An evolutionary view of the Fusarium core genome.

Fusarium, a member of the Ascomycota fungi, encompasses several pathogenic species significant to plants and animals. Some phytopathogenic species have received special attention due to their negative economic impact on the agricultural industry around the world. Traditionally, identification and taxonomic analysis of Fusarium have relied on morphological and phenotypic features, including the fungal host, leading to taxonomic conflicts that have been solved using molecular systematic technologies. In this work, we applied a phylogenomic approach that allowed us to resolve the evolutionary history of the species complexes of the genus and present evidence that supports the F. ventricosum species complex as the most basal lineage of the genus. Additionally, we present evidence that proposes modifications to the previous hypothesis of the evolutionary history of the F. staphyleae, F. newnesense, F. nisikadoi, F. oxysporum, and F. fujikuroi species complexes. Evolutionary analysis showed that the genome GC content tends to be lower in more modern lineages, in both, the whole-genome and core-genome coding DNA sequences. In contrast, genome size gain and losses are present during the evolution of the genus. Interestingly, core genome duplication events positively correlate with genome size. Evolutionary and genome conservation analysis supports the F3 hypothesis of Fusarium as a more compact and conserved group in terms of genome conservation. By contrast, outside of the F3 hypothesis, the most basal clades only share 8.8% of its genomic sequences with the F3 clade.

Dual Inhibitors of Brain Carbonic Anhydrases and Monoamine Oxidase-B Efficiently Protect against Amyloid-ß-Induced Neuronal Toxicity, Oxidative Stress, and Mitochondrial Dysfunction.

We report here the first dual inhibitors of brain carbonic anhydrases (CAs) and monoamine oxidase-B (MAO-B) for the management of Alzheimer's disease. Classical CA inhibitors (CAIs) such as methazolamide prevent amyloid-ß-peptide (Aß)-induced overproduction of reactive oxygen species (ROS) and mitochondrial dysfunction. MAO-B is also implicated in ROS production, cholinergic system disruption, and amyloid plaque formation. In this work, we combined a reversible MAO-B inhibitor of the coumarin and chromone type with benzenesulfonamide fragments as highly effective CAIs. A hit-to-lead optimization led to a significant set of derivatives showing potent low nanomolar inhibition of the target brain CAs (KIs in the range of 0.1-90.0 nM) and MAO-B (IC50 in the range of 6.7-32.6 nM). Computational studies were conducted to elucidate the structure-activity relationship and predict ADMET properties. The most effective multitarget compounds totally prevented Aß-related toxicity, reverted ROS formation, and restored the mitochondrial functionality in an SH-SY5Y cell model surpassing the efficacy of single-target drugs.

Targeting Lewy body dementia with neflamapimod-rasagiline hybrids.

Lewy body dementia (LBD) represents the second most common neurodegenerative dementia but is a quite underexplored therapeutic area. Nepflamapimod (1) is a brain-penetrant selective inhibitor of the alpha isoform of the mitogen-activated serine/threonine protein kinase (MAPK) p38α, recently repurposed for LBD due to its remarkable antineuroinflammatory properties. Neuroprotective propargylamines are another class of molecules with a therapeutical potential against LBD. Herein, we sought to combine the antineuroinflammatory core of 1 and the neuroprotective propargylamine moiety into a single molecule. Particularly, we inserted a propargylamine moiety in position 4 of the 2,6-dichlorophenyl ring of 1, generating neflamapimod-propargylamine hybrids 3 and 4. These hybrids were evaluated using several cell models, aiming to recapitulate the complexity of LBD pathology through different molecular mechanisms. The N-methyl-N-propargyl derivative 4 showed a nanomolar p38α-MAPK inhibitory activity (IC50 = 98.7 nM), which is only 2.6-fold lower compared to that of the parent compound 1, while displaying no hepato- and neurotoxicity up to 25 µM concentration. It also retained a similar immunomodulatory profile against the N9 microglial cell line. Gratifyingly, at 5 µM concentration, 4 demonstrated a neuroprotective effect against dexamethasone-induced reactive oxygen species production in neuronal cells that was higher than that of 1.

Carcinosarcoma of the parotid gland: a case report and review of the literature.

BACKGROUND: Carcinosarcoma of the parotid gland is an extremely rare malignancy comprising of 0.04-0.16% of all salivary gland tumors. This is the first case of an adenoid cystic carcinoma with chondrosarcoma to the best of our knowledge. They consist of distinct carcinomatous and sarcomatous components and may arise de novo or from a preexisting pleomorphic adenoma. CASE PRESENTATION: Herein we present a case of an 80-year-old white female who presented with progressively increasing left facial swelling over 6 weeks. Magnetic Resonance Imagining revealed a mass (3.4 cm) in the parotid gland with a predominant cystic/necrotic component. The cytology was atypical (Milan3) and a total parotidectomy and selective lymph node dissection was done. The resection showed extensive necrosis with high grade sarcomatous (chondrosarcoma) areas. The epithelial component was adenoid cystic carcinoma with perineural invasion. The patient is currently undergoing radiotherapy of the tumor bed and skull base due to propensity of perineural invasion of the adenoid cystic component. The most common carcinomas in carcinosarcomas of salivary glands are adenocarcinoma and squamous cell carcinoma. CONCLUSION: Carcinosarcoma is a high-grade aggressive lesion with a poor prognosis and should be treated aggressively. More studies are needed to understand the origin of these tumors.

Unraveling the In Vitro Toxicity Profile of Psychedelic 2C Phenethylamines and Their N-Benzylphenethylamine (NBOMe) Analogues.

Mescaline derivative (2C phenethylamines) drugs have been modified by the introduction of a N-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 para position of the 2C phenethylamines aromatic ring) and 2C-B (insertion of a bromide in the para 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. Cytotoxicity, oxidative stress, metabolic and energetic studies were performed to evaluate the main pathways involved in their toxicity. Our results demonstrated that the presence of the N-2-methoxybenzyl group significantly increased the in vitro cytotoxicity of 2C phenethylamines drugs in both cell lines, with the NBOMe drugs presenting lower EC50 values when compared to their counterparts. Consistently, our data showed a correlation between the drug's lipophilicity and the EC50 values, except for 2C-B. The 2C-B presented higher cytotoxic effects in both cell lines than mescaline-NBOMe, a result that can be explained by its higher passive permeability. All the NBOMe derivatives were able to cross the blood-brain barrier. Considering metabolic studies, the cytotoxicity of these drugs was shown to be influenced by inhibition of cytochrome P450 (CYP), which suggests a potential role of this enzyme complex, especially CYP3A4 and CYP2D6 isoenzymes in SH-SY5Y cells, in their detoxification or bioactivation. Furthermore, in differentiated SH-SY5Y cells, the drugs were able to induce mitochondrial membrane depolarization, and to disrupt GSH and ATP intracellular levels, these effects being concentration dependent and more pronounced for the NBOMe derivatives. No ROS overproduction was detected for any of the drugs in the tested experimental conditions. A correlation between a drug's lipophilicity and the EC50 values in both cell lines, except for 2C-B, was also obtained. In summary, the introduction of a NBOMe moiety to the parent drugs significantly increases their lipophilicity, brain permeability and cytotoxic effects, with GSH and ATP homeostasis disruption. The inhibition of CYP3A4 and CYP2D6 emphasized that CYP-mediated metabolism impacts the toxicity of these drugs.

A high throughput blood-brain barrier model incorporating shear stress with improved predictive power for drug discovery.

The blood-brain barrier is a key structure regulating the health of the brain and access of drugs and pathogens to neural tissue. Shear stress is a key regulator of the blood-brain barrier; however, the commonly used multi-well vitro models of the blood-brain barrier do not incorporate shear stress. In this work, we designed and validated a high-throughput system for simulating the blood-brain barrier that incorporates physiological flow and incorporates an optimized cellular model of the blood-brain barrier. This system can perform assays of blood-brain barrier function with shear stress, with 48 independent assays simultaneously. Using the high throughput assay, we conducted drug screening assays to explore the effects of compounds for opening or closing blood-brain barrier. Our studies revealed that assays with shear stress were more predictive and were able to identify compounds known to modify the blood-brain barrier function while static assays were not. Overall, we demonstrate an optimized, high throughput assay for simulating the blood-brain barrier that incorporates shear stress and is practical for use in drug screening and other high throughput studies of toxicology.

Rivastigmine-Benzimidazole Hybrids as Promising Multitarget Metal-Modulating Compounds for Potential Treatment of Neurodegenerative Diseases.

With the goal of combating the multi-faceted Alzheimer's disease (AD), a series of Rivastigmine-Benzimidazole (RIV-BIM) hybrids was recently reported by us as multitarget-directed ligands, thanks to their capacity to tackle important hallmarks of AD. In particular, they exhibited antioxidant activity, acted as cholinesterase inhibitors, and inhibited amyloid-ß (Aß) aggregation. Herein, we moved forward in this project, studying their ability to chelate redox-active biometal ions, Cu(II) and Fe(III), with widely recognized roles in the generation of oxidative reactive species and in protein misfolding and aggregation in both AD and Parkinson's disease (PD). Although Cu(II) chelation showed higher efficiency for the positional isomers of series 5 than those of series 4 of the hybrids, the Aß-aggregation inhibition appears more dependent on their capacity for fibril intercalation than on copper chelation. Since monoamine oxidases (MAOs) are also important targets for the treatment of AD and PD, the capacity of these hybrids to inhibit MAO-A and MAO-B was evaluated, and they showed higher activity and selectivity for MAO-A. The rationalization of the experimental evaluations (metal chelation and MAO inhibition) was supported by computational molecular modeling studies. Finally, some compounds showed also neuroprotective effects in human neuroblastoma (SH-SY5Y cells) upon treatment with 1-methyl-4-phenylpyridinium (MPP+), a neurotoxic metabolite of a Parkinsonian-inducing agent.

Molecular mechanisms of ferroptosis and their involvement in brain diseases.

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. RSL3, statins, Ml162 and Ml210 induce ferroptosis by inhibiting glutathione peroxidase 4 (GPX4), which is responsible for preventing the formation of lipid peroxides, and FIN56 and withaferin trigger GPX4 degradation. On the other side, ferroptosis inhibitors include ferrostatin-1, liproxstatin-1, α-tocopherol, zileuton, FSP1, CoQ10 and BH4, which interrupt the lipid peroxidation cascade. Additionally, deferoxamine, deferiprone and N-acetylcysteine, by targeting other cellular pathways, have also been classified as ferroptosis inhibitors. Increased evidence has established the involvement of ferroptosis in distinct brain diseases, including Alzheimer's, Parkinson's and Huntington's diseases, amyotrophic lateral sclerosis, multiple sclerosis, and Friedreich's ataxia. Thus, a deep understanding of how ferroptosis contributes to these diseases, and how it can be modulated, can open a new window of opportunities for novel therapeutic strategies and targets. Other studies have shown a sensitivity of cancer cells with mutated RAS to ferroptosis induction and that chemotherapeutic agents and ferroptosis inducers synergize in tumor treatment. Thus, it is tempting to consider that ferroptosis may arise as a target mechanistic pathway for the treatment of brain tumors. Therefore, this work provides an up-to-date review on the molecular and cellular mechanisms of ferroptosis and their involvement in brain diseases. In addition, information on the main ferroptosis inducers and inhibitors and their molecular targets is also provided.

Phytochemicals and quaternary phosphonium ionic liquids: Connecting the dots to develop a new class of antimicrobial agents.

INTRODUCTION: The infections by multidrug-resistant bacteria are a growing threat to human health, and the efficacy of the available antibiotics is gradually decreasing. As such, new antibiotic classes are urgently needed. OBJECTIVES: This study aims to evaluate the antimicrobial activity, safety and mechanism of action of phytochemical-based triphenylphosphonium (TPP+) conjugates. METHODS: A library of phytochemical-based TPP+ conjugates was repositioned and extended, and its antimicrobial activity was evaluated against a panel of Gram-positive (methicillin-resistant Staphylococcus aureus - MRSA) and Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii) and fungi (Candida albicans, Cryptococcus neoformans var. grubii). The compounds' cytotoxicity and haemolytic profile were also evaluated. To unravel the mechanism of action of the best compounds, the alterations in the surface charge, bacterial membrane integrity, and cytoplasmic leakage were assessed. RESULTS: Structure-activity-toxicity data revealed the contributions of the different structural components (phenolic ring, carbon-based spacers, carboxamide group, alkyl linker) to the compounds' bioactivity and safety. Dihydrocinnamic derivatives 5 m and 5n stood out as safe, potent and selective antibacterial agents against S. aureus (MIC < 0.25 µg/mL; CC50 > 32 µg/mL; HC10 > 32 µg/mL). Mechanistic studies suggest that the antibacterial activity of compounds 5 m and 5n may result from interactions with the bacterial cell wall and membrane. CONCLUSIONS: Collectively, these studies demonstrate the potential of phytochemical-based TPP+ conjugates as a new class of antibiotics.

Modulating Cytotoxicity with Lego-like Chemistry: Upgrading Mitochondriotropic Antioxidants with Prototypical Cationic Carrier Bricks.

Although the lipophilic triphenylphosphonium (TPP+) cation is widely used to target antioxidants to mitochondria, TPP+-based derivatives have shown cytotoxicity in several biological in vitro models. We confirmed that Mito.TPP 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 (Mito.PICO, Mito.ISOQ, and Mito.IMIDZ). As opposed to Mito.TPP, these novel compounds were not cytotoxic to SH-SY5Y and HepG2 cells up to 50 µM and after 24 h of incubation. All of the cationic derivatives accumulated inside the mitochondrial matrix and acted as neuroprotective agents against iron(III), hydrogen peroxide, and tert-butyl hydroperoxide insults. The overall data showed that nitrogen-based cationic carriers can modulate the biological performance of mitochondria-directed antioxidants and are an alternative to the TPP cation.

Drug discovery and amyotrophic lateral sclerosis: Emerging challenges and therapeutic opportunities.

Amyotrophic lateral sclerosis (ALS) is characterized by the degeneration of upper and lower motor neurons (MNs) leading to paralysis and, ultimately, death by respiratory failure 3-5 years after diagnosis. Edaravone and Riluzole, the only drugs currently approved for ALS treatment, only provide mild symptomatic relief to patients. Extraordinary progress in understanding the biology of ALS provided new grounds for drug discovery. Over the last two decades, mitochondria and oxidative stress (OS), iron metabolism and ferroptosis, and the major regulators of hypoxia and inflammation - HIF and NF-κB - emerged as promising targets for ALS therapeutic intervention. In this review, we focused our attention on these targets to outline and discuss current advances in ALS drug development. Based on the challenges and the roadblocks, we believe that the rational design of multi-target ligands able to modulate the complex network of events behind the disease can provide effective therapies in a foreseeable future.

Boosting caffeic acid performance as antioxidant and monoamine oxidase B/catechol-O-methyltransferase inhibitor.

Increased oxidative stress (OS) and depletion of nigrostriatal dopamine (DA) are closely linked to the neurodegeneration observed in Parkinson's Disease (PD). Caffeic acid (CA)-based antioxidants were developed, and their inhibitory activities towards monoamine oxidases (MAOs) and catechol O-methyltransferases (COMT) were screened. The results showed that the incorporation of an extra double bond maintained or even boosted the antioxidant properties of CA. α-CN derivatives displayed redox potentials (Ep) similar to CA (1) and inhibited hMAO-B with low µM IC50 values. Moreover, catechol amides acted as MB-COMT inhibitors, showing IC50 values within the low µM range. In general, CA derivatives presented safe cytotoxicity profiles at concentrations up to 10 µM. The formation of reactive oxygen species (ROS) induced by CA derivatives may be underlying the cytotoxic effects observed at higher concentrations. Catechol amides 3-6, 8-11 at 10 µM protected cells against oxidative damage. Compounds 3 and 8 were predicted to cross the blood-brain barrier (BBB) by passive diffusion. In summary, we report for the first time BBB-permeant CA-based multitarget lead compounds that may restore DAergic neurotransmission (dual hMAO-B/MB-COMT inhibition) and prevent oxidative damage. The data represents a groundbreaking advancement towards the discovery of the next generation of new drugs for PD.

Riluzole-Rasagiline Hybrids: Toward the Development of Multi-Target-Directed Ligands for Amyotrophic Lateral Sclerosis.

Polypharmacology is a new trend in amyotrophic lateral sclerosis (ALS) therapy and an effective way of addressing a multifactorial etiology involving excitotoxicity, mitochondrial dysfunction, oxidative stress, and microglial activation. Inspired by a reported clinical trial, we converted a riluzole (1)-rasagiline (2) combination into single-molecule multi-target-directed ligands. By a ligand-based approach, the highly structurally integrated hybrids 3-8 were designed and synthesized. Through a target- and phenotypic-based screening pipeline, we identified hit compound 6. It showed monoamine oxidase A (MAO-A) inhibitory activity (IC50 = 6.9 µM) rationalized by in silico studies as well as in vitro brain permeability. By using neuronal and non-neuronal cell models, including ALS-patient-derived cells, we disclosed for 6 a neuroprotective/neuroinflammatory profile similar to that of the parent compounds and their combination. Furthermore, the unexpected MAO inhibitory activity of 1 (IC50 = 8.7 µM) might add a piece to the puzzle of its anti-ALS molecular profile.

Molecular Modeling and Experimental Evaluation of Non-Chiral Components of Bergamot Essential Oil with Inhibitory Activity against Human Monoamine Oxidases.

Human monoamine oxidases (hMAOs) are well-established targets for the treatment of neurological disorders such as depression, Parkinson's disease and Alzheimer's disease. Despite the efforts carried out over the years, few selective and reversible MAO inhibitors are on the market. Thus, a continuous search for new compounds is needed. Herein, MAO inhibitors were searched among the non-chiral constituents of Bergamot Essential Oil (BEO) with the aid of computational tools. Accordingly, molecular modeling simulations were carried out on both hMAO-A and hMAO-B for the selected constituents. The theoretically predicted target recognition was then used to select the most promising compounds. Among the screened compounds, Bergamottin, a furocoumarin, showed selective hMAO-B inhibitory activity, fitting its active site well. Molecular dynamics simulations were used to deeply analyze the target recognition and to rationalize the selectivity preference. In agreement with the computational results, experimental studies confirmed both the hMAO inhibition properties of Bergamottin and its preference for the isoform B.

Early Genomic, Epidemiological, and Clinical Description of the SARS-CoV-2 Omicron Variant in Mexico City.

Omicron is the most mutated SARS-CoV-2 variant-a factor that can affect transmissibility, disease severity, and immune evasiveness. Its genomic surveillance is important in cities with millions of inhabitants and an economic center, such as Mexico City. Results. From 16 November to 31 December 2021, we observed an increase of 88% in Omicron prevalence in Mexico City. We explored the R346K substitution, prevalent in 42% of Omicron variants, known to be associated with immune escape by monoclonal antibodies. In a phylogenetic analysis, we found several independent exchanges between Mexico and the world, and there was an event followed by local transmission that gave rise to most of the Omicron diversity in Mexico City. A haplotype analysis revealed that there was no association between haplotype and vaccination status. Among the 66% of patients who have been vaccinated, no reported comorbidities were associated with Omicron; the presence of odynophagia and the absence of dysgeusia were significant predictor symptoms for Omicron, and the RT-qPCR Ct values were lower for Omicron. Conclusions. Genomic surveillance is key to detecting the emergence and spread of SARS-CoV-2 variants in a timely manner, even weeks before the onset of an infection wave, and can inform public health decisions and detect the spread of any mutation that may affect therapeutic efficacy.

Mapping Chromone-3-Phenylcarboxamide Pharmacophore: Quid Est Veritas?

Chromone-3-phenylcarboxamides (Crom-1 and Crom-2) were identified as potent, selective, and reversible inhibitors of human monoamine oxidase B (hMAO-B). Since they exhibit some absorption, distribution, metabolism, and excretion (ADME)-toxicity liabilities, new derivatives were synthesized to map the chemical structural features that compose the pharmacophore, a process vital for lead optimization. Structure-activity relationship data, supported by molecular docking studies, provided a rationale for the contribution of the heterocycle's rigidity, the carbonyl group, and the benzopyran heteroatom for hMAO-B inhibitory activity. From the study, N-(3-chlorophenyl)-4H-thiochromone-3-carboxamide (31) (hMAO-B IC50 = 1.52 ± 0.15 nM) emerged as a reversible tight binding inhibitor with an improved pharmacological profile. In in vitro ADME-toxicity studies, compound 31 showed a safe cytotoxicity profile in Caco-2, SH-SY5Y, HUVEC, HEK-293, and MCF-7 cells, did not present cardiotoxic effects, and did not affect P-gp transport activity. Compound 31 also protected SH-SY5Y cells from iron(III)-induced damage. Collectively, these studies highlighted compound 31 as the first-in-class and a suitable candidate for in vivo preclinical investigation.

Biomechanical regulation of breast cancer metastasis and progression.

Physical activity has been consistently linked to decreased incidence of breast cancer and a substantial increase in the length of survival of patients with breast cancer. However, the understanding of how applied physical forces directly regulate breast cancer remains limited. We investigated the role of mechanical forces in altering the chemoresistance, proliferation and metastasis of breast cancer cells. We found that applied mechanical tension can dramatically alter gene expression in breast cancer cells, leading to decreased proliferation, increased resistance to chemotherapeutic treatment and enhanced adhesion to inflamed endothelial cells and collagen I under fluidic shear stress. A mechanistic analysis of the pathways involved in these effects supported a complex signaling network that included Abl1, Lck, Jak2 and PI3K to regulate pro-survival signaling and enhancement of adhesion under flow. Studies using mouse xenograft models demonstrated reduced proliferation of breast cancer cells with orthotopic implantation and increased metastasis to the skull when the cancer cells were treated with mechanical load. Using high throughput mechanobiological screens we identified pathways that could be targeted to reduce the effects of load on metastasis and found that the effects of mechanical load on bone colonization could be reduced through treatment with a PI3Kγ inhibitor.

Comparative venomics and preclinical efficacy evaluation of a monospecific Hemachatus antivenom towards sub-Saharan Africa cobra venoms.

Cobras are the most medically important elapid snakes in Africa. The African genera Naja and Hemachatus include snakes with neurotoxic and cytotoxic venoms, with shared biochemical, toxinological and antigenic characteristics. We have studied the antigenic cross-reactivity of four sub-Saharan Africa cobra venoms against an experimental monospecific Hemachatus haemachatus antivenom through comparative proteomics, preclinical assessment of neutralization, and third generation antivenomics. The venoms of H. haemachatus, N. annulifera, N. mossambica and N. nigricollis share an overall qualitative family toxin composition but depart in their proportions of three-finger toxin (3FTxs) classes, phospholipases A2 (PLA2s), snake venom metalloproteinases (SVMPs), and cysteine-rich secretory proteins (CRISPs). A monospecific anti-Hemachatus antivenom produced by Costa Rican Instituto Clodomiro Picado neutralized the lethal activity of the homologous and heterologous neuro/cytotoxic (H. haemachatus) and cyto/cardiotoxic (N. mossambica and N. nigricollis) venoms of the three spitting cobras sampled, while it was ineffective against the lethal and toxic activities of the neurotoxic venom of the non-spitting snouted cobra N. annulifera. The ability of the anti-Hemachatus-ICP antivenom to neutralize toxic (dermonecrotic and anticoagulant) and enzymatic (PLA2) activities of spitting cobra venoms suggested a closer kinship of H. haemachatus and Naja subgenus Afrocobra spitting cobras than to Naja subgenus Uraeus neurotoxic taxa. These results were confirmed by third generation antivenomics. BIOLOGICAL SIGNIFICANCE: African Naja species represent the most widespread medically important elapid snakes across Africa. To gain deeper insight into the spectrum of medically relevant toxins, we compared the proteome of three spitting cobras (Hemachatus haemachatus, Naja mossambica and N. nigricollis) and one non-spitting cobra (N. annulifera). Three finger toxins and phospholipases A2 are the two major protein families among the venoms analyzed. The development of antivenoms of broad species coverage is an urgent need in sub-Saharan Africa. An equine antivenom raised against H. haemachatus venom showed cross-reactivity with the venoms of H. haemachatus, N. mossambica and N. nigricollis, while having poor recognition of the venom of N. annulifera. This immunological information provides clues for the design of optimum venom mixtures for the preparation of broad spectrum antivenoms.

Fine-Tuning the Biological Profile of Multitarget Mitochondriotropic Antioxidants for Neurodegenerative Diseases.

Neurotransmitter depletion and mitochondrial dysfunction are among the multiple pathological events that lead to neurodegeneration. Following our previous studies related with the development of multitarget mitochondriotropic antioxidants, this study aims to evaluate whether the π-system extension on the chemical scaffolds of AntiOXCIN2 and AntiOXCIN3 affects their bioactivity and safety profiles. After the synthesis of four triphenylphosphonium (TPP+) conjugates (compounds 2-5), we evaluated their antioxidant properties and their effect on neurotransmitter-metabolizing enzymes. All compounds were potent equine butyrylcholinesterase (eqBChE) and moderate electric eel acetylcholinesterase (eeAChE) inhibitors, with catechols 4 and 5 presenting lower IC50 values than AntiOXCIN2 and AntiOXCIN3, respectively. However, differences in the inhibition potency and selectivity of compounds 2-5 towards non-human and human cholinesterases (ChEs) were observed. Co-crystallization studies with compounds 2-5 in complex with human ChEs (hChEs) showed that these compounds exhibit different binging modes to hAChE and hBChE. Unlike AntiOXCINs, compounds 2-5 displayed moderate human monoamine oxidase (hMAO) inhibitory activity. Moreover, compounds 4 and 5 presented higher ORAC-FL indexes and lower oxidation potential values than the corresponding AntiOXCINs. Catechols 4 and 5 exhibited broader safety windows in differentiated neuroblastoma cells than benzodioxole derivatives 2 and 3. Compound 4 is highlighted as a safe mitochondria-targeted antioxidant with dual ChE/MAO inhibitory activity. Overall, this work is a contribution for the development of dual therapeutic agents addressing both mitochondrial oxidative stress and neurotransmitter depletion.

Design of novel monoamine oxidase-B inhibitors based on piperine scaffold: Structure-activity-toxicity, drug-likeness and efflux transport studies.

Piperine has been associated with neuroprotective effects and monoamine oxidase (MAO) inhibition, thus being an attractive scaffold to develop new antiparkinsonian agents. Accordingly, we prepared a small library of piperine derivatives and screened the inhibitory activities towards human MAO isoforms (hMAO-A and hMAO-B). Structure-activity relationship (SAR) studies pointed out that the combination of α-cyano and benzyl ester groups increased both potency and selectivity towards hMAO-B. Kinetic experiments with compounds 7, 10 and 15 indicated a competitive hMAO-B inhibition mechanism. Compounds 15 and 16, at 10 µM, caused a small but significant decrease in P-gp efflux activity in Caco-2 cells. Compound 15 stands out as the most potent piperine-based hMAO-B inhibitor (IC50 = 47.4 nM), displaying favourable drug-like properties and a broad safety window. Compound 15 is thus a suitable candidate for lead optimization and the development of multitarget-directed ligands.