Soluble Epoxide Hydrolase Activity Research Articles

Determinants of Meal-Induced Changes in Circulating FFA Epoxides, Diols, and Diol-to-Epoxide Ratios as Indices of Soluble Epoxide Hydrolase Activity.

Soluble epoxide hydrolase (sEH) is an important enzyme for metabolic and cardiovascular health. sEH converts FFA epoxides (EpFAs), many of which are regulators of various cellular processes, to biologically less active diols. In human studies, diol (sEH product) to EpFA (sEH substrate) ratios in plasma or serum have been used as indices of sEH activity. We previously showed these ratios profoundly decreased in rats during acute feeding, possibly reflecting decreases in tissue sEH activities. The present study was designed to test which tissue(s) these measurements in the blood represent and if factors other than sEH activity, such as renal excretion or dietary intake of EpFAs and diols, significantly alter plasma EpFAs, diols, and/or their ratios. The results show that postprandial changes in EpFAs and diols and their ratios in plasma were very similar to those observed in the liver but not in other tissues, suggesting that the liver is largely responsible for these changes in plasma levels. EpFAs and diols were excreted into the urine, but their levels were not significantly altered by feeding, suggesting that renal excretion of EpFAs and diols may not play a major role in postprandial changes in circulating EpFAs, diols, or their ratios. Diet intake had significant impacts on circulating EpFA and diol levels but not on diol-to-EpFA (D-to-E) ratios, suggesting that these ratios, reflecting sEH activities, may not be significantly affected by the availability of sEH substrates (i.e., EpFAs). In conclusion, changes in FFA D-to-E ratios in plasma may reflect those in the liver, which may in turn represent sEH activities in the liver, and they may not be significantly affected by renal excretion or the dietary intake of EpFAs and diols.

Anti-inflammatory of disenecionyl cis-khellactone in LPS-stimulated RAW264.7 cells and the its inhibitory activity on soluble epoxide hydrolase

The objective of the present study was to investigate anti-inflammatory effects of disenecionyl cis-khellactone (DK) isolated from Peucedanum japonicum Thunberg, a traditional edible plant, in RAW264.7 cells stimulated with lipopolysaccharide (LPS). Anti-inflammatory effects of DK were analyzed using various techniques, including NO assay, Western blot analysis, enzyme-linked immunosorbent assay (ELISA), real-time PCR, and immunofluorescence staining. It was revealed that DK reduced the production of pro-inflammatory cytokines including Monocyte chemoattractant protein-1 (MCP-1), Tumor necrosis factor-α (TNF-α), Interleukin 1β (IL-1β), and Interleukin 6 (IL-6) in RAW264.7 cells stimulated with LPS. It was revealed that DK effectively downregulated expression levels of iNOS and COX-2 due to inhibition of NF-κB activation and suppressing the phosphorylation of p38 and jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) phosphorylation. Also, soluble epoxide hydrolase activity and expression were decreased by the proinflammatory inhibitor, DK. Finally, findings of this study suggest that DK isolated from P. japonicum might have potential as a therapeutic candidate for inflammatory diseases.

Hepatic soluble epoxide hydrolase activity regulates cerebral Aβ metabolism and the pathogenesis of Alzheimer’s disease in mice

Alzheimer's disease (AD) is caused by a complex interaction between genetic and environmental factors. However, how the role of peripheral organ changes in response to environmental stimuli during aging in AD pathogenesis remains unknown. Hepatic soluble epoxide hydrolase (sEH) activity increases with age. Hepatic sEH manipulation bidirectionally attenuates brain amyloid-β (Aβ) burden, tauopathy, and cognitive deficits in AD mouse models. Moreover, hepatic sEH manipulation bidirectionally regulates the plasma level of 14,15-epoxyeicosatrienoic acid (-EET), which rapidly crosses the blood-brain barrier and modulates brain Aβ metabolism through multiple pathways. A balance between the brain levels of 14,15-EET and Aβ is essential for preventing Aβ deposition. In AD models, 14,15-EET infusion mimicked the neuroprotective effects of hepaticsEH ablation at biological and behavioral levels. These results highlight the liver's key role in AD pathology,and targeting the liver-brain axis in response to environmental stimuli may constitute a promising therapeutic approach for AD prevention.

Effects of Individual Circulating FFAs on Plasma and Hepatic FFA Epoxides, Diols, and Epoxide-Diol Ratios as Indices of Soluble Epoxide Hydrolase Activity.

Oxylipins, oxidation products of unsaturated free fatty acids (FFAs), are involved in various cellular signaling systems. Among these oxylipins, FFA epoxides are associated with beneficial effects in metabolic and cardiovascular health. FFA epoxides are metabolized to diols, which are usually biologically less active, by soluble epoxide hydrolase (sEH). Plasma epoxide-diol ratios have been used as indirect measures of sEH activity. This study was designed to examine the effects of acute elevation of individual plasma FFAs on a variety of oxylipins, particularly epoxides, diols, and their ratios. We tested if FFA epoxide-diol ratios are altered by circulating FFA levels (i.e., substrate availability) independent of sEH activity. Wistar rats received a constant intravenous infusion of olive (70% oleic acid (OA)), safflower seed (72% linoleic acid (LA)), and fish oils (rich in ω-3 FFAs) as emulsions to selectively raise OA, LA, and ω-3 FFAs (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), respectively. As expected, olive, safflower seed, and fish oil infusions selectively raised plasma OA (57%), LA (87%), EPA (70%), and DHA (54%), respectively (p < 0.05 for all). Raising plasma FFAs exerted substrate effects to increase hepatic and plasma epoxide and diol levels. These increases in epoxides and diols occurred to similar extents, resulting in no significant changes in epoxide-diol ratios. These data suggest that epoxide-diol ratios, often used as indices of sEH activity, are not affected by substrate availability or altered plasma FFA levels and that epoxide-diol ratios may be used to compare sEH activity between conditions of different circulating FFA levels.

Enhancement of the liver’s neuroprotective role ameliorates traumatic brain injury pathology

Traumatic brain injury (TBI) is a pervasive problem worldwide for which no effective treatment is currently available. Although most studies have focused on the pathology of the injured brain, we have noted that the liver plays an important role in TBI. Using two mouse models of TBI, we found that the enzymatic activity of hepatic soluble epoxide hydrolase (sEH) was rapidly decreased and then returned to normal levels following TBI, whereas such changes were not observed in the kidney, heart, spleen, or lung. Interestingly, genetic downregulation of hepatic Ephx2 (which encodes sEH) ameliorates TBI-induced neurological deficits and promotes neurological function recovery, whereas overexpression of hepatic sEH exacerbates TBI-associated neurological impairments. Furthermore, hepatic sEH ablation was found to promote the generation of A2 phenotype astrocytes and facilitate the production of various neuroprotective factors associated with astrocytes following TBI. We also observed an inverted V-shaped alteration in the plasma levels of four EET (epoxyeicosatrienoic acid) isoforms (5,6-, 8,9-,11,12-, and 14,15-EET) following TBI which were negatively correlated with hepatic sEH activity. However, hepatic sEH manipulation bidirectionally regulates the plasma levels of 14,15-EET, which rapidly crosses the blood-brain barrier. Additionally, we found that the application of 14,15-EET mimicked the neuroprotective effect of hepatic sEH ablation, while 14,15-epoxyeicosa-5(Z)-enoic acid blocked this effect, indicating that the increased plasma levels of 14,15-EET mediated the neuroprotective effect observed after hepatic sEH ablation. These results highlight the neuroprotective role of the liver in TBI and suggest that targeting hepatic EET signaling could represent a promising therapeutic strategy for treating TBI.

Aflatoxin B1 Increases Soluble Epoxide Hydrolase in the Brain and Induces Neuroinflammation and Dopaminergic Neurotoxicity.

Parkinson's disease (PD) is an increasingly common neurodegenerative movement disorder with contributing factors that are still largely unexplored and currently no effective intervention strategy. Epidemiological and pre-clinical studies support the close association between environmental toxicant exposure and PD incidence. Aflatoxin B1 (AFB1), a hazardous mycotoxin commonly present in food and environment, is alarmingly high in many areas of the world. Previous evidence suggests that chronic exposure to AFB1 leads to neurological disorders as well as cancer. However, whether and how aflatoxin B1 contributes to the pathogenesis of PD is poorly understood. Here, oral exposure to AFB1 is shown to induce neuroinflammation, trigger the α-synuclein pathology, and cause dopaminergic neurotoxicity. This was accompanied by the increased expression and enzymatic activity of soluble epoxide hydrolase (sEH) in the mouse brain. Importantly, genetic deletion or pharmacological inhibition of sEH alleviated the AFB1-induced neuroinflammation by reducing microglia activation and suppressing pro-inflammatory factors in the brain. Furthermore, blocking the action of sEH attenuated dopaminergic neuron dysfunction caused by AFB1 in vivo and in vitro. Together, our findings suggest a contributing role of AFB1 to PD etiology and highlight sEH as a potential pharmacological target for alleviating PD-related neuronal disorders caused by AFB1 exposure.

Inhibiting the phosphatase activity of soluble epoxide hydrolase attenuates chronic kidney disease-induced calcific aortic valve disease in rats

Calcific aortic valve disease (CAVD) is the most frequent valvulopathy ultimaltely leading to aortic stenosis, one of the driving causes of an increased morbidity and mortality in aging and in patients with chronic kidney disease (CKD). Up to date, there is no available pharmacological treatment to prevent the development and progression of CAVD. Previous studies suggested that the bifunctional enzyme, soluble epoxide hydrolase (sEH), is involved in the regulation of cardiovascular calcification development. Our study aimed to investigate whether the phosphatase activity of sEH is involved in CAVD. Sprague Dawley sEH-P knocking rats (sEH-P KI) were generated using CRISPR/Cas9 method. Eighteen-week-old WT and sEH-P KI rats underwent subtotal nephrectomy (5/6Nx) to mimic CKD. These animals were afterword fed with a high-phosphate chow diet (1.8% phosphorus). In parallel, sham-operated animals on a standard diet (0.9% total phosphorus) served as controls. Twelve weeks after surgery, renal and cardiac parameters were determined and histological analysis of aortic valves was performed. Twelve weeks after surgery, the development of renal dysfunction in 5/6Nx + phosphate WT rats was shown by the augmentation in plasma creatinine and urea nitrogen concentrations and the decline in estimated glomerular filtration rate compared to sham-operated WT rats. These animals also displayed anemia, polyuria and polydipsia. The genetic inhibition of sEH-P did not allow to prevent these alterations. However, inhibiting sEH-P limited hydroxyapatite crystals deposition in the aortic valve of 5/6Nx + phosphate rats compared to 5/6Nx + phosphate WT rats (Fig. 1B, C), associated with a prevention of the decrease in intercusp distance and of the increase in aortic valve mean pressure gradient and in peak aortic valve velocity (Fig. 1A). In addition, left-ventricular diastolic (E/e′) and systolic dysfunction (fractional shortening) as well as cardiac fibrosis were prevented by sEH-P inhibition. Additional experiments on recombinant human and rat sEH allowed to demonstrate that sEH-P metabolizes pyrophosphate anions (PPi), a potent inhibitor of cardiovascular calcification, and that PPi degradation is efficiently prevented by sEH-P inhibition. Taking altogether, these results demonstrate that inhibition of sEH-P prevents aortic valve calcification and its hemodynamical consequences in the 5/6Nx + phosphate rat model, and may serve as a potential therapeutic strategy for the treatment of CAVD.

Inhibition of Soluble Epoxide Hydrolase Activity by Components of Glycyrrhiza uralensis

Soluble epoxide hydrolase (sEH) is a target enzyme for the treatment of inflammation and cardiovascular disease. A Glycyrrhiza uralensis extract exhibited ~50% inhibition of sEH at 100 μg/mL, and column chromatography yielded compounds 1-11. Inhibitors 1, 4-6, 9, and 11 were non-competitive; inhibitors 3, 7, 8, and 10 were competitive. The IC50 value of inhibitor 10 was below 2 μM. Molecular simulation was used to identify the sEH binding site. Glycycoumarin (10) requires further evaluation in cells and animals.

Correction to: Increased Soluble Epoxide Hydrolase Activity Positively Correlates with Mortality in Heart Failure Patients with Preserved Ejection Fraction: Evidence from Metabolomics

Correction to: Increased Soluble Epoxide Hydrolase Activity Positively Correlates with Mortality in Heart Failure Patients with Preserved Ejection Fraction: Evidence from Metabolomics

Increased Soluble Epoxide Hydrolase Activity Positively Correlates with Mortality in Heart Failure Patients with Preserved Ejection Fraction: Evidence from Metabolomics.

The online version contains supplementary material available at 10.1007/s43657-022-00069-8.

Plasma Oxylipins and Their Precursors Are Strongly Associated with COVID-19 Severity and with Immune Response Markers.

COVID-19 is characterised by a dysregulated immune response, that involves signalling lipids acting as mediators of the inflammatory process along the innate and adaptive phases. To promote understanding of the disease biochemistry and provide targets for intervention, we applied a range of LC-MS platforms to analyse over 100 plasma samples from patients with varying COVID-19 severity and with detailed clinical information on inflammatory responses (>30 immune markers). The second publication in a series reports the results of quantitative LC-MS/MS profiling of 63 small lipids including oxylipins, free fatty acids, and endocannabinoids. Compared to samples taken from ward patients, intensive care unit (ICU) patients had 2–4-fold lower levels of arachidonic acid (AA) and its cyclooxygenase-derived prostanoids, as well as lipoxygenase derivatives, exhibiting negative correlations with inflammation markers. The same derivatives showed 2–5-fold increases in recovering ward patients, in paired comparison to early hospitalisation. In contrast, ICU patients showed elevated levels of oxylipins derived from poly-unsaturated fatty acids (PUFA) by non-enzymatic peroxidation or activity of soluble epoxide hydrolase (sEH), and these oxylipins positively correlated with markers of macrophage activation. The deficiency in AA enzymatic products and the lack of elevated intermediates of pro-resolving mediating lipids may result from the preference of alternative metabolic conversions rather than diminished stores of PUFA precursors. Supporting this, ICU patients showed 2-to-11-fold higher levels of linoleic acid (LA) and the corresponding fatty acyl glycerols of AA and LA, all strongly correlated with multiple markers of excessive immune response. Our results suggest that the altered oxylipin metabolism disrupts the expected shift from innate immune response to resolution of inflammation.

Inhibiting the phosphatase activity of soluble epoxide hydrolase reduces arterial calcification and prevents the cardiovascular complications of chronic kidney disease

Increasing evidence suggests that the bifunctional soluble epoxide hydrolase (sEH) regulates vascular calcification. This study addressed the hypothesis that the phosphatase activity of soluble epoxide hydrolase (sEH-P) is involved in this regulation. We carefully assessed the impact of sEH-P inhibition on aortic calcification using genetic and pharmacological approaches and explored the putative mechanism involved. Pharmacological and genetic inhibition of sEH-P reduced the increase in calcium deposition in rat aortic rings cultured in high-phosphate conditions. This was associated with a decreased mRNA expression of the osteochondrogenic marker Msx2 and Sox9. The deendothelialization of aortic rings abolished this anti-calcifying effect and the calcification of human aortic smooth muscle cells was not affected by sEH-P inhibition, suggesting a major role of the endothelium. Endothelial NO release appeared not involved since the level of its metabolite nitrite was not increased during sEH-P inhibition and the inhibition of NO-synthase did not prevent the anti-calcifying effect of sEH-P inhibition. However, an increased level of the calcification inhibitor pyrophosphate anions (PPi) was observed in the culture supernatant of aortic rings when sEH-P is inhibited and in vitro experiments demonstrated that PPi is released by human aortic endothelial cells and can be metabolized by sEH-P. In addition, the blockade of PPARγ, which mediate the intracellular effect of the sEH metabolites lysophosphatidic acids, prevented the anti-calcifying effect of sEH-P inhibition. Finally, the aortic calcification associated with chronic kidney disease induced by subtotal nephrectomy was reduced in sEH-P-deficient rats compared with wild-type rats. This was associated with a prevention of the development of hypertension, vascular dysfunction, cardiac hypertrophy and dysfunction. These results show that the inhibition of sEH-P prevents the development of vascular calcification by reducing the degradation of PPi and represents a promising therapeutic approach to limit the development of the cardiovascular complications of patients with chronic kidney disease.

Inhibiting the phosphatase activity of soluble epoxide hydrolase reduces arterial calcification and prevents the cardiovascular complications of chronic kidney disease

Increasing evidence suggests that the bifunctional soluble epoxide hydrolase (sEH) regulates vascular calcification. This study addressed the hypothesis that the phosphatase activity of soluble epoxide hydrolase (sEH-P) is involved in this regulation. We carefully assessed the impact of sEH-P inhibition on aortic calcification using genetic and pharmacological approaches and explored the putative mechanism involved. Pharmacological and genetic inhibition of sEH-P reduced the increase in calcium deposition in rat aortic rings cultured in high-phosphate conditions. This was associated with a decreased mRNA expression of the osteochondrogenic marker Msx2 and Sox9. The deendothelialization of aortic rings abolished this anti-calcifying effect and the calcification of human aortic smooth muscle cells was not affected by sEH-P inhibition, suggesting a major role of the endothelium. Endothelial NO release appeared not involved since the level of its metabolite nitrite was not increased during sEH-P inhibition and the inhibition of NO-synthase did not prevent the anti-calcifying effect of sEH-P inhibition. However, an increased level of the calcification inhibitor pyrophosphate anions (PPi) was observed in the culture supernatant of aortic rings when sEH-P is inhibited and in vitro experiments demonstrated that PPi is released by human aortic endothelial cells and can be metabolized by sEH-P. In addition, the blockade of PPARγ, which mediate the intracellular effect of the sEH metabolites lysophosphatidic acids, prevented the anti-calcifying effect of sEH-P inhibition. Finally, the aortic calcification associated with chronic kidney disease induced by subtotal nephrectomy was reduced in sEH-P-deficient rats compared with wild-type rats. This was associated with a prevention of the development of hypertension, vascular dysfunction, cardiac hypertrophy and dysfunction. These results show that the inhibition of sEH-P prevents the development of vascular calcification by reducing the degradation of PPi and represents a promising therapeutic approach to limit the development of the cardiovascular complications of patients with chronic kidney disease.

Chronic exposure to traffic-related air pollution reduces lipid mediators of linoleic acid and soluble epoxide hydrolase in serum of female rats

Chronic exposure to traffic-related air pollution (TRAP) is known to promote systemic inflammation, which is thought to underlie respiratory, cardiovascular, metabolic and neurological disorders. It is not known whether chronic TRAP exposure dampens inflammation resolution, the homeostatic process for stopping inflammation and repairing damaged cells. In vivo, inflammation resolution is facilitated by bioactive lipid mediators known as oxylipins, which are derived from the oxidation of polyunsaturated fatty acids. To understand the effects of chronic TRAP exposure on lipid-mediated inflammation resolution pathways, we measured total (i.e. free+bound) pro-inflammatory and pro-resolving lipid mediators in serum of female rats exposed to TRAP or filtered air (FA) for 14 months. Compared to rats exposed to FA, TRAP-exposed rats showed a significant 36–48% reduction in fatty acid alcohols, specifically, 9-hydroxyoctadecadienoic acid (9-HODE), 11,12-dihydroxyeicosatetraenoic acid (11,12-DiHETE) and 16,17-dihydroxydocosapentaenoic acid (16, 17-DiHDPA). The decrease in fatty acid diols (11,12-DiHETE and 16, 17-DiHDPA) corresponded to a significant 34–39% reduction in the diol to epoxide ratio, a marker of soluble epoxide hydrolase activity; this enzyme is typically upregulated during inflammation. The findings demonstrate that 14 months exposure to TRAP reduced pro-inflammatory 9-HODE concentration and dampened soluble epoxide hydrolase activation, suggesting adaptive immune changes in lipid mediator pathways involved in inflammation resolution.

Effects of Individual Circulating FFAs on Plasma Oxylipin Levels: Implications for FFA Epoxide‐diol Ratios as Indices of Soluble Epoxide Hydrolase Activity

Oxylipins, oxidation products of essential free fatty acids (FFAs), are involved in various cellular signaling. Among them, FFA epoxides are associated with beneficial effects in metabolic and cardiovascular health. FFA epoxides are metabolized to usually biologically less active diols by soluble epoxide hydrolase (sEH). Inhibition of sEH, which increases FFA epoxides, improves glucose homeostasis and cardiovascular health. Plasma epoxide‐diol ratios have been used as indices of sEH activity.Objective and HypothesisThe objective of this study was to examine the effects of acute elevation of plasma FFAs on oxylipins, particularly, epoxides, diols, and their ratios. We tested if FFA epoxide‐diol ratios are altered by circulating FFA levels (i.e., substrate availability) independent of sEH activity.MethodsMale Wistar rats received a constant intravenous infusion of olive (70% oleic acid [OA]), safflower seed (72% linoleic acid [LA]), and fish (rich in w‐3 FFAs) oils (20% wt/vol emulsion, 0.5 ml/h; n = 6 for each infusion) for 2 hours to selectively raise OA, LA, and w‐3 FFAs (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]), respectively. Blood samples were collected before and after the infusions and analyzed for oxylipins using LC‐MS and individual FFAs using GC‐MS. As LA, DHA, and EPA are metabolized to epoxides and diols, we evaluated their mass‐action effects to alter epoxides, diols, or their ratios. In contrast, OA is not metabolized to epoxides and diols detected in our assays, and the olive oil infusion served as control for any non‐mass‐action effects.ResultsAs expected, olive, safflower seed, and fish oil infusions selectively raised plasma OA (57%), LA (87%), and EPA (70%) and DHA (54%), respectively (P &lt; 0.05 for all). Interestingly, olive oil infusion had significant effects to decrease FFA epoxides and diols with more dramatic effects on epoxides than diols (P &lt; 0.01), resulting in large (up to 6‐fold) increases in diol‐to‐epoxide ratios. We found similar effects with safflower seed and fish oil infusions, although these infusions also showed mass action effects to increase epoxide and diol levels derived from LA (safflower seed oil) and DHA and EPA (fish oil). The decreases in FFA epoxides with acute elevation of circulating FFAs (i.e., increased substrate availability) were unexpected and appeared to be due to increased epoxide metabolism independent of sEH. We are currently examining the possibility that acute elevation of plasma FFAs stimulates glucuronidation of FFA epoxides to increase their removal via urinary excretion.ConclusionsRaising plasma FFAs has profound effects to decrease plasma FFA epoxides, significantly altering plasma epoxide‐diol ratios. These data suggest that caution should be taken in comparing epoxide‐diol ratios, as indices of sEH activity, between conditions with different circulating FFA levels. Our data also suggest that plasma FFAs regulate epoxide levels by stimulating a metabolic process independent of sEH, possibly glucuronidation followed by renal excretion.

CRISPR/Cas9-mediated inactivation of the phosphatase activity of soluble epoxide hydrolase prevents obesity and cardiac ischemic injury

IntroductionAlthough the physiological role of the C-terminal hydrolase domain of the soluble epoxide hydrolase (sEH-H) is well investigated, the function of its N-terminal phosphatase activity (sEH-P) remains unknown. ObjectivesThis study aimed to assess in vivo the physiological role of sEH-P. MethodsCRISPR/Cas9 was used to generate a novel knock-in (KI) rat line lacking the sEH-P activity. ResultsThe sEH-P KI rats has a decreased metabolism of lysophosphatidic acids to monoacyglycerols. KI rats grew almost normally but with less weight and fat mass gain while insulin sensitivity was increased compared to wild-type rats. This lean phenotype was more marked in males than in female KI rats and mainly due to decreased food consumption and enhanced energy expenditure. In fact, sEH-P KI rats had an increased lipolysis allowing to supply fatty acids as fuel to potentiate brown adipose thermogenesis under resting condition and upon cold exposure. The potentiation of thermogenesis was abolished when blocking PPARγ, a nuclear receptor activated by intracellular lysophosphatidic acids, but also when inhibiting simultaneously sEH-H, showing a functional interaction between the two domains. Furthermore, sEH-P KI rats fed a high-fat diet did not gain as much weight as the wild-type rats, did not have increased fat mass and did not develop insulin resistance or hepatic steatosis. In addition, sEH-P KI rats exhibited enhanced basal cardiac mitochondrial activity associated with an enhanced left ventricular contractility and were protected against cardiac ischemia–reperfusion injury. ConclusionOur study reveals that sEH-P is a key player in energy and fat metabolism and contributes together with sEH-H to the regulation of cardiometabolic homeostasis. The development of pharmacological inhibitors of sEH-P appears of crucial importance to evaluate the interest of this promising therapeutic strategy in the management of obesity and cardiac ischemic complications.

Plasma Oxylipin Profile Discriminates Ethnicities in Subjects with Non-Alcoholic Steatohepatitis: An Exploratory Analysis.

Non-alcoholic fatty liver disease (NAFLD) is a common liver pathology that includes steatosis, or non-alcoholic fatty liver (NAFL), and non-alcoholic steatohepatitis (NASH). Without a clear pathophysiological mechanism, it affects Hispanics disproportionately compared to other ethnicities. Polyunsaturated fatty acids (PUFAs) and inflammatory lipid mediators including oxylipin (OXL) and endocannabinoid (eCB) are altered in NAFLD and thought to contribute to its pathogenesis. However, the existence of ethnicity-related differences is not clear. We employed targeted lipidomic profiling for plasma PUFAs, non-esterified OXLs and eCBs in White Hispanics (HIS, n = 10) and Caucasians (CAU, n = 8) with biopsy-confirmed NAFL, compared with healthy control subjects (HC; n = 14 HIS; n = 8 CAU). NAFLD was associated with diminished long chain PUFA in HIS, independent of histological severity. Differences in plasma OXLs and eCBs characterized ethnicities in NASH, with lower arachidonic acid derived OXLs observed in HIS. The secondary analysis comparing ethnicities within NASH (n = 12 HIS; n = 17 CAU), confirms these ethnicity-related differences and suggests lower lipoxygenase(s) and higher soluble epoxide hydrolase(s) activities in HIS compared to CAU. While causes are not clear, these lipidomic differences might be with implications for NAFLD severity and are worth further investigation. We provide preliminary data indicating ethnicity-specific lipidomic signature characterizes NASH which requires further validation.

Hemodialysis and Plasma Oxylipin Biotransformation in Peripheral Tissue.

Factors causing the increased cardiovascular morbidity and mortality in hemodialysis (HD) patients are largely unknown. Oxylipins are a superclass of lipid mediators with potent bioactivities produced from oxygenation of polyunsaturated fatty acids. We previously assessed the impact of HD on oxylipins in arterial blood plasma and found that HD increases several oxylipins. To study the phenomenon further, we now evaluated the differences in arterial and venous blood oxylipins from patients undergoing HD. We collected arterial and venous blood samples in upper extremities from 12 end-stage renal disease (ESRD) patients before and after HD and measured oxylipins in plasma by LC-MS/MS tandem mass spectrometry. Comparison between cytochrome P450 (CYP), lipoxygenase (LOX), and LOX/CYP ω/(ω-1)-hydroxylase metabolites levels from arterial and venous blood showed no arteriovenous differences before HD but revealed arteriovenous differences in several CYP metabolites immediately after HD. These changes were explained by metabolites in the venous blood stream of the upper limb. Decreased soluble epoxide hydrolase (sEH) activity contributed to the release and accumulation of the CYP metabolites. However, HD did not affect arteriovenous differences of the majority of LOX and LOX/CYP ω/(ω-1)-hydroxylase metabolites. The HD treatment itself causes changes in CYP epoxy metabolites that could have deleterious effects in the circulation.

Liquisolid Compact Technique for the Enhancement of Solubility and Dissolution Rate of Ambrisentan: Quality by Design Approach

Soluble epoxide hydrolase inhibitors have been reported as antihypertensive, anti-inflammatory, antiulcer and anticancer actions and protect the brain, heart and kidney from damage. Exploring soluble epoxide hydrolase inhibition activity of traditional medicinal plants helps to uncover the new target to treat various complications associated with inflammatory mediators. The present study was planned to explore soluble epoxide hydrolase inhibition activity of fifty medicinal plants commonly used in the traditional medicinal system. The dried plant material of each species was grounded into a coarse powder and separately macerated with absolute methanol and ethyl acetate for 7 d. Then the solvents were evaporated and obtained extracts were solubilized in dimethyl sulfoxide (10 mg/ml) and soluble epoxide hydrolase enzyme inhibitory potencies were evaluated using a fluorescent reporting system. Moreover, preliminary phytochemical screening and high-performance thin layer chromatography analysis were carried out for two extracts that showed potent soluble epoxide hydrolase inhibition activities. The results revealed that 10 methanolic extracts and 20 ethyl acetate extracts were potentially effective in suppressing soluble epoxide hydrolase activity with inhibitory concentration value of less than 10 μg/ml. Among the 30 potentially effective plants, four seed extracts (Celastrus paniculatus, Nigella sativa, Wrightia tinctorial, Vernonia anthhelmintica and Embelia ribes), one leaves extracts (Bergera koengii), one rhizome extracts (Curcuma longa) and one root extracts (Vetiveria zizanioides) were common in both methanolic and ethyl acetate extract. In conclusion, the study report suggests that various natural products used in the traditional medicinal system have many promising soluble epoxide hydrolase inhibitors. Methanolic extracts of seeds of Celastrus paniculatus and Nigella sativa have potent soluble epoxide hydrolase inhibition activities. Further research is warranted to identify a greater number of medicinal plants and active principles responsible for soluble epoxide hydrolase inhibition activities

Evaluation of Soluble Epoxide Hydrolase Inhibition Activity of 50 Traditional Medicinal Plants: Exploring Old Drugs for the New Pharmacological Target

Soluble epoxide hydrolase inhibitors have been reported as antihypertensive, anti-inflammatory, antiulcer and anticancer actions and protect the brain, heart and kidney from damage. Exploring soluble epoxide hydrolase inhibition activity of traditional medicinal plants helps to uncover the new target to treat various complications associated with inflammatory mediators. The present study was planned to explore soluble epoxide hydrolase inhibition activity of fifty medicinal plants commonly used in the traditional medicinal system. The dried plant material of each species was grounded into a coarse powder and separately macerated with absolute methanol and ethyl acetate for 7 d. Then the solvents were evaporated and obtained extracts were solubilized in dimethyl sulfoxide (10 mg/ml) and soluble epoxide hydrolase enzyme inhibitory potencies were evaluated using a fluorescent reporting system. Moreover, preliminary phytochemical screening and high-performance thin layer chromatography analysis were carried out for two extracts that showed potent soluble epoxide hydrolase inhibition activities. The results revealed that 10 methanolic extracts and 20 ethyl acetate extracts were potentially effective in suppressing soluble epoxide hydrolase activity with inhibitory concentration value of less than 10 μg/ml. Among the 30 potentially effective plants, four seed extracts (Celastrus paniculatus, Nigella sativa, Wrightia tinctorial, Vernonia anthhelmintica and Embelia ribes), one leaves extracts (Bergera koengii), one rhizome extracts (Curcuma longa) and one root extracts (Vetiveria zizanioides) were common in both methanolic and ethyl acetate extract. In conclusion, the study report suggests that various natural products used in the traditional medicinal system have many promising soluble epoxide hydrolase inhibitors. Methanolic extracts of seeds of Celastrus paniculatus and Nigella sativa have potent soluble epoxide hydrolase inhibition activities. Further research is warranted to identify a greater number of medicinal plants and active principles responsible for soluble epoxide hydrolase inhibition activities