Novel Thiazolidin-4-ones as Potential Non-nucleoside Inhibitors of HIV-1 Reverse Transcriptase.

BACKGROUND: HIV is the causative agent of Acquired Immunodeficiency Syndrome (AIDS), an infectious disease with increasing incidence worldwide. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) play an important role in the treatment of AIDS. Although, many compounds are already being used as anti-HIV drugs, research for the development of new inhibitors continues as the virus develops resistant strains. METHODS: The best features of available NNRTIs were taken into account for the design of novel inhibitors. PASS (Prediction of activity spectra for substances) prediction program and molecular docking studies for the selection of designed compounds were used for the synthesis. Compounds were synthesized using conventional and microwave irradiation methods and HIV RT inhibitory action was evaluated by colorimetric photometric immunoassay. RESULTS: The evaluation of HIV-1 RT inhibitory activity revealed that seven compounds have significantly lower ΙC50 values than nevirapine (0.3 µΜ). It was observed that the activity of compounds depends not only on the nature of substituent and it position in benzothiazole ring but also on the nature and position of substituents in benzene ring. CONCLUSION: Twenty four of the tested compounds exhibited inhibitory action lower than 4 µΜ. Seven of them showed better activity than nevirapine, while three of the compounds exhibited IC50 values lower than 5 nM. Two compounds 9 and 10 exhibited very good inhibitory activity with IC50 1 nM.

Polymer-Lipid Microparticles for Pulmonary Delivery.

Toward engineering approaches that are designed to optimize the particle size, morphology, and mucoadhesion behavior of the particulate component of inhaler formulations, this paper presents the preparation, physicochemical characterization, and preliminary in vitro evaluation of multicomponent polymer-lipid systems that are based on "spray-drying engineered" α-lactose monohydrate microparticles. The formulations combine an active (budesonide) with a lung surfactant (dipalmitoylphosphatidylcholine) and with materials that are known for their desirable effects on morphology (polyvinyl alcohol), aerosolization (l-leucine), and mucoadhesion (chitosan). The effect of the composition of formulations on the morphology, distribution, and in vitro mucoadhesion profiles is presented along with "Calu-3 cell monolayers" data that indicate good cytocompatibility and also with simulated-lung-fluid data that are consistent with the therapeutically useful release of budesonide.

Engineered mucoadhesive microparticles of formoterol/budesonide for pulmonary administration.

In the present study, a multi-component system comprised of dipalmitylphospatidylcholine (DPPC), Chitosan, Lactose, and L-Leucine was developed for pulmonary delivery. Microparticles were engineered by the spray drying process and the selection of the critical parameters was performed by applying experimental design. The microcarriers with the appropriate size and yield were co-formulated with two active pharmaceutical ingredients (APIs), namely, Formoterol fumarate and Budesonide, and they were further investigated. All formulations exhibited spherical shape, appropriate aerodynamic performance, satisfying entrapment efficiency, and drug load. Their physicochemical properties were evaluated using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and Differential Scanning Calorimetry (DSC). The aerodynamic particle size characterization was determined using an eight-stage Andersen cascade impactor, whereas the release of the actives was monitored in vitro in simulated lung fluid. Additional evaluation of the microparticles' mucoadhesive properties was performed by ζ-potential measurements and ex vivo mucoadhesion study applying a falling liquid film method using porcine lung tissue. Cytotoxicity and cellular uptake studies in Calu-3 lung epithelial cell line were conducted to further investigate the safety and efficacy of the developed formulations.

The histone methyltransferase inhibitor A-366 enhances hemoglobin expression in erythroleukemia cells upon co-exposure with chemical inducers in culture.

BACKGROUND: Erythroleukemia is caused by the uncontrolled multiplication of immature erythroid progenitor cells which fail to differentiate into erythrocytes. By directly targeting this class of malignant cells, the induction of terminal erythroid differentiation represents a vital therapeutic strategy for this disease. Erythroid differentiation involves the execution of a well-orchestrated gene expression program in which epigenetic enzymes play critical roles. In order to identify novel epigenetic mediators of differentiation, this study explores the effects of multiple, highly specific, epigenetic enzyme inhibitors, in murine and human erythroleukemia cell lines. RESULTS: We used a group of compounds designed to uniquely target the following epigenetic enzymes: G9a/GLP, EZH1/2, SMYD2, PRMT3, WDR5, SETD7, SUV420H1 and DOT1L. The majority of the probes had a negative impact on both cell proliferation and differentiation. On the contrary, one of the compounds, A-366, demonstrated the opposite effect by promoting erythroid differentiation of both cell models. A-366 is a selective inhibitor of the G9a methyltransferase and the chromatin reader Spindlin1. Investigation of the molecular mechanism of action revealed that A-366 forced cells to exit from the cell cycle, a fact that favored erythroid differentiation. Further analysis led to the identification of a group of genes that mediate the A-366 effects and include CDK2, CDK4 and CDK6. CONCLUSIONS: A-366, a selective inhibitor of G9a and Spindlin1, demonstrates a compelling role in the erythroid maturation process by promoting differentiation, a fact that is highly beneficial for patients suffering from erythroleukemia. In conclusion, this data calls for further investigation towards the delivery of epigenetic drugs and especially A-366 in hematopoietic disorders.

Synthesis and evaluation of 99mTc/Re-tricarbonyl complexes of the triphenylphosphonium cation for mitochondrial targeting.

INTRODUCTION: Lipophilic delocalized cations accumulate in tumor cell mitochondria due to their higher transmembrane potential. In this work, this strategy was adopted for the development of 99mTc tumor-targeted imaging agents. METHODS: Two tridentate ligands containing the triphenylphosphonium cation, L1 (S-cysteinyl) and L2 (N-iminodiacetate) as well as the respective 99mTc/ReL1 and 99mTc/ReL2 tricarbonyl complexes were synthesized. The effect of the ligands and the Re complexes on cell growth in U-87 MG glioblastoma cells was assessed. In vitro stability studies and measurement of logP of the 99mTc tracers was performed. The cellular and mitochondrial uptake of the 99mTc tracers in U-87 MG cells was evaluated. Biodistribution of 99mTcL1 and 99mTcL2 were performed on SCID mice bearing U-87 MG tumors. RESULTS: The ligands L1, L2 and the Re1 and ReL2 complexes were characterized spectroscopically. Single products 99mTcL1 and 99mTcL2, >90% stable in rat serum, were obtained. LogP was 0.40±0.14 for 99mTcL1 and -0.02±0.07 for 99mTcL2. L1, ReL1 and ReL2 caused no notable cytotoxicity and L2 was found to infer 40% inhibition of cellular growth at 10-5M as well as 80% cell death in culture at 10-4M. The cell uptake of 99mTcL1 and 99mTcL2 over 4h was 1.26±0.08% and 0.06±0.01% respectively, of which 13.41±3.63% and 18.61±6.19% was distributed in the mitochondria respectively. The initial tumor uptake in mice was found to be >1% ID/g for both 99mTc tracers. CONCLUSIONS: In vitro mitochondrial and in vivo tumor targeting was observed, better in 99mTcL1, however these properties should be optimized in future studies. Advances in Knowledge and Implications for Patient Care: Continuous efforts in this direction may lead to a suitable mitochondrial-targeted 99mTc imaging agent for tumor detection.

Uncovering the pharmacological response of novel sesquiterpene derivatives that differentially alter gene expression and modulate the cell cycle in cancer cells.

The present study aimed to assess the pharmacological anticancer profile of three natural and five synthetic sesquiterpenes developed by total chemical synthesis. To this end, their properties at the cellular and molecular level were evaluated in a panel of normal and cancer cell lines. The results obtained by performing cytotoxicity assays and gene expression analysis by reverse transcription-quantitative polymerase chain reaction showed that: i) Among the sesquiterpene derivatives analyzed, VDS58 exhibited a notable anticancer profile within attached (U-87 MG and MCF-7) and suspension (K562 and MEL-745) cancer cell cultures; however, U-87 MG cells were able to recover their proliferation capacity rapidly after 48 h of exposure; ii) gene expression profiling of U-87 MG cells, in contrast to K562 cells, showed a transient induction of cyclin-dependent kinase inhibitor 1A (CDKN1) expression; iii) the expression levels of transforming growth factor ß1 (TGFB1) increased after 12 h of exposure of U-87 MG cells to VDS58 and were maintained at this level throughout the treatment period; iv) in K562 cells exposed to VDS58, TGFB1 expression levels were upregulated for 48 h and decrease afterwards; and v) the re-addition of VDS58 in U-87 MG cultures pretreated with VDS58 resulted in a notable increase in the expression of caspases (CASP3 and CASP9), BCL2­associated agonist of cell death (BAD), cyclin D1, CDK6, CDKN1, MYC proto-oncogene bHLH transcription factor (MYC), TGFB1 and tumor suppressor protein p53. This upregulation persisted only for 24 h for the majority of genes, as afterwards, only the expression of TGFB1 and MYC was maintained at high levels. Through bioinformatic pathway analysis of RNA-Seq data of parental U-87 MG and K562 cells, substantial variation was reported in the expression profiles of the genes involved in the regulation of the cell cycle. This was associated with the differential pharmacological profiles observed in the same cells exposed to VDS58. Overall, the data presented in this study provide novel insights into the molecular mechanisms of action of sesquiterpene derivatives by dysregulating the expression levels of genes associated with the cell cycle of cancer cells.

Structure, antimicrobial activity, DNA- and albumin-binding of manganese(II) complexes with the quinolone antimicrobial agents oxolinic acid and enrofloxacin.

The reaction of MnCl2 with the quinolone antibacterial drug oxolinic acid (Hoxo) results to the formation of [KMn(oxo)3(MeOH)3]. Interaction of MnCl2 with the quinolone Hoxo or enrofloxacin (Herx) and the N,N'-donor heterocyclic ligand 1,10-phenanthroline (phen) results in the formation of metal complexes with the general formula [Mn(quinolonato)2(phen)]. The crystal structures of [KMn(oxo)3(MeOH)3] and [Mn(erx)2(phen)], exhibiting a 1D polymeric and a mononuclear structure, respectively, have been determined by X-ray crystallography. In these complexes, the deprotonated bidentate quinolonato ligands are coordinated to manganese(II) ion through the pyridone oxygen and a carboxylato oxygen. All complexes can act as potential antibacterial agents with [Mn(erx)2(phen)] exhibiting the most pronounced antimicrobial activity against five different microorganisms. Interaction of the complexes with calf-thymus DNA (CT DNA), studied by UV spectroscopy, has shown that they bind to CT DNA. Competitive study with ethidium bromide (EB) has shown that all complexes can displace the DNA-bound EB indicating their binding to DNA in strong competition with EB. Intercalative binding mode is proposed for the interaction of the complexes with CT DNA and has also been verified by DNA solution viscosity measurements and cyclic voltammetry. DNA electrophoretic mobility experiments suggest that [Mn(erx)2(phen)] binds strongly to supercoiled pDNA and to linearized pDNA possibly by an intercalative manner provoking double-stranded cleavage reflecting in a nuclease-like activity. The complexes exhibit good binding propensity to human or bovine serum albumin protein showing relatively high binding constant values. The binding constants of the complexes towards CT DNA and albumins have been compared to their corresponding zinc(II) and nickel(II) complexes.