Synthesis and in vitro evaluation of leishmanicidal and trypanocidal activities of N-quinolin-8-yl-arylsulfonamides

In the present paper 12 N-quinolin-8-yl-arylsulfonamides synthesized by coupling 8-aminoquinolines with various arylsulfonylchlorides were assayed in vitro against Leishmania amazonensis, Leishmania chagasi and Trypanosoma cruzi strains. This series of new compounds were found to be selective for Leishmania spp. promastigote and amastigote forms. The most active compound was the N-(8-quinolyl)-3,5-difluoro-benzenesulfonamide 10 with an IC₅₀ against L. amazonensis and L. chagasi of 2.12 and 0.45 μM, respectively. The less cytotoxic biphenyl derivative 7 was very effective against intracellular L. amazonensis with a reduction of macrophage cell infection of 82.1% at 25 μM. In addition, a copper complex 17 of an inactive ligand was readily synthesized and showed high leishmanicidal and trypanocidal activity against both extra and intracellular forms.     

Partial rescue of Rett syndrome by ω-3 polyunsaturated fatty acids (PUFAs) oil

Evidence of enhanced oxidative stress (O.S.) and lipid peroxidation has been reported in patients with Rett syndrome (RTT), a relatively rare neurodevelopmental disorder progressing in 4-stages, and mainly caused by loss-of-function mutations in the methyl-CpG-binding protein 2. No effective therapy for preventing or arresting the neurologic regression in the disease in its various clinical presentations is available. Based on our prior evidence of enhanced O.S. and lipid peroxidation in RTT patients, herein we tested the possible therapeutic effects of ω-3 polyunsaturated fatty acids (ω-3 PUFAs), known antioxidants with multiple effects, on the clinical symptoms and O.S. biomarkers in the earliest stage of RTT. A total of 20 patients in stage I were randomized (n = 10 subjects per arm) to either oral supplementation with ω-3 PUFAs-containing fish oil (DHA: 72.9 ± 8.1 mg/kg b.w./day; EPA: 117.1 ± 13.1 mg/kg b.w./day; total ω-3 PUFAs: 246.0 ± 27.5 mg/kg b.w./day) for 6 months or no treatment. Primary outcomes were potential changes in clinical symptoms, with secondary outcomes including variations for five O.S. markers in plasma and/or erythrocytes (nonprotein bound iron, F₂-dihomo-isoprostanes, F₃-isoprostanes, F₄-neuroprostanes, and F₂-isoprostanes). A significant reduction in the clinical severity (in particular, motor-related signs, nonverbal communication deficits, and breathing abnormalities) together with a significant decrease in all the examined O.S. markers was observed in the ω-3 PUFAs supplemented patients, whereas no significant changes were evidenced in the untreated group. For the first time, these findings strongly suggest that a dietary intervention in this genetic disease at an early stage of its natural history can lead to a partial clinical and biochemical rescue.

Electronic supplementary material

The online version of this article (doi:10.1007/s12263-012-0285-7) contains supplementary material, which is available to authorized users.     

Leishmania amazonensis Growth Inhibitors: Biological and Theoretical Features of Sulfonamide 4-Methoxychalcone Derivatives

Current drugs for treating leishmaniasis are still associated with significant toxicity and failure rates. Thus, new effective and less toxic antileishmanial agents are still in need. Herein, we tested a series of sulfonamide 4-methoxychalcone derivatives against L. amazonensis promastigote and amastigote forms to identify its antileishmanial profile against this species compared to L. braziliensis. In addition, we used molecular modeling tools to determine stereoelectronic features that may lead to the antileishmanial profile. Interestingly, all tested compounds were able to affect L. amazonensis promastigote form in a concentration-dependent manner and with low cytotoxicity, except for derivative 3g. However, our results showed that compound 3f (para-Cl) presents the best profile against both L. amazonensis forms (promastigote and amastigote), differently from that observed for L. braziliensis, when compound 3i was the most active. Structure–activity relationship (SAR) analysis of these derivatives pointed molecular volume, HOMO density, and conformational aspects as important characteristics for parasitic profile. Overall, sulfonamide 4-methoxychalcone derivatives may be pointed out not only as lead compounds for treating leishmaniasis (i.e., 3f) but also as experimental tools presenting parasite-selectivity (i.e., 3i).     

MECP2 Duplication Syndrome: Evidence of Enhanced Oxidative Stress. A Comparison with Rett Syndrome

Rett syndrome (RTT) and MECP2 duplication syndrome (MDS) are neurodevelopmental disorders caused by alterations in the methyl-CpG binding protein 2 (MECP2) gene expression. A relationship between MECP2 loss-of-function mutations and oxidative stress has been previously documented in RTT patients and murine models. To date, no data on oxidative stress have been reported for the MECP2 gain-of-function mutations in patients with MDS. In the present work, the pro-oxidant status and oxidative fatty acid damage in MDS was investigated (subjects n = 6) and compared to RTT (subjects n = 24) and healthy condition (subjects n = 12). Patients with MECP2 gain-of-function mutations showed increased oxidative stress marker levels (plasma non-protein bound iron, intraerythrocyte non-protein bound iron, F₂-isoprostanes, and F₄-neuroprostanes), as compared to healthy controls (P ≤ 0.05). Such increases were similar to those observed in RTT patients except for higher plasma F₂-isoprostanes levels (P < 0.0196). Moreover, plasma levels of F₂-isoprostanes were significantly correlated (P = 0.0098) with the size of the amplified region. The present work shows unique data in patients affected by MDS. For the first time MECP2 gain-of-function mutations are indicated to be linked to an oxidative damage and related clinical symptoms overlapping with those of MECP2 loss-of-function mutations. A finely tuned balance of MECP2 expression appears to be critical to oxidative stress homeostasis, thus shedding light on the relevance of the redox balance in the central nervous system integrity.     

F2-Dihomo-isoprostanes and brain white matter damage in stage 1 Rett syndrome

Oxidative damage has been reported in Rett syndrome (RTT), a pervasive development disorder mainly caused up to 95% of cases by mutations in the X-linked methyl-CpG binding protein 2 (MeCP2) gene. We have recently synthesized F₂-Dihomo-isoprostanes (F₂-Dihomo-IsoP), peroxidation products from adrenic acid (C22:4 n − 6, AdA), a known component of myelin, and tested the potential value of F₂-Dihomo-IsoPs as a novel disease marker and its relationship with clinical presentation, and disease progression. F₂-Dihomo-IsoPs were determined by a gas chromatography/negative ion chemical ionization tandem mass spectrometry. The ent-7(RS)-F_2t-Dihomo-IsoP and 17-F_2t-Dihomo-IsoP were used as reference standards. The measured ions were the product ions at m/z 327 derived from the [M − 181]⁻ precursor ions (m/z 597) produced from both the derivatized ent-7(RS)-F_2t-Dihomo-IsoP and 17-F_2t-Dihomo-IsoP. Average plasma F₂-Dihomo-IsoP levels in RTT were about 1 order of magnitude higher than in healthy controls, being higher in typical RTT as compared to RTT variants, with a remarkable increase of about 2 orders of magnitude in patients at the earliest stage of the disease followed by a steady decrease during the natural clinical progression. These data indicate for the first time that quantification of F₂-Dihomo-IsoPs in plasma represents an early marker of the disease and may provide a better understanding of the pathogenic mechanisms behind the neurological regression in patients with RTT.     

Di-(2-ethylhexyl) phthalate and autism spectrum disorders

ASDs (autism spectrum disorders) are a complex group of neurodevelopment disorders, still poorly understood, steadily rising in frequency and treatment refractory. Extensive research has been so far unable to explain the aetiology of this condition, whereas a growing body of evidence suggests the involvement of environmental factors. Phthalates, given their extensive use and their persistence, are ubiquitous environmental contaminants. They are EDs (endocrine disruptors) suspected to interfere with neurodevelopment. Therefore they represent interesting candidate risk factors for ASD pathogenesis. The aim of this study was to evaluate the levels of the primary and secondary metabolites of DEHP [di-(2-ethylhexyl) phthalate] in children with ASD. A total of 48 children with ASD (male: 36, female: 12; mean age: 11±5 years) and age- and sex-comparable 45 HCs (healthy controls; male: 25, female: 20; mean age: 12±5 years) were enrolled. A diagnostic methodology, based on the determination of urinary concentrations of DEHP metabolites by HPLC-ESI-MS (HPLC electrospray ionization MS), was applied to urine spot samples. MEHP [mono-(2-ethylhexenyl) 1,2-benzenedicarboxylate], 6-OH-MEHP [mono-(2-ethyl-6-hydroxyhexyl) 1,2-benzenedicarboxylate], 5-OH-MEHP [mono-(2-ethyl-5-hydroxyhexyl) 1,2-benzenedicarboxylate] and 5-oxo-MEHP [mono-(2-ethyl-5-oxohexyl) 1,2-benzenedicarboxylate] were measured and compared with unequivocally characterized, pure synthetic compounds (>98%) taken as standard. In ASD patients, significant increase in 5-OH-MEHP (52.1%, median 0.18) and 5-oxo-MEHP (46.0%, median 0.096) urinary concentrations were detected, with a significant positive correlation between 5-OH-MEHP and 5-oxo-MEHP (r_s = 0.668, P<0.0001). The fully oxidized form 5-oxo-MEHP showed 91.1% specificity in identifying patients with ASDs. Our findings demonstrate for the first time an association between phthalates exposure and ASDs, thus suggesting a previously unrecognized role for these ubiquitous environmental contaminants in the pathogenesis of autism.     

Revealing the Complexity of a Monogenic Disease: Rett Syndrome Exome Sequencing

Rett syndrome (OMIM#312750) is a monogenic disorder that may manifest as a large variety of phenotypes ranging from very severe to mild disease. Since there is a weak correlation between the mutation type in the Xq28 disease-gene MECP2/X-inactivation status and phenotypic variability, we used this disease as a model to unveil the complex nature of a monogenic disorder. Whole exome sequencing was used to analyze the functional portion of the genome of two pairs of sisters with Rett syndrome. Although each pair of sisters had the same MECP2 (OMIM*300005) mutation and balanced X-inactivation, one individual from each pair could not speak or walk, and had a profound intellectual deficit (classical Rett syndrome), while the other individual could speak and walk, and had a moderate intellectual disability (Zappella variant). In addition to the MECP2 mutation, each patient has a group of variants predicted to impair protein function. The classical Rett girls, but not their milder affected sisters, have an enrichment of variants in genes related to oxidative stress, muscle impairment and intellectual disability and/or autism. On the other hand, a subgroup of variants related to modulation of immune system, exclusive to the Zappella Rett patients are driving toward a milder phenotype. We demonstrate that genome analysis has the potential to identify genetic modifiers of Rett syndrome, providing insight into disease pathophysiology. Combinations of mutations that affect speaking, walking and intellectual capabilities may represent targets for new therapeutic approaches. Most importantly, we demonstrated that monogenic diseases may be more complex than previously thought.