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Yakugaku Zasshi : Journal of the... 2019In this study, we attempted to improve the non-aqueous titration method using N,N-dimethylformamide (DMF) in the Japanese Pharmacopoeia seventeenth edition (JP XVII) for...
In this study, we attempted to improve the non-aqueous titration method using N,N-dimethylformamide (DMF) in the Japanese Pharmacopoeia seventeenth edition (JP XVII) for advancement in experimental safety. As an alternative solvent for DMF, we demonstrate titrations using dimethyl sulfoxide (DMSO), which has similar properties as and much higher safety than DMF. Five drugs (i.e., acetohexamide, glibenclamide, sulfamethoxazole, tranilast, and furosemide) listed in JP XVII use DMF as a solvent for titrations with sodium hydroxide standard solution. For these drugs, we examined whether DMF can be replaced with DMSO in quantitative analyses. As a result, a quantification similar to that of the Pharmacopoeia protocol is possible by simply replacing DMF with DMSO or using a mixed solvent of DMSO and water.
Topics: Dimethyl Sulfoxide; Dimethylformamide; Japan; Pharmacopoeias as Topic; Quality Improvement; Safety; Sodium Hydroxide; Solutions; Solvents; Titrimetry; Water
PubMed: 31474635
DOI: 10.1248/yakushi.19-00119 -
European Journal of Pharmacology Oct 2019Type 2 diabetes mellitus (T2DM) is associated with a higher risk of cancer and cancer-related mortality. Increased blood glucose and insulin levels in T2DM patients may...
Type 2 diabetes mellitus (T2DM) is associated with a higher risk of cancer and cancer-related mortality. Increased blood glucose and insulin levels in T2DM patients may be, at least in part, responsible for this effect. Indeed, lowering glucose and/or insulin levels pharmacologically appears to reduce cancer risk and progression, as has been demonstrated for the biguanide metformin in observational studies. Studies investigating the influence of sulfonylurea derivatives (SUs) on cancer risk have provided conflicting results, partly due to comparisons with metformin. Furthermore, little attention has been paid to within-class differences in systemic and off-target effects of the SUs. The aim of this systematic review is to discuss the available preclinical and clinical evidence on how the different SUs influence cancer development and risk. Databases including PubMed, Cochrane, Database of Abstracts on Reviews and Effectiveness, and trial registries were systematically searched for available clinical and preclinical evidence on within-class differences of SUs and cancer risk. The overall preclinical and clinical evidence suggest that the influence of SUs on cancer risk in T2DM patients differs between the various SUs. Potential mechanisms include differing affinities for the sulfonylurea receptors and thus differential systemic insulin exposure and off-target anti-cancer effects mediated for example through potassium transporters and drug export pumps. Preclinical evidence supports potential anti-cancer effects of SUs, which are of interest for further studies and potentially repurposing of SUs. At this time, the evidence on differences in cancer risk between SUs is not strong enough to guide clinical decision making.
Topics: Animals; Carcinogenesis; Humans; Neoplasms; Risk; Sulfonylurea Compounds
PubMed: 31408647
DOI: 10.1016/j.ejphar.2019.172598 -
Molecular Cell Nov 2017DNA lesions caused by UV damage are thought to be repaired solely by the nucleotide excision repair (NER) pathway in human cells. Patients carrying mutations within...
DNA lesions caused by UV damage are thought to be repaired solely by the nucleotide excision repair (NER) pathway in human cells. Patients carrying mutations within genes functioning in this pathway display a range of pathologies, including an increased susceptibility to cancer, premature aging, and neurological defects. There are currently no curative therapies available. Here we performed a high-throughput chemical screen for agents that could alleviate the cellular sensitivity of NER-deficient cells to UV-induced DNA damage. This led to the identification of the clinically approved anti-diabetic drug acetohexamide, which promoted clearance of UV-induced DNA damage without the accumulation of chromosomal aberrations, hence promoting cellular survival. Acetohexamide exerted this protective function by antagonizing expression of the DNA glycosylase, MUTYH. Together, our data reveal the existence of an NER-independent mechanism to remove UV-induced DNA damage and prevent cell death.
Topics: Acetohexamide; Cell Line, Tumor; DNA Damage; DNA Glycosylases; DNA Repair; Gene Expression Regulation, Enzymologic; Humans; Male; Ultraviolet Rays
PubMed: 29149600
DOI: 10.1016/j.molcel.2017.10.021 -
Analytical and Bioanalytical Chemistry Jan 2016Ultrafast affinity extraction and a two-dimensional high performance affinity chromatographic system were used to measure the free fractions for various drugs in serum...
Ultrafast affinity extraction and a two-dimensional high performance affinity chromatographic system were used to measure the free fractions for various drugs in serum and at typical therapeutic concentrations. Pooled samples of normal serum or serum from diabetic patients were utilized in this work. Several drug models (i.e., quinidine, diazepam, gliclazide, tolbutamide, and acetohexamide) were examined that represented a relatively wide range of therapeutic concentrations and affinities for human serum albumin (HSA). The two-dimensional system consisted of an HSA microcolumn for the extraction of a free drug fraction, followed by a larger HSA analytical column for the further separation and measurement of this fraction. Factors that were optimized in this method included the flow rates, column sizes, and column switching times that were employed. The final extraction times used for isolating the free drug fractions were 333-665 ms or less. The dissociation rate constants for several of the drugs with soluble HSA were measured during system optimization, giving results that agreed with reference values. In the final system, free drug fractions in the range of 0.7-9.5% were measured and gave good agreement with values that were determined by ultrafiltration. Association equilibrium constants or global affinities were also estimated by this approach for the drugs with soluble HSA. The results for the two-dimensional system were obtained in 5-10 min or less and required only 1-5 μL of serum per injection. The same approach could be adapted for work with other drugs and proteins in clinical samples or for biomedical research.
Topics: Chromatography, Affinity; Diabetes Mellitus; Humans; Pharmaceutical Preparations
PubMed: 26462924
DOI: 10.1007/s00216-015-9082-7 -
Molecules (Basel, Switzerland) Jul 2014Diabetes mellitus is a life threatening disease and scientists are doing their best to find a cost effective and permanent treatment of this malady. The recent trend is...
Diabetes mellitus is a life threatening disease and scientists are doing their best to find a cost effective and permanent treatment of this malady. The recent trend is to control the disease by target base inhibiting of enzymes or proteins. Secreted frizzled-related protein 4 (SFRP4) is found to cause five times more risk of diabetes when expressed above average levels. This study was therefore designed to analyze the SFRP4 and to find its potential inhibitors. SFRP4 was analyzed by bio-informatics tools of sequence tool and structure tool. A total of three potential inhibitors of SFRP4 were found, namely cyclothiazide, clopamide and perindopril. These inhibitors showed significant interactions with SFRP4 as compared to other inhibitors as well as control (acetohexamide). The findings suggest the possible treatment of diabetes mellitus type 2 by inhibiting the SFRP4 using the inhibitors cyclothiazide, clopamide and perindopril.
Topics: Computer Simulation; Diabetes Mellitus; Humans; Hypoglycemic Agents; Molecular Docking Simulation; Proto-Oncogene Proteins
PubMed: 25019556
DOI: 10.3390/molecules190710129 -
Current Metabolomics Sep 2013The presence of elevated glucose concentrations in diabetes is a metabolic change that leads to an increase in the amount of non-enzymatic glycation that occurs for...
The presence of elevated glucose concentrations in diabetes is a metabolic change that leads to an increase in the amount of non-enzymatic glycation that occurs for serum proteins. One protein that is affected by this process is the main serum protein, human serum albumin (HSA), which is also an important carrier agent for many drugs and fatty acids in the circulatory system. Sulfonylureas drugs, used to treat type 2 diabetes, are known to have significant binding to HSA. This study employed ultrafiltration and high-performance affinity chromatography to examine the effects of HSA glycation on the interactions of several sulfonylurea drugs (i.e., acetohexamide, tolbutamide and gliclazide) with fatty acids, whose concentrations in serum are also affected by diabetes. Similar overall changes in binding were noted for these drugs with normal HSA or glycated HSA and in the presence of the fatty acids. For most of the tested drugs, the addition of physiological levels of the fatty acids to normal HSA and glycated HSA produced weaker binding. At low fatty acid concentrations, many of these systems followed a direct competition model while others involved a mixed-mode interaction. In some cases, there was a change in the interaction mechanism between normal HSA and glycated HSA, as seen with linoleic acid. Systems with only direct competition also gave notable changes in the affinities of fatty acids at their sites of drug competition when comparing normal HSA and glycated HSA. This research demonstrated the importance of considering how changes in the concentrations and types of metabolites (e.g., in this case, glucose and fatty acids) can alter the function of a protein such as HSA and its ability to interact with drugs or other agents.
PubMed: 24349966
DOI: 10.2174/2213235x1130100005 -
British Journal of Cancer Feb 2013As metastasis is the prime cause of death from malignancies, there is vibrant interest to discover options for the management of the different mechanistic steps of...
In vitro inhibition of breast cancer spheroid-induced lymphendothelial defects resembling intravasation into the lymphatic vasculature by acetohexamide, isoxsuprine, nifedipin and proadifen.
BACKGROUND
As metastasis is the prime cause of death from malignancies, there is vibrant interest to discover options for the management of the different mechanistic steps of tumour spreading. Some approved pharmaceuticals exhibit activities against diseases they have not been developed for. In order to discover such activities that might attenuate lymph node metastasis, we investigated 225 drugs, which are approved by the US Food and Drug Administration.
METHODS
A three-dimensional cell co-culture assay was utilised measuring tumour cell-induced disintegrations of the lymphendothelial wall through which tumour emboli can intravasate as a limiting step in lymph node metastasis of ductal breast cancer. The disintegrated areas in the lymphendothelial cell (LEC) monolayers were induced by 12(S)-HETE, which is secreted by MCF-7 tumour cell spheroids, and are called 'circular chemorepellent induced defects' (CCIDs). The putative mechanisms by which active drugs prevented the formation of entry gates were investigated by western blotting, NF-κB activity assay and by the determination of 12(S)-HETE synthesis.
RESULTS
Acetohexamide, nifedipin, isoxsuprine and proadifen dose dependently inhibited the formation of CCIDs in LEC monolayers and inhibited markers of epithelial-to-mesenchymal-transition and migration. The migration of LECs is a prerequisite of CCID formation, and these drugs either repressed paxillin levels or the activities of myosin light chain 2, or myosin-binding subunit of myosin phosphatase. Isoxsuprine inhibited all three migration markers, and isoxsuprine and acetohexamide suppressed the synthesis of 12(S)-HETE, whereas proadifen and nifedipin inhibited NF-κB activation. Both the signalling pathways independently cause CCID formation.
CONCLUSION
The targeting of different mechanisms was most likely the reason for synergistic effects of different drug combinations on the inhibition of CCID formation. Furthermore, the treatment with drug combinations allowed also a several-fold reduction in drug concentrations. These results encourage further screening of approved drugs and their in vivo testing.
Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Acetohexamide; Antineoplastic Combined Chemotherapy Protocols; Blotting, Western; Breast Neoplasms; Carcinoma, Ductal, Breast; Cell Adhesion; Cell Movement; Chemotaxis; Coculture Techniques; Drug Synergism; Endothelium, Lymphatic; Enzyme Inhibitors; Female; Humans; Hypoglycemic Agents; Isoxsuprine; Lymphatic Metastasis; Lymphatic Vessels; NF-kappa B; Nifedipine; Proadifen; RNA, Messenger; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Spheroids, Cellular; Tumor Cells, Cultured; Vasodilator Agents
PubMed: 23299527
DOI: 10.1038/bjc.2012.580 -
Journal of Chromatography. A Dec 2011This study examined the use of frontal analysis and high-performance affinity chromatography for detecting heterogeneous binding in biomolecular interactions, using the...
This study examined the use of frontal analysis and high-performance affinity chromatography for detecting heterogeneous binding in biomolecular interactions, using the binding of acetohexamide with human serum albumin (HSA) as a model. It was found through the use of this model system and chromatographic theory that double-reciprocal plots could be used more easily than traditional isotherms for the initial detection of binding site heterogeneity. The deviations from linearity that were seen in double-reciprocal plots as a result of heterogeneity were a function of the analyte concentration, the relative affinities of the binding sites in the system and the amount of each type of site that was present. The size of these deviations was determined and compared under various conditions. Plots were also generated to show what experimental conditions would be needed to observe these deviations for general heterogeneous systems or for cases in which some preliminary information was available on the extent of binding heterogeneity. The methods developed in this work for the detection of binding heterogeneity are not limited to drug interactions with HSA but could be applied to other types of drug-protein binding or to additional biological systems with heterogeneous binding.
Topics: Acetohexamide; Binding Sites; Chromatography, Affinity; Drug Interactions; Humans; Immobilized Proteins; Models, Chemical; Protein Binding; Serum Albumin
PubMed: 21612784
DOI: 10.1016/j.chroma.2011.04.078 -
Journal of Chromatography. B,... Nov 2010This report examines the use of high-performance affinity chromatography as a screening tool for studying the change in binding by sulfonylurea drugs to the protein...
This report examines the use of high-performance affinity chromatography as a screening tool for studying the change in binding by sulfonylurea drugs to the protein human serum albumin (HSA) during diabetes. The effects of both the non-enzymatic glycation of HSA and the presence of fatty acids on these interactions were considered using a zonal elution format. It was found that there was a significant increase (i.e., 2.7- to 3.6-fold) in the relative retention of several sulfonylurea drugs (i.e., acetohexamide, tolbutamide, glybenclamide and gliclazide) on columns containing normal versus glycated HSA. The addition of various long chain fatty acids to the mobile phase gave the same trend in retention for the tested drugs on both the HSA and glycated HSA columns, generally leading to lower binding. Most of the fatty acids examined produced similar or moderately different relative shifts in retention; however, palmitic acid was found to produce a much larger change in retention on columns containing glycated HSA versus normal HSA under the conditions used in this study.
Topics: Chromatography, Affinity; Diabetes Mellitus; Fatty Acids; Glycosylation; Humans; Hypoglycemic Agents; Kinetics; Protein Binding; Serum Albumin; Sulfonylurea Compounds
PubMed: 20974553
DOI: 10.1016/j.jchromb.2010.09.033