Hepatic gene expression response to acute indomethacin exposure

Fish oil and indomethacin in combination potently reduce dyslipidemia and hepatic steatosis in LDLR(-/-) mice

Fish oil (FO) is a potent anti-inflammatory and lipid-lowering agent. Because inflammation can modulate lipid metabolism and vice versa, we hypothesized that combining FO with cyclooxygenase inhibitors (COXIBs), well-known anti-inflammatory drugs, can enhance the anti-inflammatory and lipid-lowering effect of FO. LDLR(-/-) mice were fed a high-fat diet supplemented with 6% olive oil or FO for 12 wk in the presence or absence of indomethacin (Indo, 6 mg/l drinking water). FO reduced plasma total cholesterol by 30% but, in combination with Indo, exerted a greater decrease (44%). The reduction of liver cholesterol ester (CE) and triglycerides (TG) by FO (63% and 41%, respectively) was enhanced by Indo (80% in CE and 64% in TG). FO + Indo greatly increased the expression of genes modulating lipid metabolism and reduced the expression of inflammatory genes compared with control. The mRNA and/or protein expression of pregnane X receptor (PXR) and cytochrome P450 isoforms that alter inflammation and/or lipid metabolism are increased to a greater extent in mice that received FO + Indo. Moroever, the nuclear level of PXR is significantly increased in FO + Indo group. Combining FO with COXIBs may exert their beneficial effects on inflammation and lipid metabolism via PXR and cytochrome P450.

Metabolomic analysis characterizes tissue specific indomethacin-induced metabolic perturbations of rats

In this study, the promising metabolomic approach integrating with ingenuity pathway analysis (IPA) was applied to characterize the tissue specific metabolic perturbation of rats that was induced by indomethacin. The selective pattern recognition analyses were applied to analyze global metabolic profiling of urine of rats treated by indomethacin at an acute dosage of reference that has been proven to induce tissue disorders in rats, evaluated throughout the time-course of -24-72 h. The results preliminarily revealed that modifications of amino acid metabolism, fatty acid metabolism and energetically associated metabolic pathways accounted for metabolic perturbation of the rats that was induced by indomethacin. Furthermore, IPA was applied to deeply analyze the biomarkers and their relations with the metabolic perturbations evidenced by pattern recognition analyses. Specific biochemical functions affected by indomethacin suggested that there is an important correlation of its effects in kidney and liver metabolism, based on the determined metabolites and their pathway-based analysis. The IPA correlation of the three major biomarkers, identified as creatinine, prostaglandin E2 and guanosine, suggested that the administration of indomethacin induced certain levels of toxicity in the kidneys and liver. The changes in the levels of biomarker metabolites allowed the phenotypical determination of the metabolic perturbations induced by indomethacin in a time-dependent manner.

Hepatic and renal toxicities of indomethacin acid, salt form and complexed forms with hydroxypropyl-β-cyclodextrin on Wistar rats after oral administration

Indomethacin (IM), a non-steroidal anti-inflammatory drug, has the capacity to induce hepatic and renal injuries when administrated systemically. The aim of this study is to assess the IM absorption from complexed forms when orally administered to rats, by means of a comparative evaluation of its capacity to induce hepatic and renal injury in different forms, namely IM acid, IM sodium salt or IM complexed with hydroxypropyl-β-cyclodextrin (HP-β-CD), using freeze- and spray-drying methods. A total of 135 Wistar rats weighing 224.4 ± 62.5 g were put into 10 groups. They were allowed free access to water but were maintained on fast for 18 h before the first administration until the end of the experiment. Water and HP-β-CD (control groups) and IM acid form, IM trihydrated-sodium-salt and IM-HP-β-CD spray- and freeze-dried, at normal and toxic doses (test groups), were orally administered once/day for 3 days. Seventy-two hours after the first administration, the animals were sacrificed and a fragment of the liver and one kidney were collected and prepared for histopathological evaluation. Lesion indexes (rated 0/4 for liver and 0/3 for kidney) were developed and the type of injury scored according to the severity of damage. A statistical analysis of the severity and incidence of lesions was carried out. Animals administered with IM complexed forms showed similar hepatic and renal lesions, both in toxic and therapeutic doses, when compared with those observed in animals administered with IM acid or salt forms. This suggests that under the present experimental conditions, IM is equally absorbed from the gastrointestinal tract, independently of the administered IM form.

Hepatic gene expression response to acute indomethacin exposure

BACKGROUND

Rising morbidity and mortality related to the use of NSAIDs has led to the withdrawal of some of these agents and reconsideration of the adverse effects and usage paradigms of commonly available NSAIDs. Our objective in this study was to assay molecular indicators of acute hepatic injury associated with the administration of indomethacin, a prototypical NSAID, metabolized by the liver that undergoes enterohepatic circulation with associated gastrointestinal adverse effects.

METHODS

Analysis of gene expression, using high-throughput, ADME (absorption, distribution, metabolism, excretion)-specific microarrays, was performed on RNA extracted from the livers of control or indomethacin treated rats, in parallel with serum enzyme tests and histological analysis of paraffin-embedded liver specimens. Male Sprague-Dawley rats (n = 45) were administered intraperitoneal injections of indomethacin for 3 days at the recommended normal dose (6.7 mg/kg), indomethacin at a high dose (20 mg/kg) or vehicle alone (controls).

RESULTS

Upon termination of the study on day 4, serum gamma-glutamyl transferase activity and alkaline phosphatase/alanine aminotransferase ratios were significantly elevated in both high- and normal-dose cohorts compared with vehicle-treated animals. Diffuse microvascular steatosis was present in hepatic serial sections obtained from all animals subjected to the high-dosage regimen. High-resolution microarray analysis (six replicates/gene/animal) identified 256 genes, after outlier removal, in 17 functional classifications that were significantly altered by the high, but not by the normal dosage. These included depression of 10 of 11 cytochrome P450 genes (2B3, 2C70, 1A2-P2, 4F1, 2E1, 3A1, 2F1, 3AP7, 2C11, phenobarb-inducible P6) and 7 of 9 genes involved in the response to reactive oxygen species (e.g. glutathione reductase, glutathione transferase, and superoxide dismutase). Of 16 genes associated with toxin removal, nine exhibited significantly decreased transcripts. There was a marked shift away from lipid metabolism (decreased expression of eight genes) towards glucose utilization associated with steatosis. Despite the compromise of detoxification programs and a shift in metabolic substrate utilization, a compensatory remodeling response was activated, including genes for metalloproteases (ADAM10, MMP10, MMP11), integrins (integrin alpha-1 and alpha-E1), and extracellular matrix molecules (platelet/endothelial cell adhesion molecule-1 and heparan sulfate proteoglycan, perlecan), as well as transcripts associated with cell proliferation. The expression levels of only five genes were significantly altered among animals receiving the normal indomethacin dosage.

CONCLUSION

These data confirmed that even brief exposure to indomethacin altered serum enzymatic activities and that high levels significantly altered gene expression in the liver and hepatic histology (by interfering with the clearance of toxins and xenobiotic substrates) and the regulation of basal metabolism.