P450 Isoforms Research Articles

A new insight into the aryl hydrocarbon receptor/cytochrome 450 signaling pathway in MG63, HOS, SAOS2, and U2OS cell lines

Osteosarcoma is the most common malignant tumor of bone, with rapid progressive growth, early distant metastases, and frequent recurrence after surgical treatment. Osteosarcoma is characterized by changes in the ratio and expression of different cytochrome P450 (CYP) isoforms that can affect the effectiveness of anticancer therapies. The inducible expression of CYP1 genes depends on the ligand-dependent functionality of the aryl hydrocarbon receptor (AHR). In this study, we examined the AHR/CYP1 signaling pathway in four osteosarcoma cell lines (MG63, HOS, SAOS2, and U2OS) induced by the known AHR ligands: indirubin, indole-3-carbinol, and beta-naphthoflavone. Using qPCR and Western blot analysis, we explored the effects of these ligands on the expression of the CYP1 genes and studied the correlation between these responses and the changes in the mRNA and protein levels of AHR and the AHR nuclear translocator (ARNT) in these osteosarcoma cell lines. The results show that the AHR/CYP1 signaling pathway retains its function only in MG63 and HOS cells, and is impaired in SAOS2 and U2OS cells. Our data should be taken into account when recommending new strategies for the treatment of osteosarcoma and when evaluating new drugs against osteosarcoma in vitro.

Effects of multi-walled carbon nanotubes in soil on earthworm growth and reproduction, enzymatic activities, and metabolomics

Increased production and environmental release of multi-walled carbon nanotubes (MWCNTs) increase soil exposure and potential risk to earthworms. However, MWCNT toxicity to earthworms remains unclear, with some studies identifying negative effects and others negligible effects. In this study, to determine whether exposure to MWCNTs negatively affects earthworms and to elucidate possible mechanisms of toxicity, earthworms were exposed to sublethal soil concentrations of MWCNTs (10, 50, and 100 mg/kg) for 28 days. Earthworm growth and reproduction, activities of cytochrome P450 (CYP) isoforms (1A2, 2C9, and 3A4) and antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and glutathione-s-transferase (GST)), and metabolomics were determined. Effects of MWCNTs on earthworms depended on exposure concentration. Exposure to MWCNTs did not significantly affect growth and reproduction of individual earthworms. Exposure to 50 mg/kg MWCNTs significantly increased activities of CYP2C9, CYP3A4, SOD, CAT, and GST but clearly reduced levels of L-aspartate, L-asparagine, and glutamine. With exposure to 100 mg/kg MWCNTs, toxic effects on earthworms were observed, with significant inhibition in activities of CYP isoenzymes and SOD, significant reductions in L-aspartate, L-asparagine, glutamine, and tryptophan, and simultaneous accumulations of citrate, isocitrate, fumarate, 2-oxoglutarate, pyruvate, D-galactose, carbamoyl phosphate, formyl anthranilate, hypoxanthine, and xanthine. Results suggest that toxicity of MWCNTs to earthworms is associated with reduced detoxification capacity, excessive oxidative stress, and disturbance of multiple metabolic pathways, including amino acids metabolism, the tricarboxylic acid cycle, pyruvate metabolism, D-galactose metabolism, and purine metabolism. The study provides new insights to better understand and predict the toxicity of MWCNTs in soil.

Controversial Interactions of Tacrolimus with Dietary Supplements, Herbs and Food

Tacrolimus is an immunosuppressive calcineurin inhibitor used to prevent rejection in allogeneic organ transplant recipients, such as kidney, liver, heart or lung. It is metabolized in the liver, involving the cytochrome P450 (CYP3A4) isoform CYP3A4, and is characterized by a narrow therapeutic window, dose-dependent toxicity and high inter-individual and intra-individual variability. In view of the abovementioned facts, the aim of the study is to present selected interactions between tacrolimus and the commonly used dietary supplements, herbs and food. The review was based on the available scientific literature found in the PubMed, Scopus and Cochrane databases. An increase in the serum concentration of tacrolimus can be caused by CYP3A4 inhibitors, such as grapefruit, pomelo, clementine, pomegranate, ginger and turmeric, revealing the side effects of this drug, particularly nephrotoxicity. In contrast, CYP3A4 inducers, such as St. John’s Wort, may result in a lack of therapeutic effect by reducing the drug concentration. Additionally, the use of Panax ginseng, green tea, Schisandra sphenanthera and melatonin in patients receiving tacrolimus is highly controversial. Therefore, since alternative medicine constitutes an attractive treatment option for patients, modern healthcare should emphasize the potential interactions between herbal medicines and synthetic drugs. In fact, each drug or herbal supplement should be reported by the patient to the physician (concordance) if it is taken in the course of immunosuppressive therapy, since it may affect the pharmacokinetic and pharmacodynamic parameters of other preparations.

Adenosine N6-methylation upregulates the expression of human CYP2B6 by altering the chromatin status

N6-Methyladenosine (m6A) modification is the most prevalent RNA modification in mammals. We have recently demonstrated that inhibition of m6A modification by 3-deazaadenosine results in an increase in the expression of the cytochrome P450 (CYP) isoforms CYP1A2, CYP2B6, and CYP2C8 in human liver-derived cells. In the present study, we aimed to clarify the mechanism of m6A-mediated regulation of CYP2B6 expression. RNA immunoprecipitation using an anti-m6A antibody revealed that CYP2B6 mRNA in human liver and hepatocarcinoma-derived HepaRG cells was m6A-modified around the stop codon. In contrast to the treatment with 3-deazaadenosine, double knockdown of methyltransferase like (METTL) 3 and METTL14 (METTL3/14) resulted in a decrease in the levels of CYP2B6 mRNA in Huh-7 and HepaRG cells and a decrease in bupropion hydroxylase activity, a marker activity of CYP2B6, in HepaRG cells. The stability of CYP2B6 mRNA was not influenced by siMETTL3/14. Reporter assays using the plasmids containing the last exon or 5′-flanking region of CYP2B6 indicated that reporter activities were not influenced by knockdown of METTL3/14. The expression levels of the constitutive androstane receptor, pregnane X receptor, and retinoid X receptor, which are the nuclear receptors regulating the transcription of CYP2B6, were not influenced by siMETTL3/14. The chromatin immunoprecipitation and formaldehyde-assisted enrichment of regulatory elements assays revealed that H3K9me2, a repressive histone marker, was enriched in the vicinity of the upstream region of CYP2B6, and knockdown of METTL3/14 induced the condensation of the chromatin structure in this region. In conclusion, we demonstrated that METTL3/14 upregulated CYP2B6 expression by altering the chromatin status.

Computational Prediction of Inhibitors and Inducers of the Major Isoforms of Cytochrome P450.

Human cytochrome P450 enzymes (CYPs) are heme-containing monooxygenases. This superfamily of drug-metabolizing enzymes is responsible for the metabolism of most drugs and other xenobiotics. The inhibition of CYPs may lead to drug–drug interactions and impair the biotransformation of drugs. CYP inducers may decrease the bioavailability and increase the clearance of drugs. Based on the freely available databases ChEMBL and PubChem, we have collected over 70,000 records containing the structures of inhibitors and inducers together with the IC50 values for the inhibitors of the five major human CYPs: 1A2, 3A4, 2D6, 2C9, and 2C19. Based on the collected data, we developed (Q)SAR models for predicting inhibitors and inducers of these CYPs using GUSAR and PASS software. The developed (Q)SAR models could be applied for assessment of the interaction of novel drug-like substances with the major human CYPs. The created (Q)SAR models demonstrated reasonable accuracy of prediction. They have been implemented in the web application P450-Analyzer that is freely available via the Internet.

Simultaneous absolute protein quantification of seven cytochrome P450 isoforms in rat liver microsomes by LC-MS/MS-based isotope internal standard method.

The cytochrome P450 (CYP) enzymes play a pivotal role in drug metabolism. LC-MS/MS-based targeting technology has been applied to the analysis of CYP enzymes, promoting drug development and drug-drug interaction studies. Rat is one of the most commonly used models for drug metabolism assessment, but LC-MS/MS assay quantifying the abundance of CYP enzymes in rats is rarely reported. Herein, an accurate and stable LC-MS/MS based method was developed and validated for the simultaneous quantification of seven major rat CYP isoforms (CYP1A2, 2B1, 2C6, 2C11, 2D1, 2E1, and 3A1) in liver microsomes. The careful optimization of trypsin digestion and chromatography combined with isotope-labeled peptide as internal standard improved the efficiency and accuracy of the analysis. Highly specific surrogate peptides were obtained by a procedure including trypsin digestion for six hours and separated on a Hypersil Gold C18 column (100 × 2.1 mm, 3 μm) using gradient elution for 15 min with a mobile phase of water containing 0.1% formic acid and acetonitrile. In the method validation, linearity, matrix effect, recovery, stability, accuracy, and precision all meet the requirements. Subsequently, this method was applied to detect seven enzymes in rat liver microsomes from four different sources, and the correlation between the abundance and activity of CYP enzymes was further analyzed. The high-throughput detection method provided in this study will provide support for pertinent pharmaceutical research based on rat models.

Pediatric AIDS-Therapeutic Successes Built on a Foundation of Pediatric Clinical Pharmacology with Pharmacokinetic-Pharmacodynamic Modeling.

Pediatric AIDS-Therapeutic Successes Built on a Foundation of Pediatric Clinical Pharmacology with Pharmacokinetic-Pharmacodynamic Modeling.

Endoplasmic Reticulum-Targeting Near-Infrared Fluorescent Probe for CYP2J2 Activity and Its Imaging Application in Endoplasmic Reticulum Stress and Tumor

CYP2J2 as an endoplasmic reticulum (ER)-expressed vital cytochrome P450 isoform participates in the metabolism of endogenous polyunsaturated fatty acids. Its abnormal expression and function are closely related to the progress of cancer and cardiovascular diseases. Herein, an ER-targeting near-infrared (NIR) fluorescent probe ER-BnXPI was developed for monitoring CYP2J2 activity, which possessed a high selectivity and sensitivity toward CYP2J2 among various CYP450 isoforms and exhibited excellent subcellular localization for ER. Then, the CYP2J2 variation behavior under the ER stress model was imaged by ER-BnXPI in living cells and successfully used for the in vivo imaging in different tumors that well distinguished tumor tissues from para-cancerous tissues. All these findings fully demonstrated that ER-BnXPI could be used as a promising tool for exploring the physiological function of CYP2J2 and provided some novel approach for the diagnosis and therapy of CYP2J2-related vascular inflammation and cancer.

Abstract 2020: Investigation of CYP450 enzymes as therapeutic targets in rhabdomyosarcoma

Abstract Introduction: Rhabdomyosarcoma (RMS) is a rare soft tissue sarcoma (STS) that predominantly affects children and teenagers. It is the most frequent STS in children and accounts for around 5-8% of total childhood cancers. The improvement of chemotherapeutic regimens has raised RMS survival chances over the last decades. However, the mortality rate remains exceptionally high in high-risk RMS patients. Duocarmycins have arisen as an opportunity for targeted therapy in cancer. These ultrapotent anticancer agents have been reengineered to generate bioprecursors that are selectively activated bycertain cytochrome P450 (CYP) isoforms (e.g. CYP1A1, CYP1B1, CYP2W1). The overexpression of these isoforms in tumors provides the possibility to locoregionally bioactivate duocarmycin prodrugs only in the tumor site. Previous studies have shown that duocarmycins can be chemically modified and deactivated by removal of a hydroxyl group in the pharmacophore, which can be reinstalled by CYPsto generate a potent DNA-targeted cytotoxic metabolite. In the past, a consistent CYP2W1overexpression in patient-derived RMS biopsies as compared to matched, non-transformed tissue was revealed. Results: Ongoing studies are focused on measuring CYP1A1, CYP1B1 and CYP2W1 expression levels in RMS cell lines and in three-dimensional spheroids as well as evaluating the antiproliferative activity of duocarmycin bioprecursors in these models. With the exception of RH30 cells (IC50=0.2µM forICT2700) the IC50 for CYP1A1- and CYP2W1-bioactivated duocarmycins (ICT2700 and ICT2706,respectively) lie in the low micromolar range in RMS monolayer cultures, suggesting that CYP1A1 andCYP2W1 might not be a suitable target in these 2D cancer models. Consistently, only RH30 cells displayed a high CYP1A1 expression in monolayer cultures among the RMS cell line panel, and noCYP2W1 expression could be identified. However, preliminary data suggests that CYP1A1 and CYP2W1enzymes might be restored when spheroids are generated from RMS cell lines. A functional 7-ethoxyresorufin-O-deethylase (EROD) assay has been validated to analyze CYP1A1- and CYP1B1-specific enzymatic activity in RMS cell lines. Vorinostat (SAHA) is an epigenetic drug currently used in the clinic for cancer treatment, and it has been associated with modulatory effects on CYP1expression. Our data suggests cell line-dependent synergistic or antagonistic effects of SAHA when combined with ICT2700, and these correlate with SAHA-induced CYP1A1 upregulation and downregulation respectively at both gene and protein levels. Conclusion: Evaluation of CYP target expression in RMS is being established to assess if duocarmycin bioprecursorscan be progressed as a novel type of therapy in RMS. Interestingly, CYP450 expression in RMS cell lines seems to vary depending on the complexity of the in vitro model used. Citation Format: Enric Arasanz Picher, Klaus Pors. Investigation of CYP450 enzymes as therapeutic targets in rhabdomyosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2020.

Inhibitory effects of Triphala on CYP isoforms in vitro and its pharmacokinetic interactions with phenacetin and midazolam in rats

ContextDirect evidence of Triphala-drug interactions has not been provided to date. ObjectiveThis study was aimed to determine the effects of Triphala on cytochrome P450 (CYP) isoforms and P-glycoprotein (P-gp) in vitro, and to investigate pharmacokinetic interactions of Triphala with CYP-probes in rats. Materials and methodsEffects of Triphala on the activities of CYP isoforms and P-gp were examined using human liver microsomes (HLMs) and Caco-2 cells, respectively. Pharmacokinetic interactions between Triphala and CYP-probes (i.e., phenacetin and midazolam) were further examined in rats. ResultsTriphala extract inhibited the activities of CYP isoforms in the order of CYP1A2>3A4>2C9>2D6 with the IC50 values of 23.6 ± 9.2, 28.1 ± 9.8, 30.41 ± 16.7 and 93.9 ± 27.5 μg/mL, respectively in HLMs. It exhibited a non-competitive inhibition of CYP1A2 and 2C9 with the Ki values of 23.6 and 30.4 μg/mL, respectively, while its inhibition on CYP3A4 was competitive manner with the Ki values of 64.9 μg/mL. The inhibitory effects of Triphala on CYP1A2 and 3A4 were not time-dependent. Moreover, Triphala did not affect the P-gp activity in Caco-2 cells. Triphala, after its oral co-administration at 500 mg/kg, increased the bioavailabilities of phenacetin and midazolam by about 61.2% and 40.7%, respectively, in rats. Discussion and conclusionsIncreases observed in the bioavailabilities of phenacetin and midazolam after oral co-administration of Triphala in rats provided a direct line of evidence to show Triphala-drug interactions via inhibition of CYP1A and CYP3A activities, respectively. These results, together with the lack of time-dependency of CYP 1A2 and 3A4 inhibition in vitro, suggested that the inhibitory effect of Triphala is primarily reversible.

Molecular modeling studies of some phytoligands from Ficus sycomorus fraction as potential inhibitors of cytochrome CYP6P3 enzyme of Anopheles coluzzii

The major obstacle in controlling malaria is the mosquito’s resistance to insecticides, including pyrethroids. The resistance is mainly due to the over-expression of detoxification enzymes such as cytochromes. Insecticides tolerance can be reduced by inhibitors of P450s involved in insecticide detoxification. Here, to design potential CYP6P3 inhibitors, a homology model of the enzyme was constructed using the crystal structure of retinoic acid-bound cyanobacterial CYP120A1 (PDB ID: 2VE3; Resolution: 2.1 Å). Molecular docking study and computational modeling were employed to determine the inhibitory potentials of some phytoligands isolated from Ficus sycomorus against Anopheles coluzzii modeled P450 isoforms, CYP6P3, implicated in resistance. Potential ligand optimization (LE) properties were analyzed using standard mathematical models. Compounds 5, 8,and 9 bound to the Heme iron of CYP6P3 within 3.14, 2.47 and 2.59 Å, respectively. Their respective binding energies were estimated to be -8.93, -10.44, and -12.56 Kcal/mol. To examine the stability of their binding mode, the resulting docking complexes of these compounds with CYP6P3 were subjected to 50 ns MD simulation. The compounds remained bound to the enzyme and Fe (Heme):O (Ligand) distance appeared to be maintained over time. The coordination of a strong ligand to the heme iron shifts the iron from the high- to the stable low-spin form and prevented oxygen from binding to the heme thereby inhibiting the catalytic activity. The LE index showed the high potential of these compounds (5 and 8) to provide a core fragment for optimization into potent P450 inhibitors.

Effects of vindoline on rat cytochrome P450 isoform activities in vitro.

A specific ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) method has been described for the simultaneous determination of the metabolites of tacrine, bupropion, diclofenac, dextromethorphan and midazolam, which are the five probe drugs of the five cytochrome P450 (CYP450) isoforms CYP1A2, CYP2B, CYP2C11, CYP2D1 and CYP3A4. The inhibition degree was determined by calculating the IC50 . The chromatographic separation was performed on a C18 column with a mobile phase consisting of 0.1% formic acid and acetonitrile. The mass spectrometric analysis was conducted in positive electrospray ionization mode. The IC50 values of CYP1A2, CYP2B, CYP2C11, CYP2D1 and CYP3A were 113.4, 83.78, 22.50, 9.081 and 52.76 μmol L-1 , respectively. The in vitro results demonstrated that vindoline could inhibit CYP2D1 activity in rats, and weak inhibitory effect on CYP2C11 and CYP3A, but had no obvious effects on CYP1A2 and CYP2B.

P-029 - Enabling insights into the cytochrome P450 isoform specific metabolism of radiotracers by CYP overexpressing hepatoblastoma cell lines

P-029 - Enabling insights into the cytochrome P450 isoform specific metabolism of radiotracers by CYP overexpressing hepatoblastoma cell lines

Exploration of Cytochrome P450 Structure and Function in In Silico Assays for Toxicity

Cytochrome P450 (CYP or P450) enzymes are known for their role in detoxifying xenobiotics and may at times cause toxicity. CYP1A1gene polymorphisms have been linked to susceptibility risks of various cancers and neoplasms, including bladder cancer. The aim of the study was to use bioinformatics tools to examine structural differences in CYP1A1 wild type and isoforms 2 and 3. Protein sequences of selected CYPs were retrieved from the NCBI protein databank and GenPept. Sequence homologies were searched for by BLAST, and by multiple sequence alignments. Protein structural characteristics such as ligand binding and secondary structure prediction were analyzed by Phyre. The CYPIA1 wild type and isoforms had 33 % variation in their amino acid residues and binding sites. The predicted binding sites for the first 6 amino acid residues were similar between the wild type and isoform two; however, the average distances from the ligands differed. The predicted secondary structure of the CYP1A1 isoform 3 exhibited the widest difference from the wild type in the percentage of disordered helix (17%), alpha helix (66%), beta strand (3%) and trans‐membrane domains (12%). Differences in nucleotide sequence between the CYP1A1 wild type and isoforms caused a change in the protein structure which further altered the trans‐membrane topology and ligand binding potential of the protein. These findings indicate structural deficits among the three Cytochrome P450 isoforms, suggesting the possible conferment of risks to toxicity and associated diseases.

Pharmacokinetic profiles, cytotoxicity, and redox metabolism of free and nanoencapsulated curcumin

To analyze the biodistribution, pharmacokinetics, and toxicity of curcumin, we made in silico predictions and performed in vitro tests to demonstrate the differences in the behavior of two cells types (peripheral blood mononuclear cells, PBMCs, and fibroblasts, HFF-1 cell line) treated with curcumin nanocapsule formulations and curcumin solution with respect to cytotoxic effects and redox metabolism. We generated in silico, ADME/Tox profile predictions of curcumin using computational tools. We produced and characterized Eudragit® L-100 and PCL nanocapsules containing curcumin using interfacial deposition of preformed polymer, evaluation of hemolytic potential in erythrocytes, cytotoxic capacity (MTT and dsDNA PicoGreen® assay), and influence on redox metabolism (nitric oxide and DCF production) of PBMCs and HFF-1 treated with curcumin nanoformulations and solution response curves. Computational results showed low biodistribution, no permeation at of the blood-brain barrier (BBB), discreet gastrointestinal absorption, a potential inhibitor of cytochrome P450 isoforms (CYP2C9 and CYP3A4), toxicity class IV, and immunomodulatory action. In vitro tests showed that cell type influenced curcumin behavior. For cytotoxicity, PBMCs showed a concentration-dependent standard, while HFF-1 cells showed that incubation time was an important variable. Redox interactions showed that nanocapsules induced NO production, and all treatments reduced DCF levels. We highlight the pleiotropic biological activities of curcumin and drug release models so that the therapeutic properties of this polyphenol might be better used. Finally, we emphasize that pharmacological safety must always be evaluated in drug delivery systems and, especially, for substances with multiple interaction pathways.

Cytochrome P450 isoforms contribution, plasma protein binding, toxicokinetics of enniatin A in rats and in vivo clearance prediction in humans

Emerging mycotoxins, such as enniatin A (ENNA), are becoming a worldwide concern owing to their presence in different types of food and feed. However, comprehensive toxicokinetic data that links intake, exposure and toxicological effects of ENNA has not been elucidated yet. Therefore, the present study investigated the in vitro (rat and human) and in vivo (rat) toxicokinetic properties of ENNA. Towards this, an easily applicable and sensitive bioanalytical method was developed and validated for the estimation of ENNA in rat plasma. ENNA exhibited high plasma protein binding (99%), high hepatic clearance and mainly underwent metabolism via CYP3A4 (74%). The in-house predicted hepatic clearance (54 mL/min/kg) and observed in vivo rat clearance (55 mL/min/kg) were comparable. The predicted in vivo human hepatic clearance was 18 mL/min/kg. ENNA underwent slow absorption (Tmax = 4 h) and rapid elimination following oral administration to rats. The absolute oral bioavailability was 47%. The toxicokinetic findings for ENNA from this study will help in designing and interpreting toxicological studies in rats. Besides, these findings could be used in physiologically based toxicokinetic (PBTK) model development for exposure predictions and risk assessment for ENNA in humans.

Expression Pattern of Entire Cytochrome P450 Genes and Response of Defenses in a Metabolic-Herbicide-Resistant Biotype of Polypogon fugax.

Enhanced herbicide metabolism mediated by cytochrome P450s has been proposed as one of the major mechanisms of resistance to fenoxaprop-P-ethyl in a metabolic-herbicide-resistant biotype of Asia minor bluegrass (Polypogon fugax Nees ex Steud.). Upon pre-treatment with the P450 inhibitor piperonyl butoxide, a remarkable reduction in metabolic rates of the phytotoxic fenoxaprop-P has been observed in the resistant plants, implying that constitutive and/or fenoxaprop-P-ethyl-induced up-regulation of specific P450 isoforms are involved in the fenoxaprop-P-ethyl resistance. However, which P450 gene(s) were responsible for the metabolic resistance is still unknown. In this present study, based on the abundant gene resources of P. fugax established previously, a total of 48 putative P450 genes were isolated from the metabolic-herbicide-resistant plants and used for gene expression analysis. The most suitable reference genes for accurate normalization of real-time quantitative PCR data were first identified in P. fugax and recognized as actin (ACT), 18S rRNA (18S), and ribulose-1,5-bisphosphate carboxylase oxygenase (RUBP) under fenoxaprop-P-ethyl stress, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and elongation factor 1α (EF1α) under mesosulfuron-methyl stress, and ACT, EF1α, eukaryotic initiation factor 4a (EIF4A), and 25S rRNA (25S) at different growth stages. Expression analysis of the putative P450 genes revealed that six genes, respectively, annotated as CYP709B1, CYP71A1-4, CYP711A1, CYP78A9, P450-11, and P450-39 were up-regulated more than 10-fold in the resistant plants by fenoxaprop-P-ethyl treatment, and all of them exhibited constitutively and/or herbicide-induced higher transcript levels in the fenoxaprop-P-ethyl-resistant than in the susceptible plants. Three genes, respectively, annotated as CYPRO4, CYP313A4, and CYP51H11 constantly up-regulated in the resistant than in the susceptible plants after fenoxaprop-P-ethyl treatment. Up-regulated expressions of these specific P450 genes were consistent with the higher P450 contents determined in the resistant plants. These results will help to elucidate the mechanisms for P450-mediated metabolic-herbicide resistance in P. fugax as well as other grass weed species.

Comparison of antagonistic effects of nanoparticle-selenium, selenium-enriched yeast and sodium selenite against cadmium-induced cardiotoxicity via AHR/CAR/PXR/Nrf2 pathways activation

Selenium (Se), a nutritionally essential mineral for humans and animals, has a significant antagonistic effect on heavy metal cadmium (Cd) biotoxicity. Still, the impact of different Se sources on alleviating Cd toxicity has received only limited attention. Therefore, the purpose of the current study was to assess the mitigation level of Cd-induced cardiotoxicity by different sources such as nanoparticles of Se, Se-rich yeast, and sodium selenite (SS). The results evidenced that the presence of Cd led to a significant increase in biochemical parameters such as lactate dehydrogenase and creatine kinase, as well as histopathological lesions in the heart of chickens. Cd exposure also resulted in more extensive effects on phase I metabolism enzymes and transcript cytochrome P450 isoforms, elevated the levels of malondialdehyde (MDA), glutathione (GSH), and hydrogen peroxide (H2O2) and depressed total superoxide dismutase (T-SOD), copper-zinc SOD (Cu-Zn SOD), total antioxidant capacity (T-AOC) and catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione-S-transferase (GST) activities. The expression of nuclear receptors, aryl hydrocarbon receptor (AHR), constitutive androstane receptor (CAR), and pregnane X receptor (PXR) was declined, down-regulated nuclear factor erythroid 2–related factor 2 (Nrf2) and its downstream targets in the Cd-treat group. Notably, Se sources application alleviated Cd toxicity by triggering AHR/CAR/PXR/Nrf2 signaling pathway to promote restoring antioxidant defense system and phase I metabolism enzymes system. However, when compared to the effectiveness of antagonism, the nanoparticles of Se were superior in relieving Cd-induced cardiotoxicity via AHR/CAR/PXR/Nrf2 pathway activation than other Se-sources.

Prenatal ethanol exposure induces dynamic changes of expression and activity of hepatic cytochrome P450 isoforms in male rat offspring

This study aimed at determining the effect of prenatal ethanol exposure (PEE) on the expression and activity of cytochrome P450 (CYP) isozymes at different life stages of male rat offspring. Pregnant Wistar rats were administered with ethanol (4 g/kg/d) intragastrically from gestational day (GD) 9–20. Male offspring’s gene and activity of CYP isozymes were analyzed on GD 20 (only expression), postnatal day (PD) 84 and 196. Using aniline as probe, we compared the enzyme kinetics of hepatic CYP2E1 between two groups. Expression of CYP isozymes was examined in rat primary hepatocytes and human hepatic cell lines treated with ethanol or/and glucocorticoid. Gene level of Cyp1a2, 2b1, 2d1, 2e1, 3a1 and aryl hydrocarbon receptor were increased in PEE group on GD 20 and PD 84 and Cyp2e1 still exhibited an increasing trend on PD 196 compared with the control. PEE inhibited CYP2D1 and 2E1 activities in male offspring on PD 84. CYP activities in two groups became the same level on PD 196. PEE induced an opposite change in gene and protein level of hepatic CYP2E1 before and after birth. In consistent with lower protein level, aniline metabolism in PEE was weaker in liver microsome. Both single and combined use of ethanol or/and glucocorticoid increased CYPs expression in vitro. In conclusion, PEE programmed a higher gene and lower protein level of CYPs in male offspring, which dwindled with age. Impairment of protein levels and enzyme activities of CYPs may affect individual metabolism of endogenous and exogenous substances in early adulthood.

Assessment of Herb-Drug Interaction Potential of Five Common Species of Licorice and Their Phytochemical Constituents

The dried roots and rhizomes of Glycyrrhiza species (G. glabra, G. uralensis and G. inflata), commonly known as licorice, have long been used in traditional medicine. In addition, two other species, G. echinata and G. lepidota are also considered “licorice” in select markets. Currently, licorice is an integral part of several botanical drugs and dietary supplements. To probe the botanicals’ safety, herb-drug interaction potential of the hydroethanolic extracts of five Glycyrrhiza species and their key constituents was investigated by determining their effects on pregnane X receptor, aryl hydrocarbon receptor, two major cytochrome P450 isoforms (CYP3A4 and CYP1A2), and the metabolic clearance of antiviral drugs. All extracts enhanced transcriptional activity of PXR and AhR (>2-fold) and increased the enzyme activity of CYP3A4 and CYP1A2. The highest increase in CYP3A4 was seen with G. echinata (4-fold), and the highest increase in CYP1A2 was seen with G. uralensis (18-fold) and G. inflata (16-fold). Among the constituents, glabridin, licoisoflavone A, glyasperin C, and glycycoumarin activated PXR and AhR, glabridin being the most effective (6- and 27-fold increase, respectively). Licoisoflavone A, glyasperin C, and glycycoumarin increased CYP3A4 activity while glabridin, glyasperin C, glycycoumarin, and formononetin increased CYP1A2 activity (>2-fold). The metabolism of antiretroviral drugs (rilpivirine and dolutegravir) was increased by G. uralensis (2.0 and 2.5-fold) and its marker compound glycycoumarin (2.3 and 1.6-fold). The metabolism of dolutegravir was also increased by G. glabra (2.8-fold) but not by its marker compound, glabridin. These results suggest that licorice and its phytochemicals could affect the metabolism and clearance of certain drugs that are substrates of CYP3A4 and CYP1A2. Supplemental data for this article is available online at https://doi.org/10.1080/19390211.2022.2050875 .