Pinealectomy and melatonin administration in rats: their effects on pulmonary edema induced by α-naphthylthiourea.

We aimed to observe the possible effects of melatonin (MLT) deprivation (pinealectomy) and exogenous MLT administration on pulmonary edema induced by alpha-naphthylthiourea (ANTU), a toxic chemical agent, in rats. Seventy animals were assigned to seven groups: control, sham pinealectomy (PINX), PINX, ANTU (10 mg/kg intraperitoneal on day 30), ANTU + MLT (10 mg/kg/day i.p. for 30 days), ANTU + PINX, and ANTU + PINX + MLT.In this study, pleural effusion (PE) formation, lung weight/body weight (LW/BW) and PE/BW ratios (fluid accumulation and weight values in the lungs) increase detected. Pre-ANTU MLT administration led to significant decreases in PE, LW/BW, and PE/BW levels. The inhibited glutathione (GSH) and superoxide dismutase (SOD) levels and high malondialdehyde (MDA) levels that ANTU increase lipid peroxidation in the study. MLT administration eliminated oxidative stress by reducing MDA and ameliorating GSH and SOD levels.Pre-ANTU MLT administration led to a significant decrease in interleukin-1 beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α) levels in the lung when compared to the ANTU group without MLT administration. Post-pinealectomy ANTU administration significantly increased IL-1ß and TNF-α levels when compared to ANTU and MLT administration without pinealectomy. Diffused inflammatory cell infiltration, interstitial pulmonary edema, and histopathological congestion were observed after the administration of ANTU. Severity of the damage was elevated in the ANTU + PINX group. MLT treatment regressed pulmonary effusion and edema and improves lung structure. In brief, the findings suggested that MLT inhibited proinflammatory mediators and could serve as a therapeutic agent to prevent inflammatory disorders.

Changes in thyroid histomorphology and thyroglobulin immunostaining upon exposure to thiourea in Triturus newts.

Amphibians are useful bioindicators for monitoring aquatic health and the influence of xenobiotics such as endocrine disrupting chemicals. Because aquatic ecosystems experience the majority of global pollution, aquatic organisms are most exposed and vulnerable to endocrine disruptors. Furthermore, penetration of endocrine disruptors into aquatic organisms especially in amphibians is even easier because of more permeable skin, resulting in high bioavailability and bioaccumulation of chemicals. One of the most potent endocrine disruptors is thiourea, which chemically blocks the synthesis of thyroid hormones and prevents metamorphosis in amphibians. We investigated the influence of thiourea on histomorphology of the thyroid gland in Triturus newts at the metamorphic stage, when thyroid hormone concentrations should reach their maximum level. Chronic exposure to thiourea induced hypertrophy and hyperplasia of follicular cells as well as a significant reduction of interstitial tissue. The intensity of the thyroglobulin immunostaining signal significantly decreases upon chronic exposure to thiourea. Successful cross-reactivity of human primary antibody in immunochemical detection of thyroglobulin in Urodela confirms potential homology in thyroglobulin structure throughout the vertebrates.

Morphological and Mechanistic Aspects of Thiourea-Induced Acute Lung Injury and Tolerance in the Rat.

Thiourea-based molecules cause pulmonary edema when administered to rats at relatively low doses. However, rats survive normally lethal doses after prior exposure to a lower, nonlethal dose; this phenomenon is known as tolerance. The present study investigated the morphological and functional aspects of acute lung injury (ALI) induced by methylphenylthiourea (MPTU) in the Wistar rat and the pulmonary response involved in prevention of the injury. We identified pulmonary endothelial cells as the main target of acute MPTU injury; they exhibited ultrastructural alterations that can result in increased vascular permeability. In tolerant rats, the lungs showed only transient endothelial changes, at 24-hour post dosing, and mild type II pneumocyte hyperplasia on day 7 post dosing. They exhibited glutathione levels similar to the controls and increased expression of flavin-containing monooxygenase 1 (FMO1), the enzyme responsible for bioactivation of small thioureas in the laboratory rat. Incubation of rat pulmonary microsomal preparations with MPTU inhibited FMO activity, indicating that tolerance is related to irreversible inhibition of FMOs. The rat model of thiourea-induced pulmonary toxicity and tolerance represents an interesting approach to investigate certain aspects of the pathogenesis of ALI and therapeutic approaches to lung diseases, such as acute respiratory distress syndrome.

Nanoparticles Loaded with a New Thiourea Derivative: Development and In vitro Evaluation Against Leishmania amazonensis.

BACKGROUND: Leishmaniasis is a neglected tropical disease caused by protozoa of the genus Leishmania. Current treatments are restricted to a small number of drugs that display both severe side effects and a potential for parasites to develop resistance. A new N-(3,4-methylenedioxyphenyl)-N'- (2-phenethyl) thiourea compound (thiourea 1) has shown promising in vitro activity against Leishmania amazonensis with an IC50 of 54.14 µM for promastigotes and an IC50 of 70 µM for amastigotes. OBJECTIVE: To develop a formulation of thiourea 1 as an oral treatment for leishmaniasis, it was incorporated into Nanoparticles (NPs), a proven approach to provide long-acting drug delivery systems. METHODS: Poly (D,L-Lactic-co-Glycolic Acid) (PLGA) polymeric NPs containing thiourea 1 were obtained through a nanoprecipitation methodology associated with solvent evaporation. The NPs containing thiourea 1 were characterized for Encapsulation Efficiency (EE%), reaction yield (% w/w), surface charge, particle size and morphology by Transmission Electron Microscopy (TEM). RESULTS: NPs with thiourea 1 showed an improved in vitro leishmanicidal activity with a reduction in its cytotoxicity against macrophages (CC50>100 µg/mL) while preserving its IC50 against intracellular amastigotes (1.46 ± 0.09 µg/mL). This represents a parasite Selectivity Index (SI) of 68.49, which is a marked advancement from the reference drug pentamidine (SI = 30.14). CONCLUSION: The results suggest that the incorporation into NPs potentiated the therapeutic effect of thiourea 1, most likely by improving the selective delivery of the drug to the phagocytic cells that are targeted for infection by L. amazonensis. This work reinforces the importance of nanotechnology in the acquisition of new therapeutic alternatives for oral treatments.

In vitro cytotoxicity evaluation of thiourea derivatives bearing Salix sp. constituent against HK-1 cell lines.

In searching for drugs from natural product scaffolds has gained interest among researchers. In this study, a series of twelve halogenated thiourea (ATX 1-12) via chemical modification of aspirin (a natural product derivative) and evaluated for cytotoxic activity against nasopharyngeal carcinoma (NPC) cell lines, HK-1 via MTS-based colorimetric assay. The cytotoxicity studies demonstrated that halogens at meta position of ATX showed promising activity against HK-1 cells (IC50 value ≤15 µM) in comparison to cisplatin, a positive cytotoxic drug (IC50 value =8.9 ± 1.9 µM). ATX 11, bearing iodine at meta position, showed robust cytotoxicity against HK-1 cells with an IC50 value of 4.7 ± 0.7 µM. Molecular docking interactions between ATX 11 and cyclooxygenase-2 demonstrated a robust binding affinity value of -8.1 kcal/mol as compared to aspirin's binding affinity value of -6.4 kcal/mol. The findings represent a promising lead molecule from natural product with excellent cytotoxic activity against NPC cell lines.

New insights into the chemical behavior of S-oxide derivatives of thiocarbonyl-containing antitubercular drugs and the influence on their mechanisms of action and toxicity.

OBJECTIVES: This work aims at getting more insights into the distinct behavior of S-oxide derivatives of thiocarbonyl-containing antitubercular drugs, in order to better understand their mechanism of action and toxicity. METHODS: Computational calculation of relative free energy (ΔΔG) of S-oxide tautomers (sulfine R-C [SO]NH2), sulfenic acid (R-C [S-OH]NH) and sulfoxide (R-C [SHO]NH) derived from thioamide and thiourea antitubercular drugs and an update of the literature data with a new point of view about how the structural features of oxidized primary metabolites (S-oxide) can influence the outcome of the reactions and be determinant for the mechanisms of action and of toxicity of these drugs. RESULTS: The calculated free energy of S-oxide tautomers, derived from thioamide and thiourea-type antitubercular drugs, supported by some experimental results, revealed that S-oxide derivatives could be found under sulfine and sulfenic acid forms depending on their chemical structures. Thiocarbonyl compounds belonging to the thioamide series are firstly oxidized, in the presence of H2O2, into the corresponding S-oxide derivatives that are more stable under the sulfine tautomeric form. Otherwise, S-oxides of thiourea-type (acyclic and cyclic) compounds tend to adopt the sulfenic acid tautomeric form preferentially. While the intermediate ethionamide-SO under sulfine form can be isolated and in the presence of H2O2 can undergo further oxidation by a mechanism yielding radical species that are toxic for Mycobacterium tuberculosis and human, thioacetazone-SO, found mainly into sulfenic acid form, is unstable and sufficiently reactive in biological conditions to intercept different biochemical pathways and manifests thus its toxicity. CONCLUSION: Based on experimental and theoretical data, we propose that S-oxide derivatives of thioamide and thiourea-type antitubercular drugs have preference for distinct tautomeric forms. S-oxide of ethioamide is preferentially under sulfine form whereas S-oxide of thiourea compound as thioacetazone is mainly found under sulfenic acid form. These structural features lead to individual chemical reactivities that might explain the distinct mechanism of action and toxicity observed for the thioamide and thiourea antitubercular drugs.

Discovery and Optimization of Selective and in Vivo Active Inhibitors of the Lysophosphatidylserine Lipase α/ß-Hydrolase Domain-Containing 12 (ABHD12).

ABHD12 is a membrane-bound hydrolytic enzyme that acts on the lysophosphatidylserine (lyso-PS) and lysophosphatidylinositol (lyso-PI) classes of immunomodulatory lipids. Human and mouse genetic studies point to a key role for the ABHD12-(lyso)-PS/PI pathway in regulating (neuro)immunological functions in both the central nervous system and periphery. Selective inhibitors of ABHD12 would offer valuable pharmacological probes to complement genetic models of ABHD12-regulated (lyso)-PS/PI metabolism and signaling. Here, we provide a detailed description of the discovery and activity-based protein profiling (ABPP) guided optimization of reversible thiourea inhibitors of ABHD12 that culminated in the identification of DO264 as a potent, selective, and in vivo active ABHD12 inhibitor. We also show that DO264, but not a structurally related inactive control probe (S)-DO271, augments inflammatory cytokine production from human THP-1 macrophage cells. The in vitro and in vivo properties of DO264 designate this compound as a suitable chemical probe for studying the biological functions of ABHD12-(lyso)-PS/PI pathways.

Syntheses, in vitro urease inhibitory activities of urea and thiourea derivatives of tryptamine, their molecular docking and cytotoxic studies.

Urease is an enzyme of amidohydrolase family and is responsible for the different pathological conditions in the human body including peptic ulcers, catheter encrustation, kidney stone formation, hepatic coma, encephalopathy, and many others. Therefore, the search for potent urease inhibitors has attracted major scientific attention in recent years. Urea and thiourea derivatives of tryptamine (1-25) were synthesized via reaction of tryptamine with different substituted phenyl isocyanates/isothiocyanates. The synthetic compounds were evaluated for their urease enzyme inhibitory activity and they exhibited good inhibitory potential against urease enzyme in the range of (IC50 = 11.4 ±â€¯0.4-24.2 ±â€¯1.5 µM) as compared to the standard thiourea (IC50 = 21.2 ±â€¯1.3 µM). Out of twenty-five compounds, fourteen were found to be more active than the standard. Limited structure-activity relationship suggested that the compounds with CH3, and OCH3 substituents at aryl part were the most potent derivatives. Compound 14 (IC50 = 11.4 ±â€¯0.4 µM) with a methyl substituent at ortho position was found to be the most active member of the series. Whereas, among halogen substituted derivatives, para substituted chloro compound 16 (IC50 = 13.7 ±â€¯0.9 µM) showed good urease inhibitory activity. These synthetic derivatives were found to be non-cytotoxic in cellular assay. Kinetic studies revealed that the compounds 11, 12, 14, 17, 21, 22, and 24 showed a non-competitive type of inhibition. In silico study identified the possible bindings interactions of potential inhibitors with the active site of enzyme. These newly identified inhibitors of urease enzyme can serve as leads for further research and development.

Identification of 2,4-dihydroxy-5-pyrimidinyl imidothiocarbomate as a novel inhibitor to Y box binding protein-1 (YB-1) and its therapeutic actions against breast cancer.

In spite of advances in breast cancer treatment and early diagnosis, drug toxicity, cancer relapse, multidrug resistance and metastasis are the major impediment to the developments of efficient drugs. However, unique druggable targets of cancer cells distinct from the normal cells provide new rationale in cancer treatment. Previous reports clearly emphasize the differential expression and localization of Y box binding protein-1 (YB-1) between normal breast tissues and different stages of breast cancer. Y box binding protein-1 is DNA as well as RNA binding protein involved in transcription and translation regulation of various proteins involved in cancer progression, apoptosis, cell cycle, epithelial to mesenchymal transition (EMT) and drug resistance. Particularly, during doxorubicin (DOX) treatment and cancer relapse conditions, YB-1 expression was very high in breast cancer tissues and localized in to nucleus which further favours DOX efflux and metastasis. Moreover, siRNA mediated silencing of YB-1 reduces breast cancer progression and metastasis. In this rationale, using an array of computational methods, 2,4-dihydroxy-5-pyrimidinyl imidothiocarbomate (DPI) has been screened out as a drug-likeness antagonist to the YB-1for cancer treatment. In this study, we determined that DPI was toxic to breast cancer cell lines as individual drug as well as in combination with DOX. Moreover, immunofluorescence and confocal studies showed that DPI decreases DOX induced YB-1 nuclear translocation and increases DOX accumulation in breast cancer cell line. A G1/G0 phase cell cycle arrest and apoptosis was also induced by DPI. Moreover, DPI modulated YB-1 downstream targets such as p53, caspase-3, CDK-1 which are involved in cell cycle progression and apoptosis. Further, metastatic functional analysis revealed that DPI inhibits cell adhesion, migration, invasion in aggressive metastatic cell line and inhibits angiogenesis in chick embryonic chorioallantoic membrane (CAM) model. Meanwhile, DPI alters the expression of YB-1 downstream targets which are involved in metastasis such as VEGFR, caveolin, E-cadherin, cytokeratins, desmin and vimentin in MDA-MB-231 xenograft in chick embryonic CAM membrane. The results clearly demonstrated that DPI inhibited YB-1 nuclear translocation, thereby exhibited anti-apoptotic, anti-proliferative and anti-metastatic activities and increases the therapeutic potential of commercial breast cancer drug doxorubicin.

Inhibition of Adipogenesis by Thiourea Derivatives.

BACKGROUND: Obesity is one of the major health problems with inherent risk of type 2 diabetes, hypertension, CVDs, etc. Adipogenesis is a major contributor in the process of obesity. Inhibition of adipocytes differentiation is one of the key approaches to treat obesity. OBJECTIVE: To discover the new inhibitors of adipogenesis as the treatment for obesity. METHOD: We describe here, the synthesis, and anti-adipogenic activity of thiourea derivatives 1-14. These derivatives were synthesized by the reactions of phenyl and pentafluorophenyl isothiocyanate with different aromatic amines. Pure compounds 1-14 were evaluated for their in vitro antiadipogenesis activity employing 3T3-L1 cells lines. RESULTS: Compounds 1-3, 5-9, and 11-14 significantly inhibited the pre-adipocyte differentiation into adipocytes, which was measured by staining the cells, and through morphological examination. Compound 10 (1-(4"-Chlorophenyl)-3-(pentafluorophenyl)-thiourea) showed a potent inhibition of adipocyte differentiation with IC50 = 740.00 ± 2.36 nM, which was more potent than the standards, epigallocatechin gallate (IC50 = 16.73 ± 1.34 µM), and curcumin (IC50 = 18.62 ± 0.74 µM). All other compounds showed a moderate to weak anti-adipogenesis activity. Compounds 1- 14 were also evaluated for their cytotoxicity. Compounds 3, 10, and 14 showed some toxicity to the cancer cell lines, while compounds 2, 3, 10, 12, and 14 showed a moderate to weak cytotoxicity against the normal cell lines. CONCLUSION: All the compounds reported in this paper are known, except compound 11. They have been identified as new inhibitors of Adipogenesis. Adipogenesis is the process of adipocytes differentiation from pre-adipocytes. This extensively studied model of cell diff differentiation. Further synthetic modifications, and optimization of anti-adipogenic activity may lead to the development of anti-obesity agents.

Synthesis, characterization, antioxidant and brine shrimp cytotoxic activity of novel 3-benzothioyl-1-(3-hydroxy-3-phenyl -3-propyl)-1-methylthiourea.

In the present research work novel ephedrine based thiourea derivative, 3-benzothioyl-1-(3-hydroxy-3-phenyl -3-propyl)-1-methylthiourea 4is synthesized and then characterized elemental analyzed via various techniques i.e., Proton NMR, carbon13 NMR and fatherly confirmed via X-ray crystallography. Compound 4 was then screened for their possible antioxidant and cytotoxic potentials. Benzoyl chloride was treated with an equimolar potassium thiocyanate in acetone to achieve benzoyl isothiocyantes. It was then treated with an equimolar (1R, 2S)-(-)-Ephedrine to obtain the 3-benzothioyl-1-(3-hydroxy-3-phenyl-3-propyl)-1-methyl thiourea4. It was then screened for antioxidant and cytotoxic potentials. The compound 4 showed excellent antioxidant activity almost comparable to ascorbic acid (standard) and have significant cytotoxic activity with LC50 value 05±0.58 ppm.

Synthesis, acute toxicity, analgesic activity and cytotoxicity of Some bisthiourea derivatives.

Bisthiourea derivatives were synthesized by the reaction of benzoylisothiocyanate and diamines to give 1,2-Bis(N'-benzoylthioureidobenzene (1), 1,3-di(benzoylthioureido)benzene (2) and 1,4-di(benzoylthioureido)benzene (3) in acetone. Acute toxicity study revealed that LD50 of compound (1) and (3) is 120 mg/kg body weight. Visceral pain induced by injecting i.p acetic acid in mice were strongly inhibited by all the compounds. 94.65, 95.25 and 85.54% analgesic activity were observed in compounds (1), (2) and (3) at 15 mg/kg and (2) and (3) shows 97.63 and 96.42% at 30 mg/kg body weight respectively while (1) gives 100% analgesic activity. 100% cytotoxicity was observed in compounds (2) and (3) and 96% in compound (1) at 750 ppm. The results suggest that these compounds may have potential values for treatment of cancer and painful disorders.

N-Aryl-N'-ethyleneaminothioureas effectively inhibit acetylcholinesterase 1 from disease-transmitting mosquitoes.

Vector control of disease-transmitting mosquitoes by insecticides has a central role in reducing the number of parasitic- and viral infection cases. The currently used insecticides are efficient, but safety concerns and the development of insecticide-resistant mosquito strains warrant the search for alternative compound classes for vector control. Here, we have designed and synthesized thiourea-based compounds as non-covalent inhibitors of acetylcholinesterase 1 (AChE1) from the mosquitoes Anopheles gambiae (An. gambiae) and Aedes aegypti (Ae. aegypti), as well as a naturally occurring resistant-conferring mutant. The N-aryl-N'-ethyleneaminothioureas proved to be inhibitors of AChE1; the most efficient one showed submicromolar potency. Importantly, the inhibitors exhibited selectivity over the human AChE (hAChE), which is desirable for new insecticides. The structure-activity relationship (SAR) analysis of the thioureas revealed that small changes in the chemical structure had a large effect on inhibition capacity. The thioureas showed to have different SAR when inhibiting AChE1 and hAChE, respectively, enabling an investigation of structure-selectivity relationships. Furthermore, insecticidal activity was demonstrated using adult and larvae An. gambiae and Ae. aegypti mosquitoes.

Moderate endoplasmic reticulum stress activates a PERK and p38-dependent apoptosis.

The endoplasmic reticulum (ER) has the ability to signal organelle dysfunction via a complex signaling network known as the unfolded protein response (UPR). In this work, hamster fibroblast cells exhibiting moderate levels of ER stress were compared to those exhibiting severe ER stress. Inhibition of N-linked glycosylation was accomplished via a temperature-sensitive mutation in the Dad1 subunit of the oligosaccharyltransferase (OST) complex or by direct inhibition with tunicamycin (Tm). Temperature shift (TS) treatment generated weak activation of ER stress signaling when compared to doses of Tm that are typically used in ER stress studies (500-1000 nM). A dose-response analysis of key ER stress signaling mediators, inositol-requiring enzyme 1 (IRE1) and protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), revealed 20-40 nM of Tm to generate activation intensity similar to TS treatment. In parental BHK21 cells, moderate (20-40 nM) and high doses (200-1000 nM) of Tm were compared to identify physiological and signaling-based differences in stress response. Inhibition of ER Ca2+ release via ITPR activity with 2-aminoethoxydiphenyl borate (2-APB) or Xestospongin C (XeC) was sufficient to protect against apoptosis induced by moderate but not higher doses of Tm. Analysis of kinase activation over a range of Tm exposures revealed the p38 stress-activated protein kinase (SAPK) to display increasing activation with Tm dosage. Interestingly, Tm induced the extracellular regulated kinases (Erk1/2) only at moderate doses of Tm. Inhibition of ER transmembrane stress sensors (IRE1, PERK) or cytosolic signaling mediators (p38, Jnk1, Erk1/2) was used to evaluate pathways involved in apoptosis activation during ER stress. Inhibition of either PERK or p38 was sufficient to reduce cell death and apoptosis induced by moderate, but not high, doses of Tm. During ER stress, cells exhibited a rapid decline in anti-apoptotic Mcl-1 and survivin proteins. Inhibition of PERK was sufficient to block this affect. This work reveals moderate doses of ER stress to generate patterns of stress signaling that are distinct from higher doses and that apoptosis activation at moderate levels of stress are dependent upon PERK and p38 signaling. Studies exploring ER stress signaling should recognize that this signaling acts as a rheostat rather than a simple switch, behaving distinctively in a dose-dependent manner.

High Potency VEGFRs/MET/FMS Triple Blockade by TAS-115 Concomitantly Suppresses Tumor Progression and Bone Destruction in Tumor-Induced Bone Disease Model with Lung Carcinoma Cells.

Approximately 25-40% of patients with lung cancer show bone metastasis. Bone modifying agents reduce skeletal-related events (SREs), but they do not significantly improve overall survival. Therefore, novel therapeutic approaches are urgently required. In this study, we investigated the anti-tumor effect of TAS-115, a VEGFRs and HGF receptor (MET)-targeted kinase inhibitor, in a tumor-induced bone disease model. A549-Luc-BM1 cells, an osteo-tropic clone of luciferase-transfected A549 human lung adenocarcinoma cells (A549-Luc), produced aggressive bone destruction associated with tumor progression after intra-tibial (IT) implantation into mice. TAS-115 significantly reduced IT tumor growth and bone destruction. Histopathological analysis showed a decrease in tumor vessels after TAS-115 treatment, which might be mediated through VEGFRs inhibition. Furthermore, the number of osteoclasts surrounding the tumor was decreased after TAS-115 treatment. In vitro studies demonstrated that TAS-115 inhibited HGF-, VEGF-, and macrophage-colony stimulating factor (M-CSF)-induced signaling pathways in osteoclasts. Moreover, TAS-115 inhibited Feline McDonough Sarcoma oncogene (FMS) kinase, as well as M-CSF and receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation. Thus, VEGFRs/MET/FMS-triple inhibition in osteoclasts might contribute to the potent efficacy of TAS-115. The fact that concomitant dosing of sunitinib (VEGFRs/FMS inhibition) with crizotinib (MET inhibition) exerted comparable inhibitory efficacy for bone destruction to TAS-115 also supports this notion. In conclusion, TAS-115 inhibited tumor growth via VEGFR-kinase blockade, and also suppressed bone destruction possibly through VEGFRs/MET/FMS-kinase inhibition, which resulted in potent efficacy of TAS-115 in an A549-Luc-BM1 bone disease model. Thus, TAS-115 shows promise as a novel therapy for lung cancer patients with bone metastasis.

Design, synthesis, molecular docking and biological evaluation of thiophen-2-iminothiazolidine derivatives for use against Trypanosoma cruzi.

In this study, we designed and synthesized a series of thiophen-2-iminothiazolidine derivatives from thiophen-2-thioureic with good anti-Trypanosoma cruzi activity. Several of the final compounds displayed remarkable trypanocidal activity. The ability of the new compounds to inhibit the activity of the enzyme cruzain, the major cysteine protease of T. cruzi, was also explored. The compounds 3b, 4b, 8b and 8c were the most active derivatives against amastigote form, with significant IC50 values between 9.7 and 6.03µM. The 8c derivative showed the highest potency against cruzain (IC50=2.4µM). Molecular docking study showed that this compound can interact with subsites S1 and S2 simultaneously, and the negative values for the theoretical energy binding (Eb=-7.39kcal·mol(-1)) indicates interaction (via dipole-dipole) between the hybridized sulfur sp(3) atom at the thiazolidine ring and Gly66. Finally, the results suggest that the thiophen-2-iminothiazolidines synthesized are important lead compounds for the continuing battle against Chagas disease.

Antibacterial, cyto and genotoxic activities of A22 compound ((S-3, 4 -dichlorobenzyl) isothiourea hydrochloride).

The A22 is a chemical compound that acts as a reversible inhibitor of a bacterial cell wall protein MreB leading the rods to the coccoid form. Thus, by changing the bacterial form, many properties can be affected, as the acquisition of nutrients, cell division, the clamping surfaces, motility and pathogenesis. Infections caused by strains of Pseudomonas aeruginosa have great clinical importance because these microorganisms can include more than one resistance mechanism acting together, limiting treatment options. Thus, it is important to investigate the action of A22 against P. aeruginosa, once there are urgent needs for new antimicrobial compounds for increase the arsenal therapeutic to treat diseases caused by this microrganism. Therefore, this study investigated for the first time the antimicrobial activity of A22 against seve standards strains of Gram negative microorganisms and twenty-eight clinical isolates of P. aeruginosa. This study performed an additional investigation to analyze the cyto and genotoxic potential effects from A22 on human peripheral blood mononuclear cells (PBMCs). The antibacterial activity of A22 was studied by broth microdilution method and time-kill assay. The cytotoxicity was evaluated by MTT assay at 24, 48 and 72 h of exposure to A22 and the genotoxicity was evaluated by the Comet assay. The susceptibility tests showed A22 has a relevant antibacterial activity against P. aeruginosa, including multidrug-resistant (MDR) clinical isolates. The A22 treatment not showed genotoxic effects against PBMCs in almost all concentrations tested at 24 and 48 h of exposure. Only for concentration of 32 µg/mL (highest tested) the damage index was significantly higher in all moments. The MTT assay demonstrated that A22 was able to maintain cell viability in all exposure times. In summary, the A22 demonstrated important anti-Pseudomonas activity and showed no cyto and genotoxic significant effect. These results need to be considered in future in vitro and in vivo studies in order to introduce the A22 as a possible therapeutic option.

Antimicrobial and Anti-biofilm Activity of Thiourea Derivatives Bearing 3-amino-1H-1,2,4-triazole Scaffold.

A set of 21 thiourea derivatives were prepared through reacting 3-amino-1H-1,2,4-triazole with the commercial aliphatic and aromatic isothiocyanates. The aliphatic isothiocyanate was used as reagent leading to substitution on NH atom of 3-aminotriazole ring, whereas the triazole amino group was substituted when isothiocyanate group was bonded to the Csp2 hybridized atom, e.g. an aryl or C=O fragment. All compounds were evaluated in vitro for the antimicrobial activity. The derivatives 1, 2, 4, 8, 9, 10 and 12 showed the highest inhibition against Gram-positive cocci (S. aureus and S. epidermidis). The observed MIC values were in the range of 4-32 µg/mL. Compounds were also tested for their in vitro antimicrobial activity against the hospital methicillin-resistant strains of S. aureus. The observed MIC values varied from 4 to 64 µg/mL. The products 4 and 10 effectively inhibited the formation of biofilms of the methicillin-resistant and standard strains of S. epidermidis. The compound 10 was found to be more promising with IC50 values of 2-6 µg/mL as compared to the control. Moreover, the cytotoxicity against the MT-4 cells of all studied thioureas was evaluated. The compound 18 was significantly cytotoxic (CC50 = 8 µM).

Synthesis, characterization, antiparasitic and cytotoxic evaluation of thioureas conjugated to polyamine scaffolds.

A series of mono- and multimeric 4-amino-7-chloroquinoline and ferrocenyl thioureas have been prepared by the reaction of a 7-chloroquinoline methyl ester and a ferrocenylimine methyl ester with various amines. These compounds were characterized using standard spectroscopic and analytical techniques. The compounds were evaluated against the NF54 (CQ-sensitive) and Dd2 (CQ-resistant) strains of Plasmodium falciparum. The quinoline compounds show enhanced activity compared to the ferrocene compounds against this parasite. Compound 5 displays the most promising activity against the NF54 strain. Compounds 5 and 6 are effective at inhibiting ß-hematin formation perhaps due to an increased number of quinoline moieties. The trimeric (12) and tetrameric (13) ferrocenyl compounds also inhibit ß-hematin formation, albeit to a lesser degree compared to the quinoline thioureas. The compounds were also screened against the G3 strain of Trichomonas vaginalis and here the ferrocene-containing compounds show a slightly higher parasite growth inhibition compared to the quinoline thioureas. The quinoline compounds were also found to be more cytotoxic compared to the ferrocenyl compounds. Compound 6 displays good cytotoxicity against WHCO1 oesophageal cancer cells.

A potentiometric flow biosensor based on ammonia-oxidizing bacteria for the detection of toxicity in water.

A flow biosensor for the detection of toxicity in water using the ammonia-oxidizing bacterium (AOB) Nitrosomonas europaea as a bioreceptor and a polymeric membrane ammonium-selective electrode as a transducer is described. The system is based on the inhibition effects of toxicants on the activity of AOB, which can be evaluated by measuring the ammonium consumption rates with the ammonium-selective membrane electrode. The AOB cells are immobilized on polyethersulfone membranes packed in a holder, while the membrane electrode is placed downstream in the flow cell. Two specific inhibitors of the ammonia oxidation-allylthiourea and thioacetamide-have been tested. The IC50 values defined as the concentration of an inhibitor causing a 50% reduction in the ammonia oxidation activity have been measured as 0.17 µM and 0.46 µM for allylthiourea and thioacetamide, respectively. The proposed sensor offers advantages of simplicity, speed and high sensitivity for measuring toxicity in water.