therapeutic dose range

Clozapine is the gold standard for treatment-resistant schizophrenia; however, its superior efficacy is accompanied by potentially serious adverse events (neutropenia, seizures, constipations, pneumonia), many of which are also concentration-dependent. As such, clozapine dose titration should be guided by therapeutic drug monitoring (TDM). However, access to TDM is often limited. The present study describes a new deep neural network that can predict the concentrations, toxicity and therapeutic dose range for clozapine and norclozapine. The model was trained on basic clinical data (biological sex, age, clozapine daily dose, BMI, CRP and number of CYP 1A2 and 3A4 substrates, inhibitors and inducers) from 69 patients with treatment-refractory patients treated with different clozapine doses. Our findings provide the training efficacy data for the model, as well as an analysis of clozapine and norclozapine blood concentrations in a test group of three additional patients, to demonstrate its practical capabilities. The model is licensed on a free and permissive 2-Clause BSD license and is available to all clinicians; it can be accessed as a web application, available at https://csk.umed.pl/clotop.

Structure identification of myricetin-phenylacetaldehyde adducts and their potential biological activities

Our previous research discovered that myricetin could effectively inhibit the formation of heterocyclic aromatic amines (HAAs) in cantonese baked foods by trapping phenylacetaldehyde to form adducts. However, the structure and biological activity of these adducts were still unknown. In this study, we identified two myricetin-phenylacetaldehyde adducts from cantonese mooncakes, BYQ-2 and BYQ-3, using pre-HPLC. These adducts were found to be the products of phenylacetaldehyde addition at the C-8 and C-6 positions of myricetin, followed by cyclization with hydroxyl groups at the C-7 and C-5 positions. Antioxidant assays revealed that BYQ-2 and BYQ-3 have stronger radical scavenging abilities than myricetin in the concentration range of 12.5 ∼ 800 μg/mL in the three samples. Additionally, both adducts showed potential health benefits by inhibiting α-glucosidase and CYP450 1A2, enzymes involved in blood sugar regulation and HAAs metabolism. BYQ-2 exhibited the highest inhibitory potency against α-glucosidase and CYP450 1A2 with IC50 values of 10.32 μg/mL and 5.44 μg/mL, respectively. Theoretical calculations suggested that hydrogen bonding and hydrophobic interactions are the primary forces driving enzyme binding, with BYQ-2 showing the highest binding energies (−7.75 kcal/mol for α-glucosidase and −9.31 kcal/mol for CYP450 1A2). Our findings suggested that myricetin inhibited HAAs in baked foods while also enhancing food safety and providing health benefits through its adduction with small molecule aldehydes. In future research, it is necessary to further evaluate the absorption and metabolic behavior as well as safety of myricetin-HAAs active intermediate adducts at the cellular and animal experimental level.

A Computational Pipeline Observes the Flexibility and Dynamics of Plant Cytochrome P450 Binding Sites.

Binding site flexibility and dynamics strongly affect the ability of proteins to accommodate substrates and inhibitors. The significance of these properties is particularly pronounced for proteins that are inherently flexible, such as cytochrome P450 enzymes (CYPs). While the research on human CYPs provides detailed knowledge on both structural and functional level, such analyses are still lacking for their plant counterparts. This study aims to bridge this gap. We developed a novel computational pipeline consisting of two steps. Firstly, we use molecular dynamics (MD) simulations to capture the full conformational ensemble for a certain plant CYP. Subsequently, we developed and applied a comprehensive methodology to analyze a number of binding site properties-size, flexibility, shape, hydrophobicity, and accessibility-using the fpocket and mdpocket packages on MD-generated trajectories. The workflow was validated on human CYPs 1A2, 2A6, and 3A4, as their binding site characteristics are well known. Not only could we confirm known binding site properties, but we also identified and named previously unseen binding site channels for CYPs 1A2 and 2A6. The pipeline was then applied to plant CYPs, leading to the first categorization of 15 chosen plant CYPs based on their binding site's (dis)similarities. This study provides a foundation for the largely uncharted fields of plant CYP substrate specificity and facilitates a more precise understanding of their largely unknown specific biological functions. It offers new insights into the structural and functional dynamics of plant CYPs, which may facilitate a more accurate understanding of the fate of agrochemicals or the biotechnological design and exploitation of enzymes with specific functions. Additionally, it serves as a reference for future structural-functional analyses of CYP enzymes across various biological kingdoms.

Liver CYP4A autophagic-lysosomal degradation (ALD): A major role for the autophagic receptor SQSTM1/p62 through an uncommon target interaction site.

The hepatic P450 hemoproteins CYPs 4A are typical N-terminally anchored Type I endoplasmic reticulum (ER)-proteins, that are inducible by hypolipidemic drugs and other "peroxisome proliferators". They are engaged in the ω-/ω-1-oxidation of various fatty acids including arachidonic acid, prostaglandins and leukotrienes and in the biotransformation of some therapeutic drugs. Herein we report that of the mammalian liver CYPs 4A, human CYP4A11 and mouse Cyp4a12a are preferential targets of the ER-lysosome-associated degradation (ERLAD). Consequently, these proteins are stabilized both as 1%Triton X100-soluble and -insoluble species in mouse hepatocytes and HepG2-cells deficient in the autophagic initiation ATG5-gene. Although these proteins exhibit surface LC3-interacting regions (LIRs) that would target them directly to the autophagosome, they nevertheless interact intimately with the autophagic receptor SQSTM1/p62. Through structural deletion analyses and site-directed mutagenesis, we have identified the Cyp4A-interacting p62 subdomain to lie between residues 170 and 233, which include its Traf6-binding and LIM-binding subdomains. Mice carrying a liver-specific genetic deletion of p62 residues 69-251 (p62Mut) that includes the CYP4A-interacting subdomain also exhibit Cyp4a-protein stabilization both as Triton X100-soluble and -insoluble species. Consistently, p62Mut mouse liver microsomes exhibit enhanced ω- and ω-1-hydroxylation of arachidonic acid to its physiologically active metabolites 19- and 20-HETEs relative to the corresponding wild-type mouse liver microsomes. Collectively, our findings suggest that any disruption of CYP4A ERLAD results in functionally active P450 protein and consequent production of proinflammatory metabolites on one hand, and insoluble aggregates on the other, which may contribute to pathological aggregates i.e. Mallory-Denk bodies/inclusions, hallmarks of many liver diseases.

In Vivo Chemosuppressive Effects of Kolaviron on 7,12-Dimethylbenzanthracene-Induced Mammary Lesions are Associated with Changes in Levels of Estrogen Receptor-α, CYP 1A1, Proinflammatory Cytokines, and Alterations to Metabolic Pathways Implicated in Mammary Carcinogenesis.

Garcinia kola is a medicinal food commonly consumed in Sub-Sahara Africa, for which Kolaviron (KV) is the active portion. As a follow-up to our earlier chemopreventive studies, we investigated the chemotherapeutic effects of KV on experimentally induced mammary carcinogenesis in female Wistar rats. Mammary carcinogenesis was induced using 80 mg/kg of 7,12-dimethylbenzanthracene (DMBA) administered by oral gavage. One hundred-fifty days post-DMBA induction, estrogen receptor-α (ER-α) levels were determined in the experimental rats before treatment with KV commenced. Treatment was done using 50, 100, and 200 mg/kg KV thrice a week for 4 weeks, after which the experiment was terminated. Significantly higher levels of estrogen receptor-α, CYP 1A1, malondialdehyde, formation of lobular neoplastic cells, epithelial hyperplasia, lymphocyte infiltration, and increased cytokine (interleukin-6 and tumor necrosis factor-α) activity were observed in DMBA-induced rats, which were attenuated in KV-treated rats. Tyrosine metabolism was exclusively enriched in DMBA-induced rats in contrast to KV-treated rats. Collectively, the results point to the chemotherapeutic potential of KV.

In vitro and in vivo preclinical pharmacokinetic characterization of aficamten, a small molecule cardiac myosin inhibitor

Aficamten, a small molecule selective inhibitor of cardiac myosin, was characterised in preclinical in vitro and in vivo studies. Protein binding in human plasma was 10.4% unbound and ranged from 1.6% to 24.9% unbound across species. Blood-to-plasma ratios ranged from 0.69 to 1.14 across species. Aficamten hepatic clearance in human was predicted to be low from observed high metabolic stability in vitro in human liver microsomes. Aficamten demonstrated high permeability in Caco-2 cell monolayers. Aficamten in vivo clearance was low across species at 8.8, 2.1, 3.3, and 11 mL/min/kg in mouse, rat, dog, and monkey, respectively. The volume of distribution was low-to-high ranging from 0.53 in rat to 11 L/kg in dog. Oral bioavailability ranged from 41% in monkey to 98% in mouse. Aficamten was metabolised in vitro to eight metabolites with hydroxylated metabolites M1a and M1b predominating. CYP phenotyping indicated multiple CYPs (2C8, 2C9, 2D6, and 3A4) contributing to the metabolism of aficamten. Human clearance (1.1 mL/min/kg) and volume of distribution (6.5 L/kg) were predicted using 4-species allometry employing ‘rule-of-exponents’. A predicted 69 hour half-life is consistent with observed half-life in human Phase-1. No CYP-based drug-drug interaction liability as a precipitant was predicted for aficamten.

Assessing the impact of aprepitant on response to dose-intensive cyclophosphamide, etoposide, and cisplatin (DICEP).

Despite evidence demonstrating the effectiveness of aprepitant for chemotherapy-induced nausea and vomiting (CINV), its use in stem cell transplant settings across Canada is not standard. While pharmacokinetic data exists, the clinical significance of cytochrome P450 3A4 (CYP 3A4) inhibition of cyclophosphamide by aprepitant is unclear. Reduced activation of cyclophosphamide may reduce the effectiveness of dose-intensive cyclophosphamide, etoposide, and cisplatin (DICEP). To compare response rates to DICEP in patients with Hodgkin lymphoma (HL) and diffuse large B-cell lymphoma (DLBCL) in the presence and absence of aprepitant. A retrospective review of patients who received full-dose DICEP for relapsed/refractory HL or DLBCL between June 1995 and September 2018 at the Foothills Medical Centre (FMC) in Calgary, Alberta, Canada was conducted. Descriptive statistics were used to assess response rate, as defined by the 2007 International Working Group response criteria. Of the 218 patients included in this study, 87.6% of patients in the control group and 88.5% of patients in the aprepitant group responded to DICEP (difference 0.025 [95% CI, -0.066 to 0.114], p = 0.827). Univariate analyses for age, sex, type of cancer, stage of cancer, number of prior relapses, and relapse status were not significant. No significant differences were observed for secondary outcomes. Response rates to DICEP in relapsed/refractory HL and DLBCL patients were similar regardless of aprepitant use. Considering these results and the effectiveness of aprepitant in CINV, its addition to standard antiemetic therapy in patients receiving DICEP should be given strong consideration in the transplant setting.

Assessment of Nutritional Status of Children aged 1-5 years attending the Outdoor Patients Department of Sheikh Zayed Hospital, Rahim Yar Khan, Pakistan

Background: Cytochrome P450 enzymes play vital roles in metabolizing drugs, endogenous compounds, and environmental pollutants. Among them, Cytochrome P450 1A2 (CYP1A2), CYP1A1 and CYP1B are particularly important for activating carcinogens. Computational modeling of CYP1A2 is essential for understanding its interactions with various molecules, substrates, and inhibitors. Objective: To characterize the structure of CYP1A2 and explore the binding of alpha-naphthoflavone to its active site. Study Design: In Silico study (Computational modeling). Place of Study: International Center of Medical Sciences Research (ICMSR), Islamabad, Pakistan. Material and Methods: Using the Swiss PDB Viewer, the structural features of CYP1A2 were assessed, focusing on key residues, motifs, helices, and conserved regions. Results: Our findings identified specific binding sites for Alpha-Naphthoflavone (ANF), highlighting its potential as a potent inhibitor of CYP1A2. This research contributes to our knowledge of the clinical and toxicological implications associated with CYP1A2. Conclusion: Structural differences were found between CYP1A2 and related enzymes, with less than 40% sequence identity compared to several other P450s. The study predominantly compares CYP1A2 with CYP 2A6 and CYP3A4 due to these differences. T he developed structural models offer a fast and precise method for studying CYP1A2, aiding in understanding its role in drug metabolism and toxicology.

Metabolic profiling of a new synthetic cannabinoid receptor agonist, ADMB-FUBIATA, with human liver microsomes, human primary hepatocytes and human recombinant CYP450 enzymes using LC-quadrupole-orbitrap MS

A novel synthetic cannabinoid receptor agonist (SCRA), ADMB-FUBIATA, featuring an acetamide-linked structure, has emerged on the illicit drug market. To provide dependable verification of its consumption and identify reliable biomarkers, we investigated an in vitro metabolism study of ADMB-FUBIATA incubated with human primary hepatocytes (HPHs) for the first time and correlated our findings with those from human liver microsomes (HLMs). In this work, ADMB-FUBIATA (10 μM) was incubated with HLM and HPH for 1 and 5 h, respectively, and then subjected to LC-quadrupole-orbitrap MS. A total of 25 metabolites across 8 metabolic pathways were identified after incubation with HLM and HPH, respectively. Monohydroxylation and N-dealkylation were the major metabolic pathways, and formation to ketone was first identified. In addition, the metabolism of ADMB-FUBIATA were found to be mediated by multiple CYP450 enzymes, predominantly CYP2C19, 2D6, and 3A4. This research also initially characterized the fragmentation patterns of the metabolites of ADMB-FUBIATA, elaborating on their structural relationship with ADMB-FUBIATA analogs. To effectively monitor ADMB-FUBIATA abuse, metabolites M4 and M1 were proposed as reliable biomarkers by cross-validating the HLM and HPH incubation results.

An Unusual Case Report of Iatrogenic Metrorrhagia and Hematochezia Following Itraconazole

Abstract Itraconazole is an effective triazole antimycotic drug that has a desirable pharmacokinetic profile to combat various fungal pathogens. It acts by inhibiting ergosterol biosynthesis in fungal cell membranes. Itraconazole is not totally selective toward Cytochrome P450 family 3 subfamily A member 4 (CYP450 3A4), but exhibits the most potent inhibition of CYP450 3A4. Thus, these drugs interfere with CYP450 3A4 proteins expressed in the liver, intestine, kidney, adrenals, ovary, and testis. We present a case report of metrorrhagia and hematochezia following intake of itraconazole, a commonly used azole drug against dermatophytic infection. This article strongly highlights eliciting menstrual history and gynecological- and surgical-related problems before prescribing itraconazole. Also, to be aware of the vaginal bleeding being the unusual side effects of itraconazole.

Pattern of CYP3A5 and MDR-1 single nucleotide polymorphism and its impact on Tacrolimus levels and clinical outcomes in living renal allograft recipient

Abstract Introduction Renal transplant is best form of renal replacement therapy. Most favored immunosuppression includes Tacrolimus, mycophenolate mofetil and steroids. Tacrolimus has narrow therapeutic index and requires therapeutic drug monitoring (TDM). However, there is wide variation in tacrolimus level with weight based fixed dosage regimens. This variability is due to polymorphism of major pathways of metabolism ie CYP3A5 and MDR1 genes. Fast metabolizer require higher dosage and slow metabolizer require lower dosage. Genotype based dosing strategy may be useful to achieve early therapeutic level and reduce infections and rejections. Methodology 160 transplant patients at tertiary care hospital in India were included in this study from 2016 to 2018. Genetic polymorphism analysis in CYP3A5 and MDR1 gene was carried out at time of transplant. All patients were given a fixed weight-based dosage of Tacrolimus. Data was analyzed in relation to genotype polymorphism. Results and discussion 69.2% of Wild variants of CYP 3A5 (Fast metabolizers) have low initial tacrolimus levels. 51.5% of Homo variants (Slow metabolizers) have high initial tac levels. However, all variants achieve optimum tacrolimus levels at same time (mean 12.4 days). There were higher number of infections among slow metabolizers. Conclusion A fixed dosing regimen with TDM result in high and low initial tacrolimus levels in slow and fast metabolizers respectively and more infections in slow metabolizers. However, graft rejections being fewer in number, were not different. A larger sample with genotype based dosing is required to test such a strategy.

A Scoping Review on Recent Progress on Purpurin and its Derivatives

Background: Purpurin is being used as a red dye for many decades. But recently, due to its pharmacological properties, purpurin and its derivatives have attracted a lot of researchers for the treatment of various ailments, such as cancer, Alzheimer’s disease, depression, etc. Objectives: The objective of this study is to provide an overview of its pharmacological properties, pharmacokinetic studies, synthesis, isolation, quality assurance, and patent studies. Method: A systemic scoping review was undertaken. Three databases (Pubmed, Scopus, and Google Scholar) and patent websites were searched using relevant words (e.g., purpurin, purpurin derivatives, anticancer, toxicity, etc.). All outcomes for studies that met the inclusion criteria were included in the review. Extracted data were accumulated using tables, figures, and accompanying narrative descriptive summaries. The review was reported using the preferred reporting items for scoping review (PRISMAScR) guidelines. Sixty-eight studies and eighty-six patents met the inclusion criteria, mostly preclinical (in vitro, in vivo, and in silico) studies performed in rats, mice, dogs, and zebrafish, followed by one clinical trial study. Results: The potent antioxidant nature of purpurin is the main reason behind its vast pharmacological properties. It acts by decreasing mitochondrial stress and by acting on the endoplasmic reticulum. It also crosses the BBB barrier, has high GI absorption, and follows the Lipinski rule, which makes it a good drug for various neurodegenerative disorders. It inhibits various CYP-450, CYP 1A2, and CYP 3A4 enzymes, which are responsible for causing mutations. It gets photosensitized by UV light and causes ROSdependent apoptosis in cancer cells. Conclusion: This scoping review highlights purpurin and its derivatives as highly prized moieties in the treatment of various neurological conditions and cancer. The unique nature of purpurin is responsible for its pharmacological properties, which are due to the presence of hydroxyl and keto groups at specific positions. It gets photosensitized by UV and laser light and acts as an anticancer drug. But the lack of robust evaluation in clinical studies is another major concern. Purpurin can be seen in the prescription in the future, although a lot of work still needs to be done.

Identification of New Substrates and Inhibitors of Human CYP2A7.

CYP2A7 is one of the most understudied human cytochrome P450 enzymes and its contributions to either drug metabolism or endogenous biosynthesis pathways are not understood, as its only known enzymatic activities are the conversions of two proluciferin probe substrates. In addition, the CYP2A7 gene contains four single-nucleotide polymorphisms (SNPs) that cause missense mutations and have minor allele frequencies (MAFs) above 0.5. This means that the resulting amino acid changes occur in the majority of humans. In a previous study, we employed the reference standard sequence (called CYP2A7*1 in P450 nomenclature). For the present study, we created another CYP2A7 sequence that contains all four amino acid changes (Cys311, Glu169, Gly479, and Arg274) and labeled it CYP2A7-WT. Thus, it was the aim of this study to identify new substrates and inhibitors of CYP2A7 and to compare the properties of CYP2A7-WT with CYP2A7*1. We found several new proluciferin probe substrates for both enzyme variants (we also performed in silico studies to understand the activity difference between CYP2A7-WT and CYP2A7*1 on specific substrates), and we show that while they do not act on the standard CYP2A6 substrates nicotine, coumarin, or 7-ethoxycoumarin, both can hydroxylate diclofenac (as can CYP2A6). Moreover, we found ketoconazole, 1-benzylimidazole, and letrozole to be CYP2A7 inhibitors.

Assessment of microplastic-contaminated liver through gene expression profiling of four commercial fish species in the Lagos Lagoon, Nigeria

Microplastic (MP) occurrence in the Lagos Lagoon has been on a progressive increase in recent years. The potential impacts and hazards of MPs on commercially available fish species from the Lagoon have been understudied. This study aims to assess molecular damage due to microplastic accumulation in the liver of four commercial fish species (Oreochromis niloticus, Chrysichthys nigrodigitatus, Clarias gariepinus, and Gymnarchus niloticus) sourced directly from the Lagoon. The results revealed that MP load in the liver of the fish species ranged between 7.2 ± 1.9 and 9.5 ± 4.4 particles/individual, with G. niloticus recording the maximum concentration. The observed extracted MPs are predominantly black and blue fibres while the Fourier Transform Infrared spectroscopy revealed polyethylene dominance in the plastic polymers. Relative gene expression results revealed statistically significant downregulation of the CYP 1a gene and upregulation of the HSP 70 gene in all the microplastic-laden liver samples except in G. niloticus. The findings from this study suggest that microplastic contamination in fish tissues may exacerbate cellular toxicity in commercially available biota in the Lagos Lagoon, thereby calling for urgent measures to curb microplastic and ultimately plastic pollution. However, there's a need for in-depth research on the effects of environmentally relevant microplastics on edible fish tissues to further elucidate their molecular impact.

Proof-of-concept studies with a computationally designed Mpro inhibitor as a synergistic combination regimen alternative to Paxlovid

As the SARS-CoV-2 virus continues to spread and mutate, it remains important to focus not only on preventing spread through vaccination but also on treating infection with direct-acting antivirals (DAA). The approval of Paxlovid, a SARS-CoV-2 main protease (Mpro) DAA, has been significant for treatment of patients. A limitation of this DAA, however, is that the antiviral component, nirmatrelvir, is rapidly metabolized and requires inclusion of a CYP450 3A4 metabolic inhibitor, ritonavir, to boost levels of the active drug. Serious drug-drug interactions can occur with Paxlovid for patients who are also taking other medications metabolized by CYP4503A4, particularly transplant or otherwise immunocompromised patients who are most at risk for SARS-CoV-2 infection and the development of severe symptoms. Developing an alternative antiviral with improved pharmacological properties is critical for treatment of these patients. By using a computational and structure-guided approach, we were able to optimize a 100 to 250 μM screening hit to a potent nanomolar inhibitor and lead compound, Mpro61. In this study, we further evaluate Mpro61 as a lead compound, starting with examination of its mode of binding to SARS-CoV-2 Mpro. In vitro pharmacological profiling established a lack of off-target effects, particularly CYP450 3A4 inhibition, as well as potential for synergy with the currently approved alternate antiviral, molnupiravir. Development and subsequent testing of a capsule formulation for oral dosing of Mpro61 in B6-K18-hACE2 mice demonstrated favorable pharmacological properties, efficacy, and synergy with molnupiravir, and complete recovery from subsequent challenge by SARS-CoV-2, establishing Mpro61 as a promising potential preclinical candidate.

Harnessing machine learning to predict cytochrome P450 inhibition through molecular properties.

Cytochrome P450 enzymes are a superfamily of enzymes responsible for the metabolism of a variety of medicines and xenobiotics. Among the Cytochrome P450 family, five isozymes that include 1A2, 2C9, 2C19, 2D6, and 3A4 are most important for the metabolism of xenobiotics. Inhibition of any of these five CYP isozymes causes drug-drug interactions with high pharmacological and toxicological effects. So, the inhibition or non-inhibition prediction of these isozymes is of great importance. Many techniques based on machine learning and deep learning algorithms are currently being used to predict whether these isozymes will be inhibited or not. In this study, three different molecular or substructural properties that include Morgan, MACCS and Morgan (combined) and RDKit of the various molecules are used to train a distinct SVM model against each isozyme (1A2, 2C9, 2C19, 2D6, and 3A4). On the independent dataset, Morgan fingerprints provided the best results, while MACCS and Morgan (combined) achieved comparable results in terms of balanced accuracy (BA), sensitivity (Sn), and Mathews correlation coefficient (MCC). For the Morgan fingerprints, balanced accuracies (BA), Mathews correlation coefficients (MCC), and sensitivities (Sn) against each CYPs isozyme, 1A2, 2C9, 2C19, 2D6, and 3A4 on an independent dataset ranged between 0.81 and 0.85, 0.61 and 0.70, 0.72 and 0.83, respectively. Similarly, on the independent dataset, MACCS and Morgan (combined) fingerprints achieved competitive results in terms of balanced accuracies (BA), Mathews correlation coefficients (MCC), and sensitivities (Sn) against each CYPs isozyme, 1A2, 2C9, 2C19, 2D6, and 3A4, which ranged between 0.79 and 0.85, 0.59 and 0.69, 0.69 and 0.82, respectively.

Activity-Based Protein Profiling to Probe Relationships between Cytochrome P450 Enzymes and Early-Age Metabolism of Two Polycyclic Aromatic Hydrocarbons (PAHs): Phenanthrene and Retene.

A growing body of literature has linked early-life exposures to polycyclic aromatic hydrocarbons (PAH) with adverse neurodevelopmental effects. Once in the body, metabolism serves as a powerful mediator of PAH toxicity by bioactivating and detoxifying PAH metabolites. Since enzyme expression and activity vary considerably throughout human development, we evaluated infant metabolism of PAHs as a potential contributing factor to PAH susceptibility. We measured and compared rates of phenanthrene and retene (two primary PAH constituents of woodsmoke) metabolism in human hepatic microsomes from individuals ≤21 months of age to a pooled sample (n = 200) consisting primarily of adults. We used activity-based protein profiling (ABPP) to characterize cytochrome P450 enzymes (CYPs) in the same hepatic microsome samples. Once incubated in microsomes, phenanthrene demonstrated rapid depletion. Best-fit models for phenanthrene metabolism demonstrated either 1 or 2 phases, depending on the sample, indicating that multiple enzymes could metabolize phenanthrene. We observed no statistically significant differences in phenanthrene metabolism as a function of age, although samples from the youngest individuals had the slowest phenanthrene metabolism rates. We observed slower rates of retene metabolism compared with phenanthrene also in multiple phases. Rates of retene metabolism increased in an age-dependent manner until adult (pooled) metabolism rates were achieved at ∼12 months. ABPP identified 28 unique CYPs among all samples, and we observed lower amounts of active CYPs in individuals ≤21 months of age compared to the pooled sample. Phenanthrene metabolism correlated to CYPs 1A1, 1A2, 2C8, 4A22, 3A4, and 3A43 and retene metabolism correlated to CYPs 1A1, 1A2, and 2C8 measured by ABPP and vendor-supplied substrate marker activities. These results will aid efforts to determine human health risk and susceptibility to PAHs exposure during early life.

Single Nucleotide Polymorphisms of CYP3A4 and CYP3A5 in Romanian Kidney Transplant Recipients: Effect on Tacrolimus Pharmacokinetics in a Single-Center Experience.

Background: This study examines the impact of CYP3A4 and CYP 3A5 genotypes on tacrolimus (Tac) pharmacokinetics in Romanian kidney transplanted patients. Methods: We included 112 kidney recipients genotyped for CYP3A5*3, CYP3A4*1.001, and CYP3A4*22. Patients were categorized into poor, intermediate, rapid, and ultra-rapid metabolizers based on the functional defects linked to CYP3A variants. Results: Predominantly male (63.4%) with an average age of 40.58 years, the cohort exhibited a high prevalence of the CYP3A4*1/*1 (86.6%) and CYP3A5*3/*3 (77.7%) genotypes. CYP3A4*1.001 and CYP3A5*1 alleles significantly influenced the Tac concentration-to-dose (C0/D) ratio in various post-transplant periods, while the CYP3A4*22 allele showed no such effect (p = 0.016, p < 0.001). Stepwise regression highlighted the CYP3A4*1.001's impact in early post-transplant phases, with hematocrit and age also influencing Tac variability. Conclusions: The study indicates a complex interaction of CYP3A4 and CYP3A5 genotypes on Tac metabolism, suggesting the necessity for personalized medication approaches based on genetic profiling in kidney transplant recipients.