Publications by authors named "Fernando Remiao"

Article Synopsis
  • "Purple Drank" is a drink combining promethazine and codeine, known for its hallucinogenic effects but can be dangerous in high doses.
  • The study investigated how these drugs bind to human serum albumin (HSA) using high-performance affinity chromatography, finding PMZ and its metabolites bind strongly to HSA while codeine has a lower binding affinity.
  • Displacement experiments and molecular docking indicated that all three compounds bind to HSA at both sites, with competition mainly between PMZ and codeine occurring at site II, and the binding wasn't affected by the chirality (enantiomers).
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Substituted phenethylamines including 2C (2,5-dimethoxyphenethylamines) and NBOMe (-(2-methoxybenzyl)phenethylamines) drugs are potent psychoactive substances with little to no knowledge available on their toxicity. In the present in vitro study, we explored the mechanisms underlying the neurotoxicity of six substituted phenethylamines: 2C-T-2, 2C-T-4, 2C-T-7 and their corresponding NBOMes. These drugs were synthesized and chemically characterized, and their cytotoxicity (0-1000 μM) was evaluated in differentiated SH-SY5Y cells and primary rat cortical cultures, by the NR uptake and MTT reduction assays.

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Mycoses are one of the major causes of morbidity/mortality among immunocompromised individuals. Considering the importance of these infections, the World Health Organization (WHO) defined a priority list of fungi for health in 2022 that include as belonging to the critical priority group and () to the medium priority group. The existence of few available antifungal drugs, their high toxicity, the acquired fungal resistance, and the appearance of new species with a broader spectrum of resistance, points out the need for searching for new antifungals, preferably with new and multiple mechanisms of action.

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Nitrocatechols are the standard pharmacophore to develop potent tight-binding inhibitors of catechol -methyltransferase (COMT), which can be used as coadjuvant drugs to manage Parkinson's disease. Tolcapone is the most potent drug of this class, but it has raised safety concerns due to its potential to induce liver damage. Tolcapone-induced hepatotoxicity has been attributed to the nitrocatechol moiety; however, other nitrocatechol-based COMT inhibitors, such as entacapone, are safe and do not damage the liver.

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Tolcapone is an orally active catechol-O-methyltransferase (COMT) inhibitor used as adjuvant therapy in Parkinson's disease. However, it has a highly hepatotoxic profile, as recognized by the U.S.

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Article Synopsis
  • The recent rise in pharmaceutical misuse, especially among teens, highlights serious health risks associated with drugs like promethazine (PMZ), often consumed in a dangerous concoction known as "Purple Drank."
  • Newly conducted research focused on separating PMZ and its toxic metabolites into their individual chiral forms, revealing significant differences in toxicity among them.
  • The study found that one metabolite, (R,S)-DMPMZ, was much more toxic than PMZ itself, pointing to a potential risk in its metabolic activation, while another metabolite, (R,S)-PMZSO, showed little to no toxicity, indicating a detoxification process.
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Article Synopsis
  • The blood-brain barrier (BBB) protects the brain by preventing toxic substances from the bloodstream while allowing essential nutrients to pass through, presenting challenges for drug testing and toxicity assessments.
  • Current research focuses on improving in vitro models of the BBB, which can be complex due to specific cellular features that restrict how substances move through.
  • The study reviews various in vitro approaches, emphasizing the shift from simple cell layers to more advanced multicellular models that better mimic the brain’s environment, critical for understanding neurodegenerative diseases and drug permeability.
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Doxorubicin (DOX; also known as adriamycin) serves as a crucial antineoplastic agent in cancer treatment; however, its clinical utility is hampered by its' intrinsic cardiotoxicity. Although most DOX biotransformation occurs in the liver, a comprehensive understanding of the impact of DOX biotransformation and its' metabolites on its induced cardiotoxicity remains to be fully elucidated. This study aimed to explore the role of biotransformation and DOX's main metabolites in its induced cardiotoxicity in human differentiated cardiac AC16 cells.

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P-glycoprotein (P-gp) is a crucial membrane transporter situated on the cell's apical surface, being responsible for eliminating xenobiotics and endobiotics. P-gp modulators are compounds that can directly or indirectly affect this protein, leading to changes in its expression and function. These modulators can act as inhibitors, inducers, or activators, potentially causing drug-drug interactions (DDIs).

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Doxorubicin (DOX) is a topoisomerase II inhibitor used in cancer therapy. Despite its efficacy, DOX causes serious adverse effects, such as short- and long-term cardiotoxicity. This work aimed to assess the short- and long-term cardiotoxicity of DOX and the role of inflammation and antioxidant defenses on that cardiotoxicity in a mice model.

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Article Synopsis
  • Doxorubicin (DOX) is a powerful cancer treatment that can cause serious heart damage, particularly in older patients, who are often underrepresented in clinical research.
  • The study used elderly mice to investigate how DOX affects the heart over different time periods, revealing that DOX leads to heart damage characterized by inflammation and fibrosis both shortly after treatment and in the long-term.
  • Key findings included increased markers of inflammation and cell damage immediately after treatment, while persistent heart issues and altered protein expressions were noted two months later, highlighting the long-lasting effects of DOX on cardiac health.
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Currently, multidrug-resistant (MDR) infections are one of the most important threats, driving the search for new antimicrobial compounds. Cationic peptide antibiotics (CPAs) and ceragenins (CSAs) contain in their structures cationic groups and adopt a facially amphiphilic conformation, conferring the ability to permeate the membranes of bacteria and fungi. Keeping these features in mind, an amine steroid, DOCA-NH2, was found to be active against reference strains and MDR isolates of Gram-positive and and Gram-negative and .

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Mescaline derivative (2C phenethylamines) drugs have been modified by the introduction of a -2-methoxybenzyl group to originate a new series of compounds with recognized and potent psychedelic effects, the NBOMe-drugs. Although they are prevalent in unregulated drug markets, their toxicity profile is still poorly understood, despite several reports highlighting cases of acute intoxication, with brain and liver toxicity. Thus, in this study, mescaline, 2C-N (insertion of a nitro in the position of the 2C phenethylamines aromatic ring) and 2C-B (insertion of a bromide in the position of the 2C phenethylamines aromatic ring) and their corresponding NBOMe counterparts, mescaline-NBOMe, 25N-NBOMe and 25B-NBOMe, were synthetized and the in vitro neuro- and hepatocytotoxicity evaluated in differentiated SH-SY5Y and HepG2 cell lines, respectively.

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The binding affinity to human serum albumin (HSA) of a series of fourteen synthetic cathinones, new psychoactive substances widely abused, was investigated by high-performance affinity chromatography (HPAC). Zonal elution experiments were conducted to measure the retention times of each synthetic cathinone on an HSA column, which enabled the calculation of the percentage of the drug bound. For some synthetic cathinones, enantioselectivity on HSA was found.

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Ferroptosis is a type of regulated cell death promoted by the appearance of oxidative perturbations in the intracellular microenvironment constitutively controlled by glutathione peroxidase 4 (GPX4). It is characterized by increased production of reactive oxygen species, intracellular iron accumulation, lipid peroxidation, inhibition of system Xc-, glutathione depletion, and decreased GPX4 activity. Several pieces of evidence support the involvement of ferroptosis in distinct neurodegenerative diseases.

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The intranasal route has been suggested as a promising alternative to improve the direct transport of molecules to the brain, avoiding the need to cross the blood-brain barrier (BBB). In this area, the use of lipid nanoparticles, namely solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), has been highlighted as a promising strategy to improve the treatment of neurodegenerative diseases. In this work, formulations containing SLN and NLC that were loaded with astaxanthin that was obtained from different sources (astaxanthin extract (AE) from the algae and pure astaxanthin (PA) from the fungi ) were prepared for nose-to-brain administration, and comparative in vitro experiments were performed to evaluate the biocompatibility of the formulations with nasal (RPMI 2650) and neuronal (SH-SY5Y) cells.

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Textiles are important components for the development of lightweight and flexible displays useful in smart materials. In particular, halochromic textiles are fibrous materials with a color-changing ability triggered by pH variations mainly based on pH-sensitive dye molecules. Recently, a novel class of 2-aminoimidazole azo dyes was developed with distinct substituent patterns.

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Alzheimer's disease (AD) is one of the most prevalent neurodegenerative diseases that affect millions of people worldwide, with both prevalence and incidence increasing with age. It is characterized by cognitive decline associated, specifically, with degeneration of cholinergic neurons. The problem of this disease is even more fundamental as the available therapies remain fairly limited and mainly focused on symptoms' relief.

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The combination of two or more agents capable of acting in synergy has been reported as a valuable tool to fight against pathogens. Silver nanoparticles (AgNPs) present a strong antimicrobial action, although their cytotoxicity for healthy cells at active concentrations is a major concern. Azoimidazole moieties exhibit interesting bioactivities, including antimicrobial activity.

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Synthetic cathinones, such as 3,4-methylenedioxypyrovalerone (MDPV), are widely abused due to their psychostimulant effects. As they are chiral molecules, studies of their stereochemical stability (racemization can occur in certain temperatures and acidic/basic environments) and of their biological and/or toxicity effects (enantiomers might display different properties) are of great relevance. In this study, the liquid chromatography (LC) semi-preparative enantioresolution of MDPV was optimized to collect both enantiomers with high recovery rates and enantiomeric ratio (e.

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Ferroptosis is a type of regulated cell death characterized by intracellular accumulation of iron and reactive oxygen species, inhibition of system Xc-, glutathione depletion, nicotinamide adenine dinucleotide phosphate oxidation and lipid peroxidation. Since its discovery and characterization in 2012, many efforts have been made to reveal the underlying mechanisms, modulating compounds, and its involvement in disease pathways. Ferroptosis inducers include erastin, sorafenib, sulfasalazine and glutamate, which, by inhibiting system Xc-, prevent the import of cysteine into the cells.

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A novel route is described to obtain 2-aminoimidazole azo dyes with a unique substituent pattern in the heteroaryl unit that provides halochromic properties, exhibiting vibrant colours that change from magenta to deep blue. Potent antimicrobial properties against infectious yeasts were demonstrated. No cytotoxicity was detected for concentrations lower than 16 μg mL.

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Article Synopsis
  • MDPV is a synthetic cathinone that has psychoactive effects and is widely abused, but studies on its enantioselectivity and intestinal permeability are limited.
  • An in vitro study was conducted using a Caco-2 monolayer to assess the permeability of MDPV's enantiomers, employing a validated UHPLC-UV method for detection and quantification.
  • Results showed that both enantiomers of MDPV have high intestinal permeability, with observed enantioselectivity and efflux suggesting facilitation through a diffusion mechanism.
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Although the lipophilic triphenylphosphonium (TPP) cation is widely used to target antioxidants to mitochondria, TPP-based derivatives have shown cytotoxicity in several biological models. We confirmed that is cytotoxic to both human neuronal (SH-SY5Y) and hepatic (HepG2) cells, decreasing intracellular adenosine triphosphate (ATP) levels, leading to mitochondrial membrane depolarization and reduced mitochondrial mass after 24 h. We surpassed this concern using nitrogen-derived cationic carriers (, , and ).

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Article Synopsis
  • * These agents range from natural substances like adrenaline and noradrenaline to synthetic drugs such as isoproterenol and substances like caffeine and cocaine, with a focus on the newly discovered trace amine associated receptors (TAARs) in humans.
  • * The review highlights the pharmacological and toxicological aspects of natural sympathomimetic agents, particularly trace amines and those derived from plants, aiming to raise awareness about their safety in the community.
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