CYP2E1 Research Articles

New Insights into the Pathogenesis of Alcoholic Liver Disease Based on Global Research.

Alcoholic liver disease (ALD) is the leading cause of death among alcohol-related diseases, yet its pathogenesis remains incompletely understood. This article employs data mining methods to conduct an indepth study of articles on ALD published in the past three decades, aiming to elucidate the pathogenesis of ALD. Firstly, articles related to the pathogenesis of ALD were retrieved from the Web of Science (WOS) database. CiteSpace 6.1.R2 and VOSviewer 1.6.18 were used to visually analyze the authors, institutions, journals, and keywords of the published articles. Secondly, by thoroughly reading the top 100 most cited articles and focusing on research hotspots such as cytochrome P450 2E1 (CYP2E1), gut microbiota, acetaldehyde dehydrogenase (ALDH), and alcohol dehydrogenase (ADH), the pathogenesis of ALD was preliminarily explored. Finally, the pathogenesis of ALD was further analyzed based on disease databases. A total of 1521 articles were retrieved from the WOS database, and 384 of these were selected for in-depth reading. From GeneCards, 9084 genes related to ALD were identified. KEGG enrichment analysis was performed using DAVID, and the hsa04936: Alcoholic liver disease pathway was selected for visualization. This study preliminarily elucidates the pathogenesis of ALD, which may be associated with the release of acetaldehyde, reactive oxygen species (ROS), and various pro-inflammatory factors during alcohol metabolism. It is also closely related to gut microbiota dysbiosis and increased intestinal permeability induced by multiple factors.

Post-COVID metabolic enzyme alterations in K18-hACE2 mice exacerbate alcohol-induced liver injury through transcriptional regulation.

Coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses a significant threat to global public health. Despite reports of liver injury during viral disease, the occurrence and detailed mechanisms underlying the development of secondary exogenous liver injury, particularly in relation to changes in metabolic enzymes, remain to be fully elucidated. Therefore, this study was aimed to investigate the mechanisms underlying SARS-CoV-2-induced molecular alterations in hepatic metabolism and the consequent secondary liver injury resulting from alcohol exposure. We investigated the potential effects of SARS-CoV-2 infection on alcohol-induced liver injury in Keratin 18 promoter-human angiotensin converting enzyme 2 (K18-hACE2) transgenic mice. Mice were intranasally infected with 1×102 PFU of SARS-CoV-2. Following a 14 d recovery period from infection, the recovered mice were orally administered alcohol at 6 g/kg. Prior SARS-CoV-2 infection aggravated alcohol-induced liver injury based on increased alanine aminotransferase levels and cytoplasmic vacuolation. Interestingly, infected mice exhibited lower blood alcohol levels and higher levels of acetaldehyde, a toxic alcohol metabolite, compared to uninfected mice after the same period of alcohol consumption. Along with alterations of several metabolic process-related terms identified through RNA sequencing, notably, upregulation of cytochrome P450 2E1 (CYP2E1) and CYP1A2 was observed in infected mice compared to control value prior to alcohol exposure, with no significant impact of SARS-CoV-2 on intestinal damage. Tumor necrosis factor-alpha persistently showed upregulated expression in the infected mice; it also enhanced aryl hydrocarbon receptor and Sp1 expressions and their binding activity to Cyp1a2 and Cyp2e1 promoters, respectively, in hepatocytes, promoting the upregulation of their transcription. Our findings suggest that SARS-CoV-2 infection exacerbates alcohol-induced liver injury through the transcriptional activation of Cyp1a2 and Cyp2e1, providing valuable insights for the development of clinical recommendations on long COVID.

4-Methylpyrazole-mediated inhibition of Cytochrome P450 2E1 protects renal epithelial cells, but not bladder cancer cells, from cisplatin toxicity.

This study demonstrates that cytochrome P450 2E1 (CYP2E1) is a critical mechanistic target in the prevention of cisplatin-induced nephrotoxicity (CIN). It also indicates that CYP2E1 plays an important role in mediating sex-specific differences in CIN. Finally, this study reveals that targeting CYP2E1 with 4methylpyrazole offers a promising prophylactic approach to reducing CIN in clinical settings while preserving the anti-cancer efficacy of cisplatin.

Effects of mixed exposure to PFAS on adolescent non-alcoholic fatty liver disease: Integrating evidence from human cohorts, toxicogenomics, and animal models to uncover mechanisms and potential target sites.

Extensive evidence suggests a correlation between environmental pollutants, specifically perfluoroalkyl and polyfluoroalkyl substances (PFAS) and non-alcoholic fatty liver disease (NAFLD). This study aims to investigate the association and underlying mechanisms of PFAS-induced NAFLD in adolescents by employing a comprehensive approach of population-based studies, toxicogenomics, and animal models. A total of 2014 freshmen from Dali University were recruited for this study, with 1694 participants undergoing serum testing for PFAS exposure. Additionally, Comparative Toxicogenomics Database analysis and PFAS exposure experiments were conducted by orally administering PFAS to 8-week-old adult C57/6 J mice for 28 days. Epidemiological analysis of the adolescent cohort revealed that perfluorohexanesulfonic acid and perfluorooctanoic acid are significant risk factors for NAFLD in adolescents. Toxicogenomic analysis revealed that the negative regulation of gap junction assembly and glutathione derivative biosynthesis contributes to NAFLD development. Animal model studies further demonstrated that combined PFAS exposure led to pathological changes in hepatocytes, including inflammation and steatosis, elevated liver enzymes, cholestasis, and bile canalicular blockage. This study reveals that PFAS exposure serves as a significant risk factor for hepatic steatosis/NAFLD in adolescents. The activation of cytochrome P4502E1 and glutathione S-transferase A1 signaling highlights new molecular targets for PFAS-induced disruptions in hepatic lipid metabolism.

Effects of Acute Alcohol Intoxication on Testicular Dna Stability, Gene Expression of Cytochromes CYP3A and CYP2E1, and Serum Pool of Free Amino Acids in Rats

Background. Alcohol's toxic effects on the organism is a long-known medical problem. Alcohol's damaging effect is the end result of the complex interplay between ethanol metabolism, inflammation and innate immunity. Previously, we studied the long-term consequences of chronic alcoholism and demonstrated that especially profound changes were in testes on the level of proteome and genome. Objective. This work aimed to study short-term acute alcohol intoxication (AAI) effects for rat testis DNA fragmentation, cytochromes CYP3А and CYP2Е1 genes expression, and serum pool of free amino acids in rats. Methods. Wistar albino male rats were divided into 2 groups (8 animals in each group): 1 – Control (intact rats), and 2 – AAI (rats with short-term acute alcohol intoxication). AAI was induced by repeated administration per os 40% ethanol solution in a dose 7 ml/kg body weight, for 7 days. Contents of amino acids in serum, testes mRNA CYP2E1 and CYP3A2 expression, and DNA fragmentation were evaluated. Results. In our experiments, the development of acute alcohol intoxication (AAI) led to increased DNA fragmentation processes in the testes of adult rats compared to the control group. Additionally, in the serum of ethanol-treated rats, the levels of histidine increased by 1.67 times and glutamine by 1.13 times in correlation with this pathology. Conversely, the levels of valine, phenylalanine, as well as non-essential and essential amino acids, decreased. Furthermore, there was a statistically significant increase in the expression of CYP2E1 and CYP3A2 genes in rat testes under the conditions of AAI. Conclusions. In conclusion, investigation of rats' short-term alcohol administration effects permitted us to obtain the picture of complex metabolomic changes at the different levels. The main outcome of rats short-term ethanol administration in our experiments seems to be to some extent similar to changes described for rats with chronic alcohol consumption. Our results demonstrated profound changes in testes affecting the state of the genome, transcription processes and the exchange of amino acids and proteins. We suggest that the revealed testicular metabolic disorders could have negative implications on cellular regulation of spermatogenesis even under short-term ethanol exposure.

Glutathione's Role in Liver Metabolism and Hangover Symptom Relief: Dysregulation of Protein S-Glutathionylation and Antioxidant Enzymes.

Hangovers from alcohol consumption cause symptoms like headaches, nausea, and fatigue, disrupting daily activities and overall well-being. Over time, they can also lead to inflammation and oxidative stress. Effective hangover relief alleviates symptoms, prevents dehydration, and replenishes energy needed for daily tasks. Natural foods considered high in antioxidants and antiinflammatory properties may aid in the hepatic breakdown of alcohol. The study aims to investigate the impact of glutathione or its enriched yeast extract, which is recognized for its antioxidant characteristics, on alcohol metabolism and alleviating hangovers in a rat model exposed to binge drinking. In this study, glutathione and its enriched yeast extract controlled hangover behaviour patterns, including locomotor activity. Additionally, it enhanced the activities of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) following ethanol ingestion (3 g/kg). Further, the incorporation of glutathione led to an increase in the expression of antioxidant enzymes, such as SOD and catalase, by activating the nuclear erythroid 2-related factor 2 (Nrf2) signaling pathway. This activation reduced the excessive production of reactive oxygen species (ROS) and malondialdehyde. Next, glutathione modulated the activity of cytochrome P450 2E1 (CYP2E1) and the protein expressions of Bax and Bcl2. Besides, in vitro and in vivo investigations with glutathione demonstrated a regulating effect on the pan-s-glutathionylation and its associated protein expression, glutaredoxin 1 (Grx1), glutathione-S-transferase Pi (GST-π), and glutathione reductase (GR). Together, these findings suggest that glutathione or its enriched yeast extract as a beneficial dietary supplement for alleviating hangover symptoms by enhancing alcohol metabolism and its associated Nrf2/Keap1 signalings.

The pyruvate dehydrogenase kinase inhibitor dichloroacetate mitigates alcohol-induced hepatic inflammation and metabolic disturbances in mice.

Dichloroacetate (DCA), a pan-pyruvate dehydrogenase kinase inhibitor, ameliorates multiple pathological conditions and tissue injury and shows strong potential for clinical applications. Here, we investigated the preventive effects of DCA in a murine model of alcohol-associated liver disease. C57BL/6J mice were subjected to the acute-on-chronic model of alcohol-associated liver disease and treated with DCA. Livers were assessed in liver histology, biochemistry, and gene expression. Mass spectrometry was used to compare protein expression and metabolite levels. DCA inhibited hepatic expression of inflammatory genes but did not prevent steatosis and hepatocellular injury in ethanol-fed mice. Consistently, DCA repressed the expression of mRNAs for inflammatory genes in LPS-stimulated murine bone-marrow-derived macrophages and human monocytic THP-1 cells and inhibited both gene expression and protein release of interleukin-1 beta. DCA prevented hepatic accumulation of isovaleric acid in ethanol-fed mice, a short-chain fatty acid primarily produced by gut microbiota. In vitro, isovaleric acid potentiated LPS's effects, while DCA prevented this proinflammatory action. Ethanol feeding increased the expression of proteins involved in diverse metabolic pathways, including branched-chain amino acid (BCAA) degradation. In ethanol-fed mice, hepatic Fischer's ratio (the molar ratio of BCAAs to aromatic amino acids Phe and Tyr) and BTR (the molar ratio of BCAAs to Tyr) showed a decrease compared to pair-fed mice; however, this decrease was not observed in DCA-treated ethanol-fed mice. DCA blunted the ethanol-induced increase of BCKDHA, the rate-limiting enzyme in BCAA catabolism, and cytochrome P450 2E1. Ethanol-induced hepatic inflammatory responses and metabolic disturbances were prevented by DCA in mice, indicating the potential to develop pyruvate dehydrogenase kinase inhibitors as an effective therapy to treat alcohol-associated liver disease.

Cytochrome P450 2E1 inhibitor Q11 is effective on hepatocellular carcinoma by promoting peritumor neutrophil chemotaxis.

Current studies found that the peritumoral tissue of hepatocellular carcinoma (HCC) may be different from normal liver tissue based on proteomics, and related to progression, recurrence and metastasis of HCC. Our previous study proposed "peritumor microenvironment (PME)" to summarize the influence of peritumor tissue on occurrence and progression of HCC. Peritumor CYP2E1 activity was significantly elevated in HCC, and related to occurrence and progression of HCC. However, the effectiveness and mechanism of inhibiting CYP2E1 against HCC remain unclear. In this study, by integrating the advantages of proteomics and transcriptomics, we reanalyzed the various influencing factors in PME. Although there were large differences in the occurrence and progression, the immunity and inflammation still played crucial roles. Peritumor neutrophil were "pro-tumor" phenotype in the stage of progression, while it showed cytotoxicity for tumor cell in the occurrence stage. CYP2E1 activity is associated with peritumor neutrophil infiltration and occurrence of HCC. CYP2E1 inhibitor Q11 showed anti-tumor effects in an orthotopic HCC mouse model by promoting secretion of chemokines and infiltration of neutrophils in peritumor tissue. Overall, these findings provided a reasonable mechanism of anti-tumor effects of CYP2E1 inhibitors, which may be a new strategy for the prevention and treatment of HCC.

Ethyltoluenes Regulate Inflammatory and Cell Fibrosis Signaling in the Liver Cell Model.

Crude oil naphtha fraction C9 alkylbenzenes consist of trimethylbenzenes, ethyltoluenes, cumene, and n-propylbenzene. The major fraction of C9 alkylbenzenes is ethyltoluenes (ETs) consisting of three isomers: 2-ethyltoluene (2-ET), 3-ethyltoluene (3-ET), and 4-ethyltoluene (4-ET). Occupational and environmental exposure to ETs can occur via inhalation and ingestion and cause several health problems. Exposure to ETs causes eye and upper respiratory tract irritation, coughing, gagging, vomiting, griping, diarrhea, distress, and depressed respiration. Previous studies suggest that ETs target the respiratory tract and liver and produce several lesions in the nose, lungs, and liver areas. In the current study, we investigated the impact of low concentrations of ETs on cell metabolism, cell inflammation, steatosis, and fibrosis signaling in liver cell models in vitro. Dose-dependent exposure of 2-ET, 3-ET, and 4-ET to HepaRG and hepatocellular carcinoma (HCC) HepG2 and SK-Hep1 cells affects cell survival/real-time proliferation and increases ROS production. ETs induce inflammatory CAT, SOD1, CXCL8, IL1B, HMOX1, NAT1 (3), and STAT3 gene expression. Exposure of 2-ET, 3-ET, and 4-ET to HepaRG and HCC HepG2 and SK-Hep1 cells affects mitochondrial respiration/cellular energetics and upregulates metabolic CYP1-A1, CYP1-A2, CYP2-D6, CYP2-E1, CYP3-A4, CYP3-B4, and VEGFA gene expression. However, no significant change in lipogenesis-related gene expression and modulation of cell steatosis was observed after ET exposure. Acute exposure to induvial ETs and in combination or chronic 2-ET exposure alone modulates cell fibrosis markers such as AST, FGF-23, Cyt-7 p21, TGFβ, TIMP2, and MMP2 in liver cell models, suggesting that ETs target liver cells and may dysregulate liver function.

Piperine as an Herbal Alternative for the Prevention of Drug-Induced Liver Damage Caused by Paracetamol.

Background/Objective: Hepatic drug intoxication is becoming increasingly common with the increasing use of chronic medications. Piperine has emerged as a promising alternative for protecting the liver against drug-induced injury. We evaluated the prophylactic effects of piperine in C57BL/6 mice with an acute liver injury induced by a paracetamol (APAP) overdose. Methods: Piperine was administered at a dose of 20 mg/kg (P20) or 40 mg/kg (P40) for eight consecutive days before the animals were exposed to a hepatotoxic dose of paracetamol (500 mg/kg). The animals were euthanized 3 h after the paracetamol overdose. Results: The prophylactic treatment with piperine (P20 and P40) maintained the levels of alanine aminotransferase (ALT) and the biomarkers of oxidative damage (TBARS and carbonylated proteins), which were statistically similar to those for the control group. The extent of hepatocyte necrosis and TNF-α (tumor necrosis factor-alpha) levels were lower than those in the group exposed to liver injury (APAP group). Piperine modulated the gene expression of CYP2E1 (cytochrome P4502E1) and the inflammasome pathway (NLRP3, CASP-1, IL-1β, and IL-18), which play a crucial role in the inflammatory response. In the P40 group, the degree of hepatic hyperemia was similar to that in the control group, as was the increase in metalloproteinase 9 (MMP-9) activity. Conclusion: Piperine has demonstrated beneficial and promising effects for the prevention of liver injury resulting from paracetamol-induced drug intoxication.

Kehuang capsule inhibits MAPK and AKT signaling pathways to mitigate CCl4-induced acute liver injury

Background and aimsKehuang (KH) capsule is an herbal medical product approved for the treatment of liver diseases, including liver injury, in China. However, the mechanism is still unclear. This study aimed to elucidate the protective effects of KH capsule against carbon tetrachloride (CCl4)-induced acute liver injury (ALI) in a murine model. MethodsMice were randomly divided into control, model (CCl4), CCl4+KH_Low and CCl4+KH_High group. Liver enzyme levels and histological changes were assessed to evaluate liver injury. Oxidative stress markers and inflammatory cell infiltration in liver tissues were measured. Additionally, network pharmacology was employed to explore the potential mechanisms of KH capsule. ResultsKH capsule significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, as well as the necrotic area in liver tissue. KH capsule also decreased the infiltration of macrophages and neutrophils, thereby inhibiting the expression of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β). Furthermore, KH capsule decreased liver malondialdehyde (MDA) levels and increased superoxide dismutase (SOD) activity. The number of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL)-positive cells in liver tissue was also reduced. The expression of nuclear factor erythroid 2 related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) proteins was significantly elevated, while the protein expression of cytochrome P450 2E1 (CYP2E1) was significantly reduced. Mass spectrometry identified genistein, galangin, wogonin, skullcapflavone II, and hispidulin as potential active ingredients of KH capsule. Network pharmacology analysis revealed enrichment in the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT) signaling pathways. Western blot analysis confirmed that KH capsule suppressed AKT, extracellular signal-regulated kinase (ERK), and p38 signaling. ConclusionsThese findings suggest that KH capsule exerts protective effects against CCl4-induced ALI, with the inhibition of MAPK and PI3K-AKT signaling pathways playing a crucial role in its mechanism of action.

The Synergistic and Opposing Roles of ω-Fatty Acid Hydroxylase (CYP4A11) and ω-1 Fatty Acid Hydroxylase (CYP2E1) in Chronic Liver Disease

Cytochrome P450 fatty acid hydroxylase consists of members of the CYP4 family that ω-hydroxylate fatty acids and the CYP2E1 that ω-1 hydroxylates fatty acids. Although ω and ω-1 hydroxylation of fatty acids have been thought to play a minor role in fatty acid metabolism (less than 20%), it plays a vital role in excess liver fatty acids overload seen in fasting, diabetes, metabolic disorder, and over-consumption of alcohol and high-fat diet. This pathway provides anabolic metabolites for gluconeogenesis, succinate, and acetate for lipogenesis. The CYP4A and CYP2E1 genes are activated in fasting and several metabolic disorders, suggesting a synergistic role in preventing fatty acid-induced lipotoxicity with the consequence of increased liver cholesterol and lipogenesis leading to increased Lipid Droplet (LD) deposition. During the progression of Metabolic Dysfunction-associated Steatotic Liver Disease (MASLD), activation of Phospholipase A2 (PLA2) releases arachidonic acid that CYP4A11 and CYP2E1 P450s metabolize to produce 20-hydroxyeicosatetraenoic acid (20-HETE) and 19-HETE, respectively. These metabolites have opposing roles in the progression of MASLD and chronic liver disease (CLD). This report discusses the synergistic role of the CYP4A and CYP2E1 P450s in the metabolism of saturated and unsaturated fatty acids and their opposite physiological role in the metabolism of Arachidonic Acid (AA). We finally discuss the role of ethanol in disrupting the synergistic and opposing roles of the CYP4A and CYP2E1 genes in MASLD and CLD.

NDMA enhances claudin-1 and -6 expression viaCYP2E1/ROS in AGS cells

Carcinogenic N-nitroso compounds, especially N-nitroso dimethylamine, increase the risk of gastric cancer development. Cytochrome P450-2E1 metabolizes this compound, thus generating an oxidant microenvironment. We aimed to evaluate in gastric adenocarcinoma cells if its effect on CYP2E1 and ROS affects signaling pathways associated with gastric cancer oncogenesis. The impact of N- nitroso dimethylamine upon CYP2E1 and ROS activation/secretion was evaluated by the DCFDA assay protocol, TER measurements, Stat3, pSTAT3, ERK1/2, and pERK1/2 expression, claudins-1 and -6 expression, and finally mRNA values of IL-1β IL-6, IL-8 and TNFα. Our results showed that exposure to N- N-nitroso dimethylamine disrupts the regulation of Stat3 and Erk1/2, alters the expression of claudin-1 and claudin-6 tight junction proteins, and increases the secretion of pro-inflammatory cytokines. These alterations induce a continuous local inflammatory process, an event identified as a gastric cancer promoter. In summary, N-nitroso dimethylamine can disrupt cell mechanisms associated with gastric cancer oncogenesis.

Cisplatin induces kidney damage through the down-regulation of Prx I by autophagic degradation

In this study, we investigated the potential role of PrxI in cis-diamminedichloroplatinum (cisplatin)-induced renal damage in mice. The anticancer drug cisplatin is a chemotherapeutic agent that is widely used to treat solid tumors. Cisplatin-induced nephrotoxicity is a serious dose-limiting side effect, primarily caused by oxidative stress. The oxidative stress further damages DNA, membranes, and mitochondria, and increases endoplasmic reticulum (ER) stress. Cisplatin produces reactive oxygen species (ROS) through Cytochrome P450 2E1 (CYP2E1) and localizes to the surface of the ER, where CYP2E1 is located.Among the six Prx isoforms, Prx I was selectively degraded in cisplatin-treated kidneys during severe renal function damage. Prx I degradation is blocked in mouse proximal tubular cells treated with 3-methyladenine, an autophagy inhibitor, and in MEF lacking ATG7. Moreover, increased ROS levels on the ER surface due to CYP2E1 overexpression further accelerated Prx I degradation. These results suggest that Prx I degradation is largely mediated through autophagy, which is promoted by cisplatin-induced ER stress. Ablation of Prx I exacerbated cisplatin-induced nephrotoxicity and significantly increased the abundance of oxidative stress, ER stress, and inflammatory markers in the kidney, indicating that Prx I plays a protective role against cisplatin-induced nephrotoxicity.

Artemisia Argyi essential oil ameliorates acetaminophen-induced hepatotoxicity via CYP2E1 and γ-glutamyl cycle reprogramming

BackgroundThe hepatotoxicity induced by acetaminophen (APAP), a commonly used antipyretic, analgesic and anti-inflammatory drug in clinical practice, has received accumulated attention. Artemisia argyi essential oil (AAEO), a volatile oil component extracted from traditional Chinese medicine Artemisia argyi H.Lév. & Vaniot, has great hepatoprotective effects. However, the potential role of AAEO in APAP-induced hepatotoxicity has not been characterized. The present study aimed to investigate the effects of AAEO on hepatic metabolic changes in mice exposed to APAP. MethodsIn this study, 300.00 mg/kg acetaminophen was used to establish liver injury model in C57BL/6 J mice. Hepatoprotective effect of AAEO on APAP-induced hepatotoxicity in mice was investigated by detecting liver function enzymes and histopathological examination. Secondly, UPLC-MS/MS was used to analyze the to analyze the small molecule metabolites and metabolic pathways induced by AAEO treatment; In addition, the effect of AAEO on APAP-induced oxidative stress and inflammation were evaluated by detecting the levels of glutathione peroxidase 4, malondialdehyde, reactive oxygen species and inflammatory factors. Finally, the active components of AAEO were preliminarily screened by cellular assays. The hepatoprotective effect of AAEO against APAP-induced hepatotoxicity was examined through the Western blotting, after the CYP2E1 gene was knocked down in AML12 cells by siRNA transfection. ResultsCompared with the APAP group, AAEO could reduce the abnormal increase in the levels of liver function enzymes caused by APAP. AAEO could enhance the antioxidant capacity by down-regulating the biosynthesis pathway of unsaturated fatty acids and promoting the activity of antioxidant enzymes SOD and CAT in liver tissue induced by APAP. Our study revealed that AAEO promoted GSH synthesis and covalently combined to form APAP-GSH conjugates to reduce the accumulation of APAP in liver tissue. In addition, the chemical constituents in AAEO were analyzed by GC–MS/MS, and it was determined to identify that dihydro-beta-ionone and (-)-verbenone in AAEO might have a significant protective effect on hepatocyte survival after APAP exposure. Further studies on the hepatoprotective mechanism of AAEO indicated that it might reduce the production of toxic metabolites by regulating CYP2E1 levels. ConclusionAAEO exerted hepatoprotective effects on acetaminophen-induced hepatotoxicity in mice via regulating the activity of CYP2E1 and regulating the γ-glutamyl cycle pathway.

Transgenic expression of human cytochrome P450 2E1 in C. elegans and rat PC-12 cells sensitizes to ethanol-induced locomotor and mitochondrial effects

Chronic alcohol (ethanol) use is increasing in the United States and has been linked to numerous health issues in multiple organ systems including neurological dysfunction and diseases. Ethanol toxicity is mainly driven by the metabolite acetaldehyde, which is generated through three pathways: alcohol dehydrogenase (ADH2), catalase (CAT), and cytochrome P450 2E1 (CYP2E1). ADH2, while the main ethanol clearance pathway in the liver, is not expressed in the mammalian brain, resulting in CAT and CYP2E1 driving local metabolism of ethanol in the central nervous system. CYP2E1 is known to generate reactive metabolites and reactive oxygen species and localizes to the mitochondria (mtCYP2E1) and endoplasmic reticulum (erCYP2E1). We sought to understand the consequences of mtCYP2E1 and erCYP2E1 in the nervous system during acute ethanol exposure. To answer this question, we generated transgenic Caenorhabditis elegans roundworms expressing human CYP2E1 in the mitochondria, endoplasmic reticulum, or both and exposed them to ethanol. We found that at lower concentrations, wild-type and mtCYP2E1-expressing worms had a small but significant inhibition of locomotion, whereas the erCYP2E1-expressing worms showed protection from this inhibition. At higher doses, all strains had reduced locomotion, but the erCYP2E1-expressing worms recovered faster than wild-type controls. CYP2E1 expression, regardless of organellar targeting, reduced mitochondrial respiration in response to ethanol. Similarly, transgenic expression of CYP2E1 in either organelle in PC-12 rat neuronal cell lines sensitized them to ethanol-induced cell death. Together, these findings suggest that subcellular localization of CYP2E1 impacts behavioral effects of ethanol and should be further studied in the mammalian central nervous system.

Polygala fallax Hemsl polysaccharides alleviated alcoholic fatty liver disease by modifying lipid metabolism via AMPK

Alcoholic fatty liver disease (AFLD) is characterized by excessive lipid accumulation in the liver. This study aimed to investigate the protective effects and mechanisms of Polygala fallax Hemsl polysaccharides (PFPs) on AFLD. PFPs were purified and structurally characterized. An AFLD model was established in mice using alcohol and a high-fat diet. A significant reduction in hepatic steatosis was observed following PFPs treatment, evidenced by decreased fat deposition in liver tissues. Additionally, PFPs reduced various liver injury markers, increased levels of antioxidant enzymes, and improved significantly liver function. RNA sequencing revealed that PFPs improved lipid and CYP450 metabolic pathway abnormalities in AFLD mice. Furthermore, PFPs activated the AMPK pathway, reducing lipid accumulation and enhancing lipid metabolism. A HepG2 cell model treated with ethanol and oleic acid showed significant biochemical improvements with PFPs pretreatment, including reduced lipid accumulation and lower reactive oxygen species (ROS) levels. To further elucidate the AMPK and PFPs correlation in AFLD, an AMPK inhibitor (compound C) was used. In vitro and in vivo qRT-PCR and Western blot results confirmed that PFPs protected against AFLD by activating AMPK phosphorylation, regulating lipid synthesis, and inhibiting lipid accumulation. PFPs also modulated CYP2E1 and oxidative stress-related gene expression, affecting liver metabolism.

Different ethanol exposure durations affect cytochrome P450 2E1-mediated sevoflurane metabolism in rat liver

BackgroundChronic alcohol users often exhibit an increased minimum alveolar concentration (MAC) of sevoflurane, yet the specific mechanism remains unclear. It has been reported that ethanol exposure can upregulate the protein expression and enzyme activity of cytochrome P450 2E1 (CYP2E1). CYP2E1 is a key enzyme that converts 2–5% of sevoflurane into equimolar amounts of hexafluoroisopropanol (HFIP) and F−. This study aims to explore whether ethanol exposure could alter sevoflurane metabolism through CYP2E1 modulation, potentially explaining the increased MAC observed in alcohol users.MethodsEighty adult male Sprague-Dawley (SD) rats were randomly divided into two groups and received either 50% ethanol (dose: 3 g/kg) or 0.9% saline twice daily by gavage. After 1, 2, 3, and 4 weeks of gavage, ten rats were randomly selected from each group to undergo 1-hour anesthesia with 2.3% sevoflurane. Blood samples were collected after anesthesia to measure the concentration of free HFIP using gas chromatography. Additionally, the left lobe tissue of the liver was collected for the analysis of CYP2E1 protein expression by Western blot and CYP2E1 enzyme activity by colorimetric assay. Correlations between these parameters were analyzed using Pearson’s correlation.ResultsIn the ethanol group, CYP2E1 expression, activity, and the concentration of free HFIP were significantly higher at all time points compared to the control group (P < 0.05), except for protein expression in the first week (P > 0.05). Within-group comparisons indicated no significant changes in any of the parameters for the control group (P > 0.05). In the ethanol group, there was no difference in free HFIP concentration between the first and second weeks (P > 0.05), but a significant increase was observed in the third and fourth weeks (P < 0.01); protein expression and enzyme activity significantly varied over time, especially showing a notable increase from the first to the third and fourth weeks (P < 0.05). Correlation analysis revealed strong positive correlations between free HFIP concentration and CYP2E1 activity (r = 0.7898), free HFIP concentration and CYP2E1 expression (r = 0.8418), and CYP2E1 activity and expression (r = 0.8740), all with P < 0.001.ConclusionsEthanol exposure increased both the expression and enzymatic activity of CYP2E1, consequently enhancing the metabolism of sevoflurane.

Combinatory Effects of Acrylamide and Deoxynivalenol on In Vitro Cell Viability and Cytochrome P450 Enzymes of Human HepaRG Cells.

Acrylamide (AA) can be formed during the thermal processing of carbohydrate-rich foods. Deoxynivalenol (DON), a mycotoxin produced by Fusarium spp., contaminates many cereal-based products. In addition to potential co-exposure through a mixed diet, co-occurrence of AA and DON in thermally processed cereal-based products is also likely, posing the question of combinatory toxicological effects. In the present study, the effects of AA (0.001-3 mM) and DON (0.1-30 µM) on the cytotoxicity, gene transcription, and expression of major cytochrome P450 (CYP) enzymes were investigated in differentiated human hepatic HepaRG cells. In the chosen ratios of AA-DON (10:1; 100:1), cytotoxicity was clearly driven by DON and no overadditive effects were observed. Using quantitative real-time PCR, about twofold enhanced transcript levels of CYP1A1 were observed at low DON concentrations (0.3 and 1 µM), reflected by an increase in CYP1A activity in the EROD assay. In contrast, CYP2E1 and CYP3A4 gene transcription decreased in a concentration-dependent manner after incubation with DON (0.01-0.3 µM). Nevertheless, confocal microscopy showed comparably constant protein levels. The present study provided no indication of an induction of CYP2E1 as a critical step in AA bioactivation by co-occurrence with DON. Taken together, the combination of AA and DON showed no clear physiologically relevant interaction in HepaRG cells.

A comprehensive study of CYP2E1 and its role in carcass characteristics and chemical lamb meat quality in different Indonesian sheep breeds.

The role of CYP2E1 in oxidation is essential for its effects on meat quality. This study used 200 Indonesian sheep (Ovis aries) to determine the SNP g allele frequencies. g. 50658168 T>C of CYP2E1 gene located in 3´-UTR region and their genetic association with lamb quality traits, including carcass characteristics, retail cut carcass, physicochemical lamb, fatty acid, cholesterol, flavor and odor, and mineral content. Further, the level of CYP2E1 mRNA and CYP2E1 protein expression in muscle were determined and correlated with lamb quality traits. CYP2E1 gene polymorphisms were identified using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) analysis. The CYP2E1 mRNA expression levels in phenotypically divergent sheep populations were analyzed using Quantitative Real Time-PCR (qRT-PCR). Immunohistochemistry (IHC) and hematoxylin-eosin (HE) staining analysis used three samples each in the high and low lamb quality groups based on pH value and tenderness. An association study of CYP2E1 gene polymorphisms was performed using General Linear Model (GLM) analysis. The genetic association between the CC, CT, and TT genotypes at the SNP g. 50658168 T>C CYP2E1 gene and lamb quality traits were significant (P<0.05), including carcass characteristics, retail cut carcass, fatty acid, cholesterol, flavor, and odor. Lambs with the CT genotype had a higher mRNA and protein expression in high lamb quality traits. The highest CYP2E1 protein expression was localized in the longissimus dorsi. The group sample with high lamb quality had a higher area and perimeter of muscle cells. CYP2E1 can be used as a genetic marker for selecting sheep with high meat quality.