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Vivo Activity (vivo + activity)
Selected AbstractsN-[2-(Indan-1-yl)-3-mercapto-propionyl] Amino Acids as Highly Potent Inhibitors of the Three Vasopeptidases (NEP, ACE, ECE): In vitro and in vivo Activities.CHEMINFORM, Issue 48 2002Bernard-Pierre Roques Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of Aromatase Inhibitors and Dual Aromatase Steroid Sulfatase Inhibitors by Linking an Arylsulfamate Motif to 4-(4H -1,2,4-triazol-4-ylamino)benzonitrile: SAR, Crystal Structures, in,vitro and in,vivo ActivitiesCHEMMEDCHEM, Issue 11 2008Christian Bubert Dr. Abstract 4-(((4-Cyanophenyl)(4H -1,2,4-triazol-4-yl)amino)methyl)phenyl sulfamate (6,a) was the first dual aromatase,sulfatase inhibitor (DASI) reported. Several series of its derivatives with various linker systems between the steroid sulfatase (STS) and the aromatase inhibitory pharmacophores were synthesised and evaluated in JEG-3 cells. The X-ray crystal structures of the aromatase inhibitors, DASI precursors 42,d and 60, and DASI 43,h were determined. Nearly all derivatives show improved in,vitro aromatase inhibition over 6,a but decreased STS inhibition. The best aromatase inhibitor is 42,e (IC50=0.26,nM) and the best DASI is 43,e (IC50,aromatase=0.45,nM, IC50,STS=1200,nM). SAR for aromatase inhibition shows that compounds containing an alkylene- and thioether-based linker system are more potent than those that are ether-, sulfone-, or sulfonamide-based, and that the length of the linker has a limited effect on aromatase inhibition beyond two methylene units. Compounds 43,d,f were studied in,vivo (10,mg,kg,1, single, p.o.). The most potent DASI is 43,e, which inhibited PMSG-induced plasma estradiol levels by 92,% and liver STS activity by 98,% 3,h after dosing. These results further strengthen the concept of designing and developing DASIs for potential treatment of hormone-related cancers. [source] Apixaban, an oral, direct and highly selective factor Xa inhibitor: in vitro, antithrombotic and antihemostatic studiesJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2008P. C. WONG Summary.,Background:,Apixaban is an oral, direct and highly selective factor Xa (FXa) inhibitor in late-stage clinical development for the prevention and treatment of thromboembolic diseases. Objective:,We evaluated the in vitro properties of apixaban and its in vivo activities in rabbit models of thrombosis and hemostasis. Methods:,Studies were conducted in arteriovenous-shunt thrombosis (AVST), venous thrombosis (VT), electrically mediated carotid arterial thrombosis (ECAT) and cuticle bleeding time (BT) models. Results:,In vitro, apixaban is potent and selective, with a Ki of 0.08 nm for human FXa. It exhibited species difference in FXa inhibition [FXa Ki (nm): 0.16, rabbit; 1.3, rat; 1.7, dog] and anticoagulation [EC2× (,m, concentration required to double the prothrombin time): 3.6, human; 2.3, rabbit; 7.9, rat; 6.7, dog]. Apixaban at 10 ,m did not alter human and rabbit platelet aggregation to ADP, ,-thrombin, and collagen. In vivo, the values for antithrombotic ED50 (dose that reduced thrombus weight or increased blood flow by 50% of the control) in AVST, VT and ECAT and the values for BT ED3× (dose that increased BT by 3-fold) were 0.27 ± 0.03, 0.11 ± 0.03, 0.07 ± 0.02 and > 3 mg kg,1 h,1 i.v. for apixaban, 0.05 ± 0.01, 0.05 ± 0.01, 0.27 ± 0.08 and > 3 mg kg,1 h,1 i.v. for the indirect FXa inhibitor fondaparinux, and 0.53 ± 0.04, 0.27 ± 0.01, 0.08 ± 0.01 and 0.70 ± 0.07 mg kg,1 day,1 p.o. for the oral anticoagulant warfarin, respectively. Conclusions:,In summary, apixaban was effective in the prevention of experimental thrombosis at doses that preserve hemostasis in rabbits. [source] Effect of unionized ammonia, viscosity and protozoan contamination on the enzyme activity of the rotifer Brachionus plicatilisAQUACULTURE RESEARCH, Issue 4 2000A B. De Araujo Substrates that are cleaved to yield fluorescent products can be used to quickly quantify enzyme activity in vivo with image analysis or in vitro with fluorometry. This study was carried out to determine whether enzyme activity in rotifers is useful for assessing the physiological condition of rotifers. Neonates of Brachionus plicatilis Müller hatched from cysts were exposed to a concentration series of unionized ammonia ranging from 0 to 9.8 p.p.m., increasing seawater viscosity relative to 1.17 to control sea water by the addition of methyl cellulose and the addition of the protozoan Euplotes sp. to a density of 40 mL,1. Rotifer glucosidase and esterase activities decreased with increasing unionized ammonia and viscosity respectively. Activities of glucosidase and phospholipase decreased with increasing protozoan contamination. There was a significant relationship between enzyme activities and rotifer population growth. In vivo activities of certain rotifer enzymes can therefore serve as biomarkers for the rapid assessment of environmental stressors in rotifer mass cultures. [source] Combined effect of IL-17 and blockade of nitric oxide biosynthesis on haematopoiesis in miceACTA PHYSIOLOGICA, Issue 1 2010A. Krsti Abstract Aim:, The study was undertaken to extend our investigation concerning both the in vivo activity of interleukin (IL)-17 and the specific role of nitric oxide (NO) in IL-17-induced effects in the process of haematopoiesis. Methods:, CBA mice were simultaneously treated with IL-17 and/or nitric oxide synthase (NOS) inhibitor, l -NAME, for 5 days and changes within various haematopoietic cell lineages in bone marrow, spleen and peripheral blood were analysed. Results:, Findings showed that administration of both IL-17 and l -NAME stimulated increase in net haematopoiesis in normal mice. IL-17-enhanced myelopoiesis was characterized by stimulation of both femoral and splenic haematopoietic progenitor cells and morphologically recognizable granulocytes. Additionally, IL-17 induced alterations in the frequency of erythroid progenitor cells in both bone marrow and spleen, accompanied with their mobilization to the peripheral blood. As a consequence of these changes in the erythroid cell compartments, significant reticulocytosis was observed, which evidenced that in IL-17-treated mice effective erythropoiesis occurred. Exposure of mice to NOS inhibitor also increased the number of both granulocyte-macrophage and erythroid progenitors in bone marrow and spleens, and these alterations were followed by the mobilization of erythroid progenitors and elevated content of reticulocytes in peripheral blood. The specific role of NO in IL-17-induced haematopoiesis was demonstrated only in the IL-17-reducing effect on bone marrow late stage erythroid progenitors, CFU-E. Conclusion:, The results demonstrated the involvement of both IL-17 and NO in the regulation of haematopoietic cell activity in various haematopoietic compartments. They further suggest that IL-17 effects are differentially mediated depending on the haematopoietic microenvironments. [source] The N-terminal cysteine pair of yeast sulfhydryl oxidase Erv1p is essential for in vivo activity and interacts with the primary redox centreFEBS JOURNAL, Issue 7 2003Götz Hofhaus Yeast Erv1p is a ubiquitous FAD-dependent sulfhydryl oxidase, located in the intermembrane space of mitochondria. The dimeric enzyme is essential for survival of the cell. Besides the redox-active CXXC motif close to the FAD, Erv1p harbours two additional cysteine pairs. Site-directed mutagenesis has identified all three cysteine pairs as essential for normal function. The C-terminal cysteine pair is of structural importance as it contributes to the correct arrangement of the FAD-binding fold. Variations in dimer formation and unique colour changes of mutant proteins argue in favour of an interaction between the N-terminal cysteine pair with the redox centre of the partner monomer. [source] Mechanism of activation of the double-stranded-RNA-dependent protein kinase, PKRFEBS JOURNAL, Issue 13 2001Role of dimerization, cellular localization in the stimulation of PKR phosphorylation of eukaryotic initiation factor-2 (eIF2) An important defense against viral infection involves inhibition of translation by PKR phosphorylation of the , subunit of eIF2. Binding of viral dsRNAs to two dsRNA-binding domains (dsRBDs) in PKR leads to relief of an inhibitory region and activation of eIF2 kinase activity. Interestingly, while deletion of the regulatory region of PKR significantly induces activity in vitro, the truncated kinase does not inhibit translation in vivo, suggesting that these sequences carry out additional functions required for PKR control. To delineate these functions and determine the order of events leading to activation of PKR, we fused truncated PKR to domains of known function and assayed the chimeras for in vivo activity. We found that fusion of a heterologous dimerization domain with the PKR catalytic domain enhanced autophosphorylation and eIF2 kinase function in vivo. The dsRBDs also mediate ribosome association and we proposed that such targeting increases the localized concentration of PKR, enhancing interaction between PKR molecules. We addressed this premise by linking the truncated PKR to RAS sequences mediating farnesylation and membrane localization and found that the fusion protein was functional in vivo. These results indicate that cellular localization along with oligomerization enhances interaction between PKR molecules. Alanine substitution for the phosphorylation site, threonine 446, impeded in vivo and in vitro activity of the PKR fusion proteins, while aspartate or glutamate substitutions partially restored the function of the truncated kinase. These results indicate that both dimerization and cellular localization play a role in transient protein,protein interactions and that trans -autophosphorylation is the final step in the mechanism of activation of PKR. [source] Engineering therapeutic monoclonal antibodiesIMMUNOLOGICAL REVIEWS, Issue 1 2008Xiao-yun Liu Summary: During last two decades, the chimerization and humanization of monoclonal antibodies (mAbs) have led to the approval of several for the treatment of cancer, autoimmune diseases, and transplant rejection. Additional approaches have been used to further improve their in vivo activity. These include combining them with other modalities such as chemotherapy and redesigning them for improved pharmacokinetics, effector function, and signaling activity. The latter has taken advantage of new insights emerging from an increased understanding of the cellular and molecular mechanisms that are involved in the interaction of immunoglobulin G with Fc receptors and complement as well as the negative signaling resulting from the hypercrosslinking of their target antigens. Hence, mAbs have been redesigned to include mutations in their Fc portions, thereby endowing them with enhanced or decreased effector functions and more desirable pharmacokinetic properties. Their valency has been increased to decrease their dissociation rate from cells and enhance their ability to induce apoptosis and cell cycle arrest. In this review we discuss these redesigned mAbs and current data concerning their evaluation both in vitro and in vivo. [source] The sodium pump ,1 sub-unit: a disease progression,related target for metastatic melanoma treatmentJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 9b 2009Véronique Mathieu Abstract Melanomas remain associated with dismal prognosis because they are naturally resistant to apoptosis and they markedly metastasize. Up-regulated expression of sodium pump , sub-units has previously been demonstrated when comparing metastatic to non-metastatic melanomas. Our previous data revealed that impairing sodium pump ,1 activity by means of selective ligands, that are cardiotonic steroids, markedly impairs cell migration and kills apoptosis-resistant cancer cells. The objective of this study was to determine the expression levels of sodium pump , sub-units in melanoma clinical samples and cell lines and also to characterize the role of ,1 sub-units in melanoma cell biology. Quantitative RT-PCR, Western blotting and immunohistochemistry were used to determine the expression levels of sodium pump , sub-units. In vitro cytotoxicity of various cardenolides and of an anti-,1 siRNA was evaluated by means of MTT assay, quantitative videomicroscopy and through apoptosis assays. The in vivo activity of a novel cardenolide UNBS1450 was evaluated in a melanoma brain metastasis model. Our data show that all investigated human melanoma cell lines expressed high levels of the ,1 sub-unit, and 33% of human melanomas displayed significant ,1 sub-unit expression in correlation with the Breslow index. Furthermore, cardenolides (notably UNBS1450; currently in Phase I clinical trials) displayed marked anti-tumour effects against melanomas in vitro. This activity was closely paralleled by decreases in cMyc expression and by increases in apoptotic features. UNBS1450 also displayed marked anti-tumour activity in the aggressive human metastatic brain melanoma model in vivo. The ,1 sodium pump sub-unit could represent a potential novel target for combating melanoma. [source] Influence of therapy on the antioxidant status in patients with melanomaJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 2 2008V. Gadjeva DSc Summary Background and objective:, Some anticancer drugs can result in increased production of reactive oxygen species (ROS). Alkylating agents are the most frequently used drugs in chemotherapeutic regimens for the treatment of malignant melanoma. It is known that triazenes exhibit in vivo activity by alkylation of nucleic acids and proteins, but there is no data about ROS formation during oxidative metabolism. Single agents of most interest for treatment of malignant melanomas include 5-(3,3-dimethyltriazene-1-yl)-imidazole-4-carboxamide (DTIC) and nitrosoureas such as 1-(2-chloroethyl) -3-cyclohexyl-1-nitrosourea (CCNU), but complete response to these drugs is rare. The present study aimed to determine whether an oxidative stress occurs during the clinical course of melanoma and the influence of therapy on the antioxidant status of patients with melanoma. For this purpose, we investigated plasma concentrations of MDA as indices of the levels of lipid peroxidation products. In addition, we studied the activities of the antioxidant enzymes superoxide dismutases (SOD) and catalase (CAT) in patients with melanoma before any treatment, after surgical removal of melanoma, and after chemotherapy with DTIC or in combination with CCNU of the operated patients. Methods:, Twenty one patients with melanoma were studied. Patients were operated prior to chemotherapy. After recovery for 10,20 days postoperatively, they were studied again for MDA, SOD and CAT activity. The patients were divided into two groups according to the chemotherapy (3,7 treatment cycles): with DTIC , given orally daily for 5 days, every 3 weeks as a single 2200 mg/kg dose and with the combination , DTIC (the same dose) + CCNU , administered orally at a dosage of 120 mg/m2 once every 40 days in accordance with protocols, approved by the Bulgarian Ministry of Health. The total amount of lipid peroxidation products in plasma was assayed. Results and discussion:, Plasma levels of MDA and CAT activity were significantly higher, and erythrocyte SOD activity significantly lower, in patients with melanoma, than in control healthy volunteers (P < 0·0001). Ten to twenty days after surgery, oxidative stress decreased but levels of MDA increased as a result of therapy. Important sources of increased ROS production may be the monocytes, phagocytosis of tumour cells and the cancer tissues. Plasma MDA in patients treated with DTIC + CCNU were significantly higher (P < 0·001), but erythrocyte SOD statistically lower (P < 0·00001), compared with patients treated with DTIC only. However, a combination of DTIC + CCNU did not attenuate oxidative stress, or reduced antioxidant status. Patients treated with this combination are at bigger risk of oxidative injury. Therefore, this disturbance might be due to augmented generation of toxic ROS, possibly from the metabolism of CCNU. Conclusion:, Increased oxidative stress follows an imbalance in antioxidant defence in non-treated patients with melanoma. The impaired antioxidant system favours accumulation of ROS, which may promote the cancer process. After complete removal of melanoma tissues, oxidative stress decreased. The antioxidant status of melanoma patients operated on was influenced by the different chemotherapeutic regimens used and may play an important role in the response. Patients on DTIC + CCNU are at higher risk of oxidative injury. This drug combination probably exerts its toxic activity by ROS, which could be products of the metabolism of CCNU. [source] Applying pattern recognition methods plus quantum and physico-chemical molecular descriptors to analyze the anabolic activity of structurally diverse steroidsJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 3 2008Yoanna María Alvarez-Ginarte Abstract The great cost associated with the development of new anabolic,androgenic steroid (AASs) makes necessary the development of computational methods that shorten the drug discovery pipeline. Toward this end, quantum, and physicochemical molecular descriptors, plus linear discriminant analysis (LDA) were used to analyze the anabolic/androgenic activity of structurally diverse steroids and to discover novel AASs, as well as also to give a structural interpretation of their anabolic,androgenic ratio (AAR). The obtained models are able to correctly classify 91.67% (86.27%) of the AASs in the training (test) sets, respectively. The results of predictions on the 10% full-out cross-validation test also evidence the robustness of the obtained model. Moreover, these classification functions are applied to an "in house" library of chemicals, to find novel AASs. Two new AASs are synthesized and tested for in vivo activity. Although both AASs are less active than some commercially AASs, this result leaves a door open to a virtual variational study of the structure of the two compounds, to improve their biological activity. The LDA-assisted QSAR models presented here, could significantly reduce the number of synthesized and tested AASs, as well as could increase the chance of finding new chemical entities with higher AAR. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008 [source] Synthesis, characterization and in vivo activity of salmon calcitonin coconjugated with lipid and polyethylene glycolJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 4 2009Weiqiang Cheng Abstract An irreversible lipidized salmon calcitonin (sCT) analog, Mal-sCT, was previously shown to have comparable hypocalcemic activity to sCT in vivo. This study reports on the synthesis, characterization and pharmacological activity of novel PEGylated Mal-sCT analogs. Mal-sCT, prepared by conjugating sCT via thio-ether bonds with aqueous-soluble palmitic acid derivative at Cys 1 and Cys 7, was reacted with mPEG-succinimide (mPEG-Suc, 5 kDa). The products were purified and then identified by MALDI-TOF MS and HPLC. Mal-sCT was conjugated with 1 (1PEG-Mal-sCT) or 2 (2PEG-Mal-sCT) PEG chains at Lys 11 and Lys 18, the former being the preferred site of conjugation at higher mPEG-Suc/Mal-sCT ratio. Circular dichroism analysis showed the PEGylated Mal-sCT analogs to possess a robust helical conformation, while size measurement by dynamic light scattering indicated a propensity of the peptides to self-aggregate in aqueous solutions. Both 1PEG-Mal-sCT and 2PEG-Mal-sCT were more stable in rodent intestinal fluids than sCT or Mal-sCT. However, 1PEG-Mal-sCT had comparable hypocalcemic activity to Mal-sCT when injected subcutaneously in the rat, while 2PEG-Mal-sCT was inactive. 1PEG-Mal-sCT was inactive when administered orally in the rat. This study suggested PEGylation of Mal-sCT increased the stability of the lipidized peptide to enzyme degradation, but did not enhance its hypocalcemic activity. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:1438,1451, 2009 [source] Glycoengineering: The effect of glycosylation on the properties of therapeutic proteinsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 8 2005Angus M. Sinclair Abstract Therapeutic proteins have revolutionized the treatment of many diseases but low activity or rapid clearance limits their utility. New approaches have been taken to design drugs with enhanced in vivo activity and half-life to reduce injection frequency, increase convenience, and improve patient compliance. One recently used approach is glycoengineering, changing protein-associated carbohydrate to alter pharmacokinetic properties of proteins. This technology has been applied to erythropoietin and resulted in the discovery of darbepoetin alfa (DA), a hyperglycosylated analogue of erythropoietin that contains two additional N-linked carbohydrates, a threefold increase in serum half-life and increased in vivo activity compared to recombinant human erythropoietin (rHuEPO). The increased serum half-life allows for less frequent dosing to maintain target hemoglobin levels in anemic patients. Carbohydrates on DA and other molecules can also increase molecular stability, solubility, increase in vivo biological activity, and reduce immunogenicity. These properties are discussed. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:1626,1635, 2005 [source] Effect of benzyl isothiocyanate on tomato fruit infection development by Alternaria alternataJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2005R Troncoso-Rojas Abstract Benzyl isothiocyanate (BITC) is known to be a strong antifungal compound in vitro against different fungi. The effectiveness of benzyl isothiocyanate to control Alternaria alternata growth in vitro and in vivo was tested. BITC in vitro activity was evaluated in A alternata growing on potato dextrose agar and exposed to 0.025, 0.05, 0.1, 0.2 or 0.4 mg ml,1. In vivo activity was evaluated by exposing A alternata -inoculated tomato fruits for either 18 or 36 h to 0.28 or 0.56 mg ml,1 BITC packed on low-density polyethylene film (LDPF) bags. Additionally, the effect of BITC on post-harvest physiology and tomato quality throughout storage at 20 °C was evaluated daily by monitoring respiration rate and ethylene production, whereas total soluble solids, pH, titratable acidity and fresh weight loss were measured every 3 days. Results showed that the minimal inhibitory concentration of BITC in vitro was 0.1 mg ml,1. A combined use of 0.56 mg ml,1 BITC with LDPF for 18 h was the optimum treatment to control Alternaria rot in packed tomato fruit. No effect of BITC on respiration rate, ethylene production, total soluble solids, pH, weight loss and titratable acidity was observed. Results suggest that BITC can be used as a post-harvest treatment to control Alternaria rot in tomato fruit without detrimental effects on the tomato post-harvest quality. Copyright © 2005 Society of Chemical Industry [source] Determination of the In Vitro Susceptibility of Feline Tritrichomonas foetus to 5 Antimicrobial AgentsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2007Elizabeth J. Kather Background: The nitroimidazole, ronidazole, has been demonstrated to have in vitro and in vivo activity against the protozoan Tritrichomonas foetus in cats. The purpose of this study was to evaluate the in vitro susceptibility of feline T foetus isolates obtained from naturally infected cats to 5 antimicrobial agents and to compare the in vitro time kill of ronidazole and metronidazole. Hypothesis: We hypothesized that nitroimidazoles have in vitro activity against T foetus, whereas furazolidone, omeprazole, and paromomycin do not. Animals: Fecal specimens were cultured from 4 naturally infected Bengal cats with a history of T foetus -associated diarrhea. Methods: A 24-hour susceptibility assay was performed on all 4 isolates for the 5 antimicrobial agents. A time-kill microdilution method was performed on 2 isolates for metronidazole and ronidazole. Results: Paromomycin and omeprazole showed no in vitro effect at concentrations ±80 ,g/mL. There was no significant difference in 24-hour susceptibilities among metronidazole, ronidazole, and furazolidone. In addition, only the results of the highest concentration tested (80 ,g/mL) and concentrations of 1.25 and 2.5 ,g/mL revealed significant differences in the rate of trophozoite killing, with ronidazole having a faster reduction in trophozoite survival. Conclusions and Clinical Importance: Time-kill assays demonstrated ronidazole had a higher lethal activity compared with metronidazole. These findings contrast with a previously published report and may reflect strain variation, different methodologies, or both. The lack of clinical response seen with metronidazole administration to treat feline trichomoniasis may not reflect inherent resistance but rather in vivo events involving drug distribution and pharmacokinetics. [source] Characterization of an acyl-CoA: carboxylate CoA-transferase from Aspergillus nidulans involved in propionyl-CoA detoxificationMOLECULAR MICROBIOLOGY, Issue 3 2008Christian B. Fleck Summary Filamentous fungi metabolize toxic propionyl-CoA via the methylcitrate cycle. Disruption of the methylcitrate synthase gene leads to an accumulation of propionyl-CoA and attenuates virulence of Aspergillus fumigatus. However, addition of acetate, but not ethanol, to propionate-containing medium strongly reduces the accumulation of propionyl-CoA and restores growth of the methylcitrate synthase mutant. Therefore, the existence of a CoA-transferase was postulated, which transfers the CoASH moiety from propionyl-CoA to acetate and, thereby, detoxifying the cell. In this study, we purified the responsible protein from Aspergillus nidulans and characterized its biochemical properties. The enzyme used succinyl-, propionyl- and acetyl-CoA as CoASH donors and the corresponding acids as acceptor molecules. Although the protein displayed high sequence similarity to acetyl-CoA hydrolases this activity was hardly detectable. We additionally identified and deleted the coding DNA sequence of the CoA-transferase. The mutant displayed weak phenotypes in the presence of propionate and behaved like the wild type when no propionate was present. However, when a double-deletion mutant defective in both methylcitrate synthase and CoA-transferase was constructed, the resulting strain was unable to grow on media containing acetate and propionate as sole carbon sources, which confirmed the in vivo activity of the CoA-transferase. [source] Initial testing of the aurora kinase a inhibitor MLN8237 by the Pediatric Preclinical Testing Program (PPTP),PEDIATRIC BLOOD & CANCER, Issue 1 2010John M. Maris MD Abstract Background MLN8237 is a small molecule inhibitor of Aurora Kinase A (AURKA) that is currently in early phase clinical testing. AURKA plays a pivotal role in centrosome maturation and spindle formation during mitosis. Procedures MLN8237 was tested against the Pediatric Preclinical Testing Program (PPTP) in vitro panel at concentrations ranging from 1.0,nM to 10,µM and was tested against the PPTP in vivo panels at a dose of 20,mg/kg administered orally twice daily,×,5 days. Treatment duration was 6 weeks for solid tumor xenografts and 3 weeks for ALL xenografts. Results MLN8237 had a median IC50 of 61,nM against the PPTP in vitro panel. The ALL cell lines were more sensitive and the rhabdomyosarcoma cell lines less sensitive than the remaining PPTP cell lines. In vivo, MLN8237 induced significant differences in event-free survival (EFS) distributions compared to controls in 32/40 (80%) solid tumor models and all (6/6) ALL models. Maintained complete responses (CRs) were observed in 3 of 7 neuroblastoma xenografts, and all 6 evaluable ALL xenografts achieved CR (n,=,4) or maintained CR (n,=,2) status. Maintained CRs were observed among single xenografts in other panels, including the Wilms tumor, rhabdoid tumor, rhabdomyosarcoma, Ewing sarcoma, osteosarcoma, and medulloblastoma. Conclusions The in vivo activity observed against the neuroblastoma panel far exceeds that observed for standard agents evaluated against the panel by the PPTP. High levels of in vivo activity were also observed against the ALL xenograft panel. These data support expedited clinical development of MLN8237 in childhood cancer. Pediatr Blood Cancer 2010;55:26,34. © 2010 Wiley-Liss, Inc. [source] Insecticidal 2-hydroxy-3-alkyl-1,4-naphthoquinones: correlation of inhibition of ubiquinol cytochrome c oxidoreductase (complex III) with insecticidal activityPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 3 2002Philip J Jewess Abstract The insecticidal and in vitro activities of four homologous series of 2-hydroxy and acetoxy-3-substituted-1,4-naphthoquinones have been measured and correlated with their (Log) octanol/water partition coefficients (Log Ko/w). In vitro activity against mitochondrial complex III was only exhibited by 2-hydroxy-3-alkyl-1,4-naphthoquinones, indicating that the 2-acetoxy compounds act as pro-insecticides. Good correlation was observed between in vivo activity against the two-spotted spider mite, Tetranychus urticae and inhibition of complex III isolated from blowfly flight muscle. Both hydroxy and acetoxy analogues of individual compounds exhibited similar levels of in vivo activity with optimum activity for analogues with Log Ko/w values of 7,8. In contrast, the acetoxy derivatives showed superior in vivo activity against the tobacco whitefly, Bemisia tabaci. Complex III isolated from whitefly was optimally inhibited by hydroxy analogues with lower Log Ko/w values (6.0,6.5) and was also more sensitive than the blowfly enzyme to all the compounds tested. © 2002 Society of Chemical Industry [source] Pharmacological and Functional Characterization of Novel EP and DP Receptor Agonists: DP1 Receptor Mediates Penile Erection in Multiple SpeciesTHE JOURNAL OF SEXUAL MEDICINE, Issue 2 2008Nadia Brugger PhD ABSTRACT Introduction., Despite the widespread use of prostaglandin E1 as an efficacious treatment for male erectile dysfunction for more than two decades, research on prostanoid function in penile physiology has been limited. Aim., To characterize the pharmacological and physiological activity of novel subtype-selective EP and DP receptor agonists. Methods., Radioligand binding and second messenger assays were used to define receptor subtype specificity of the EP and DP agonists. Functional activity was further characterized using isolated human and rabbit penile cavernosal tissue in organ baths. In vivo activity was assessed in rabbits and rats by measuring changes in cavernous pressure after intracavernosal injection of receptor agonists. Main Outcome Measures., Receptor binding and signal transduction, smooth muscle contractile activity, erectile function. Results., In organ bath preparations of human cavernosal tissue contracted with phenylephrine, EP2- and EP4-selective agonists exhibited variable potency in causing relaxation. One of the compounds caused mild contraction, and none of the compounds was as effective as PGE1 (EC50 = 0.23 µM). There was no consistent correlation between the pharmacological profile (receptor binding and second messenger assays) of the EP agonists and their effect on cavernosal tissue tone. In contrast, the DP1-selective agonist AS702224 (EC50 =29 nM) was more effective in relaxing human cavernosal tissue than either PGE1, PGD2 (EC50 = 58 nM), or the DP agonist BW245C (EC50 =59 nM). In rabbit cavernosal tissue, PGE1 and PGD2 caused only contraction, while AS702224 and BW245C caused relaxation. Intracavernosal administration of AS702224 and BW245C also caused penile tumescence in rabbits and rats. For each compound, the erectile response improved with increasing dose and was significantly higher than vehicle alone. Conclusions., These data suggest that AS702224 is a potent DP1-selective agonist that causes penile erection. The DP1 receptor mediates relaxation in human cavernosal tissue, and stimulates pro-erectile responses in rat and rabbit. Thus, rabbits and rats can be useful models for investigating the physiological function of DP1 receptors. Brugger N, Kim NN, Araldi GL, Traish AM, and Palmer SS. Pharmacological and functional characterization of novel EP and DP receptor agonists: DP1 receptor mediates penile erection in multiple species. J Sex Med 2008;5:344,356. [source] Pharmacokinetics of E-6087, a new anti-inflammatory agent, in rats and dogsBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 6 2001Raquel F. Reinoso Abstract The pharmacokinetics of E-6087, a newly developed cyclooxygenase-2 inhibitor, was studied in rats and dogs after single oral and intravenous doses. In both animal species, E-6087 was characterized by a long elimination half-life (20,35 h), a low plasma clearance (0.10,0.22 l h,1 kg,1) and a relatively large volume of distribution (2,6 l kg,1). Oral bioavailability was lower in dogs than in rats whereas a faster elimination was found in rats. Multiple peaks were present regardless of administration route and animal species, suggesting the existence of enterohepatic circulation. Gender effect on the pharmacokinetics of E-6087 was only found in rats, with greater exposure and longer elimination in females than in males. Food intake reduced the bioavailability (,22%) with no apparent changes in the absorption rate. After oral dosing of 1, 5 and 25 mg kg,1 to rats, linearity was lost at the highest dose due to the low aqueous solubility of E-6087. Drug absorption was improved by micronization. E-6087 and E-6132, (a pharmacologically active metabolite), showed different pharmacokinetics. The higher percentage of E-6087 at early times suggests that E-6087 is the main compound responsible for in vivo activity, although E-6132 would contribute to the activity at later times. Copyright © 2001 John Wiley & Sons, Ltd. [source] In vitro and in vivo antineoplastic activity of a novel bromopyrrole and its potential mechanism of actionBRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2010Sheng Xiong Background and purpose:, Many bromopyrrole compounds have been reported to have in vitro antineoplastic activity. In a previous study, we isolated N-(4, 5-dibromo-pyrrole-2-carbonyl)-L-amino isovaleric acid methyl ester (B6) from marine sponges. Here, we investigated the in vitro and in vivo antineoplastic activity of B6 and its potential mechanism. Experimental approach:, The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine the in vitro antineoplastic activity of B6. Flow cytometry, western blot analysis and morphological observations were used to investigate its mechanism of action. A mouse xenograft model was used to determine its in vivo activity. Key results:, B6 inhibited the proliferation of various human cancer cells in vitro, with highest activity on LOVO and HeLa cells. B6 also exhibited significant growth inhibitory effects in vivo in a xenograft mouse model. Acute toxicity analysis suggested that B6 has low toxicity. B6-treated cells arrested in the G1 phase of the cell cycle and had an increased fraction of sub-G1 cells. In addition, the population of Annexin V-positive/propidium iodide-negative cells increased, indicating the induction of early apoptosis. Indeed, B6-treated cells exhibited morphologies typical of cells undergoing apoptosis. Western blotting showed cleaved forms of caspase-9 and caspase-3 in cells exposed to B6. Moreover, B6-promoted Ca2+ release and apoptosis was associated with elevated intracellular Ca2+concentration. Conclusions and implications:, B6 has significant antineoplastic activity in vitro as well as in vivo. It inhibits tumour cell proliferation by arresting the cell cycle and inducing apoptosis. With its low toxicity, B6 represents a promising antineoplastic, primary compound. [source] Dual modulation of urinary bladder activity and urine flow by prostanoid EP3 receptors in the conscious ratBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2009MJ Jugus Background and purpose:, Cyclooxygenase inhibitors function to reduce levels of prostaglandin E2 (PGE2) and are broadly efficacious in models of bladder overactivity. We therefore investigated a regulation of urinary bladder function in conscious rats by modulation of the EP3 receptor for PGE2. Experimental approach:, The activity of the EP3 receptor agonist GR63799X, and EP3 receptor antagonists, CM9 and DG041, at recombinant EP3 receptors was evaluated in vitro. In vivo, intraduodenal dosing during conscious, continuous-filling cystometry of spontaneously hypertensive rats was utilized to determine the urodynamic effect of EP3 receptor modulation. Key results:, GR63799X dose-dependently (0.001,1 mg·kg,1) reduced bladder capacity, as indicated by a reduction in both the micturition interval and volume of urine per void. In contrast, CM9 (10 and 30 mg·kg,1) and DG041 (30 mg·kg,1) enhanced bladder capacity, as indicated by significantly longer micturition intervals and larger void volumes. CM9 and DG041 inhibited the responses to GR63799X supporting the in vivo activity of these pharmacological agents at the EP3 receptor. In addition to its effect on bladder capacity, GR63799X increased endogenous urine production. Intra-arterial infusion of saline mimicked the enhancement of urine flow observed with GR63799X, and the response was inhibited by CM9. Conclusions and implications:, These data support the EP3 receptor as a modulator of urinary bladder activity in the conscious rat, and in addition, indicate a role for EP3 receptor activity in regulating urine flow. [source] NV-128, a novel isoflavone derivative, induces caspase-independent cell death through the Akt/mammalian target of rapamycin pathwayCANCER, Issue 14 2009Ayesha B. Alvero MD Abstract BACKGROUND: Resistance to apoptosis is 1 of the key events that confer chemoresistance and is mediated by the overexpression of antiapoptotic proteins, which inhibit caspase activation. The objective of this study was to evaluate whether the activation of an alternative, caspase-independent cell death pathway could promote death in chemoresistant ovarian cancer cells. The authors report the characterization of NV-128 as an inducer of cell death through a caspase-independent pathway. METHODS: Primary cultures of epithelial ovarian cancer (EOC) cells were treated with increasing concentration of NV-128, and the concentration that caused 50% growth inhibition (GI50) was determined using a proprietary assay. Apoptotic proteins were characterized by Western blot analyses, assays that measured caspase activity, immunohistochemistry, and flow cytometry. Protein-protein interactions were determined using immunoprecipitation. In vivo activity was measured in a xenograft mice model. RESULTS: NV-128 was able to induce significant cell death in both paclitaxel-resistant and carboplatin-resistant EOC cells with a GI50 between 1 ,g/mL and 5 ,g/mL. Cell death was characterized by chromatin condensation but was caspase-independent. The activated pathway involved the down-regulation of phosphorylated AKT, phosphorylated mammalian target of rapamycin (mTOR), and phosphorylated ribosomal p70 S6 kinase, and the mitochondrial translocation of beclin-1 followed by nuclear translocation of endonuclease G. CONCLUSIONS: The authors characterized a novel compound, NV-128, which inhibits mTOR and promotes caspase-independent cell death. The current results indicated that inhibition of mTOR may represent a relevant pathway for the induction of cell death in cells resistant to the classic caspase-dependent apoptosis. These findings demonstrate the possibility of using therapeutic drugs, such as NV-128, which may have beneficial effects in patients with chemoresistant ovarian cancer. Cancer 2009. © 2009 American Cancer Society. [source] NMR solution structure of a potent cyclic nonapeptide inhibitor of ICAM-1-mediated leukocyte adhesion produced by homologous amino acid substitutionCHEMICAL BIOLOGY & DRUG DESIGN, Issue 4 2004L.O. Sillerud Abstract:, We have previously described a disulfide-linked cyclic nonapeptide (inhibitory peptide-01, IP01), with the sequence CLLRMRSIC, which binds to intercellular adhesion molecule-1 (ICAM-1), and blocks binding to its counter-structure, the integrin ,L,2 (leukocyte functional antigen-1, LFA-1) (Sillerud et al., J. Peptide Res. 62, 2003: 97). We now report the optimization of this peptide by means of single homologous amino acid substitutions to yield a new peptide (IP02-K6; CLLRMKSAC) which shows an approximately sixfold improvement in inhibitory activity of multivalent leukocyte binding (inhibition constant for 50% inhibition, IC50 = 90 ,m) compared with IP01 (IC50 = 580 ,m). This improvement in activity gives IP02-K6 potent in vivo activity in a murine model of ischemia reperfusion injury (Merchant et al., Am. J. Physiol. Heart Circ. 284, 2003: H1260). In order to determine the structural features relevant to ICAM-1-binding, we have determined the structure of IP02-K6 using proton nuclear magnetic resonance (NMR) spectroscopy and restrained molecular modeling. In our previously reported study of solution models of IP01, we observed three interconverting conformations during low-temperature molecular dynamics simulation. In the present study, we find a single conformation of IP02-K6 similar to one of the previously found conformations of IP01 (family C). In particular, an R4-S7 , -turn is present in similar proportions in both conformation C of IP01 and in IP02-K6; this motif is important in binding to ICAM-1 because this turn enables the IP02-K6 backbone to drape over proline-36 on ICAM-1. The NMR-derived solution model of IP02-K6 was found to dock at the ,L,2 -binding site on ICAM-1 with no changes in peptide backbone conformation. This docking model displaced five of the 15 ,L,2 residues at the ICAM-1-binding site and provided a rationale for understanding the quantitative relationship between IP02-K6 structure and biologic activity. [source] Diorganotin(IV) Derivatives of Substituted Benzohydroxamic Acids with High Antitumor ActivityCHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2004Qingshan Li Abstract A series of diorganotin(IV) and dichlorotin(IV) derivatives of 4-X-benzohydroxamic acids, [HL1 (X = Cl) or HL2 (X = OCH3)] formulated as [R2SnL2] (R = Me, Et, nBu, Ph or Cl; L = L1 or L2), along with their corresponding mixed-ligand complexes [R2Sn(L1)(L2)] have been prepared and characterized by FT-IR, 1H, 13C, and 119Sn NMR spectroscopy, mass spectrometry, elemental analysis, and melting points. In addition, single-crystal X-ray diffraction analyses were carried out for [Me2SnL2] (L = L1 or L2), which show coordination structures intermediate between distorted octahedra and bicapped tetrahedra. The hydroxamate ligands are asymmetrically coordinated by the oxygen atoms, the carbonyl oxygen atom is further away from the metal center than the other oxygen atom. The complexes are stable monomeric species; most of them are soluble not only in chlorohydrocarbon solvents, but also in alcohols and hydroalcoholic solutions. In polar solvents, the mixed-ligand complexes gradually decompose into the corresponding single-ligand complex couples. The complexes exhibit in vitro antitumor activities (against a series of human tumor cell lines) which, in some cases, are identical to, or even higher than, that of cisplatin. For the dialkyltin complexes, the activity increases with the length of the carbon chain of the alkyl ligand and is higher in the case of the chloro-substituted benzohydroxamato ligand. The [nBu2Sn(L1)2] complex displays a high in vivo activity against H22 liver and BGC-823 gastric tumors, and has a relatively low toxicity. [source] ,,,-Cyclopentaneglycine Dipeptides Capped with Biaryls as Tachykinin NK2 Receptor AntagonistsCHEMMEDCHEM, Issue 7 2008Marina Porcelloni Dr. Abstract The NK2 receptor belongs to the family of tachykinin neurotransmitters. It has been reported to be involved in several pathological conditions, and selective antagonists are potentially useful drugs for the treatment of asthma, irritable bowel syndrome, cystitis, and depression. Starting from in-house capped dipeptide libraries, we were able to identify a number of molecules with sub-nanomolar binding affinity for the hNK2 receptor. All were characterized by a rigid core structure with a strong constraint induced by an ,,,-cyclopentaneglycine fragment. Herein we report the further elaboration of three initial basic structures. The planar benzothiophene group was substituted with a series of biphenyl and heterobiphenyl moieties that are well tolerated in terms of receptor affinity. The new compounds also maintained good antagonist potency in an in,vitro functional assay, and a number of them showed significant in,vivo activity after intravenous administration in our guinea pig model. [source] Medicinal Chemistry Optimization of Acyldepsipeptides of the Enopeptin Class AntibioticsCHEMMEDCHEM, Issue 7 2006Berthold Hinzen The therapy of life-threatening infections is significantly weakened by the global spread of antibiotic resistance. Synthetic exploration of enopeptin type acyldepsipeptide antibiotics revealed a remarkable structure,activity relationship. New compounds with improved in,vitro antibiotic activity against Gram-positive pathogens (including multiresistant strains) and in,vivo activity in mouse models of lethal infection are described. [source] In vivo activity of 11,-hydroxysteroid dehydrogenase type 1 and free fatty acid-induced insulin resistanceCLINICAL ENDOCRINOLOGY, Issue 4 2005K. Mai Summary Introduction, Free fatty acids (FFAs) induce hepatic insulin resistance and enhance hepatic gluconeogenesis. Glucocorticoids (GCs) also stimulate hepatic gluconeogenesis. The aim of this study was to investigate whether the FFA-induced hepatic insulin resistance is mediated by increased activity of hepatic 11,-hydroxysteroid dehydrogenase type 1 (11,-HSD1), accompanied by elevated hepatic cortisol levels. Methods, Following a 10-h overnight fast, six healthy male volunteers were investigated. A euglycaemic hyperinsulinaemic clamp was performed during lipid or saline infusion. To assess hepatic 11,-HSD1 activity, plasma cortisol levels were measured after oral administration of cortisone acetate during lipid or saline infusion. In addition, 11,-HSD activities were determined in vivo by calculating the urinary ratios of GC metabolites. Results, Lipid infusion increased FFAs (5·41 ± 1·00 vs. 0·48 ± 0·20 mmol/l; P < 0·005) and significantly increased insulin resistance [glucose infusion rate (GIR) 6·02 ± 2·60 vs. 4·08 ± 2·15 mg/kg/min; P < 0·005]. After lipid and saline infusions no changes in 11,-HSD1 activity were found, neither by changes in cortisone acetate to cortisol conversion nor by differences in urinary free cortisol (UFF) or cortisone (UFE), 5,-tetrahydrocortisol (THF), 5,-THF, cortisone (THE), UFF/UFE and (5,-THF + THF)/THE ratios. Conclusions, We found no change in hepatic and whole-body 11,-HSD1 activity during acute FFA-induced insulin resistance. Further studies are necessary to clarify whether 11,-HSD1 in muscle and adipose tissue is influenced by FFAs and whether 11,-HSD1 is involved in other conditions of insulin resistance. [source] | ||||||||||||||||||||||||||||