Explore the vast range of titles available.

Cytochrome P450 reductase (CPR) abstracts electrons from Nicotinamide adenine dinucleotide phosphate H (NADPH), transferring them to an active Cytochrome P450 (CYP) site to provide a functional CYP. In the present study, a yeast strain was genetically engineered to delete the endogenous CPR gene. A human CYP expressed in a CPR-null (yRD−) strain was inactive. It was queried if Bax—which induces apoptosis in yeast and human cells by generating reactive oxygen species (ROS)—substituted for the absence of CPR. Since Bax-generated ROS stems from an initial release of electrons, is it possible for these released electrons to be captured by an inactive CYP to make it active once again? In this study, yeast cells that did not contain any CPR activity (i.e., because the yeasts’ CPR gene was completely deleted) were used to show that (a) human CYPs produced within CPR-null (yRD-) yeast cells were inactive and (b) low levels of the pro-apoptotic human Bax protein could activate inactive human CYPs within this yeast cells. Surprisingly, Bax activated three inactive CYP proteins, confirming that it could compensate for CPR’s absence within yeast cells. These findings could be useful in research, development of bioassays, bioreactors, biosensors, and disease diagnosis, among others.

The oxazaphosphorine alkylating drugs, cyclophosphamide and its structural isomer, ifosamide, are frequently employed in the field of oncology for cancer treatment and immunosuppression purposes. An effective treatment method against cyclophosphamide toxicity has been suggested using plant extracts with high levels of antioxidant constituents. This study evaluates in vitro anticancer activity and anticipates the potential of quinic acid from A. muricata fruit to impact cyclophosphamide metabolism using CYP 450 isoenzyme inhibition. The phytochemicals in the ethanolic extract of A. muricata fruit were initially identified and validated using Q-TOF LC-MS. The MTT assay, a widely used method in cancer research, was employed to assess the potential anticancer activity against MCF-7 cancer cell lines in an in vitro setting. In molecular docking, one of the isolated compounds, quinic acid, was therefore indented to be docked with CYP-450 proteins. In Q-TOF LC/MS analysis, the different peaks were obtained at different retention times, and the quinic acid was at the retention time of 3.1 minutes. The extract showed remarkable in vitro anticancer activity (IC50 value of 240.709 μg/mL) against MCF-7 cancer cell lines. The molecular docking study showed the most effective inhibition on CYP 3A4, CYP 2D6, CYP 2B6 and CYP 2C9 proteins, which indicated the interaction of quinic acid with CYP proteins and herbal drug interaction.

Background Cytochrome P450 monooxygenases (termed CYPs or P450s) are hemoproteins ubiquitously found across all kingdoms, playing a central role in intracellular metabolism, especially in metabolism of drugs and xenobiotics. The explosive growth of genome sequencing brings a new set of challenges and issues for researchers, such as a systematic investigation of CYPs across all kingdoms in terms of identification, classification, and pan-CYPome analyses. Such investigation requires an automated tool that can handle an enormous amount of sequencing data in a timely manner. Results CYPminer was developed in the Python language to facilitate rapid, comprehensive analysis of CYPs from genomes of all kingdoms. CYPminer consists of two procedures i) to generate the Genome-CYP Matrix (GCM) that lists all occurrences of CYPs across the genomes, and ii) to perform analyses and visualization of the GCM, including pan-CYPomes (pan- and core-CYPome), CYP co-occurrence networks, CYP clouds, and genome clustering data. The performance of CYPminer was evaluated with three datasets from fungal and bacterial genome sequences. Conclusions CYPminer completes CYP analyses for large-scale genomes from all kingdoms, which allows systematic genome annotation and comparative insights for CYPs. CYPminer also can be extended and adapted easily for broader usage.

Human Cytochrome P450 (CYP) enzymes constitute a superfamily of membrane-bound hemoproteins that are responsible for the metabolism of a wide variety of clinically, physiologically, and toxicologically important compounds. These heme-thiolate monooxygenases play a pivotal role in the detoxification of xenobiotics, participating in the metabolism of many structurally diverge compounds. This short-review is intended to provide a summary on the major roles of CYPs in Phase I xenobiotic metabolism. The manuscript is focused on eight main topics that include the most relevant aspects of past and current CYP research. Initially, (I) a general overview of the main aspects of absorption, distribution, metabolism, and excretion (ADME) of xenobiotics are presented. This is followed by (II) a background overview on major achievements in the past of the CYP research field. (III) Classification and nomenclature of CYPs is briefly reviewed, followed by (IV) a summary description on CYP’s location and function in mammals. Subsequently, (V) the physiological relevance of CYP as the cornerstone of Phase I xenobiotic metabolism is highlighted, followed by (VI) reviewing both genetic determinants and (VI) nongenetic factors in CYP function and activity. The last topic of the review (VIII) is focused on the current challenges of the CYP research field.

The 1-methyl-4-phenylpyridinium (MPP+) is a parkinsonian-inducing toxin that promotes neurodegeneration of dopaminergic cells by directly targeting complex I of mitochondria. Recently, it was reported that some Cytochrome P450 (CYP) isoforms, such as CYP 2D6 or 2E1, may be involved in the development of this neurodegenerative disease. In order to study a possible role for CYP induction in neurorepair, we designed an in vitro model where undifferentiated neuroblastoma SH-SY5Y cells were treated with the CYP inducers β-naphthoflavone (βNF) and ethanol (EtOH) before and during exposure to the parkinsonian neurotoxin, MPP+. The toxic effect of MPP+ in cell viability was rescued with both βNF and EtOH treatments. We also report that this was due to a decrease in reactive oxygen species (ROS) production, restoration of mitochondrial fusion kinetics, and mitochondrial membrane potential. These treatments also protected complex I activity against the inhibitory effects caused by MPP+, suggesting a possible neuroprotective role for CYP inducers. These results bring new insights into the possible role of CYP isoenzymes in xenobiotic clearance and central nervous system homeostasis.

CYP 3A4 and CYP 3A5 are two important members of the human cytochrome P450 family. Although their overall structures are similar, the local structures of the active site are different, which directly leads to obvious individual differences in drug metabolic efficacy and toxicity. In this work, midazolam (MDZ) was selected as the probe substrate, and its interaction with two proteins, CYP 3A4 and CYP 3A5, was studied by molecular dynamics simulation (MD) along with the calculation of the binding free energy. The results show that two protein–substrate complexes have some similarities in enzyme–substrate binding; that is, in both complexes, Ser119 forms a high occupancy hydrogen bond with MDZ, which plays a key role in the stability of the interaction between MDZ and the enzymes. However, the complex formed by CYP 3A4 and MDZ is more stable, which may be attributed to the sandwich structure formed by the fluorophenyl group of the substrate with Leu216 and Leu482. Our study interprets the binding differences between two isoform–substrate complexes and reveals a structure–function relationship from the atomic perspective, which is expected to provide a theoretical basis for accurately measuring the effectiveness and toxicity of drugs for individuals in the era of precision medicine.

Cytochrome P450 (CYP) enzymes are membrane-bound hemoproteins crucial for drug and xenobiotic metabolism. While more than 50 CYPs have been identified in humans, the isoforms from CYP1, 2, and 3 families contribute to the metabolism of about 80% of clinically approved drugs. To evaluate the effects of environmental chemicals on the activities of these important CYP enzyme families, we screened the Tox21 10K compound library to identify chemicals that inhibit CYP1A2, 2C9, 2C19, 2D6, and 3A4 enzymes. The data obtained from these five screenings were analyzed to reveal the structural classes responsible for inhibiting multiple and/or selective CYPs. Some known structural compound classes exhibiting pan-CYP inhibition, such as azole fungicides, along with established clinical inhibitors of CYPs, including erythromycin and verapamil inhibiting CYP3A4 and paroxetine and terbinafine inhibiting CYP2D6, were all confirmed in the current study. In addition, some selective CYP inhibitors, previously unknown but with potent activity (IC50 values < 1 µM), were identified. Examples included yohimbine, an indole alkaloid, and loteprednol, a corticosteroid, which showed inhibitory activity in CYP2D6 and 3A4 assays, respectively. These findings suggest that assessment of a candidate compound’s impact on CYP function may allow pre-emptive mitigation of potential adverse reactions and toxicity during drug development or toxicological characterization of environmental chemicals.

Pharmacogenomics is the use of genomic and other “omic” information to individualize drug selection and drug use to avoid adverse drug reactions and to maximize drug efficacy. The science underlying pharmacogenomics has evolved rapidly over the 50 years since it was first suggested that genetics might influence drug response phenotypes. That process has occurred in parallel with advances in DNA sequencing and other molecular technologies, with striking increases in our understanding of the human genome. There are now many validated examples of the clinical utility of pharmacogenomics, and this type of clinical genomic information is increasingly being generated in clinical laboratories, incorporated into electronic health records, and used to “tailor” or individualize drug therapy. This review will survey the origins and development of pharmacogenomics; it will address some of the challenges associated with the clinical implementation of pharmacogenomics; and it will attempt to foresee future advances in this important genomic discipline, one that almost certainly will be among the earliest and most widely adopted aspects of clinical genomics.

Pollution and its effects have been of major concern in recent decades. Many strategies and markers have been developed to assess their effects on biota. Cytochrome P450 (CYP) genes have received significant attention in this context because of their relationship with detoxification and activation of exogenous compounds. While their expression has been identified as a pollution exposure biomarker, in most cases, it has been tested only after acute exposures and for CYP genes associated with exogenous compounds. To elucidate CYP gene expression patterns under chronic pollution exposure, we have used the silverside Basilichthys microlepidotus as a model, which inhabits the Maipo River Basin, a freshwater system with different pollution levels. We performed next-generation RNA sequencing of liver and gill tissues from polluted and non-polluted populations. We found most CYP genes were not dysregulated by pollution, and the seven genes that were present and differentially expressed in liver and gill were mainly downregulated. Three CYP genes associated with exogenous compounds showed differential expression in the gill, while four CYP genes associated with endogenous compounds showed differential expression in the liver. The findings presented here highlight the importance of CYP genes, his family, tissues and his interaction in the context of pollution biomarkers use.

Currently used hepatocyte cell systems for assessment of drug metabolism include hepatoma cell lines and primary human hepatocyte (PHH) cultures. We investigated the suitability of the validated Basel phenotyping cocktail (caffeine [CYP1A2], efavirenz [CYP2B6], losartan [CYP2C9], omeprazole [CYP2C19], metoprolol [CYP2D6], midazolam [CYP3A4]) and characterized four hepatocyte cell systems (HepG2 cells, HepaRG cells, and primary cryopreserved human hepatocytes in 2-dimensional [2D] culture or in 3D-spheroid co-culture) regarding basal metabolism and CYP inducibility. Under non-induced conditions, all CYP activities could be determined in 3D-PHH, CYP2B6, CYP2C19, CYP2D6, and CYP3A4 in 2D-PHH and HepaRG, and CYP2C19 and CYP3A4 in HepG2 cells. The highest non-induced CYP activities were observed in 3D-PHH and HepaRG cells. mRNA expression was at least four-fold higher for all CYPs in 3D-PHH compared to the other cell systems. After treatment with 20 μM rifampicin, mRNA increased 3- to 50-fold for all CYPs except CYP1A2 and 2D6 for HepaRG and 3D-PHH, 4-fold (CYP2B6) and 17-fold (CYP3A4) for 2D-PHH and four-fold (CYP3A4) for HepG2. In 3D-PHH at least a two-fold increase in CYP activity was observed for all inducible CYP isoforms while CYP1A2 and CYP2C9 activity did not increase in 2D-PHH and HepaRG. CYP inducibility assessed using the same phenotyping probes was also best reflected by the 3D-PHH model. Our studies show that 3D-PHH and (with some limitations) HepaRG are suitable cell systems for assessing drug metabolism and CYP induction . HepG2 cells are less suited to assess CYP induction of the 2C and 3A family. The Basel phenotyping cocktail is suitable for the assessment of CYP activity and induction also .