Mitona Pujadas

Epigallocatechin-3-gallate, a DYRK1A inhibitor, rescues cognitive deficits in Down syndrome mouse models and in humans

SCOPE Trisomy for human chromosome 21 results in Down syndrome (DS), which is among the most complex genetic perturbations leading to intellectual disability. Accumulating data suggest that overexpression of the dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A), is a critical pathogenic mechanisms in the intellectual deficit. METHODS AND RESULTS Here we show that the green tea flavonol epigallocatechin-gallate (EGCG), a DYRK1A inhibitor, rescues the cognitive deficits of both segmental trisomy 16 (Ts65Dn) and transgenic mice overexpressing Dyrk1A in a trisomic or disomic genetic background, respectively. It also significantly reverses cognitive deficits in a pilot study in DS individuals with effects on memory recognition, working memory and quality of life. We used the mouse models to ensure that EGCG was able to reduce DYRK1A kinase activity in the hippocampus and found that it also induced significant changes in plasma homocysteine levels, which were correlated with Dyrk1A expression levels. Thus, we could use plasma homocysteine levels as an efficacy biomarker in our human study. CONCLUSION We conclude that EGCG is a promising therapeutic tool for cognitive enhancement in DS, and its efficacy may depend of Dyrk1A inhibition.

MDMA (ecstasy) pharmacokinetics in a CYP2D6 poor metaboliser and in nine CYP2D6 extensive metabolisers.

(CYP)isoform 2D6 [2]. HHMA is further metabolised to 4-hydroxy, 3-methoxymethamphetamine (HMMA) bycatechol- O-methyltransferase (COMT). HMMA in-duces vasopressin secretion to a higher extent thanMDMA and has been postulated to contribute to hyp-onatraemia observed in some MDMA acute intoxica-tions [4]. The CYP2D6 gene is highly polymorphic andmany variations affect the expression or activity of theenzyme. Approximately 7–10% of European Caucasianspresent a metabolic deficiency and are termed poormetabolisers (PM) [12]. Evidence that individuals pos-sessingacompromiseinCYP2D6activitywouldbemoresusceptible to acute toxic effects of MDMA has beenlacking. A previous metabolic bioactivation of MDMA,regulated partially by this enzyme, is needed to elicitneurotoxic effects in the central nervous system. It ispostulated that the chemical species involved inserotonergic neurotoxicity are catechol thiol conjugatemetabolites of the drug (HHMA) [8]. The functionalpolymorphisms in CYP2D6 could influence the devel-opment of MDMA neurotoxicity. During a trial de-signed to study the pharmacology of two consecutivedoses of MDMA [3], one subject was found to possessthe CYP2D6*4/*4 genotype and was classified as a PM.The objective of this paper was to compare the results ofthis subject with those of nine others previously pub-lished. Furthermore, the paper includes pharmacokineticdata on MDMA metabolites not previously published.

Human Pharmacology of Mephedrone in Comparison with MDMA.

Mephedrone (4-methylmethcathinone) is a novel psychoactive substance popular among drug users because it displays similar effects to MDMA (3,4-methylenedioxymethamphetamine, ecstasy). Mephedrone consumption has been associated with undesirable effects and fatal intoxications. At present, there is no research available on its pharmacological effects in humans under controlled and experimental administration. This study aims to evaluate the clinical pharmacology of mephedrone and its relative abuse liability compared with MDMA. Twelve male volunteers participated in a randomized, double-blind, crossover, and placebo-controlled trial. The single oral dose conditions were: mephedrone 200 mg, MDMA 100 mg, and placebo. Outcome variables included physiological, subjective, and psychomotor effects, and pharmacokinetic parameters. The protocol was registered in ClinicalTrials.gov (NCT02232789). Mephedrone produced a significant increase in systolic and diastolic blood pressure, heart rate, and pupillary diameter. It elicited stimulant-like effects, euphoria, and well-being, and induced mild changes in perceptions with similar ratings to those observed after MDMA administration although effects peaked earlier and were shorter in duration. Maximal plasma concentration values for mephedrone and MDMA peaked at 1.25 h and 2.00 h, respectively. The elimination half-life for mephedrone was 2.15 h and 7.89 h for MDMA. In a similar manner to MDMA, mephedrone exhibits high abuse liability. Its earlier onset and shorter duration of effects, probably related to its short elimination half-life, could explain a more compulsive pattern of use as described by the users.

Metabolic disposition and biological significance of simple phenols of dietary origin: hydroxytyrosol and tyrosol

Abstract Hydroxytyrosol and tyrosol are dietary phenolic compounds present in virgin olive oil and wine. Both compounds are also endogenously synthesized in our body as byproducts of dopamine and tyramine metabolisms, respectively. Over the last decades, research into hydroxytyrosol and tyrosol has experienced an increasing interest due to the role that these compounds may play in the prevention of certain pathologies (e.g. cardiovascular, metabolic, neurodegenerative diseases and cancer). The translation of promising in vitro and in vivo biological effects from preclinical studies to the context of human disease prevention initially depends on whether the dose ingested becomes available at the site of action. In this regard, information regarding the bioavailability and metabolic disposition of hydroxytyrosol and tyrosol is of most importance to evaluate the impact they may have on human health. In this review, we discuss and summarize the state of the art of the scientific evidence regarding the processes of absorption, distribution, metabolism and excretion of both hydroxytyrosol and tyrosol. We also examine the impact of these compounds and their metabolites on biological activity in terms of beneficial health effects. Finally, we evaluate the different analytical approaches that have been developed to measure the plasma and urinary levels of hydroxytyrosol, tyrosol and their metabolites.

Substance use among non-fatally injured patients attended at emergency departments in Spain

AIMS To describe the prevalence of recent use of alcohol, medication, and illegal drugs among patients who attended emergency departments (EDs) as a result of suffering an injury due to any external mechanism and to identify factors associated with alcohol and drug use. METHODS A cross-sectional study was conducted in eight university hospitals in Spain. Participants were adult patients admitted to a trauma ED. Oral fluid was used to test for psychoactive substances analyzed by gas chromatography-mass spectrometry. Socio-demographic data and information on circumstances of the injury were collected through interviews. RESULTS The analysis included 1579 patients admitted to the EDs (56.4% men). Among young people (< 40 years), 21.4% of men and 8.5% of women were positive for any illegal substance, primarily cannabinoids or cocaine; 24.7% of men and 14.8% of women were positive for alcohol. Among patients > or = 40 years, 7.4% of men and 1.6% of women were positive for any illegal substance, and 16.3% and 11.0% respectively for alcohol. Prevalence of substance detected varied across mechanism of injury, gender and age group. Night-time injury was associated with substance use. CONCLUSIONS A high proportion of injured patients who were treated in an EDs tested positive for psychoactive drugs. Routine testing at trauma departments would maximize the identification of patients who may benefit from referral to specialized addiction treatment centers, or brief interventions.

Maternal hair testing for the assessment of fetal exposure to drug of abuse during early pregnancy: Comparison with testing in placental and fetal remains

UNLABELLED Drug use by pregnant women in the first trimester of pregnancy and subsequent fetal exposure during early gestation can be assessed only by repetitive/systematic maternal blood/urine analysis or segmental hair analysis. No evidence of any relationship between maternal/fetal exposure during this specific period of gestation has been demonstrated to date in a human model. METHODS To clarify drugs toxicokinetics and transplacental passage during early pregnancy, the presence of the most widely used recreational drugs of abuse and metabolites was investigated in the proximal 4cm hair segments of women undergoing voluntary termination of pregnancy (n=280) during the 12th week of gestation and the results were compared to those from placenta and fetal tissue samples in order to verify whether maternal hair testing can reflect fetal exposure and, if so, to what extent. Hair, placenta and fetal remains were analyzed by validated gas chromatography mass spectrometry assays. RESULTS Eighty one positive hair samples were identified: 60 were positive for cannabis (74.1%), 28 for cocaine (34.6%), 7 for opiates (8.6%), 3 for MDMA (3.7%) and 18.5% were positive for more than one drug. The positive hair test results were confirmed in placenta/fetal tissues in 10 cases out of 60 for cannabis (16. 7%); in 7 out of 28 for cocaine (25%); and none for the 6 opiates positive cases and 3 MDMA cases, respectively. CONCLUSION Drugs/metabolites in hair of pregnant women can be used as biomarkers of past drug use (repetitive or sporadic), although the use is not always reflected in fetal/placental tissues. There are several possible hypotheses to explain the results: (1) the use occurred before the start of pregnancy, (2) past sporadic consumption which could be measured in hair but not in fetal and placental remains because of the narrow window of drug detection in placental/fetal tissues; (3) the sensitivity of the analytical methods was not high enough for the detection of the minute amount of drugs of abuse and metabolites which reached these tissues (4) there is a large variability in the transplacental passage of drugs of abuse and in the placentas metabolizing capacity.

Analysis of free hydroxytyrosol in human plasma following the administration of olive oil.

Hydroxytyrosol (HT) from olive oil, a potent bioactive molecule with health benefits, has a poor bioavailability, its free form (free HT) being undetectable so far. This fact leads to the controversy whether attained HT concentrations after olive oil polyphenol ingestion are too low to explain the observed biological activities. Due to this, an analytical methodology to determine free HT in plasma is crucial for understanding HT biological activity. Plasma HT instability and low concentrations have been major limitations for its quantification in clinical studies. Here, we describe a method to detect and quantify free HT in human plasma by using liquid chromatography coupled to tandem mass spectrometry. The method encompasses different steps of sample preparation including plasma stabilization, protein precipitation, selective derivatization with benzylamine, and purification by solid-phase extraction. A high sensitivity (LOD, 0.3ng/mL), specificity and stability of HT is achieved following these procedures. The method was validated and its applicability was demonstrated by analyzing human plasma samples after olive oil intake. A pharmacokinetic comparison was performed measuring free HT plasma concentrations following the intake of 25mL of ordinary olive oil (nearly undetectable concentrations) versus an extra-virgin olive oil (Cmax=4.40ng/mL). To our knowledge, this is the first time that an analytical procedure for quantifying free HT in plasma after olive oil dietary doses has been reported. The present methodology opens the door to a better understanding of the relationship between HT plasma concentrations and its beneficial health effects.

Moderate consumption of wine, through both its phenolic compounds and alcohol content, promotes hydroxytyrosol endogenous generation in humans. A randomized controlled trial

In humans, urinary hydroxytyrosol (OHTyr) concentrations have been associated to alcohol and wine consumption. To explore the role of wine components on promoting an endogenous OHTyr generation we performed a cross-over, double-blind, randomized controlled clinical trial (n = 28 healthy volunteers). Ethanol (wine and vodka), dealcoholized wine, and placebo were administered. Alcohol, dealcoholized wine, and particularly wine promoted a de novo OHTyr generation in vivo in humans. Potential OHTyr precursors (tyrosine, tyrosol, tyramine) were investigated in rats. Tyrosol was metabolized to OHTyr. Collating both studies, it is postulated that an increased Tyr bioavailability, a shift to a reductive pathway in dopamine and tyramine oxidative metabolism, and the biotransformation of Tyr to OHTyr were mechanisms involved in the OHTyr endogenous generation.

Inhibition of MDMA-induced increase in cortisol does not prevent acute impairment of verbal memory.

Ecstasy use is commonly linked with memory deficits in abstinent ecstasy users. Similar impairments are being found during ecstasy intoxication after single doses of ± 3,4 metylenedioxymethamphetamine (MDMA). The concordance of memory impairments during intoxication and abstinence suggests a similar neuropharmacological mechanism underlying acute and chronic memory impairments. The mechanism underlying this impairment is to date not known. We hypothesized that cortisol might play an important role in this mechanism as cortisol, implicated in the regulation of memory performance, can be brought out of balance by stressors like MDMA.

Ethanol induces hydroxytyrosol formation in humans.

Previous studies in animals have shown an increase of hydroxytyrosol (OHTyr), a potent phenolic antioxidant and a minor metabolite of dopamine (also called 3,4-dihydroxyphenylethanol or DOPET), after ethanol intake. The interaction between ethanol and dopamine metabolism is the probable mechanism involved. The aim of the study was to establish the contribution of the dose of ethanol on OHTyr formation. 24 healthy male volunteers were included. Subjects were distributed in three different cohorts and each volunteer received two doses of ethanol or placebo. Doses of ethanol administered were 6, 12, 18, 24, 30 and 42 g. Study design was double-blind, randomized, crossover and controlled. Hydroxytyrosol, tyrosol (Tyr), 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) urinary excretion, ethanol plasma concentrations and drunkenness were evaluated along a 6-h period. Urinary excretion of OHTyr and Tyr increased with ethanol administered dose. A reduction in the ratio DOPAC/OHTyr from placebo to the highest dose was observed, compatible with a shift in the dopamine metabolism to preferently produce OHTyr instead of DOPAC. Also a dose-dependent increase in plasma ethanol concentrations and subjective effects was observed. This study demonstrates an endogenous production of OHTyr and Tyr in relation to ethanol administered dose in humans. Biological effects of both phenols from this source should be investigated in future studies.