Mechanistic Insights of Neuroprotective Efficacy of Verapamil-Loaded Carbon Quantum Dots against LPS-Induced Neurotoxicity in Rats

Alzheimer's disease (AD) is a neurodegenerative disease that badly impacts patients and their caregivers. AD is characterized by deposition of amyloid beta (Aβ) and phosphorylated tau protein (pTau) in the brain with underlying neuroinflammation. We aimed to develop a neuroprotective paradigm by loading verapamil (VRH) into hyaluronic acid-modified carbon quantum dots (CQDs) and comparing its effectiveness with the free form in an AD-like model in rats induced by lipopolysaccharide (LPS). The experimental rats were divided into seven groups: control, LPS, CQDs, early free VRH (FVRH), late FVRH, early verapamil carbon quantum dots (VCQDs), and late VCQDs. Characterizations of VCQDs, the behavioral performance of the rats, histopathological and immunohistochemical changes, some AD hallmarks, oxidative stress biomarkers, neuro-affecting genes, and DNA fragmentation were determined. VRH was successfully loaded into CQDs, which was confirmed by the measured parameters. VRH showed enhancement in cognitive functions, disruption to the architecture of the brain, decreased Aβ and pTau, increased antioxidant capacity, modifiable expression of genes, and a decline in DNA fragmentation. The loaded therapy was superior to the free drug. Moreover, the early intervention was better than the late, confirming the implication of the detected molecular targets in the development of AD. VRH showed multifaceted mechanisms in combating LPS-induced neurotoxicity through its anti-inflammatory and antioxidant properties, thereby mitigating the hallmarks of AD. Additionally, the synthesized nanosystem approach exhibited superior neuroprotection owing to the advantages offered by CQDs. However, finding new actionable biomarkers and molecular targets is of decisive importance to improve the outcomes for patients with AD.

Decoding the Role of CYP450 Enzymes in Metabolism and Disease: A Comprehensive Review

Cytochrome P450 (CYP450) is a group of enzymes that play an essential role in Phase I metabolism, with 57 functional genes classified into 18 families in the human genome, of which the CYP1, CYP2, and CYP3 families are prominent. Beyond drug metabolism, CYP enzymes metabolize endogenous compounds such as lipids, proteins, and hormones to maintain physiological homeostasis. Thus, dysregulation of CYP450 enzymes can lead to different endocrine disorders. Moreover, CYP450 enzymes significantly contribute to fatty acid metabolism, cholesterol synthesis, and bile acid biosynthesis, impacting cellular physiology and disease pathogenesis. Their diverse functions emphasize their therapeutic potential in managing hypercholesterolemia and neurodegenerative diseases. Additionally, CYP450 enzymes are implicated in the onset and development of illnesses such as cancer, influencing chemotherapy outcomes. Assessment of CYP450 enzyme expression and activity aids in evaluating liver health state and differentiating between liver diseases, guiding therapeutic decisions, and optimizing drug efficacy. Understanding the roles of CYP450 enzymes and the clinical effect of their genetic polymorphisms is crucial for developing personalized therapeutic strategies and enhancing drug responses in diverse patient populations.

Attenuation of phenobarbital-induced cytochrome P450 expression in carbon tetrachloride-induced hepatitis in mice models

Certain pathological conditions, such as inflammation, are known to affect basal cytochrome P450 (CYP) expression by modulating transcriptional regulation, and the pharmacokinetics of drugs can vary among patients. However, changes in drug-induced CYP expression under pathological conditions have not been elucidated in detail. Here, we investigated the effects of hepatic inflammation and injury on phenobarbital-induced expression of CYP isoforms in mice. Phenobarbital was administered once as a CYP inducer in the carbon tetrachloride-induced hepatitis model mice. The mRNA expression levels of Cyp3a11 and Cyp2b10 in the liver and small intestine were measured using reverse transcription polymerase chain reaction. The enzymatic activity of CYP3A in liver S9 was evaluated using midazolam as the substrate. Phenobarbital increased the mRNA expression of Cyp3a11 and Cyp2b10 in the liver of healthy mice, but not in the small intestine. Increased mRNA expression of hepatic Cyp3a11 and Cyp2b10 by phenobarbital was significantly suppressed in the hepatitis model mice. Hepatitis also suppressed the increased CYP3A enzymatic activity induced by phenobarbital in liver S9, consistent with the results of Cyp3a11 mRNA expression. These results suggest that the inducibility of CYP by phenobarbital may vary in patients with hepatitis, indicating that pharmacokinetic drug-drug interactions can be altered under certain pathological conditions.

The Role of Cytochrome P450 Enzymes in COVID-19 Pathogenesis and Therapy

Coronavirus disease 2019 (COVID-19) has become a new public health crisis threatening the world. Dysregulated immune responses are the most striking pathophysiological features of patients with severe COVID-19, which can result in multiple-organ failure and death. The cytochrome P450 (CYP) system is the most important drug metabolizing enzyme family, which plays a significant role in the metabolism of endogenous or exogenous substances. Endogenous CYPs participate in the biosynthesis or catabolism of endogenous substances, including steroids, vitamins, eicosanoids, and fatty acids, whilst xenobiotic CYPs are associated with the metabolism of environmental toxins, drugs, and carcinogens. CYP expression and activity are greatly affected by immune response. However, changes in CYP expression and/or function in COVID-19 and their impact on COVID-19 pathophysiology and the metabolism of therapeutic agents in COVID-19, remain unclear. In this analysis, we review current evidence predominantly in the following areas: firstly, the possible changes in CYP expression and/or function in COVID-19; secondly, the effects of CYPs on the metabolism of arachidonic acid, vitamins, and steroid hormones in COVID-19; and thirdly, the effects of CYPs on the metabolism of therapeutic COVID-19 drugs.

PXR mediates mifepristone-induced hepatomegaly in mice

Mifepristone (Mif), an effective synthetic steroidal antiprogesterone drug, is widely used for medical abortion and pregnancy prevention. Due to its anti-glucocorticoid effect, high-dose Mif is also used to treat Cushing's syndrome. Mif was reported to active pregnane X receptor (PXR) in vitro and PXR can induce hepatomegaly via activation and interaction with yes-associated protein (YAP) pathway. High-dose Mif was reported to induce hepatomegaly in rats and mice, but the underlying mechanism remains unclear. Here, the role of PXR was studied in Mif-induced hepatomegaly in C57BL/6 mice and Pxr-knockout mice. The results demonstrated that high-dose Mif (100 mg · kg^-1 · d^-1, i.p.) treatment for 5 days significantly induced hepatomegaly with enlarged hepatocytes and promoted proliferation, but low dose of Mif (5 mg · kg^-1 · d^-1, i.p.) cannot induce hepatomegaly. The dual-luciferase reporter gene assays showed that Mif can activate human PXR in a concentration-dependent manner. In addition, Mif could promote nuclear translocation of PXR and YAP, and significantly induced the expression of PXR, YAP, and their target proteins such as CYP3A11, CYP2B10, UGT1A1, ANKRD, and CTGF. However, Mif (100 mg · kg^-1 · d^-1, i.p.) failed to induce hepatomegaly in Pxr-knockout mice, as well as hepatocyte enlargement and proliferation, further indicating that Mif-induced hepatomegaly is PXR-dependent. In summary, this study demonstrated that PXR-mediated Mif-induced hepatomegaly in mice probably via activation of YAP pathway. This study provides new insights in Mif-induced hepatomegaly, and provides novel evidence on the crucial function of PXR in liver enlargement and regeneration.

Global Microbiota-Dependent Histone Acetylation Patterns Are Irreversible and Independent of Short Chain Fatty Acids

BACKGROUND AND AIMS

Although germ-free mice are an indispensable tool in studying the gut microbiome and its effects on host physiology, they are phenotypically different than their conventional counterparts. While antibiotic-mediated microbiota depletion in conventional mice leads to physiologic alterations that often mimic the germ-free state, the degree to which the effects of microbial colonization on the host are reversible is unclear. The gut microbiota produce abundant short chain fatty acids (SCFAs), and previous studies have demonstrated a link between microbial-derived SCFAs and global hepatic histone acetylation in germ-free mice.

APPROACH AND RESULTS

We demonstrate that global hepatic histone acetylation states measured by mass spectrometry remained largely unchanged despite loss of luminal and portal vein SCFAs after antibiotic-mediated microbiota depletion. In contrast to stable hepatic histone acetylation states, we see robust hepatic transcriptomic alterations after microbiota depletion. Additionally, neither dietary supplementation with supraphysiologic levels of SCFA nor the induction of hepatocyte proliferation in the absence of microbiota-derived SCFAs led to alterations in global hepatic histone acetylation.

CONCLUSIONS

These results suggest that microbiota-dependent landscaping of the hepatic epigenome through global histone acetylation is static in nature, while the hepatic transcriptome is responsive to alterations in the gut microbiota.

Transcriptomic Analyses Reveal 2 and 4 Family Members of Cytochromes P450 (CYP) Involved in LPS Inflammatory Response in Pharynx of Ciona robusta

Cytochromes P450 (CYP) are enzymes responsible for the biotransformation of most endogenous and exogenous agents. The expression of each CYP is influenced by a unique combination of mechanisms and factors including genetic polymorphisms, induction by xenobiotics, and regulation by cytokines and hormones. In recent years, Ciona robusta, one of the closest living relatives of vertebrates, has become a model in various fields of biology, in particular for studying inflammatory response. Using an in vivo LPS exposure strategy, next-generation sequencing (NGS) and qRT-PCR combined with bioinformatics and in silico analyses, compared whole pharynx transcripts from naïve and LPS-exposed C. robusta, and we provide the first view of cytochrome genes expression and miRNA regulation in the inflammatory response induced by LPS in a hematopoietic organ. In C. robusta, cytochromes belonging to 2B,2C, 2J, 2U, 4B and 4F subfamilies were deregulated and miRNA network interactions suggest that different conserved and species-specific miRNAs are involved in post-transcriptional regulation of cytochrome genes and that there could be an interplay between specific miRNAs regulating both inflammation and cytochrome molecules in the inflammatory response in C. robusta.

IL-6 downregulates hepatic carboxylesterases via NF-κB activation in dextran sulfate sodium-induced colitis

Ulcerative colitis (UC) is associated with increased levels of inflammatory factors, which is attributed to the abnormal expression and activity of enzymes and transporters in the liver, affecting drug disposition in vivo. This study aimed to examine the impact of intestinal inflammation on the expression of hepatic carboxylesterases (CESs) in a mouse model of dextran sulfate sodium (DSS)-induced colitis. Two major CESs isoforms, CES1 and CES2, were down-regulated, accompanied by decreases in hepatic microsomal metabolism of clopidogrel and irinotecan. Meanwhile, IL-6 levels significantly increased compared with other inflammatory factors in the livers of UC mice. In contrast, using IL-6 antibody simultaneously reversed the down-regulation of CES1, CES2, pregnane X receptor (PXR), and constitutive androstane receptor (CAR), as well as the nuclear translocation of NF-κB in the liver. We further confirmed that treatment with NF-κB inhibitor abolished IL-6-induced down-regulation of CES1, CES2, PXR, and CAR in vitro. Thus, it was concluded that IL-6 represses hepatic CESs via the NF-κB pathway in DSS-induced colitis. These findings indicate that caution should be exercised concerning the proper and safe use of therapeutic drugs in patients with UC.

Changes and sex- and age-related differences in the expression of drug metabolizing enzymes in a KRAS-mutant mouse model of lung cancer

Background

This study aimed to systematically profile the alterations and sex- and age-related differences in the drug metabolizing enzymes (DMEs) in a KRAS-mutant mouse model of lung cancer (KRAS mice).

Methodology

In this study, the LC-MS/MS approach and a probe substrate method were used to detect the alterations in 21 isoforms of DMEs, as well as the enzymatic activities of five isoforms, respectively. Western blotting was applied to study the protein expression of four related receptors.

Results

The proteins contents of CYP2C29 and CYP3A11, were significantly downregulated in the livers of male KRAS mice at 26 weeks (3.7- and 4.4-fold, respectively, p < 0.05). SULT1A1 and SULT1D1 were upregulated by 1.8- to 7.0- fold at 20 (p = 0.015 and 0.017, respectively) and 26 weeks (p = 0.055 and 0.031, respectively). There were positive correlations between protein expression and enzyme activity for CYP2E1, UGT1A9, SULT1A1 and SULT1D1 (r² ≥ 0.5, p < 0.001). Western blotting analysis revealed the downregulation of AHR, FXR and PPARα protein expression in male KRAS mice at 26 weeks. For sex-related differences, CYP2E1 was male-predominant and UGT1A2 was female-predominant in the kidney. UGT1A1 and UGT1A5 expression was female-predominant, whereas UGT2B1 exhibited male-predominant expression in liver tissue. For the tissue distribution of DMEs, 21 subtypes of DMEs were all expressed in liver tissue. In the intestine, the expression levels of CYP2C29, CYP27A1, UGT1A2, 1A5, 1A6a, 1A9, 2B1, 2B5 and 2B36 were under the limitation of quantification. The subtypes of CYP7A1, 1B1, 2E1 and UGT1A1, 2A3, 2B34 were detected in kidney tissue.

Conclusions

This study, for the first time, unveils the variations and sex- and age-related differences in DMEs in C57 BL/6 (WT) mice and KRAS mice.

[Pharmacokinetic changes related to acute infection. Examples from the SARS-CoV-2 pandemic]

The knowledge of factors of pharmacokinetic variability is important in order to personalize pharmacological treatment, particularly for drugs with a narrow therapeutic range for which pharmacological therapeutic monitoring is recommended. Inflammation is a protective response against acute infections and injuries that contributes to intra- and inter-individual variability in drug exposure by modulating the activity of enzymes involved in drug metabolism, and by altering the binding of drugs to plasma proteins. The understanding of the impact of inflammation on drug metabolism and the related clinical consequences allow to better take into consideration the effect of inflammation on the variability of drug exposure. We first summarized the molecular mechanisms by which inflammation contributes to the inhibition of drug metabolism enzymes. We then presented an updated overview of the consequences of the outcome of acute infectious event on pharmacokinetic exposure of drugs with a narrow therapeutic range and that are substrates of cytochrome P450, and the related clinical consequences. Finally, in the context of the COVID-19 pandemic, we reported examples of drug overexposures in COVID- 19 infected patients.

Involvement of cytochrome P450 enzymes in inflammation and cancer: a review

Cytochrome P450 (CYP) enzymes are responsible for the biotransformation of drugs, xenobiotics, and endogenous substances. This enzymatic activity can be modulated by intrinsic and extrinsic factors, modifying the organism's response to medications. Among the factors that are responsible for enzyme inhibition or induction is the release of proinflammatory cytokines, such as interleukin-1 (IL-1), IL-6, tumor necrosis factor α (TNF-α), and interferon-γ (IFN-γ), from macrophages, lymphocytes, and neutrophils. These cells are also present in the tumor microenvironment, participating in the development of cancer, a disease that is characterized by cellular mutations that favor cell survival and proliferation. Mutations also occur in CYP enzymes, resulting in enzymatic polymorphisms and modulation of their activity. Therefore, the inhibition or induction of CYP enzymes by proinflammatory cytokines in the tumor microenvironment can promote carcinogenesis and affect chemotherapy, resulting in adverse effects, toxicity, or therapeutic failure. This review discusses the relevance of CYPs in hepatocarcinoma, breast cancer, lung cancer, and chemotherapy by reviewing in vitro, in vivo, and clinical studies. We also discuss the importance of elucidating the relationships between inflammation, CYPs, and cancer to predict drug interactions and therapeutic efficacy.

Inflammation is a major regulator of drug metabolizing enzymes and transporters: Consequences for the personalization of drug treatment

Inflammation is an evolutionary process that allows survival against acute infection or injury. Inflammation is also a pathophysiological condition shared by numerous chronic diseases. In addition, inflammation modulates important drug-metabolizing enzymes and transporters (DMETs), thus contributing to intra- and interindividual variability of drug exposure. A better knowledge of the impact of inflammation on drug metabolism and its related clinical consequences would help to personalize drug treatment. Here, we summarize the kinetics of inflammatory mediators and the underlying transcriptional and post-transcriptional mechanisms by which they contribute to the inhibition of important DMETs. We also present an updated overview of the effect of inflammation on the pharmacokinetic parameters of most of the drugs that are DMET substrates, for which therapeutic drug monitoring is recommended. Furthermore, we provide opinions on how to integrate the inflammatory status into pharmacogenetics, therapeutic drug monitoring, and population pharmacokinetic strategies to improve the personalization of drug treatment for each patient.

Characterization of a long-term mouse primary liver 3D tissue model recapitulating innate-immune responses and drug-induced liver toxicity

Three-dimensional liver in vitro systems have recently attracted a lot of attention in drug development. These systems help to gain unprecedented insights into drug-induced liver injury (DILI), as they more closely reproduce liver biology, and as drug effects can be studied in isolated and controllable microenvironments. Many groups established human-based in vitro models but so far neglected the animal equivalent, although the availability of both models would be desirable. Animal in vitro models enable back- and forward translation of in vitro and in vivo findings, bridge the gap between rodent in vivo and human in vitro scenarios, and ultimately support the interpretation of data generated with preclinical species and humans. Since mice are often used in drug development and physiologically relevant in vitro systems are lacking, we established, for the first time, a mouse liver model that encompasses primary parenchymal and non-parenchymal cells with preserved viability and functionality over three weeks. Using our three-dimensional liver spheroids, we were able to predict the toxicity of known DILI compounds, demonstrated the interaction cascades between the different cell types and showed evidence of drug-induced steatosis and cholestasis. In summary, our mouse liver spheroids represent a valuable in vitro model that can be applied to study DILI findings, reported from mouse studies, and offers the potential to detect immune-mediated drug-induced liver toxicity.

Involvement of P450s and nuclear receptors in the hepatoprotective effect of quercetin on liver injury by bacterial lipopolysaccharide

Objective: Quercetin (Que), a flavonoid, possesses anti-inflammatory and antioxidant properties. It has been shown to protect against liver injury induced by various factors. This study was designed to investigate the underlying mechanism of its protective effect against lipopolysaccharide (LPS)- induced liver damage.Methods: Mice were pretreated with Que for 7 consecutive days and then exposed to LPS. To study the hepatoprotective effect of Que, oxidative stress parameters, inflammatory cytokine levels in liver and serum liver function indexes were examined. Protein and mRNA expression of nuclear orphan receptors and cytochrome P450 enzymes were measured by Western Blotting and qPCR, respectively.Results: Que significantly reduced circulating ALT, AST, ALP, and ameliorated LPS-induced histological alterations. In addition, Que obviously decreased markers of oxidative stress and pro-inflammatory cytokines. Furthermore, Que carried out the hepatoprotective effect via regulation of the expression of nuclear orphan receptors (CAR, PXR) and cytochrome P450 enzymes (CYP1A2, CYP2E1, CYP2D22, CYP3A11).Conclusions: Our findings suggested that Que pretreatment could ameliorate LPS-induced liver injury.

Expression of Cyp2c/Cyp2j subfamily members and oxylipin levels during LPS-induced inflammation and resolution in mice

Inflammatory stimuli, such as bacterial LPS, alter the expression of many cytochromes P450. CYP2C and CYP2J subfamily members actively metabolize fatty acids to bioactive eicosanoids, which exhibit potent anti-inflammatory effects. Herein, we examined mRNA levels of the 15 mouse Cyp2c and 7 mouse Cyp2j isoforms in liver, kidney, duodenum, and brain over a 96-h time course of LPS-induced inflammation and resolution. Plasma and liver eicosanoid levels were also measured by liquid chromatography with tandem mass spectrometry. Expression changes in Cyp2c and Cyp2j isoforms were both isoform and tissue specific. Total liver Cyp2c and Cyp2j mRNA content was reduced by 80% 24 h after LPS but recovered to baseline levels by 96 h. Total Cyp2c and Cyp2j mRNA in kidney (-19%) and duodenum (-64%) were reduced 24 h after LPS but recovered above baseline by 72 h. Total Cyp2c and Cyp2j mRNA content in brain was elevated at all time points after LPS dosing. Plasma eicosanoids transiently increased 3-6 h after administration of LPS. In liver, esterified oxylipin levels decreased during acute inflammation and before recovering. The biphasic suppression and recovery of mouse Cyp2c and Cyp2j isoforms and associated changes in eicosanoid levels during LPS-induced inflammation and resolution may have important physiologic consequences.-Graves, J. P., Bradbury, J. A., Gruzdev, A., Li, H., Duval, C., Lih, F. B., Edin, M. L., Zeldin, D. C. Expression of Cyp2c/Cyp2j subfamily members and oxylipin levels during LPS-induced inflammation and resolution in mice.

Eicosanoids derived from cytochrome P450 pathway of arachidonic acid and inflammatory shock

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Septic shock, the most common form of vasodilatory shock, is a subset of sepsis in which circulatory and cellular/metabolic abnormalities are severe enough to increase mortality. Inflammatory shock constitutes the hallmark of sepsis, but also a final common pathway of any form of severe long-term tissue hypoperfusion. The pathogenesis of inflammatory shock seems to be due to circulating substances released by pathogens (e.g., bacterial endotoxins) and host immuno-inflammatory responses (e.g., changes in the production of histamine, bradykinin, serotonin, nitric oxide [NO], reactive nitrogen and oxygen species, and arachidonic acid [AA]-derived eicosanoids mainly through NO synthase, cyclooxygenase, and cytochrome P450 [CYP] pathways, and proinflammatory cytokine formation). Therefore, refractory hypotension to vasoconstrictors with end-organ hypoperfusion is a life threatening feature of inflammatory shock. This review summarizes the current knowledge regarding the role of eicosanoids derived from CYP pathway of AA in animal models of inflammatory shock syndromes with an emphasis on septic shock in addition to potential therapeutic strategies targeting specific CYP isoforms responsible for proinflammatory/anti-inflammatory mediator production.

Relationship between CYP3A29 and pregnane X receptor in landrace pigs: Pig CYP3A29 has a similar mechanism of regulation to human CYP3A4

The objective of this study was to provide evidence of the validity of utilizing pigs as a model to study the regulation of human CYP3A4, with special emphasis on drug-drug interactions. We determined the mRNA expression and distribution of CYP3A and metabolic nuclear receptors in different tissues isolated from landrace pigs. Our results showed that CYP3A and metabolic nuclear receptor mRNAs were most highly expressed in liver tissues. The expression of the metabolic nuclear receptor pregnane X receptor (PXR) had a significant correlation with expression of CYP3A29, an analog of human CYP3A4. The correlation between their transcriptional levels was further demonstrated using LPS and TNF-α. The mRNA and protein expression of CYP3A29 and PXR in HepLi cells was significantly reduced by LPS and TNF-α treatment. CYP3A29 promoter activity was dramatically elevated by PXR over expression, whereas LPS and TNF-α treatment inhibited the enhanced CYP3A29 promoter activity that was induced by PXR; presumably through inhibition of PXR promoter activity. Furthermore, the inhibition of CYP3A29 promoter activity by LPS and TNF-α treatment was blocked by knockdown of PXR or retinoid X receptor (RXR). These data suggest high similarity in the regulation mechanism of pig CYP3A29 and human CYP3A4. Our research provided a significant evaluation to determine whether pigs are suitable as an experimental animal model.

Potentiating effect of acetaminophen and carbon tetrachloride-induced hepatotoxicity is mediated by activation of receptor interaction protein in mice

When multiple drugs or chemicals are used in combination, it is important to understand the risk of their interactions and predict potential additive effects. The aim of the current study was to investigate the molecular mechanism(s) accounting for the additive/synergistic effect of combination treatment with acetaminophen (APAP) and carbon tetrachloride (CCl₄). Mice were intraperitoneally administered vehicle or 100 mg/kg (5 mL/kg) APAP and 30 min after vehicle or 15 mg/kg (5 mL/kg) CCl₄. Sixteen hours after treatment, mice from each group were sacrificed and the livers were removed. CCl₄ administration caused slight glycogen depletion; this effect was more pronounced following co-administration of APAP and CCl₄. ATP and NADPH levels showed the same trend as glycogen levels. The levels of receptor interacting protein 1 and 3 increased following combination treatment with APAP and CCl₄. In contrast, levels of the glutamate cysteine ligase catalytic subunit and glutamate cysteine ligase modifier subunits were not significantly affected by combination treatment. APAP and CCl₄ co-administration potentiated the phosphorylation of c-Jun N-terminal kinase and p38 kinases, although phosphorylated activation of extracellular signal-regulated kinase was not changed. Our results suggest that APAP and CCl₄ co-administration potentiates hepatotoxicity in an additive/synergistic manner via receptor interacting protein activation.

Pharmacokinetics of Morphine in Rats with Adjuvant-induced Arthritis

We investigated the in vivo dynamics and analgesic effect of morphine using an adjuvant-induced arthritis (AA) rat as a model of chronic inflammation. Morphine generally binds to μ-opioid receptors in the brain to exert its effects. After several minutes, it is metabolized by glucuronidation via a UDP-glucuronosyltransferase (UGT). Here, we showed that in AA rats, UGT activity in liver microsomes was reduced. Morphine-free serum fractions in AA rats were also decreased (control, 84.9%; AA, 63.9%) and the expression of ATP-binding cassette, sub-family B (MDR/TAP), member 1 (ABCB1), which plays a crucial role in morphine bile excretion, decreased to 23.0% that of the control group. However, we observed no significant difference between the AA and control groups regarding blood concentrations of morphine and morphine-3-glucuronide. In contrast, the analgesic effect of morphine increased 4-fold in AA rats. Our results showed that the pharmacokinetics of morphine is not changed, but the pharmacodynamics of morphine is enhanced in chronic inflammation.

Non-toxic Level of Acetaminophen Potentiates Carbon Tetrachloride-Induced Hepatotoxicity in Mice

A wide range of medications are routinely used to maintain and improve human health. Hence, it is essential that we understand and predict adverse effects caused by the combined use of multiple medications. In the present study, we investigated whether the combination of carbon tetrachloride (CCl₄) and acetaminophen (APAP) had a detrimental effect on the liver. Mice injected with APAP (100 mg/kg) showed no significant changes in hepatic injury markers (alanine aminotransferase and aspartate aminotransferase), histopathological findings, pro-inflammatory cytokine levels, or hepatic oxidative stress. In contrast, a single injection of CCl₄ (15 mg/kg) led to a significant increase in hepatic injury, in addition to an increase in pro-inflammatory cytokine levels and oxidative stress. Co-administration of APAP and CCl₄ resulted in exacerbation of these hepatic injuries. Our results suggest that a non-toxic dose of APAP has the potential to increase CCl₄-induced liver damage and oxidative stress.

Comparative pharmacokinetic study of pyranocoumarins and khellactone in normal and acute lung injury rats after oral administration of Peucedanum praeruptorum Dunn extracts using a rapid and sensitive liquid chromatography-tandem mass spectrometry method

Pyranocoumarins are the main constitutes in Peucedanum praeruptorum Dunn and possess various biological activities. In this article, we developed and validated a rapid and sensitive liquid chromatography-tandem mass spectrometry method for the targeted quantification of the pyranocoumarins, praeruptorin A, praeruptorin B and praeruptorin E, and khellactone, which is a common metabolite of these pyranocoumarins in rat plasma samples. We then performed a comparative pharmacokinetic study of these pyranocoumarins and khellactone in normal and lipopolysaccharide-induced acute lung injury (ALI) in rats following oral administration of P. praeruptorum Dunn extracts. Calibration curves gave desirable linearity (r > 0.99) and the lower limit of quantifications were sufficient for quantitative analysis. The precision and accuracy were assessed by intra-batch and inter-batch assays, and the relative standard deviations were all within 10.23% and the accuracy (relative error) was between -5.52% and 8.68%. The extraction recoveries, matrix effects and stability were also acceptable. The pharmacokinetic study revealed that the area under the concentration-time curve (0-t) of khellactone in ALI rats was significantly decreased compared with the normal rats. Meanwhile, the systemic exposures of these pyranocoumarins were slightly higher in the ALI rats than those in normal rats were. The pharmacokinetic study in the pathological state might provide information that was more comprehensive to guide the clinical usage of P. praeruptorum Dunn.

The Impact of MicroRNA-223-3p on IL-17 Receptor D Expression in Synovial Cells

OBJECTIVE

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease affecting joints. Elevated plasma levels of microRNA-223-3p (miR-223-3p) in patients with RA are implicated in the pathogenesis of the disease. This study aimed to analyze the functional role of miR-223-3p in the pathogenesis of RA by overexpressing miR-223-3p in synovial cell lines.

METHODS

Arthritis was induced in the RA model of SKG mice by injection of ß-glucan. The histopathologic features of joints were examined using hematoxylin and eosin and immunohistochemical staining. Plasma levels of miRNA were determined by panel real-time PCR analysis. Target genes of the differentially expressed miRNAs in SKG mice were analyzed using miRNA target prediction algorithms. The dual-luciferase reporter system was used to evaluate the relationship between miR-223-3p and IL-17 receptor D (IL-17RD). The activity of miR-223-3p was analyzed by transfection of plasmid vectors overexpressing miR-223-3p into IL-17RD-expressing NIH3T3 and MH7A cell lines. Il6 and Il17rd mRNA expression was analyzed by quantitative real-time PCR. IL-17RD protein expression was analyzed by western blot analysis.

RESULTS

We identified 17 upregulated miRNAs (fold change > 2.0) in plasma of SKG mice injected with ß-glucan relative to untreated SKG mice. Il17rd was identified as the candidate target gene of miR-223-3p using five miRNA target prediction algorithms. The transfection of plasmid vectors overexpressing miR-223-3p into NIH3T3 and MH7A cells resulted in the downregulation of Il17rd expression and upregulation of Il6 expression. Expression of miR-223-3p and Il6 mRNA in MH7A cells was upregulated; however, that of Il17rd mRNA was downregulated following TNF-α stimulation. IL-17RD expression in synovial tissues from SKG mice and RA patients was inversely correlated with the severity of arthritis.

CONCLUSION

This study is the first to demonstrate that miR-223-3p downregulates IL-17RD in both mouse and human cells; miR-223-3p may contribute to the pathogenesis of RA by downregulating the expression of IL-17RD and upregulating that of IL-6 in synovial cells.

Influence of High-fat and High-cholesterol Diet on Major CYP Activities in the Liver

We previously reported that a high-fat and high-cholesterol (HFHC) diet for 12 weeks induced non-alcoholic steatohepatitis (NASH) and influenced major CYP subtype gene expression levels and activities in a mouse model. In the present study, we determined the effects of the HFHC diet on CYP expression levels and activities prior to the establishment of NASH. When male C57BL/6J mice were fed the HFHC or a normal chow diet (Control) ad libitum for 4 weeks, body weights were significantly lower, whereas liver weights and hepatic lipid contents were significantly higher in the HFHC group than in the Control group. Under these conditions, hepatic microsomal luciferin-H (human CYP2C9 substrate) hydroxylation activity was significantly lower in the HFHC group than in the Control group. In order to investigate drug efficacy in mice fed the HFHC diet, an intraperitoneal glucose tolerance test was conducted with or without a pretreatment with tolbutamide (a CYP2C substrate) after 4 weeks of feeding. The plasma glucose-lowering effects of tolbutamide were attenuated in the HFHC group even though luciferin-H hydroxylation activity was suppressed in this group. The reason for this discrepancy was attributed to the mRNA expression levels of Cyp2c44 being lower and those of Cyp2c29 and Cyp2c66, which are involved in the metabolism of tolbutamide, being higher in the HFHC group than in the Control group. These results indicate that the expression of Cyp2c in the liver is influenced by the HFHC diet prior to the establishment of NASH and its regulation differed among the subtypes examined.

Identification of Candidate Target Cyp Genes for microRNAs Whose Expression Is Altered by PCN and TCPOBOP, Representative Ligands of PXR and CAR

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in mRNA post-transcriptional regulation. The deregulation of miRNAs affects the expression of drug-metabolizing enzymes, drug transporters, and nuclear receptors, all of which are important in regulating drug metabolism. miRNA expression can be altered by several endogenous or exogenous agents, such as steroid hormones, carcinogens, and therapeutic drugs. However, it is unclear whether hepatic miRNA expression is regulated by nuclear receptors, such as pregnane X receptor (PXR) and constitutive androstane receptor (CAR), which are indispensable for the expression of the CYPs. Here we investigated the effects of the mouse PXR and CAR ligands pregnenolone-16α-carbonitrile (PCN) and 1,4-bis[(3,5-dichloropyridin-2-yl)oxy]benzene (TCPOBOP) on hepatic miRNA expression in mice. We found that the expression of 9 miRNAs was increased (>2-fold) and of 4 miRNAs was decreased (>50%) in response to PCN, while TCPOBOP treatment led to the up-regulation of 8 miRNAs and down-regulation of 6 miRNAs. Using several miRNA target prediction algorithms, we found that the predicted target genes included several lesser known Cyp genes (Cyp1a1, Cyp1b1, Cyp2b10, Cyp2c38, Cyp2u1, Cyp4a12a/b, Cyp4v3, Cyp17a1, Cyp39a1, and Cyp51). We analyzed the expression of these genes in response to PCN and TCPOBOP and found changes in their mRNA levels, some of which were negatively correlated with the expression of their corresponding miRNAs, suggesting that miRNAs may play a role in regulating Cyp enzyme expression. Further studies will be required to fully elucidate the miRNA regulatory mechanisms that contribute to modulating CYP expression.

Regulation of drug-metabolizing enzymes by local and systemic liver injuries

INTRODUCTION

Drug metabolism and disposition are critical in maintaining the chemical and functional homeostasis of xenobiotics/drugs and endobiotics. The liver plays an essential role in drug metabolism and disposition due to its abundant expression of drug-metabolizing enzymes (DMEs) and transporters. There is growing evidence to suggest that many hepatic and systemic diseases can affect drug metabolism and disposition by regulating the expression and/or activity of DMEs and transporters in the liver.

AREAS COVERED

This review focuses on the recent progress on the regulation of DMEs by local and systemic liver injuries. Liver ischemia and reperfusion (I/R) and sepsis are used as examples of local and systemic injury, respectively. The reciprocal effect of the expression and activity of DMEs on animals' sensitivity to local and systemic liver injuries is also discussed.

EXPERT OPINION

Local and systemic liver injuries have a major effect on the expression and activity of DMEs in the liver. Understanding the disease effect on DMEs is clinically important due to the concern of disease-drug interactions. Future studies are necessary to understand the mechanism by which liver injury regulates DMEs. Human studies are also urgently needed in order to determine whether the results in animals can be replicated in human patients.

Screening and Confirmatory Analyses of Flunixin in Tissues and Bodily Fluids after Intravenous or Intramuscular Administration to Cull Dairy Cows with or without Lipopolysaccharide Challenge

Twenty cull dairy cows (645 ± 83 kg) were treated with 2.2 mg/kg bw flunixin by intravenous (IV) or intramuscular (IM) administration with, or without, exposure to lipopolysaccharide in a two factor balanced design. The usefulness of screening assays to identify violative flunixin levels in a variety of easily accessible ante-mortem fluids in cattle was explored. Two animals with violative flunixin liver residue and/or violative 5-hydroxy flunixin milk residues were correctly identified by a flunixin liver ELISA screen. Oral fluid did not produce anticipated flunixin concentration profiles using ELISA determination. One cow that had liver and milk violative residues, and one cow that had a milk violation at the prescribed withdrawal period were correctly identified by flunixin milk lateral flow analyses. The ratio of urinary flunixin and 5-hydroxy flunixin may be useful for predicting disruption of metabolism caused by disease or other factors potentially leading to violative liver flunixin residues.

Pulmonary Inflammation Impacts on CYP1A1-Mediated Respiratory Tract DNA Damage Induced by the Carcinogenic Air Pollutant Benzo[a]pyrene

Pulmonary inflammation can contribute to the development of lung cancer in humans. We investigated whether pulmonary inflammation alters the genotoxicity of polycyclic aromatic hydrocarbons (PAHs) in the lungs of mice and what mechanisms are involved. To model nonallergic acute inflammation, mice were exposed intranasally to lipopolysaccharide (LPS; 20 µg/mouse) and then instilled intratracheally with benzo[a]pyrene (BaP; 0.5 mg/mouse). BaP-DNA adduct levels, measured by (32)P-postlabeling analysis, were approximately 3-fold higher in the lungs of LPS/BaP-treated mice than in mice treated with BaP alone. Pulmonary Cyp1a1 enzyme activity was decreased in LPS/BaP-treated mice relative to BaP-treated mice suggesting that pulmonary inflammation impacted on BaP-induced Cyp1a1 activity in the lung. Our results showed that Cyp1a1 appears to be important for BaP detoxification in vivo and that the decrease of pulmonary Cyp1a1 activity in LPS/BaP-treated mice results in a decrease of pulmonary BaP detoxification, thereby enhancing BaP genotoxicity (ie, DNA adduct formation) in the lung. Because less BaP was detoxified by Cyp1a1 in the lungs of LPS/BaP-treated mice, more BaP circulated via the blood to extrapulmonary tissues relative to mice treated with BaP only. Indeed, we observed higher BaP-DNA adduct levels in livers of LPS/BaP-treated mice compared with BaP-treated mice. Our results indicate that pulmonary inflammation could be a critical determinant in the induction of genotoxicity in the lung by PAHs like BaP. Cyp1a1 appears to be involved in both BaP bioactivation and detoxification although the contribution of other enzymes to BaP-DNA adduct formation in lung and liver under inflammatory conditions remains to be explored.

Excretory, Secretory, and Tissue Residues after Label and Extra-label Administration of Flunixin Meglumine to Saline- or Lipopolysaccharide-Exposed Dairy Cows

Twenty lactating dairy cattle were intravenously infused with either lipopolysaccharide (LPS) (n = 10) or sterile saline (n = 10). Five cattle in each group received three doses of flunixin meglumine administered by either intravenous infusion or intramuscular injection at 24 h intervals. Milk, urine, and tissues were collected. Thirty-six hours after the last flunixin administration, milk from six cows contained 5-hydroxyflunixin (5OHF) levels greater than the milk tolerance of 2 ng/mL; by 48 h, milk from two cows, a saline and a LPS-treated animal, had violative milk concentrations of 5OHF. A single animal treated with LPS and intramuscular flunixin contained violative flunixin residues in liver. The ratio of urinary flunixin/5OHF was correlated (P < 0.01; R(2) = 0.946) with liver flunixin residues in LPS-treated animals, but not (P = 0.96; R(2) = 0.003) in cows treated with saline in lieu of LPS. Violative residues of flunixin in dairy cattle may be related to LPS inhibition of flunixin metabolism.

Inflammation-induced phenoconversion of polymorphic drug metabolizing enzymes: hypothesis with implications for personalized medicine

Phenoconversion transiently converts genotypic extensive metabolizers (EMs) into phenotypic poor metabolizers (PMs) of drugs, potentially with corresponding changes in clinical response. This phenomenon, typically resulting from coadministration of medications that inhibit certain drug metabolizing enzymes (DMEs), is especially well documented for enzymes of the cytochrome P450 family. Nonclinical evidence gathered over the last two decades also strongly implicates elevated levels of some proinflammatory cytokines, released during inflammation, in down-regulation of drug metabolism, especially by certain DMEs of the P450 family, thereby potentially causing transient phenoconversion. Clinically, phenoconversion of NAT2, CYP2C19, and CYP2D6 has been documented in inflammatory conditions associated with elevated cytokines, such as human immunodeficiency virus infection, cancer, and liver disease. The potential of other inflammatory conditions to cause phenoconversion has not been studied but experimental and anecdotal clinical evidence supports infection-induced down-regulation of CYP1A2, CYP3A4, and CYP2C9 as well. Collectively, the evidence supports a hypothesis that certain inflammatory conditions associated with elevated proinflammatory cytokines may cause phenoconversion of certain DMEs. Since inflammatory conditions associated with elevated levels of proinflammatory cytokines are highly prevalent, phenoconversion of genotypic EM patients into transient phenotypic PMs may be more frequent than appreciated. Since drug pharmacokinetics, and therefore the clinical response, is influenced by DME phenotype rather than genotype per se, phenoconversion (whatever its cause) can have a significant impact on the analysis and interpretation of genotype-focused clinical outcome association studies. There is a risk that focusing on genotype alone may miss important associations between clinical outcomes and DME phenotypes, thus compromising future prospects of personalized medicine.

Pharmacogenomic characterization of gemcitabine response--a framework for data integration to enable personalized medicine

Supplemental Digital Content is available in the text.

Objectives

Response to the oncology drug gemcitabine may be variable in part due to genetic differences in the enzymes and transporters responsible for its metabolism and disposition. The aim of our in-silico study was to identify gene variants significantly associated with gemcitabine response that may help to personalize treatment in the clinic.

Methods

We analyzed two independent data sets: (a) genotype data from NCI-60 cell lines using the Affymetrix DMET 1.0 platform combined with gemcitabine cytotoxicity data in those cell lines, and (b) genome-wide association studies (GWAS) data from 351 pancreatic cancer patients treated on an NCI-sponsored phase III clinical trial. We also performed a subset analysis on the GWAS data set for 135 patients who were given gemcitabine+placebo. Statistical and systems biology analyses were performed on each individual data set to identify biomarkers significantly associated with gemcitabine response.

Results

Genetic variants in the ABC transporters (ABCC1, ABCC4) and the CYP4 family members CYP4F8 and CYP4F12, CHST3, and PPARD were found to be significant in both the NCI-60 and GWAS data sets. We report significant association between drug response and variants within members of the chondroitin sulfotransferase family (CHST) whose role in gemcitabine response is yet to be delineated.

Conclusion

Biomarkers identified in this integrative analysis may contribute insights into gemcitabine response variability. As genotype data become more readily available, similar studies can be conducted to gain insights into drug response mechanisms and to facilitate clinical trial design and regulatory reviews.

Hepatic early inflammation induces downregulation of hepatic cytochrome P450 expression and metabolic activity in the dextran sulfate sodium-induced murine colitis

Ulcerative colitis (UC) patients may have increased concentrations of drugs in their blood. We hypothesized that this response is mainly due to a decrease in the expression and activity of the drug-metabolizing enzyme, cytochrome P450 (CYP), in the liver. In this study, we have tried to demonstrate the hypothesis. UC was induced in mice by treatment with dextran sulfate sodium (DSS) solution. The mRNA and protein expression levels of CYP, inflammatory cytokine levels, and the metabolic activity of CYP3A in the liver were measured. The nuclear translocations of nuclear factor kappa B (NF-κB), pregnane X receptor (PXR), and constitutive androstane receptor (CAR) were analyzed. The levels of hepatic inflammatory cytokines increased in the DSS-treated group. The hepatic mRNA and protein expression of CYP (CYP1A, CYP2C, CYP2D, CYP2E, and CYP3A) and the CYP3A metabolic activity significantly decreased compared to the control group. Hepatic NF-κB nuclear translocation significantly increased in the DSS-treated group. In contrast, the nuclear translocations of PXR and CAR were decreased. Lipopolysaccharides from inflammatory sites in the colon induce hepatic inflammation in DSS-induced murine colitis. This inflammation then causes an increase in the nuclear translocation of hepatic NF-κB and a decrease in the nuclear translocation of PXR and CAR, resulting in the decreased expression and activities of CYP. The results of this study indicated that at the onset of UC, the decreased activity of hepatic CYP causes an increase in the concentrations of drugs in the blood, leading to an increase in the incidence of adverse reactions.

Nuclear receptors in the cross-talk of drug metabolism and inflammation

Inflammation and infection have long been known to affect the activity and expression of enzymes involved in hepatic and extrahepatic drug clearance. Significant advances have been made to elucidate the molecular mechanisms underlying the complex cross-talk between inflammation and drug-metabolism alterations. The emergent role of ligand-activated transcriptional regulators, belonging to the nuclear receptor (NR) superfamily, is now well established. The NRs, pregnane X receptor, constitutive androstane receptor, retinoic X receptor, glucocorticoid receptor, and hepatocyte nuclear factor 4, and the basic helix-loop-helix/Per-ARNT-Sim family member, aryl hydrocarbon receptor, are the main regulators of the detoxification function. According to the panel of mediators secreted during inflammation, a cascade of numerous signaling pathways is activated, including nuclear factor kappa B, mitogen-activated protein kinase, and the Janus kinase/signal transducer and activator of transcription pathways. Complex cross-talk is established between these signaling pathways regulating either constitutive or induced gene expression. In most cases, a mutual antagonism between xenosensor and inflammation signaling occurs. This review focuses on the molecular and cellular mechanisms implicated in this cross-talk.

Three novel cytochrome P450 genes identified in the marine polychaete Perinereis nuntia and their transcriptional response to xenobiotics

Polychaetes have previously been used as bioindicators of environmental pollution. Their ability to eliminate organic pollutants such as polycyclic aromatic hydrocarbons (PAH) has been extensively analyzed. However, the cytochrome P450 monooxygenases (CYP) genes in polychaetes, which catalyze the first step of oxidative degradation of PAHs, have received little attention. Based on the partial sequences of three CYP genes that were enriched by subtractive cDNA libraries of the polychaete Perinereis nuntia, we amplified and sequenced the full-length cDNA of these novel CYP genes. These genes were named CYP4BB2, CYP423A1 and CYP424A1 by the Cytochrome P450 Nomenclature Committee. The deduced amino acid sequence of CYP4BB2 in P. nuntia showed 68% sequence identity to CYP4BB1 in Nereis virens, and was listed as a new member of the CYP4BB subfamily. The sequence of CYP423A1 and CYP424A1 both share less than 40% sequence identity to all known CYP enzymes and were classed into new CYP families. CYP family members are composite parts of a larger group called a clan. CYP4BB2 and CYP424A1 are listed as CYP4 clan members, while CYP423A1 is of the CYP2 clan. The 3D structures of these P. nuntia CYPs were successfully predicted by homology-modeling using the SWISS-MODEL workspace. The models of CYP424A1 and CYP4BB2 were created using 1jpzB (CYP102A) as a template, while CYP423A1 utilized 3czhB (CYP2R1) as its template. The presence of characteristic CYP superfamily motifs, such as the F-G⋯C-G amino acid sequence, and the conservation of the three-dimensional CYP structure shown by the modeling, suggested that these novel P. nuntia CYP genes may contain conserved functional domains of CYP monooxygenases. To examine the effect of xenobiotics on living organisms, we analyzed the transcriptional levels of these three new CYP genes in sandworms (P. nuntia) exposed to seawater artificially contaminated with benzo[a]pyrene (BaP). We also exposed individuals to industrial wastewater collected from Quanzhou Bay, Fujian, China, which was known to be contaminated with PAHs. Worms exposed to BaP had significantly higher levels of CYP4BB2, CYP423A1 and CYP424A1 mRNA. Transcription was up-regulated 5.9-, 5.3- and 12.3-folds respectively compared with the control worms living in clean seawater. The transcriptional levels of CYPs in worms cultured in the diluted wastewater collected from Quanzhou Bay, all positively correlated with the levels of PAHs detected in the water. The transcriptional up-regulation of the three CYP genes observed in this study, suggest the monooxygenases encoded by these CYP genes may play an important role in the detoxification of PAHs in this polychaete worm. These CYPs maybe essential for the adaptation of worms to contaminated environments and may be useful in the assessment of xenobiotic exposure.

Alcohol cirrhosis alters nuclear receptor and drug transporter expression in human liver

Unsafe use of alcohol results in approximately 2.5 million deaths worldwide, with cirrhosis contributing to 16.6% of reported deaths. Serum insulin levels are often elevated in alcoholism and may result in diabetes, which is why alcoholic liver disease and diabetes often are present together. Because there is a sizable population with these diseases alone or in combination, the purpose of this study was to determine whether transporter expression in human liver is affected by alcoholic cirrhosis, diabetes, and alcoholic cirrhosis coexisting with diabetes. Transporters aid in hepatobiliary excretion of many drugs and toxic chemicals and can be determinants of drug-induced liver injury. Drug transporter expression and transcription factor-relative mRNA and protein expression in normal, diabetic, cirrhotic, and cirrhosis with diabetes human livers were quantified. Cirrhosis significantly increased ABCC4, 5, ABCG2, and solute carrier organic anion (SLCO) 2B1 mRNA expression and decreased SLCO1B3 mRNA expression in the liver. ABCC1, 3-5, and ABCG2 protein expression was also upregulated by alcoholic cirrhosis. ABCC3-5 and ABCG2 protein expression was also upregulated in diabetic cirrhosis. Cirrhosis increased nuclear factor E2-related factor 2 mRNA expression, whereas it decreased pregnane-X-receptor and farnesoid-X-receptor mRNA expression in comparison with normal livers. Hierarchical cluster analysis indicated that expressions of ABCC2, 3, and 6; SLCO1B1 and 1B3; and ABCC4 and 5 were more closely related in the livers from this cohort. Overall, alcoholic cirrhosis altered transporter expression in human liver.

Eicosanoids in metabolic syndrome

Chronic persistent inflammation plays a significant role in disease pathology of cancer, cardiovascular disease, and metabolic syndrome (MetS). MetS is a constellation of diseases that include obesity, diabetes, hypertension, dyslipidemia, hypertriglyceridemia, and hypercholesterolemia. Nonalcoholic fatty liver disease (NAFLD) is associated with many of the MetS diseases. These metabolic derangements trigger a persistent inflammatory cascade, which includes production of lipid autacoids (eicosanoids) that recruit immune cells to the site of injury and subsequent expression of cytokines and chemokines that amplify the inflammatory response. In acute inflammation, the transcellular synthesis of antiinflammatory eicosanoids resolve inflammation, while persistent activation of the autacoid-cytokine-chemokine cascade in metabolic disease leads to chronic inflammation and accompanying tissue pathology. Many drugs targeting the eicosanoid pathways have been shown to be effective in the treatment of MetS, suggesting a common linkage between inflammation, MetS and drug metabolism. The cross-talk between inflammation and MetS seems apparent because of the growing evidence linking immune cell activation and metabolic disorders such as insulin resistance, dyslipidemia, and hypertriglyceridemia. Thus modulation of lipid metabolism through either dietary adjustment or selective drugs may become a new paradigm in the treatment of metabolic disorders. This review focuses on the mechanisms linking eicosanoid metabolism to persistent inflammation and altered lipid and carbohydrate metabolism in MetS.