4-phenylbutyric acid improves sepsis-induced cardiac dysfunction by modulating amino acid metabolism and lipid metabolism via Comt/Ptgs2/Ppara.

INTRODUCTION: Cardiac dysfunction after sepsis the most common and severe sepsis-related organ failure. The severity of cardiac damage in sepsis patients was positively associated to mortality. It is important to look for drugs targeting sepsis-induced cardiac damage. Our previous studies found that 4-phenylbutyric acid (PBA) was beneficial to septic shock by improving cardiovascular function and survival, while the specific mechanism is unclear. OBJECTIVES: We aimed to explore the specific mechanism and PBA for protecting cardiac function in sepsis. METHODS: The cecal ligation and puncture-induced septic shock models were used to observe the therapeutic effects of PBA on myocardial contractility and the serum levels of cardiac troponin-T. The mechanisms of PBA against sepsis were explored by metabolomics and network pharmacology. RESULTS: The results showed that PBA alleviated the sepsis-induced cardiac damage. The metabolomics results showed that there were 28 metabolites involving in the therapeutic effects of PBA against sepsis. According to network pharmacology, 11 hub genes were found that were involved in lipid metabolism and amino acid transport following PBA treatment. The further integrated analysis focused on 7 key targets, including Comt, Slc6a4, Maoa, Ppara, Pparg, Ptgs2 and Trpv1, as well as their core metabolites and pathways. In an in vitro assay, PBA effectively inhibited sepsis-induced reductions in Comt, Ptgs2 and Ppara after sepsis. CONCLUSIONS: PBA protects sepsis-induced cardiac injury by targeting Comt/Ptgs2/Ppara, which regulates amino acid metabolism and lipid metabolism. The study reveals the complicated mechanisms of PBA against sepsis.

Opicapone for Parkinson's disease: clinical evidence and future perspectives.

Since 2016, opicapone (OPC), a potent third-generation, long-acting, once-daily, peripheral catechol-O-methyltransferase inhibitor, is approved as an add-on to levodopa in Parkinson's disease patients with motor fluctuations. OPC 50 mg has showed to be able in reducing OFF time by an average of about 60 min daily compared with placebo, to further reduce OFF-time of about 39 min, when switched from ENT to OPC and to be safe. These beneficial effects of OPC were maintained for 1 year. Recently, several post hoc analysis and few pilot observational open-label studies, have suggested its efficacy and wider applicability for different phenotypes of motor complications and for Parkinson's disease stages. Here we review OPC applicability and perspectives, in the light of the more recently published analysis.

Lay abstract Opicapone (OPC) is a recently marketed drug for treatment of Parkinson's disease. It has been approved in Europe in 2016 and it is currently available in several countries, including Italy, Germany, Portugal, Spain, UK, Japan and US. The clinical indication of OPC is the presence of 'OFF-period', that means moments during which anti-parkinsonian medications are not doing effect and tremor or slowness are coming out. OPC is used in co-administration with levodopa, at night, once a daily. OPC does not slow the progression of the disease but can reduce of 1 h/day the 'OFF periods'. It is well tolerated. It can be taken in concomitant with other anti-parkinsonian medications, but it can be required to readapt the dose of levodopa.

Possible synergies between isatin, an endogenous MAO inhibitor, and antiparkinsonian agents on the dopamine release from striatum of freely moving rats.

Isatin is an endogenous indole that inhibits monoamine oxidase (MAO). When exogenously administered, it increases the striatal dopamine and acetylcholine levels and presents neuroprotective effects in the brain. Previous studies show that intrastriatal administration of isatin increased the in vivo dopamine release from striatum in a concentration-dependent form. In the present work, we investigated the effects of combined administration of isatin together with other substances actually used in antiparkinsonian pharmacotherapy on in vivo dopamine overflow. For this, we co-administered isatin with the MAO inhibitors selegiline and clorgyline, l-DOPA, the catechol-o-methyl-transferase (COMT) inhibitors tropolone and dinitrocatechol, with the dopaminergic agonist ropinirole, and with the psychostimulant caffeine, in order to evaluate possible synergies between these substances to increase the dopamine extracellular levels in freely moving rats. Intrastriatal administration of isatin (10 mM, 60 min) significantly increased dopamine release to 1164 ± 152%, compared to the baseline. Co-administration of isatin together with selegiline (1 mM) or clorgyline (1 mM) alone or in combinations showed a similar profile to increase in vivo dopamine release. Intrastriatal infusion of isatin together with antiparkinsonian drugs l-DOPA (25 µM), tropolone (1 mM), dinitrocatechol (100 µM), amantadine (5 mM) and caffeine (5 mM) significantly elevated extracellular dopamine levels more than any single drug, showing a good neurochemical synergy by improving the effect of isatin on the extracellular dopamine levels in the striatum. Infusion of isatin + ropinirole (5 mM) did not change the isatin-induced increase in dopamine overflow. These results could be useful to carry out further investigations with a possible clinical application.

Mice exposed to maternal androgen excess and diet-induced obesity have altered phosphorylation of catechol-O-methyltransferase in the placenta and fetal liver.

BACKGROUND/OBJECTIVES: Maternal obesity together with androgen excess in mice negatively affects placental function and maternal and fetal liver function as demonstrated by increased triglyceride content with dysfunctional expression of enzymes and transcription factors involved in de novo lipogenesis and fat storage. To identify changes in molecular pathways that might promote diseases in adulthood, we performed a global proteomic analysis using a liquid-chromatography/mass-spectrometry system to investigate total and phosphorylated proteins in the placenta and fetal liver in a mouse model that combines maternal obesity with maternal androgen excess. METHODS: After ten weeks on a control diet (CD) or high fat/high sugar-diet, dams were mated with males fed the CD. Between gestational day (GD) 16.5 and GD 18.5, mice were injected with vehicle or dihydrotestosterone (DHT) and sacrificed at GD 18.5 prior to dissection of the placentas and fetal livers. Four pools of female placentas and fetal livers were subjected to a global proteomic analysis. Total and phosphorylated proteins were filtered by ANOVA q < 0.05, and this was followed by two-way ANOVA to determine the effect of maternal obesity and/or androgen exposure. RESULTS: In placenta, phosphorylated ATP-citrate synthase was decreased due to maternal obesity, and phosphorylated catechol-O-methyltransferase (COMT) was differentially expressed due to the interaction between maternal diet and DHT exposure. In fetal liver, five total proteins and 48 proteins phosphorylated in one or more sites, were differentially expressed due to maternal obesity or androgen excess. In fetal liver, phosphorylated COMT expression was higher in fetus exposed to maternal obesity. CONCLUSION: These results suggest a common regulatory mechanism of catecholamine metabolism in the placenta and the fetal liver as demonstrated by higher phosphorylated COMT expression in the placenta and fetal liver from animals exposed to diet-induced maternal obesity and lower expression of phosphorylated COMT in animals exposed to maternal androgen excess.

Inhibitors of MAO-B and COMT: their effects on brain dopamine levels and uses in Parkinson's disease.

MAO-B and COMT are both enzymes involved in dopamine breakdown and metabolism. Inhibitors of these enzymes are used in the treatment of Parkinson's disease. This review article describes the scientific background to the localization and function of the enzymes, the physiological changes resulting from their inhibition, and the basic and clinical pharmacology of the various inhibitors and their role in treatment of Parkinson's disease.

Pharmacogenomic Testing in Child and Adolescent Psychiatry: An Evidence-Based Review.

Significant advances have been made in the application of pharmacogenomic testing for the treatment of patients with psychiatric disorders. Over the past decade, a number of studies have evaluated the utility of pharmacogenomic testing in pediatric patients with psychiatric disorders. The evidence base for pharmacogenomic testing in youth with depressive and anxiety disorders as well as attention/deficit hyperactivity disorder (ADHD) is reviewed in this article. General pharmacogenomic principles are summarized and functional polymorphisms in P450 enzymes (and associated metabolizer phenotypes), the serotonin transporter promoter polymorphisms, serotonin 2A receptor genes (e.g., HT2AR) and catecholamine pathway genes (e.g., COMT) are reviewed. These commonly tested pharmacogenomic markers are discussed with regard to studies of drug levels, efficacy and side effects. The translation of pharmacogenomics to individualized/precision medicine in pediatric patients with ADHD, anxiety and depressive disorders has accelerated; however, its application remains challenging given that there are numerous divergent pathways between medication/medication dose and clinical response and side effects. Nonetheless, by leveraging variations in individual genes that may be relevant to medication metabolism or medication target engagement, pharmacogenomic testing may have a role in predicting treatment response, side effects and medication selection in youth with ADHD, depressive and anxiety disorders.

DNA methylation of membrane-bound catechol-O-methyltransferase in Malaysian schizophrenia patients.

AIM: This study examined catechol-O-methyltransferase (COMT) DNA methylation in the peripheral blood of schizophrenia patients and also in healthy controls to investigate its potential use as a peripheral biomarker of schizophrenia and its relations with the clinical variables of schizophrenia patients. METHODS: We examined the DNA methylation levels of COMT using genomic DNA from the peripheral blood of schizophrenia patients (n = 138) and healthy control participants (n = 132); all were Malaysian Malays. The extracted DNA was bisulfite converted, and the percentage methylation ratio value was calculated based on the results following a MethyLight protocol analysis. RESULTS: The percentage methylation ratio of COMT was lower in schizophrenia than it was in the healthy controls (P < 0.001) and was different between the body mass index (P = 0.003) and antipsychotic (P = 0.004) groups. The COMT DNA methylation rate was lower in patients receiving atypical antipsychotics (P = 0.004) and risperidone (P = 0.049) as compared to typical antipsychotics. The Excitement and Depressed subdomains of the Positive and Negative Syndrome Scale were inversely related (P < 0.001) and therefore predictors (Excitement: b = -11.396, t = -4.760, P < 0.001; Depressed: b = -7.789, t = -3.487, P = 0.001) of COMT DNA methylation. CONCLUSION: Our results suggested that the methylation level was affected by the severity of the clinical symptoms of schizophrenia and might also be influenced by pharmacological treatment. The epigenetic alteration of COMT in the peripheral blood could be a potential peripheral biomarker of schizophrenia.

Opicapone for the treatment of Parkinson's disease.

INTRODUCTION: Parkinson's disease (PD) is a progressive neurodegenerative disease. The currently available treatment options only have a symptomatic effect. With disease progression almost all antiparkinsonian pharmacological classes are tried, but the gold standard of pharmacological management is still L-dopa. Various strategies can be used to raise the dopaminergic tone. Catechol-O-methyltransferase (COMT) inhibitors attain this goal by decreasing L-dopa peripheral metabolism. Areas covered: Opicapone (Ongentys®) is a new COMT inhibitor developed to fulfill the need for more potent, safer and longer acting COMT inhibitors. This review puts into context opicapone's indications, its chemical and preclinical data, the pharmacodynamics and pharmacokinetic characteristics, and the efficacy and safety results delivered by clinical trials. Expert opinion: Opicapone is an efficacious COMT inhibitor. Its proprieties make it adequate for a once-a-day oral dose regimen. It has proved to reduce the off-time and to increase the on-time without troublesome dyskinesias in PD patients with motor fluctuations. The reported adverse events suggest an overall safe and well-tolerated profile. The most common adverse events were dyskinesia, and there were no issues of concern for hepatotoxicity, severe diarrhoea or chromaturia. Further evidence is still needed to conclude how it compares with other drugs for the treatment of motor fluctuations.

Serotonin- and Dopamine-Related Gene Expression in db/db Mice Islets and in MIN6 ß-Cells Treated with Palmitate and Oleate.

High circulating nonesterified fatty acids (NEFAs) concentration, often reported in diabetes, leads to impaired glucose-stimulated insulin secretion (GSIS) through not yet well-defined mechanisms. Serotonin and dopamine might contribute to NEFA-dependent ß-cell dysfunction, since extracellular signal of these monoamines decreases GSIS. Moreover, palmitate-treated ß-cells may enhance the expression of the serotonin receptor Htr2c, affecting insulin secretion. Additionally, the expression of monoamine-oxidase type B (Maob) seems to be lower in islets from humans and mice with diabetes compared to nondiabetic islets, which may lead to increased monoamine concentrations. We assessed the expression of serotonin- and dopamine-related genes in islets from db/db and wild-type (WT) mice. In addition, the effect of palmitate and oleate on the expression of such genes, 5HT content, and GSIS in MIN6 ß-cell was determined. Lower Maob expression was found in islets from db/db versus WT mice and in MIN6 ß-cells in response to palmitate and oleate treatment compared to vehicle. Reduced 5HT content and impaired GSIS in response to palmitate (-25%; p < 0.0001) and oleate (-43%; p < 0.0001) were detected in MIN6 ß-cells. In conclusion, known defects of GSIS in islets from db/db mice and MIN6 ß-cells treated with NEFAs are accompanied by reduced Maob expression and reduced 5HT content.

Effect of 3 Single-Dose Regimens of Opicapone on Levodopa Pharmacokinetics, Catechol-O-Methyltransferase Activity and Motor Response in Patients With Parkinson Disease.

This study determined the effects of single doses of opicapone (OPC), a novel third-generation catechol-O-methyltransferase (COMT) inhibitor, on levodopa and 3-O-methyl-levodopa (3-OMD) pharmacokinetics (PK), COMT activity and motor fluctuations in patients with Parkinson disease (PD). Subjects received, in a double-blind manner, 25, 50, and 100 mg OPC or placebo (PLC) in 4 separate treatment periods. The washout period between doses was at least 10 days. During each period, the OPC/PLC capsules were to be coadministered with the morning dose of 100/25 mg levodopa/carbidopa (LC) or levodopa/benserazide (LB) on day 3. In relation to PLC, levodopa exposure increased 3.7%, 16.4%, and 34.8% following 25, 50, or 100 mg OPC, respectively. Maximum S-COMT inhibition (Emax ) ranged from 67.8% (25 mg OPC) to 100% (100 mg OPC). Peak and extent of S-COMT inhibition were dose-dependent. Maximum decrease in the plasma 3-OMD was observed following administration of 100 mg OPC. Opicapone administered concomitantly with standard-release 100/25 mg LC or LB improved motor performance. Treatments were generally well tolerated and safe. It was concluded that OPC is a new COMT inhibitor that significantly decreased COMT activity and increased systemic exposure to levodopa in PD patients with motor fluctuations.

Opicapone pharmacokinetics and pharmacodynamics comparison between healthy Japanese and matched white subjects.

Opicapone (OPC) is a novel third-generation catechol-O-methyltransferase (COMT) inhibitor. This randomized, double-blind, parallel, placebo-controlled and multiple ascending dose study in 3 sequential groups of up to 38 (19 Japanese plus 19 white subjects) aimed to compare the pharmacokinetics (PK) and pharmacodynamics (PD; COMT activity) of opicapone between healthy Japanese and matched white subjects. Enrolled subjects received a once-daily morning administration of OPC (5, 25, or 50 mg) or placebo for 10 days, with plasma and urine concentrations of opicapone and its metabolites measured up to 144 hours postdose, including S-COMT activity. Geometric mean ratios (GMRs) and confidence intervals (95%CIs) for the main PK and PD parameters of OPC were evaluated between populations. Both the PK and PD of OPC were similar in the Japanese and white populations. Overall, only minimal differences were noted between the 2 populations, which were not deemed to be statistically significant. When both populations were separated based on their COMT genotype, the observed PK and PD differences were also negligible. In conclusion, the PK and PD profiles of OPC were similar in the Japanese and white populations. Thus, ethnicity and COMT polymorphisms had no significant impact on the OPC PK and PD in the conditions of the study.

Brain catechol-O-methyltransferase (COMT) inhibition by tolcapone counteracts recognition memory deficits in normal and chronic phencyclidine-treated rats and in COMT-Val transgenic mice.

The critical involvement of dopamine in cognitive processes has been well established, suggesting that therapies targeting dopamine metabolism may alleviate cognitive dysfunction. Catechol-O-methyl transferase (COMT) is a catecholamine-degrading enzyme, the substrates of which include dopamine, epinephrine, and norepinephrine. The present work illustrates the potential therapeutic efficacy of COMT inhibition in alleviating cognitive impairment. A brain-penetrant COMT inhibitor, tolcapone, was tested in normal and phencyclidine-treated rats and COMT-Val transgenic mice. In a novel object recognition procedure, tolcapone counteracted a 24-h-dependent forgetting of a familiar object as well as phencyclidine-induced recognition deficits in the rats at doses ranging from 7.5 to 30 mg/kg. In contrast, entacapone, a COMT inhibitor that does not readily cross the blood-brain barrier, failed to show efficacy at doses up to 30 mg/kg. Tolcapone at a dose of 30 mg/kg also improved novel object recognition performance in transgenic mice, which showed clear recognition deficits. Complementing earlier studies, our results indicate that central inhibition of COMT positively impacts recognition memory processes and might constitute an appealing treatment for cognitive dysfunction related to neuropsychiatric disorders.

Development of an HTRF Assay for the Detection and Characterization of Inhibitors of Catechol-O-Methyltransferase.

Catechol-O-methyltransferase (COMT) plays an important role in the deactivation of catecholamine neurotransmitters and hormones. Inhibitors of COMT, such as tolcapone and entacapone, are used clinically in the treatment of Parkinson's disease. Discovery of novel inhibitors has been hampered by a lack of suitable assays for high-throughput screening (HTS). Although assays using esculetin have been developed, these are affected by fluorescence, a common property of catechol-type compounds. We have therefore evaluated a new homogenous time-resolved fluorescence (HTRF)-based assay from CisBio (Codolet, France), which measures the production of S-adenosyl-L-homocysteine (SAH). The assay has been run in both HTS and medium-throughput screening (MTS) modes. The assay was established using membranes expressing human membrane-bound COMT and was optimized for protein and time to give an acceptable signal window, good potency for tolcapone, and a high degree of translation between data in fluorescence ratio and data in terms of [SAH] produced. pIC50 values for the hits from the HTS mode were determined in the MTS mode. The assay also proved suitable for kinetic studies such as Km,app determination.

Effect of opicapone on levodopa pharmacokinetics, catechol-O-methyltransferase activity and motor fluctuations in patients with Parkinson's disease.

BACKGROUND AND PURPOSE: Opicapone (OPC) is a novel third generation catechol-O-methyltransferase (COMT) inhibitor that enhances levodopa availability. This study investigated the effects of OPC in comparison with placebo on levodopa pharmacokinetics, tolerability and safety, COMT activity and motor response to levodopa in Parkinson's disease (PD) patients with motor fluctuations. METHODS: This was a randomized, multicentre, double-blind and placebo-controlled study in four parallel groups of PD patients treated with standard-release 100/25 mg levodopa/carbidopa or levodopa/benserazide and with motor fluctuations (wearing-OFF phenomenon). Subjects were sequentially assigned to be administered, once-daily, up to 28 days (maintenance phase), placebo (n = 10) or 5 (n = 10), 15 (n = 10) and 30 mg (n = 10) OPC. Two levodopa tests were performed, one at baseline and another following the maintenance phase. Subjects kept a diary to record motor fluctuations (ON/OFF periods) throughout the study. RESULTS: In relation to placebo, levodopa exposure (AUC0-6) increased 24.7%, 53.9% and 65.6% following 5, 15 and 30 mg OPC, respectively. Maximum COMT inhibition (Emax) ranged from 52% (5 mg OPC) to 80% (30 mg OPC). The study was not designed to detect any significant differences in motor performance, but the exploratory analysis performed shows improvement in various motor outcomes, including a dose-dependent change in absolute OFF time corresponding to a percentage decrease of 4.16% (P > 0.05), 29.55% (P > 0.05) and 32.71% (P < 0.05) with 5, 15 and 30 mg OPC, respectively. Treatments were generally well tolerated and safe. CONCLUSIONS: OPC is a promising new COMT inhibitor that significantly decreased COMT activity, increased systemic exposure to levodopa and improved motor response.

A transient inhibition and permanent lack of catechol-O-methyltransferase have minor effects on feeding pattern of female rodents.

Abnormal feeding behaviours have long been linked to disruptions in brain dopaminergic activity. Dopamine is metabolized, amongst others, by catechol-O-methyltransferase (COMT). Normally, COMT only plays a subordinate role in dopamine metabolism. However, changes in COMT activity, especially in the prefrontal cortex, become more important during events that evoke dopamine release. The current study investigated the effect of acute COMT inhibition on feeding in Wistar rats and C57BL/6 mice using a selective, brain penetrating COMT inhibitor (OR-1139). Furthermore, the effect of a long-term lack of COMT on feeding behaviour was studied in COMT-deficient (COMT -/-) mice. Apart from following the gross feeding behaviour of fasted rats and mice, the first 4 hr of re-feeding were recorded with a video camera to allow a more detailed analysis of feeding microstructure. In the acute study, rats and mice received a single injection of OR-1139 (3, 10 or 30 mg/kg), just before the experiment. We found that rats and mice receiving OR-1139 had fewer very short meals but more long meals than the controls. Treated mice even ate more frequently than the controls, but other feeding parameters remained unchanged. Conversely, COMT -/- mice displayed an increased latency to initiate the first meal and spent less total time eating than wild-type mice. In conclusion, although decreased/lack of COMT activity did not robustly alter feeding behaviour of female rodents, we observed some alterations in the microstructure of feeding. However, these minor changes were highly dependent on the extent and fashion in which COMT was manipulated.

Atrial natriuretic factor decreases renal dopamine turnover and catabolism without modifying its release.

Atrial natriuretic factor (ANF) and dopamine (DA) are both important regulators of sodium and water transport across renal proximal tubules. Many evidences suggest that some of ANF inhibitory effects on sodium and water reabsorption are mediated by dopaminergic mechanisms. We have previously reported that ANF stimulates extraneuronal DA uptake in external renal cortex by activation of NPR-A receptors coupled to cGMP signal and PKG. Moreover, ANF enhanced DA-induced inhibition of Na(+)-K(+) ATPase activity. The aim of the present study was to evaluate if ANF could alter also renal DA release, catabolism and turn over. The results indicate that ANF did not affect basal secretion of the amine in external renal cortex or its KCl-induced release, but diminished DA turn over. Moreover, ANF diminished COMT and did not alter MAO activity. In conclusion, present results as well as previous findings show that ANF modifies DA metabolism in rat external renal cortex by enhancing DA uptake and decreasing COMT activity. All those effects, taken together, may favor DA accumulation into renal cells and increase its endogenous content and availability. This would permit D1 receptor recruitment and stimulation and in turn, Na(+), K(+)-ATPase activity over inhibition that results in decreased sodium reabsorption. Therefore, ANF and DA could act via a common pathway to enhance natriuresis and diuresis.

Molecular targets for treating cognitive dysfunction in schizophrenia.

Cognitive impairment is a core feature of schizophrenia as deficits are present in the majority of patients, frequently precede the onset of other positive symptoms, persist even with successful treatment of positive symptoms, and account for a significant portion of functional impairment in schizophrenia. While the atypical antipsychotics have produced incremental improvements in the cognitive function of patients with schizophrenia, overall treatment remains inadequate. In recent years, there has been an increased interest in developing novel strategies for treating the cognitive deficits in schizophrenia, focusing on ameliorating impairments in working memory, attention, and social cognition. Here we review various molecular targets that are actively being explored for potential drug discovery efforts in schizophrenia and cognition. These molecular targets include dopamine receptors in the prefrontal cortex, nicotinic and muscarinic acetylcholine receptors, the glutamatergic excitatory synapse, various serotonin receptors, and the gamma-aminobutyric acid (GABA) system.

Chronic antipsychotics treatment regulates MAOA, MAOB and COMT gene expression in rat frontal cortex.

Chronic antipsychotic drugs treatment may regulate the expression of a variety of genes in the brain, which may underscore their clinical efficacy and/or side effects. In this study, we measured the mRNA levels of three genes encoding the catabolic enzymes of biogenic amine neurotransmitters, i.e., monoamine oxidase A (MAOA), B (MAOB) and catechol O-methyltransferase (COMT), in rat frontal cortex following 4 weeks' treatment of various antipsychotic drugs using quantitative PCR. Significantly elevated mRNA levels of MAOB and COMT were first observed in frontal cortex of rats treated with risperidone (1mg/kg) when compared to control animals. Further study showed that chronic treatment of olanzapine (2mg/kg), but not haloperidol (1mg/kg) or clozapine (20mg/kg), resulted in significantly increased mRNA levels of MAOA, MAOB and COMT in rat frontal cortex as compared to control animals. These results indicate that chronic treatment of different antipsychotic drugs may differentially regulate the gene expression of three catabolic enzymes of biogenic amine neurotransmitters, and which may partly account for the molecular mechanism of their different clinical efficacy.

Absorption, metabolism, degradation and urinary excretion of rosmarinic acid after intake of Perilla frutescens extract in humans.

BACKGROUND: Rosmarinic acid (RA) is a natural polyphenolic substance contained in many Lamiaceae herbs such as Perilla frutescens. Previous studies have shown RA has antioxidative and anti-inflammatory activity. However, little is known on the absorption, metabolism, degradation and excretion of RA. AIM OF THE STUDY: The aim of this study in healthy humans was to determine the absorption, metabolism, and urinary excretion of RA after a single intake of perilla extract (PE). METHOD: Six healthy men (mean age 37.2 +/- 6.2 y and mean body mass index 22.0 +/- 1.9 kg/m(2)) were enrolled in the study that was a crossover design involving single intakes of PE containing 200 mg RA and placebo with a 10 day interval between treatments. Blood samples were collected before intake and at designated time intervals, while urine samples were collected over the periods 0-6 h, 6-24 h and 24-48 h after intake. RA and its related metabolites in plasma and urine were measured by LC-MS. RESULTS: RA, methylated RA (methyl-RA), caffeic acid (CAA), ferulic acid (FA) and a trace of m-coumaric acid (COA) were detected in the urine after intake of PE. In plasma, RA, methyl-RA and FA were detected, with maximum levels obtained 0.5, 2 and 0.5 h after intake of PE, respectively. The majority of these components in both plasma and urine were present as conjugated forms (glucuronide and/or sulfated). The proportion of RA and its related metabolites excreted in the urine was 6.3 +/- 2.2% of the total dose, with approximately 75% of these components being excreted within 6 h after intake of PE. CONCLUSIONS: RA contained in PE was absorbed, conjugated and methylated following intake, with a small proportion of RA being degraded into various components, such as conjugated forms of CAA, FA and COA. These metabolites were then rapidly excreted in the urine.

Entacapone protects from angiotensin II-induced inflammation and renal injury.

OBJECTIVES AND DESIGN: Angiotensin II (Ang II)-induced renal damage is associated with perivascular inflammation and increased oxidative stress. We tested the hypothesis whether entacapone, a catechol-O-methyltransferase (COMT) inhibitor exerting antioxidative and anti-inflammatory properties, protects against the Ang II-induced inflammatory response and end-organ damage. METHODS: Samples from double-transgenic rats harbouring human renin and human angiotensinogen genes (dTGR) and normotensive Sprague-Dawley rats (SD) were assessed by light microscopy, immunohistochemistry, reverse transcriptase-polymerase chain reaction (RT-PCR), and high pressure liquid chromatography. The effects of entacapone treatment for 3 weeks were examined in dTGR and SD. RESULTS: Entacapone completely prevented cardiovascular mortality and decreased albuminuria by 85% in dTGR. Entacapone ameliorated Ang II-induced vascular and glomerular damage, leucocyte infiltration, and intercellular adhesion molecule-1 (ICAM-1) overexpression in the kidneys. Serum 8-isoprostane concentration, as well as renal nitrotyrosine and 8-hydroxydeoxyguanosine expressions, all markers of oxidative stress, were markedly increased in dTGR and normalized by entacapone. Entacapone also decreased p22phox mRNA expression in the kidney. COMT expression was increased by 500% locally in the renal vascular wall in dTGR; however, COMT activity in the whole kidney remained unchanged. Urinary dopamine excretion, a marker of renal dopaminergic tone, was decreased by 50% in untreated dTGR. Even though entacapone decreased renal COMT activity by 40%, the renal dopaminergic tone remained unchanged in entacapone-treated dTGR. CONCLUSION: Our findings suggest that entacapone provides protection against Ang II-induced renal damage through antioxidative and anti-inflammatory mechanisms, rather than by COMT inhibition-induced changes in renal dopaminergic tone.