In Vitro, In Vivo and In Silico Effectiveness of LASSBio-1386, an N-Acyl Hydrazone Derivative Phosphodiesterase-4 Inhibitor, Against Leishmania amazonensis

Synthesis and Characterization of New N-acyl Hydrazone Derivatives of Carprofen as Potential Tuberculostatic Agents

N-acyl hydrazone (NAH) is recognized as a promising framework in drug design due to its versatility, straightforward synthesis, and attractive range of biological activities, including antimicrobial, antitumoral, analgesic, and anti-inflammatory properties. In the global context of increasing resistance of pathogenic bacteria to antibiotics, NAHs represent potential solutions for developing improved treatment alternatives. Therefore, this research introduces six novel derivatives of (EZ)-N'-benzylidene-2-(6-chloro-9H-carbazol-2-yl)propanehydrazide, synthesized using a microwave-assisted method. In more detail, we joined two pharmacophore fragments in a single molecule, represented by an NSAID-type carprofen structure and a hydrazone-type structure, obtaining a new series of NSAID-N-acyl hydrazone derivatives that were further characterized spectrally using FT-IR, NMR, and HRMS investigations. Additionally, the substances were assessed for their tuberculostatic activity by examining their impact on four strains of M. tuberculosis, including two susceptible to rifampicin (RIF) and isoniazid (INH), one susceptible to RIF and resistant to INH, and one resistant to both RIF and INH. The results of our research highlight the potential of the prepared compounds in fighting against antibiotic-resistant M. tuberculosis strains.

Screening of potential inhibitors of Leishmania major N-myristoyltransferase from Azadirachta indica phytochemicals for leishmaniasis drug discovery by molecular docking, molecular dynamics simulation and density functional theory methods

Leishmaniasis is one of the most neglected parasitic diseases worldwide. The toxicity of current drugs used for its treatment is a major obstacle to their effectiveness, necessitating the discovery and development of new therapeutic agents for better disease control. In Leishmania parasites, N-Myristoyltransferase (NMT) has been identified as a promising target for drug development. Thus, exploring well-known medicinal plants such as Azadirachta indica and their phytochemicals can offer a diverse range of treatment options, potentially leading to disease prevention and control. To assess the therapeutic potential of these compounds, their ADMET prediction and drug-likeness properties were analyzed. The top 4 compounds were selected which had better and significantly low binding energy than the reference molecule QMI. Based on the binding energy score of the top compounds, the results show that Isonimocinolide has the highest binding affinity (-9.8 kcal/mol). In addition, a 100 ns MD simulation of the four best compounds showed that Isonimocinolide and Nimbolide have good stability with LmNMT. These compounds were then subjected to MMPBSA (last 30 ns) calculation to analyze protein-ligand stability and dynamic behavior. Nimbolide and Meldenin showed lowest binding free energy i.e. -84.301 kJ/mol and -91.937 kJ/mol respectively. DFT was employed to calculate the HOMO-LUMO energy gap, global reactivity parameters, and molecular electrostatic potential of all hit molecules. The promising results obtained from MD simulations and MMPBSA analyses provide compelling evidence for the potential use of these compounds in future drug development efforts for the treatment of leishmaniasis.Communicated by Ramaswamy H. Sarma.

JNK molecule is a toxic target for IPEC-J2 cell barrier damage induced by T-2 toxin

The most prevalent contaminated mycotoxin in feed and grain is T-2 toxin. The T-2 toxin's primary action target is the gut because it is the main organ of absorption. T-2 toxin can cause intestinal damage, but, few molecular mechanisms have been elucidated. It is important to discover the key pathways by which T-2 toxin causes enterotoxicity. In this research, IPEC-J2 cells are used as a cell model to investigate the function of the MAPK signaling pathway in T-2 toxin-induced intestinal epithelial cell damage. Throughout this research, T-2 toxin results in functional impairment in IPEC-J2 cells by reducing the TJ proteins Claudin, Occludin-1, ZO-1, N-cadherin, and CX-43 expression. T-2 toxin significantly reduced the survival of IPEC-J2 cells and increased LDH release in a dose-dependent way. T-2 toxin induced IPEC-J2 cell oxidative stress by raising ROS and MDA content, and mitochondrial damage was indicated by a decline in MMP and an increase in the opening degree of MPTP. T-2 toxin upregulated the expression of ERK, P38 and JNK, which triggered the MAPK signaling pathway. In addition, T-2 toxin caused IPEC-J2 cell inflammation responses reflected by increased the levels of inflammation-related factors IL-8, p65, P-p65 and IL-6, and down-regulated IL-10 expression level. Inhibition JNK molecule can ease IPEC-J2 cell functional impairment and inflammatory response. In conclusion, as a consequence of the T-2 toxin activating the JNK molecule, oxidative stress and mitochondrial damage are induced, which impair cellular inflammation.

Recent Advances in Chemotherapeutics for Leishmaniasis: Importance of the Cellular Biochemistry of the Parasite and Its Molecular Interaction with the Host

Leishmaniasis, a category 1 neglected protozoan disease caused by a kinetoplastid pathogen called Leishmania, is transmitted through dipteran insect vectors (phlebotomine, sand flies) in three main clinical forms: fatal visceral leishmaniasis, self-healing cutaneous leishmaniasis, and mucocutaneous leishmaniasis. Generic pentavalent antimonials have long been the drug of choice against leishmaniasis; however, their success is plagued with limitations such as drug resistance and severe side effects, which makes them redundant as frontline therapy for endemic visceral leishmaniasis. Alternative therapeutic regimens based on amphotericin B, miltefosine, and paromomycin have also been approved. Due to the unavailability of human vaccines, first-line chemotherapies such as pentavalent antimonials, pentamidine, and amphotericin B are the only options to treat infected individuals. The higher toxicity, adverse effects, and perceived cost of these pharmaceutics, coupled with the emergence of parasite resistance and disease relapse, makes it urgent to identify new, rationalized drug targets for the improvement in disease management and palliative care for patients. This has become an emergent need and more relevant due to the lack of information on validated molecular resistance markers for the monitoring and surveillance of changes in drug sensitivity and resistance. The present study reviewed the recent advances in chemotherapeutic regimens by targeting novel drugs using several strategies including bioinformatics to gain new insight into leishmaniasis. Leishmania has unique enzymes and biochemical pathways that are distinct from those of its mammalian hosts. In light of the limited number of available antileishmanial drugs, the identification of novel drug targets and studying the molecular and cellular aspects of these drugs in the parasite and its host is critical to design specific inhibitors targeting and controlling the parasite. The biochemical characterization of unique Leishmania-specific enzymes can be used as tools to read through possible drug targets. In this review, we discuss relevant metabolic pathways and novel drugs that are unique, essential, and linked to the survival of the parasite based on bioinformatics and cellular and biochemical analyses.

A Betulinic Acid Derivative, BA5, Induces G0/G1 Cell Arrest, Apoptosis Like-Death, and Morphological Alterations in Leishmania sp

Leishmaniasis are endemic diseases caused by different species of intracellular parasites of the genus Leishmania. Due to the high toxicity and drug resistance of current antileishmanial drugs, it is necessary to identify new and more effective drugs. Previously, we investigated the immunomodulatory and anti-Trypanosoma cruzi action of BA5, a derivative of betulinic acid. In the present study, we investigated the in vitro activity of BA5 against different species of Leishmania and their action mechanism. BA5 exhibited low cytotoxicity against macrophages and inhibited the proliferation of promastigote forms of Leishmania amazonensis (IC₅₀ = 4.5 ± 1.1 μM), Leishmania major (IC₅₀ = 3.0 ± 0.8 μM), Leishmania braziliensis (IC₅₀ = 0.9 ± 1.1 μM) and Leishmania infantum (IC₅₀ = 0.15 ± 0.05 μM). Incubation with BA5 reduced the percentage of Leishmania amazonensis-infected macrophages and the number of intracellular parasites (IC₅₀ = 4.1 ± 0.7 μM). To understand the mechanism of action underlying BA5 antileishmanial activity (incubation at IC₅₀/2_, IC₅₀ or 2xIC₅₀ values of the drug), we investigated ultrastructural changes by scanning electron microscopy and evaluated cell cycle, membrane mitochondrial potential, and cell death against promastigote forms of Leishmania amazonensis by flow cytometry. Promastigotes incubated with BA5 presented membrane blebbing, flagella damage, increased size, and body deformation. Flow cytometry analysis showed that parasite death is mainly caused by apoptosis-like death, arrested cell cycle in G0/G1 phase and did not alter the membrane mitochondrial potential of Leishmania amazonensis. Surprisingly, the combination of BA5 and amphotericin B, an assay used to determine the degree of drug interaction, revealed synergistic effects (CI = 0.15 ± 0.09) on promastigotes forms of Leishmania amazonensis. In conclusion, BA5 compound is an effective and selective antileishmanial agent.

Potential Role of Individual and Combined Effects of T-2 Toxin, HT-2 Toxin and Neosolaniol on the Apoptosis of Porcine Leydig Cells

T-2 toxin usually co-occurs with HT-2 toxin and neosolaniol (NEO) in the grains and feed. Our previous studies found that T-2 toxin and its metabolites’ binary or ternary combination exposure to porcine Leydig cells (LCs) displayed synergism in certain range of dosage and cannot be predicted based on individual toxicity. However, the possible mechanism of these mycotoxins’ combined exposure to cell lesions remains unknown. Based on 50% cell viability, the mechanism of apoptosis in porcine Leydig cells was investigated after exposure to T-2, HT-2, NEO individual and binary or ternary combinations. Compared with control, the adenosine triphosphate (ATP) content decreased, reactive oxygen species (ROS) level increased, and mitochondrial membrane potential (MMP) decreased in all treated groups. Additionally, the cell apoptosis rates were significantly increased in test groups (p < 0.05), and the B-cell lymphoma 2 (Bcl-2) Associated X (Bax)/Bcl-2 ratio and the expression of caspase 3, caspase 8, cytochrome c (Cytc) in the treated group are all significantly higher than the control group. Moreover, the expression of Cytc and caspase 8 gene in NEO and T-2+NEO groups was significantly higher than that in other individual and combined groups. It can be concluded that the toxicities of T-2, HT-2, and NEO individually and in combination can induce apoptosis related to the oxidative stress and mitochondrial damage, and the synergistic effect between toxins may be greater than a single toxin effect, which is beneficial for assessing the possible risk of the co-occurrences in foodstuffs to human and animal health.