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1.
Inorg Chem ; 60(17): 13669-13680, 2021 Sep 06.
Article in English | MEDLINE | ID: mdl-34424670

ABSTRACT

Alzheimer's disease (AD) is associated with the presence of amyloid plaques in the brain mainly comprised of aggregated forms of amyloid-ß (Aß). Molecules radiolabeled with technetium-99m that cross the blood-brain barrier (BBB) and selectively bind to Aß plaques have the potential to assist in the diagnosis of AD using single-photon emission computed tomography imaging. In this work, three new tetradentate ligands of pyridyl, amide, amine and thiol donors, featuring a styrylpyridyl group that is known to interact with amyloid plaques, were prepared. The new ligands formed charge-neutral and lipophilic complexes with the [Tc═O]3+ and [Re═O]3+ motifs, and two rhenium complexes were characterized by X-ray crystallography. The rhenium(V) complexes interact with synthetic Aß1-40 and amyloid plaques on human brain tissue. Two of the new ligands were radiolabeled with 99mTc using a kit-based approach, and their biodistribution in wild-type mice was evaluated. The presence of amide donors in the tetradentate ligand increased the stability of the respective [Tc═O]3+ complexes but reduced brain uptake. While the complexes were able to cross the BBB, the degree of uptake in the brain was not sufficient to justify further investigation of these complexes.


Subject(s)
Alzheimer Disease/diagnostic imaging , Coordination Complexes/chemistry , Organotechnetium Compounds/chemistry , Radiopharmaceuticals/chemistry , Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Animals , Brain/diagnostic imaging , Coordination Complexes/chemical synthesis , Coordination Complexes/metabolism , Coordination Complexes/pharmacokinetics , Humans , Ligands , Mice , Organotechnetium Compounds/chemical synthesis , Organotechnetium Compounds/metabolism , Organotechnetium Compounds/pharmacokinetics , Peptide Fragments/metabolism , Pyridines/chemical synthesis , Pyridines/chemistry , Pyridines/metabolism , Pyridines/pharmacokinetics , Radiopharmaceuticals/chemical synthesis , Radiopharmaceuticals/metabolism , Radiopharmaceuticals/pharmacokinetics , Rhenium/chemistry , Styrenes/chemical synthesis , Styrenes/chemistry , Styrenes/metabolism , Styrenes/pharmacokinetics
2.
Cytokine ; 148: 155688, 2021 12.
Article in English | MEDLINE | ID: mdl-34455232

ABSTRACT

Arthritis, a primary autoimmune disorder having a global incidence of 2.03% person/year, is presently being treated by many commercially available drugs that treat symptomatically or improve the disease's clinical state; however, all the therapies pose varying amount of side effects. Therefore, it has become a fundamental need to search for therapeutics that offer better efficacy and safety profile, and the natural or nature-derived products are known for their outstanding performance in this arena. OA-DHZ, known to possess anti-inflammatory and analgesic properties, when explored for its efficacy against arthritis in adjuvant-induced arthritis (AIA) model, was found to inhibit paw edema by 34% and TNF-α, IL-6, and IL-1ß by 67%, 39%, and 45% respectively when compared to diseased control. It was also able to reduce the inflamed spleen size by 45% and successfully normalized biochemical and hematological changes that followed arthritis. In vitro studies revealed that the underlying mechanism for inhibiting arthritis progression might be due to NF-κB /MAPK pathway modulation. OA-DHZ also showed selective inhibition of COX-2 in vitro while showing gastroprotective effects when evaluated for ulcerogenic and antiulcer potential in vivo. In contrast to the results obtained from in vivo experimentation, there is a disparity in the pharmacokinetic profile of OA-DHZ, where it showed low oral exposure and high clearance rate. OA-DHZ being antiarthritic acting via NF-κB /MAPK/ COX inhibition while showing gastroprotective effects, can be a suitable candidate to be in the drug pipeline and further exploration.


Subject(s)
Arthritis/drug therapy , Cyclooxygenase Inhibitors/therapeutic use , Mitogen-Activated Protein Kinases/metabolism , NF-kappa B/metabolism , Protective Agents/therapeutic use , Stomach/pathology , Styrenes/therapeutic use , Administration, Oral , Animals , Arthritis/blood , Arthritis/pathology , Cyclooxygenase Inhibitors/pharmacology , Cytokines/metabolism , Enzyme Activation/drug effects , Female , Inflammation/complications , Inflammation/drug therapy , Inflammation/pathology , Inflammation Mediators/metabolism , Lipopolysaccharides , MAP Kinase Signaling System/drug effects , Macrophages/drug effects , Macrophages/pathology , Mice , Protective Agents/pharmacology , Protein Transport/drug effects , RAW 264.7 Cells , Rats, Wistar , Spleen/drug effects , Spleen/pathology , Stomach Ulcer/complications , Stomach Ulcer/drug therapy , Stomach Ulcer/pathology , Styrenes/administration & dosage , Styrenes/pharmacokinetics , Styrenes/pharmacology , Weight Loss/drug effects
3.
Int J Pharm ; 579: 119151, 2020 Apr 15.
Article in English | MEDLINE | ID: mdl-32070761

ABSTRACT

Drug-in-cyclodextrin-in-liposome (DCL) represents a very promising approach for preserving essential oil (EO) components, thereby extending their shelf life and activity. In this study, we examined the effect of chemical structure, octanol/water partition coefficient (log P), and Henry's law constant (Hc) on the encapsulation and the release of monoterpenes (eucalyptol, pulegone, terpineol, and thymol) and phenylpropenes (estragole and isoeugenol) from DCLs. Hydroxypropyl-ß-cyclodextrin/EO component (HP-ß-CD/EO component) inclusion complexes were prepared in aqueous solution and loaded into liposomes by the ethanol injection method. The phospholipid:cholesterol:EO component molar ratio determined for DCL structures was affected by characteristics of EO components. The presence of a propenyl tail or a hydroxyl group in the structure of EO component may improve its loading into DCLs. Furthermore, low encapsulation efficiency (EE) was obtained for DCLs exhibiting high cholesterol membrane content. In addition, a positive linear relationship was found between the loading ratio of monoterpenes into DCLs and their hydrophobic character expressed as log P. The release of components from DCLs was influenced by their EE into the formulations. Finally, DCL formulations retain considerable amounts of EO components after 10 months.


Subject(s)
Drug Carriers/chemistry , Drug Compounding/methods , Oils, Volatile/pharmacokinetics , 2-Hydroxypropyl-beta-cyclodextrin/chemistry , Cholesterol/chemistry , Cyclodextrins/chemistry , Drug Liberation , Hydrophobic and Hydrophilic Interactions , Liposomes , Monoterpenes/administration & dosage , Monoterpenes/chemistry , Monoterpenes/pharmacokinetics , Oils, Volatile/administration & dosage , Oils, Volatile/chemistry , Polymethacrylic Acids/chemistry , Solubility , Styrenes/administration & dosage , Styrenes/chemistry , Styrenes/pharmacokinetics
4.
Contrast Media Mol Imaging ; 2019: 8085039, 2019.
Article in English | MEDLINE | ID: mdl-31281235

ABSTRACT

In this work, one kind of biocompatible and all-in-one dual-modal nanoprobe, based on Au nanoparticles and NIR emissive semiconducting fluorescence polymers, was developed by the one-step solvent-mediated self-assembly method for in vivo X-ray computed tomography (CT) and fluorescence bioimaging for the first time. After preparation, a series of comprehensive evaluations were performed, and the nanoprobe exhibited smart size and modification, good compatibility, inducement of autophagy, long blood circulation, unconspicuous in vivo toxicity, and excellent fluorescence/CT imaging effects. Overall, the studies in this work assuredly indicate that the synthesized Au@FP nanoparticles as a noninvasive contrast agent is suitable for in vivo fluorescence/X-ray CT bimodality biomedical imaging and diagnosis.


Subject(s)
Biocompatible Materials , Contrast Media , Fluorescent Dyes , Gold , Metal Nanoparticles , Multimodal Imaging/methods , Optical Imaging/methods , Quantum Dots , Surface-Active Agents , Tomography, X-Ray Computed/methods , Animals , Astrocytes/drug effects , Astrocytes/metabolism , Autophagy , Benzothiazoles/chemical synthesis , Benzothiazoles/pharmacokinetics , Benzothiazoles/toxicity , Biocompatible Materials/chemical synthesis , Biocompatible Materials/pharmacokinetics , Biocompatible Materials/toxicity , Cells, Cultured , Contrast Media/toxicity , Fluorenes/pharmacokinetics , Fluorenes/toxicity , Fluorescence Resonance Energy Transfer , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/pharmacokinetics , Fluorescent Dyes/toxicity , Gold/pharmacokinetics , Gold/toxicity , Human Umbilical Vein Endothelial Cells , Humans , Infrared Rays , Male , Metal Nanoparticles/toxicity , Polyethylene Glycols/pharmacokinetics , Polyethylene Glycols/toxicity , Polymers/pharmacokinetics , Polymers/toxicity , Quantum Dots/chemistry , Quantum Dots/toxicity , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species , Solubility , Styrenes/chemical synthesis , Styrenes/pharmacokinetics , Styrenes/toxicity , Surface-Active Agents/chemical synthesis , Surface-Active Agents/pharmacokinetics , Surface-Active Agents/toxicity , Tissue Distribution
5.
Bioconjug Chem ; 27(5): 1314-23, 2016 05 18.
Article in English | MEDLINE | ID: mdl-27045547

ABSTRACT

Aß plaques deposited on blood vessels are associated with cerebral amyloid angiopathy (CAA). In an effort to selectively map these Aß plaques, we are reporting a new series of (68)Ga labeled styrylpyridine derivatives with high molecular weights. In vitro binding to Aß plaques in post-mortem Alzheimer's disease (AD) brain tissue showed that these (68)Ga labeled bivalent styrylpyridines displayed good affinities and specificity (Ki < 30 nM). In vitro autoradiography using post-mortem AD brain sections showed specific binding of these (68)Ga complexes to Aß plaques. Biodistribution studies in normal mice showed very low initial brain uptakes (<0.3% dose/g) indicating a low blood-brain barrier (BBB) penetration. The preliminary results suggest that (68)Ga labeled bivalent styrylpyridines may be promising candidates as PET imaging radiotracers for detecting CAA.


Subject(s)
Cerebral Amyloid Angiopathy/complications , Gallium Radioisotopes , Plaque, Amyloid/complications , Plaque, Amyloid/diagnostic imaging , Polyethylene Glycols/chemistry , Positron-Emission Tomography/methods , Pyridines/chemistry , Styrenes/chemistry , Animals , Blood-Brain Barrier/metabolism , Mice , Pyridines/metabolism , Pyridines/pharmacokinetics , Styrenes/metabolism , Styrenes/pharmacokinetics , Tissue Distribution
6.
Drug Test Anal ; 8(2): 221-7, 2016 Feb.
Article in English | MEDLINE | ID: mdl-25975936

ABSTRACT

Piperaquine-dihydroartemisinin combination is the latest addition to the repertoire of ACTs recommended by the World Health Organization (WHO) for treatment of falciparum malaria. Due to the increasing resistance to artemisinin derivatives, CSIR-CDRI has developed a prospective short acting, trioxane antimalarial derivative, CDRI 97-78. In the present study, a liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the simultaneous quantification of piperaquine (PPQ) and 97-63, the active metabolite of CDRI 97-78 found in vivo, was developed and validated in 100 µL rat plasma using halofantrine as internal standard. PPQ and 97-63 were separated using acetonitrile:methanol (50:50, v/v) and ammonium formate buffer (10 mM, pH 4.5) in the ratio of 95:5(v/v) as mobile phase under isocratic conditions at a flow rate of 0.65 mL/min on Waters Atlantis C18 (4.6 × 50 mm, 5.0 µm) column. The extraction recoveries of PPQ and 97-63 ranged from 90.58 to 105.48%, while for the internal standard, it was 94.27%. The method was accurate and precise in the linearity range 3.9-250 ng/mL for both the analytes, with a correlation coefficient (r) of ≥ 0.998. The intra- and inter-day assay precision ranged from 2.91 to 8.45% and; intra- and inter-day assay accuracy was between 92.50 and 110.20% for both the analytes. The method was successfully applied to study the effect of oral co-administration of PPQ on the pharmacokinetics of CDRI 97-78 in Sprague-dawley rats and vice versa. The co-administration of CDRI 97-78 caused significant decrease in AUC0-∞ of PPQ from 31.52 ± 2.68 to 14.84 ± 4.33 h*µg/mL. However, co-administration of PPQ did not have any significant effect on the pharmacokinetics of CDRI 97-78.


Subject(s)
Antimalarials/blood , Bridged Bicyclo Compounds, Heterocyclic/blood , Bridged Bicyclo Compounds, Heterocyclic/pharmacokinetics , Quinolines/blood , Spiro Compounds/blood , Styrenes/blood , Animals , Antimalarials/pharmacokinetics , Area Under Curve , Calibration , Chromatography, High Pressure Liquid , Drug Interactions , Indicators and Reagents , Prospective Studies , Quality Control , Quinolines/pharmacokinetics , Rats , Rats, Sprague-Dawley , Reproducibility of Results , Spectrometry, Mass, Electrospray Ionization , Spiro Compounds/pharmacokinetics , Styrenes/pharmacokinetics , Tandem Mass Spectrometry
7.
J Med Chem ; 58(18): 7241-57, 2015 Sep 24.
Article in English | MEDLINE | ID: mdl-26327138

ABSTRACT

In order to explore novel tau-imaging agents that can selectively detect neurofibrillary tangles in Alzheimer's disease (AD) brains, we designed and synthesized a series of heterocyclic phenylethenyl and (3-pyridinyl)ethenyl derivatives with or without a dimethyl amino group. In in vitro autoradiography using AD brain sections, all radioiodinated ligands with a dimethyl amino group bound to Aß deposits in the sections. In contrast, the ligands without a dimethyl amino group showed different patterns of radioactivity accumulation in the sections depending on the kind of heterocycle contained in their molecules. Particularly, a phenylethenyl benzimidazole derivative ([(125)I]64) showed marked radioactivity accumulation in the temporal lobe which corresponded with the distribution of tau deposits. [(125)I]64 also showed the most favorable pharmacokinetics in normal mouse brains (3.69 and 0.06% ID/g at 2 and 60 min postinjection, respectively) among all ligands in this study. Taken together, these results suggest that [(123)I]64 may be a new candidate tau-imaging agent.


Subject(s)
Alzheimer Disease/diagnostic imaging , Benzimidazoles/chemistry , Brain/diagnostic imaging , Neurofibrillary Tangles/diagnostic imaging , Pyridines/chemistry , Radiopharmaceuticals/chemistry , Styrenes/chemistry , tau Proteins/metabolism , Aged , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Animals , Autoradiography , Benzimidazoles/chemical synthesis , Benzimidazoles/pharmacokinetics , Benzofurans/chemical synthesis , Benzofurans/chemistry , Benzofurans/pharmacokinetics , Benzothiazoles/chemical synthesis , Benzothiazoles/chemistry , Benzothiazoles/pharmacokinetics , Benzoxazoles/chemical synthesis , Benzoxazoles/chemistry , Benzoxazoles/pharmacokinetics , Brain/metabolism , Brain/pathology , Humans , Iodine Radioisotopes , Male , Mice , Neurofibrillary Tangles/metabolism , Pyridines/chemical synthesis , Pyridines/pharmacokinetics , Radionuclide Imaging , Radiopharmaceuticals/chemical synthesis , Radiopharmaceuticals/pharmacokinetics , Stereoisomerism , Structure-Activity Relationship , Styrenes/chemical synthesis , Styrenes/pharmacokinetics , Temporal Lobe/diagnostic imaging , Temporal Lobe/metabolism , Temporal Lobe/pathology , Thiophenes/chemical synthesis , Thiophenes/chemistry , Thiophenes/pharmacokinetics
8.
PLoS One ; 8(9): e73493, 2013.
Article in English | MEDLINE | ID: mdl-24039960

ABSTRACT

Nerve damage is a major morbidity associated with numerous surgical interventions. Yet, nerve visualization continues to challenge even the most experienced surgeons. A nerve-specific fluorescent contrast agent, especially one with near-infrared (NIR) absorption and emission, would be of immediate benefit to patients and surgeons. Currently, there are only three classes of small molecule organic fluorophores that penetrate the blood nerve barrier and bind to nerve tissue when administered systemically. Of these three classes, the distyrylbenzenes (DSBs) are particularly attractive for further study. Although not presently in the NIR range, DSB fluorophores highlight all nerve tissue in mice, rats, and pigs after intravenous administration. The purpose of the current study was to define the pharmacophore responsible for nerve-specific uptake and retention, which would enable future molecules to be optimized for NIR optical properties. Structural analogs of the DSB class of small molecules were synthesized using combinatorial solid phase synthesis and commercially available building blocks, which yielded more than 200 unique DSB fluorophores. The nerve-specific properties of all DSB analogs were quantified using an ex vivo nerve-specific fluorescence assay on pig and human sciatic nerve. Results were used to perform quantitative structure-activity relationship (QSAR) modeling and to define the nerve-specific pharmacophore. All DSB analogs with positive ex vivo fluorescence were tested for in vivo nerve specificity in mice to assess the effect of biodistribution and clearance on nerve fluorescence signal. Two new DSB fluorophores with the highest nerve to muscle ratio were tested in pigs to confirm scalability.


Subject(s)
Contrast Media/metabolism , Fluorescent Dyes/metabolism , Optical Imaging/methods , Sciatic Nerve/metabolism , Styrenes/metabolism , Adult , Animals , Contrast Media/chemistry , Contrast Media/pharmacokinetics , Female , Fluorescent Dyes/chemistry , Fluorescent Dyes/pharmacokinetics , Humans , Mice , Rats , Sciatic Nerve/chemistry , Spectrometry, Fluorescence , Spectroscopy, Near-Infrared , Structure-Activity Relationship , Styrenes/chemistry , Styrenes/pharmacokinetics , Swine , Tissue Distribution
9.
Clin Cancer Res ; 19(1): 85-95, 2013 Jan 01.
Article in English | MEDLINE | ID: mdl-23124440

ABSTRACT

PURPOSE: Mantle cell lymphoma (MCL) is an incurable B-cell lymphoma, and new therapeutic strategies are urgently needed. EXPERIMENTAL DESIGN: The effects of ON 013105, a novel benzylstyryl sulfone kinase inhibitor, alone or with doxorubicin or rituximab, were examined in Granta 519 and Z138C cells. For in vivo studies, CB17/SCID mice were implanted subcutaneously with Z138C cells and treated with various combinations of ON 013105, doxorubicin, and rituximab. Tumor burden and body weight were monitored for 28 days. RESULTS: ON 013105 induced mitochondria-mediated apoptosis in MCL cells. Death was preceded by translocation of tBid to the mitochondria and cytochrome c release. In addition, ON 013105-treated cells exhibited reduced levels of cyclin D1, c-Myc, Mcl-1, and Bcl-xL. Using nuclear magnetic resonance (NMR) spectroscopy, we showed specific binding of ON 013105 to eIF4E, a critical factor for the initiation of protein translation. We proffer that this drug-protein interaction preferentially prevents the translation of the aforementioned proteins and may be the mechanism by which ON 013105 induces apoptosis in MCL cells. Efficacy studies in a mouse xenograft model showed that ON 013105 inhibited MCL tumor growth and that combining ON 013105 with rituximab reduced tumor burden further with negligible unwanted effects. CONCLUSIONS: Our findings suggest that ON 013105, alone or in combination with rituximab, may be a potent therapeutic agent to treat MCLs.


Subject(s)
Antibodies, Monoclonal, Murine-Derived/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Apoptosis/drug effects , Lymphoma, Mantle-Cell/metabolism , Lymphoma, Mantle-Cell/pathology , Styrenes/administration & dosage , Sulfones/administration & dosage , Tumor Burden/drug effects , Animals , Antibiotics, Antineoplastic/administration & dosage , Cell Line, Tumor , Cyclin D1/genetics , Cyclin D1/metabolism , Disease Models, Animal , Doxorubicin/administration & dosage , Eukaryotic Initiation Factor-4E/metabolism , Female , Gene Expression , Lymphoma, Mantle-Cell/drug therapy , Lymphoma, Mantle-Cell/genetics , Mice , Mitochondria/drug effects , Mitochondria/metabolism , Protein Binding , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Rituximab , Styrenes/metabolism , Styrenes/pharmacokinetics , Sulfones/metabolism , Sulfones/pharmacokinetics
10.
J Med Chem ; 55(2): 883-92, 2012 Jan 26.
Article in English | MEDLINE | ID: mdl-22236086

ABSTRACT

In the present study, a styryltriazole and four resveratrol derivatives were synthesized as candidates for ß-amyloid (Aß) plaque imaging. On the basis of their binding affinities to Aß(1-42) aggregates, the styryltriazole (1, K(i) = 12.8 nM) and one resveratrol derivative (5, K(i) = 0.49 nM) were labeled with (18)F. In normal mice, tissue distribution of [(18)F]5 showed good initial brain uptake (3.26% ID/g at 2 min) but slow wash-out from brains (2-to-60 min uptake ratio: 2.9). Furthermore, it underwent in vivo metabolic defluorination (1.88% ID/g at 2 min and 9.73% ID/g at 60 min). In contrast, [(18)F]1 displayed high initial brain uptake (5.38% ID/g at 2 min) with rapid wash-out from brains (0.52% ID/g at 60 min; 2-to-60 min uptake ratio: 10.3). These results indicate that [(18)F]1 has in vivo kinetics comparable to PET radiopharmaceuticals currently under commercial development, demonstrating that [(18)F]1 is a desirable PET radioligand for Aß plaque imaging.


Subject(s)
Amyloid beta-Peptides/metabolism , Aniline Compounds/chemical synthesis , Brain/metabolism , Plaque, Amyloid/metabolism , Radiopharmaceuticals/chemical synthesis , Stilbenes/chemical synthesis , Styrenes/chemical synthesis , Triazoles/chemical synthesis , Aniline Compounds/chemistry , Aniline Compounds/pharmacokinetics , Animals , Brain/diagnostic imaging , Fluorine Radioisotopes , Male , Mice , Mice, Inbred ICR , Peptide Fragments/metabolism , Radioligand Assay , Radionuclide Imaging , Radiopharmaceuticals/chemistry , Radiopharmaceuticals/pharmacokinetics , Resveratrol , Stereoisomerism , Stilbenes/chemistry , Stilbenes/pharmacokinetics , Structure-Activity Relationship , Styrenes/chemistry , Styrenes/pharmacokinetics , Tissue Distribution , Triazoles/chemistry , Triazoles/pharmacokinetics , Triazoles/pharmacology
11.
Gastroenterology ; 142(2): 316-25.e1-12, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22079593

ABSTRACT

BACKGROUND & AIMS: Copolymers of hydroxyethyl methacrylate and styrene sulfonate complex with isolated gliadin (the toxic fraction of gluten) and prevent damage to the intestinal barrier in HLA-HCD4/DQ8 mice. We studied the activity toward gluten and hordein digestion and biologic effects of poly(hydroxyethyl methacrylate-co-styrene sulfonate (P(HEMA-co-SS)). We also investigated the effect of gliadin complex formation in intestinal biopsy specimens from patients with celiac disease. METHODS: We studied the ability of P(HEMA-co-SS) to reduce digestion of wheat gluten and barley hordein into immunotoxic peptides using liquid chromatography-mass spectrometry. The biodistribution and pharmacokinetic profile of orally administered P(HEMA-co-SS) was established in rodents using tritium-labeled polymer. We assessed the capacity of P(HEMA-co-SS) to prevent the immunologic and intestinal effects induced by a gluten-food mixture in gluten-sensitized HLA-HCD4/DQ8 mice after short-term and long-term administration. We measured the effects of gliadin complex formation on cytokine release ex vivo using intestinal biopsy specimens from patients with celiac disease. RESULTS: P(HEMA-co-SS) reduced digestion of wheat gluten and barley hordein in vitro, thereby decreasing formation of toxic peptides associated with celiac disease. After oral administration to rodents, P(HEMA-co-SS) was predominantly excreted in feces, even in the presence of low-grade mucosal inflammation and increased intestinal permeability. In gluten-sensitized mice, P(HEMA-co-SS) reduced paracellular permeability, normalized anti-gliadin immunoglobulin A in intestinal washes, and modulated the systemic immune response to gluten in a food mixture. Furthermore, incubation of P(HEMA-co-SS) with mucosal biopsy specimens from patients with celiac disease showed that secretion of tumor necrosis factor-α was reduced in the presence of partially digested gliadin. CONCLUSIONS: The copolymer P(HEMA-co-SS) reduced digestion of wheat gluten and barley hordein and attenuated the immune response to gluten in a food mixture in rodents. It might be developed to prevent or reduce gluten-induced disorders in humans.


Subject(s)
Celiac Disease/metabolism , Digestion/drug effects , Glutens/metabolism , Intestinal Mucosa/drug effects , Polyhydroxyethyl Methacrylate/analogs & derivatives , Polystyrenes/pharmacology , Styrenes/pharmacology , Animals , Celiac Disease/drug therapy , Celiac Disease/immunology , Chromatography, Liquid , Female , Gliadin/metabolism , Gliadin/toxicity , Glutens/toxicity , Humans , Intestinal Absorption/drug effects , Intestinal Mucosa/immunology , Intestinal Mucosa/pathology , Jejunum/drug effects , Jejunum/immunology , Jejunum/pathology , Male , Mass Spectrometry , Mice , Permeability/drug effects , Polyhydroxyethyl Methacrylate/pharmacokinetics , Polyhydroxyethyl Methacrylate/pharmacology , Polyhydroxyethyl Methacrylate/therapeutic use , Polystyrenes/pharmacokinetics , Polystyrenes/therapeutic use , Protein Binding , Random Allocation , Rats , Styrenes/pharmacokinetics , Styrenes/therapeutic use
12.
J Med Chem ; 54(23): 8085-98, 2011 Dec 08.
Article in English | MEDLINE | ID: mdl-22011144

ABSTRACT

ß-Amyloid plaques (Aß plaques) in the brain are associated with cerebral amyloid angiopathy (CAA). Imaging agents that could target the Aß plaques in the living human brain would be potentially valuable as biomarkers in patients with CAA. A new series of (18)F styrylpyridine derivatives with high molecular weights for selectively targeting Aß plaques in the blood vessels of the brain but excluded from the brain parenchyma is reported. The styrylpyridine derivatives, 8a-c, display high binding affinities and specificity to Aß plaques (K(i) = 2.87, 3.24, and 7.71 nM, respectively). In vitro autoradiography of [(18)F]8a shows labeling of ß-amyloid plaques associated with blood vessel walls in human brain sections of subjects with CAA and also in the tissue of AD brain sections. The results suggest that [(18)F]8a may be a useful PET imaging agent for selectively detecting Aß plaques associated with cerebral vessels in the living human brain.


Subject(s)
Amyloid beta-Peptides/metabolism , Cerebral Amyloid Angiopathy/diagnostic imaging , Plaque, Amyloid/diagnostic imaging , Pyridines/chemical synthesis , Radiopharmaceuticals/chemical synthesis , Styrenes/chemical synthesis , Animals , Autoradiography , Brain/blood supply , Cerebral Amyloid Angiopathy/pathology , Fluorine Radioisotopes , Humans , Mice , Mice, Inbred ICR , Plaque, Amyloid/pathology , Positron-Emission Tomography , Pyridines/pharmacokinetics , Radiopharmaceuticals/pharmacokinetics , Stereoisomerism , Structure-Activity Relationship , Styrenes/pharmacokinetics , Tissue Distribution
14.
J Med Chem ; 50(20): 4986-92, 2007 Oct 04.
Article in English | MEDLINE | ID: mdl-17845017

ABSTRACT

beta-Amyloid (Abeta) binding affinities and specificities for six bis-styrylbenzenes with multiple magnetically equivalent fluorine atoms in the form of a tetrafluorophenyl core or symmetrical trifluoromethyl and trifluoromethoxy groups were determined by means of fluorescence titrations with amyloid peptide Abeta1-40 and a novel in vitro fluorescence-based assay using APP/PS1 transgenic mouse brain sections. Bis-styrylbenzenes with a tetrafluorophenyl core had increased Abeta binding affinities compared to their monofluorophenyl or phenyl counterparts. Bis-styrylbenzenes with carboxylic acid functional groups had lower Abeta binding affinities than their neutral counterparts. Selected bis-styrylbenzenes were demonstrated to have good blood-brain barrier penetration capabilities. These data extend the SAR of bis-styrylbenzene Abeta binding and provide direction for the development of a noninvasive probe for early detection of Alzheimer's disease using 19F MRI.


Subject(s)
Amyloid beta-Peptides/metabolism , Peptide Fragments/metabolism , Styrenes/chemical synthesis , Amyloid beta-Peptides/chemistry , Animals , Blood-Brain Barrier/metabolism , Fluorescence , Fluorobenzenes/chemical synthesis , Fluorobenzenes/pharmacokinetics , Fluorobenzenes/pharmacology , Ligands , Mice , Mice, Transgenic , Peptide Fragments/chemistry , Protein Binding , Stereoisomerism , Structure-Activity Relationship , Styrenes/pharmacokinetics , Styrenes/pharmacology
15.
J Med Chem ; 50(9): 2157-65, 2007 May 03.
Article in English | MEDLINE | ID: mdl-17411026

ABSTRACT

We report a series of radioiodinated styrylpyridines as single photon emission computed tomography probes for imaging Abeta plaques in the brain of patients with Alzheimer's disease (AD). In vitro binding showed that all of the styrylpyridines displayed very good binding affinities in postmortem AD brain homogenates (Ki = 3.6 to 15.5 nM). No-carrier-added samples of 13a, 13b, 16a, 16b, and 16e (radioiodinated with 125I) were successfully prepared. The in vivo biodistribution in normal mice, at 2 min after injection, showed excellent initial brain penetrations (4.03, 6.22, 5.43, and 8.04% dose/g for [125I]13a, 13b, 16a, and 16b, respectively). Furthermore, in vitro autoradiography of AD brain sections showed that the high binding signal was specifically due to the presence of Abeta plaques. Taken together, these results strongly suggest that these styrylpyridines are useful for imaging Abeta plaques in the living human brain.


Subject(s)
Alzheimer Disease/diagnostic imaging , Brain/diagnostic imaging , Plaque, Amyloid/metabolism , Pyridines/chemical synthesis , Radiopharmaceuticals/chemical synthesis , Styrenes/chemical synthesis , Amyloid beta-Peptides/metabolism , Animals , Autoradiography , Binding, Competitive , Brain/metabolism , Cell Line , Humans , Iodine Radioisotopes , Male , Mice , Mice, Inbred ICR , Pyridines/chemistry , Pyridines/pharmacokinetics , Radioligand Assay , Radiopharmaceuticals/chemistry , Radiopharmaceuticals/pharmacokinetics , Structure-Activity Relationship , Styrenes/chemistry , Styrenes/pharmacokinetics , Tissue Distribution , Tomography, Emission-Computed, Single-Photon
16.
Nucl Med Biol ; 34(1): 89-97, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17210465

ABSTRACT

Positron emission tomography (PET) imaging of beta-amyloid (Abeta) plaques in the brain is a potentially valuable tool for studying the pathophysiology of Alzheimer's disease (AD). It may also be applicable for measuring the effectiveness of therapeutic drugs aimed at lowering Abeta plaques in the brain. We have successfully reported a series of 18F-labeled fluoropegylated stilbenes for PET imaging studies. Encouraging results clearly demonstrated the usefulness of 18F-labeled stilbenes as potential Abeta plaque-imaging agents. In the present study, we applied a similar approach to a styrylpyridine backbone structure. Among all derivatives examined, (E)-2-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)-5-(4-dimethylaminostyryl)-pyridine (2) displayed high binding affinity in postmortem AD brain homogenates (Ki=2.5+/-0.4 nM, with [125I]IMPY as radioligand). No-carrier-added [18F]2 was successfully prepared by [18F]fluoride displacement of the corresponding tosylate precursor with a high labeling yield (30-40%) and a high radiochemical purity (>99%). Specific activity at the end of synthesis was determined to be 1500-2000 Ci/mmol. The tracer [18F]2 showed adequate lipophilicity (log P=3.22). In vivo biodistribution of [18F]2 in normal mice exhibited excellent initial brain penetration and rapid washout (7.77% and 1.03% dose/g in the brain at 2 and 30 min after intravenous injection, respectively)--properties that are highly desirable for Abeta-plaque-specific brain imaging agents. Autoradiography of AD brain sections and homogenate binding with postmortem AD brain tissues confirmed the high binding signal of [18F]2 due to the presence of Abeta plaques. These preliminary results suggest that novel PET tracers may be potentially useful for the imaging of Abeta plaques in the living human brain.


Subject(s)
Brain/diagnostic imaging , Brain/metabolism , Plaque, Amyloid/diagnostic imaging , Plaque, Amyloid/metabolism , Pyridines/pharmacokinetics , Animals , Fluorine Radioisotopes/chemistry , Fluorine Radioisotopes/pharmacokinetics , Humans , Isotope Labeling/methods , Male , Metabolic Clearance Rate , Mice , Mice, Inbred ICR , Organ Specificity , Positron-Emission Tomography/methods , Pyridines/chemistry , Radiopharmaceuticals/pharmacokinetics , Styrenes/chemistry , Styrenes/pharmacokinetics , Tissue Distribution
17.
J Med Chem ; 49(20): 6111-9, 2006 Oct 05.
Article in English | MEDLINE | ID: mdl-17004725

ABSTRACT

Alzheimer's disease (AD) is pathologically characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain, and thus, the in vivo imaging of plaques and tangles would be beneficial for the early diagnosis of AD. It has been suggested that 5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,4,6-heptatrien-3-one (curcumin) may be responsible for low age-adjusted prevalence of AD in India. In the present study, eight novel derivatives of curcumin and 4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one (dehydrozingerone) were synthesized and their binding affinities for beta-amyloid (Abeta) aggregates were measured. Of these ligands, fluoropropyl-substituted curcumin (8) showed the highest binding affinity (Ki=0.07 nM), and therefore, 8 was radiolabeled and evaluated as a potential probe for Abeta plaque imaging. Partition coefficient measurement and biodistribution in normal mice demonstrated that [18F]8 has a suitable lipophilicity and reasonable initial brain uptake. Metabolism studies also indicated that [18F]8 is metabolically stable in the brain. These results suggest that [18F]8 is a suitable radioligand for Abeta plaque imaging.


Subject(s)
Amyloid/metabolism , Curcumin/analogs & derivatives , Curcumin/chemical synthesis , Guaiacol/analogs & derivatives , Radiopharmaceuticals/chemical synthesis , Styrenes/chemical synthesis , Amyloid beta-Peptides/metabolism , Animals , Brain/diagnostic imaging , Brain/metabolism , Curcumin/pharmacokinetics , Fluorine Radioisotopes , Guaiacol/chemical synthesis , Guaiacol/chemistry , Guaiacol/pharmacokinetics , Isotope Labeling , Ligands , Male , Mice , Mice, Inbred ICR , Positron-Emission Tomography , Radiopharmaceuticals/chemistry , Radiopharmaceuticals/pharmacokinetics , Styrenes/pharmacokinetics , Tissue Distribution , Tomography, Emission-Computed, Single-Photon
18.
J Surg Res ; 135(1): 61-7, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16716356

ABSTRACT

BACKGROUND: Healing of a skin wound requires net protein deposition to repair the tissue defect and new epidermal cells to cover the wound. However, the true course of changes in rates of cell proliferation and protein deposition following skin injury has not been previously determined. This experiment was to measure DNA fractional synthetic rate (FSR), reflecting cell division, and protein FSR and fractional breakdown rate (FBR) in skin wound at three times after injury. MATERIALS AND METHODS: The experiment consisted of a surgery and a tracer infusion on separate days. During the surgery (day 0), a donor wound was created and indwelling catheters were inserted into the carotid artery and jugular vein under general anesthesia. On day 1, day 3, or day 7, stable isotope tracer infusion was performed in conscious rabbits to determine DNA FSR and protein FSR and FBR in the wound. RESULTS: Protein FSR and FBR in the day 7 wound were 20.5 +/- 8.4 and 12.6 +/- 4.7%/day, respectively, which were greater (P < 0.01-0.05) than the corresponding values in the day 1 and day 3 wounds. Net protein deposition (FSR-FBR) in day 7 wound (7.9 +/- 6.0%/day) was greater (P < 0.05) than in day 3 wound (0.8 +/- 2.4%/day). DNA FSRs were 1.94 +/- 0.58, 2.43 +/- 0.96, 2.86 +/- 0.90%/day in the day 1, day 3 and day 7 wounds, respectively (P = 0.2). CONCLUSIONS: The flow phase in the wound is characterized by increased protein synthesis rather than cell proliferation; net protein deposition in the wound is a major cause of protein requirements in severe burns.


Subject(s)
Epidermal Cells , Epidermis/metabolism , Protein Biosynthesis/physiology , Skin Transplantation , Wound Healing/physiology , Animals , Carbon Isotopes , Cell Division/physiology , Epidermis/surgery , Leucine/pharmacokinetics , Male , Models, Biological , Rabbits , Siloxanes/pharmacokinetics , Styrenes/pharmacokinetics , Tissue Donors
19.
Drug Chem Toxicol ; 29(1): 39-55, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16455589

ABSTRACT

Vinyl toluene is one of several methylstyrene monomers that provide improved performance in resins for specialty paints, hydrocarbon resins for adhesives, specialty polymers, and unsaturated polyester resins. The purpose of this study was to determine a permeability coefficient (Kp) and short-term absorption rate for vinyl toluene using human cadaver skin mounted in an in vitro static diffusion cell model with an exposure area of 0.64 cm2. For the Kp determination, vinyl toluene was applied at a rate of 100 microL/cm2 to 6 skin replicates representing 4 human subjects. Serial receptor fluid samples were collected at 1, 2, 4, 8, 12, 24, 36, and 48 h postapplication and analyzed for vinyl toluene by HPLC-UV. Based on the slope at steady-state (203.3 microg cm(-2) h(-1) +/- 120.0 microg cm(-2) h(-1)) and the concentration of the applied dose of vinyl toluene, taken as its density (894,600 microg/cm3), the Kp was calculated to be 2.27 x 10(-4) cm/h (+/-1.34 x 10(-4) cm/h). For the short-term absorption experiments, 12 skin replicates representing 3 human subjects were employed. Following 10- and 60-min exposures to a finite dose of vinyl toluene (10 microL/cm2), the respective short-term absorption rates were calculated to be 66.0 (+/-29.9) and 104.2 (+/-63.0) microg cm(-2) h(-1). These data provide industrial hygienists and safety personnel values to estimate the amount of vinyl toluene that may be absorbed via the dermal exposure route, given a variety of exposure scenarios, and the time it takes (skin absorption time) to reach a body burden equal to the Occupational Safety and Health Administrative permissible exposure level (OSHA PEL) or ACGIH TLV.


Subject(s)
Skin Absorption , Skin/metabolism , Styrenes/pharmacokinetics , Cadaver , Diffusion Chambers, Culture/instrumentation , Diffusion Chambers, Culture/methods , Humans , Organ Culture Techniques , Permeability
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