Lisa Marinelli

A glutathione derivative with chelating and in vitro neuroprotective activities: synthesis, physicochemical properties, and biological evaluation

Metal‐ion dysregulation and oxidative stress have been linked to the progressive neurological decline associated with neurodegenerative disorders such as Alzheimer’s and Parkinson’s diseases. Herein we report the synthesis and chelating, antioxidant, and in vitro neuroprotective activities of a novel derivative of glutathione, GS(HQ)H, endowed with an 8‐hydroxyquinoline group as a metal‐chelating moiety. In vitro results showed that GS(HQ)H may be stable enough to be absorbed unmodified and arrive intact to the blood–brain barrier, that it may be able to remove CuII and ZnII from the Aβ peptide without causing any copper or zinc depletion in vivo, and that it protects SHSY‐5Y human neuroblastoma cells against H2O2‐ and 6‐OHDA‐induced damage. Together, these findings suggest that GS(HQ)H could be a potential neuroprotective agent for the treatment of neurodegenerative diseases in which a lack of metal homeostasis has been reported as a key factor.

Solid lipid nanoparticles loaded with lipoyl–memantine codrug: Preparation and characterization

Solid lipid nanoparticles (SLNs) are considered very attractive drug-delivery systems (DDS) able to enhance the efficacy of some therapeutic agents in several pathologies difficult to treat in a conventional way. Starting from these evidences, this study describes the preparation, physicochemical characterization, release, and in vitro cytotoxicity of stealth SLNs as innovative approach to improve solubility and absorption through the gastrointestinal tract of lipoyl-memantine (LA-MEM), a potential anti-Alzheimer codrug. Physico-chemical properties of LA-MEM loaded SLNs have been intensively investigated. Differential scanning calorimetry (DSC) was used to clarify the state and crystalline structure of the formulation. The results obtained from particles size analysis, polydispersity (PDI), and zeta potential measurements allowed the identification of the optimized formulation, which was characterized by a drug-lipid ratio 1:5, an average intensity diameter of 170nm, a PDI of 0.072, a zeta potential of -33.8mV, and an entrapment efficiency of 88%. Moreover, in vitro stability and release studies in both simulated gastric fluid (SGF) and simulated intestinal fluid (SIF), and preliminary in vitro cytotoxicity studies revealed that LA-MEM loaded SLNs could represent potential candidate for an in vivo investigation as DDS for the brain since it resulted devoid of citotoxicity and able to release the free codrug.

Synthesis of a novel cyclic prodrug of S-allyl-glutathione able to attenuate LPS-induced ROS production through the inhibition of MAPK pathways in U937 cells.

A novel cyclic prodrug of S-allyl-glutathione (CP11), obtained by using an acyloxy-alkoxy linker, was estimated for its pharmacokinetic and biological properties. The stability of CP11 was evaluated at pH 1.2, 7.4, in simulated fluids with different concentrations of enzymes, and in human plasma. The anti-inflammatory ability of CP11 was assessed in U937 cells, an immortalized human monocyte cell line. Results showed that CP11 is stable at acidic pH showing a possible advantage for oral delivery due to the longer permanence in the stomach. Having a permeability coefficient of 2.49 × 10(-6) cm s(-1), it was classified as discrete BBB-permeable compound. Biological studies revealed that CP11 is able to modulate inflammation mediated by LPS in U937 cells preventing the increase of ROS intracellular levels through interaction with the MAPK pathway.

Transdermal donepezil on the treatment of Alzheimer's disease

Alzheimer’s disease (AD) is the most common type of senile dementia, characterized by cognitive deficits related to degeneration of cholinergic neurons. The first anti-Alzheimer drugs approved by the Food and Drug Administration were the cholinesterase inhibitors (ChEIs), which are capable of improving cholinergic neurotransmission by inhibiting acetylcholinesterase. The most common ChEIs used to treat cognitive symptoms in mild to moderate AD are rivastigmine, galantamine, and donepezil. In particular, the lattermost drug has been widely used to treat AD patients worldwide because it is significantly less hepatotoxic and better tolerated than its predecessor, tetrahydroaminoacridine. It also demonstrates high selectivity towards acetylcholinesterase inhibition and has a long duration of action. The formulations available for donepezil are immediate release (5 or 10 mg), sustained release (23 mg), and orally disintegrating (5 or 10 mg) tablets, all of which are intended for oral-route administration. Since the oral donepezil therapy is associated with adverse events in the gastrointestinal system and in plasma fluctuations, an alternative route of administration, such as the transdermal one, has been recently attempted. The goal of this paper is to provide a critical overview of AD therapy with donepezil, focusing particularly on the advantages of the transdermal over the oral route of administration.

Solid lipid nanoparticles as a drug delivery system for the treatment of neurodegenerative diseases

ABSTRACT Introduction: The failure of many molecules as CNS bioactive compounds is due to many restrictions: poor water solubility, intestinal absorption, in vivo stability, bioavailability, therapeutic effectiveness, side effects, plasma fluctuations, and difficulty crossing physiological barriers, like the brain blood barrier (BBB), to deliver the drug directly to the site of action. Area covered: Nanotechnology-based approaches with the employment of liposomes, micelles, dendrimers, and solid lipid nanoparticles (SLN) as drug delivery systems, are used to overcome the above reported limitations. Here, we focus on the delivery of drugs based on SLN formulation to treat neurodegenerative diseases. Notably, SLN have the ability to protect drugs from chemical and enzymatic degradation, direct the active compound towards the target site with a substantial reduction of toxicity for the adjacent tissues, and pass physiological barriers increasing bioavailability without resorting to high dosage forms. Expert opinion: We believe that SLN could represent a suitable tool to pass the BBB and permit drugs to reach damaged areas of the CNS in patients affected by neurodegenerative pathologies, such as Alzheimer’s and Parkinson’s diseases.

Carvacrol Codrugs: A New Approach in the Antimicrobial Plan

Objective The increasing prevalence of antibiotic-resistant bacterial infections led to identify alternative strategies for a novel therapeutic approach. In this study, we synthesized ten carvacrol codrugs – obtained linking the carvacrol hydroxyl group to the carboxyl moiety of sulphur-containing amino acids via an ester bond – to develop novel compounds with improved antimicrobial and antibiofilm activities and reduced toxicity respect to carvacrol alone. Method All carvacrol codrugs were screened against a representative panel of Gram positive (S. aureus and S. epidermidis), Gram negative (E. coli and P. aeruginosa) bacterial strains and C. albicans, using broth microdilution assays. Findings Results showed that carvacrol codrug 4 possesses the most notable enhancement in the anti-bacterial activity displaying MIC and MBC values equal to 2.5 mg/mL for all bacterial strains, except for P. aeruginosa ATCC 9027 (MIC and MBC values equal to 5 mg/mL and 10 mg/mL, respectively). All carvacrol codrugs 1-10 revealed good antifungal activity against C. albicans ATCC 10231. The cytotoxicity assay showed that the novel carvacrol codrugs did not produce human blood hemolysis at their MIC values except for codrugs 8 and 9. In particular, deepened experiments performed on carvacrol codrug 4 showed an interesting antimicrobial effect on the mature biofilm produced by E. coli ATCC 8739, respect to the carvacrol alone. The antimicrobial effects of carvacrol codrug 4 were also analyzed by TEM evidencing morphological modifications in S. aureus, E. coli, and C. albicans. Conclusion The current study presents an insight into the use of codrug strategy for developing carvacrol derivatives with antibacterial and antibiofilm potentials, and reduced cytotoxicity.

Surfactant Hydrogels for the Dispersion of Carbon-Nanotube-Based Catalysts

Novel hydrogel phases based on positively charged and zwitterionic surfactants, namely, N-[p-(n-dodecyloxybenzyl)]-N,N,N-trimethylammonium bromide (pDOTABr) and p-dodecyloxybenzyldimethylamine oxide (pDOAO), which combine pristine carbon nanotubes (CNTs), were obtained, thus leading to stable dispersions and enhanced cross-linked networks. The composite hydrogel featuring a well-defined nanostructured morphology and an overall positively charged surface was shown to efficiently immobilise a polyanionic and redox-active tetraruthenium-substituted polyoxometalate (Ru4POM) by complementary charge interactions. The resulting hybrid gel has been characterised by electron microscopy techniques, whereas the electrostatic-directed assembly has been monitored by means of fluorescence spectroscopy and ζ-potential tests. This protocol offers a straightforward supramolecular strategy for the design of novel aqueous-based electrocatalytic soft materials, thereby improving the processability of CNTs while tuning their interfacial decoration with multiple catalytic domains. Electrochemical evidence confirms that the activity of the catalyst is preserved within the gel media.

Haloperidol metabolite II prodrug: Asymmetric synthesis and biological evaluation on rat C6 glioma cells

In a previous work we reported the antiproliferative effects of (±)-MRJF4, a novel haloperidol metabolite II (HP-mII) (a sigma-1 antagonist and sigma-2 agonist) prodrug, obtained through conjugation to 4-phenylbutyric acid (PhBA) [a histone deacetylase inhibitor (HDACi)] via an ester bond. As a continuation of this work, here we report the asymmetric synthesis of compounds (R)-(+)-MRJF4 and (S)-(-)-MRJF4 and the evaluation of their biological activity on rat C6 glioma cells, derived from glioblastoma multiforme (GBM), which is the most common and deadliest central nervous system (CNS) invasive malignancy. Favourable physicochemical properties, high permeability in the parallel artificial membrane permeability assay (PAMPA), good enzymatic and chemical stability, in vivo anticancer activity, associated with the capacity to reduce cell viability and to increase cell death by apoptosis, render compound (R)-(+)-MRJF4 a promising candidate for the development of a useful therapeutic for gliomas therapy.

New Flurbiprofen Derivatives: Synthesis, Membrane Affinity and Evaluation of in Vitro Effect on β-Amyloid Levels

Alzheimer’s disease (AD) is characterized by irreversible and progressive loss of memory and cognition and profound neuronal loss. Current therapeutic strategies for the treatment of AD have been directed to a variety of targets with the aim of reversing or preventing the disease but, unfortunately, the available treatments often produce no significant clinical benefits. During the last decades compounds that inhibit or modulate γ-secretase, reducing β amyloid (Aβ) levels, have been considered as potential therapeutics for AD. Among these the (R)-enantiomer of flurbiprofen (FLU) seems to be very promising, but it shows low brain penetration. In this study, in order to improve the properties of FLU against Alzheimer’s pathogenesis we synthesized some novel FLU lipophilic analogues. Lipophilicity of the new molecules has been characterized in terms of clogP, log KC18/W and log K IAM/W values. Permeability has been determined in both gastrointestinal PAMPA (PAMPA-GI) at different pH values and in brain blood barrier PAMPA (PAMPA-BBB) models. They were also tested for their ability to inhibit in vitro γ-secretase activity using rat CTXTNA2 astrocytes. Interestingly, the investigated molecules demonstrated to reduce Aβ 42 levels without affecting the amyloid precursor protein APP level in a clear concentrations-dependent manner.

Early life exposure to permethrin: a progressive animal model of Parkinson's disease.

INTRODUCTION Oxidative stress, alpha-synuclein changes, mitochondrial complex I defects and dopamine loss, observed in the striatum of rats exposed to the pesticide permethrin in early life, could represent neuropathological hallmarks of Parkinsons disease (PD). Nevertheless, an animal model of PD should also fulfill criteria of face and predictive validities. This study was designed to: 1) verify dopaminergic status in the striatum and substantia nigra pars compacta; 2) recognize non-motor symptoms; 3) investigate the time-course development of motor disabilities; 4) assess L-Dopa effectiveness on motor symptoms in rats previously exposed to permethrin in early life. METHODS The permethrin-treated group received 34mg/kg daily of permethrin from postnatal day 6 to 21, whereas the age-matched control group was administered with the vehicle only. RESULTS At adolescent age, the permethrin-treated group showed decreased levels of dopamine in the striatum, loss of dopaminergic neurons in the substantia nigra pars compacta and cognitive impairments. Motor coordination defects appeared at adult age (150days old) in permethrin-treated rats on rotarod and beam walking tasks, whereas no differences between the treated and control groups were detected on the foot print task. Predictive validity was evaluated by testing the ability of L-Dopa (5, 10 or 15mg/kg, os) to restore the postural instability in permethrin-treated rats (150days old) tested in a beam walking task. The results revealed full reversal of motor deficits starting from 10mg/kg of L-Dopa. DISCUSSION The overall results indicate that this animal model replicates the progressive, time-dependent nature of the neurodegenerative process in Parkinsons disease.