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The objective of our research was to determine the effects of xanthohumol (XN), a flavonoid isolated from hops (Humulus lupulus), and the anti-inflammatory drug niflumic acid (NA), separately and in combination with each other, on the proliferation of human cancer cells. Additionally, so as to understand the mechanism underlying the anticancer properties of the tested compounds, their effects on the biophysical parameters of a model membrane were assessed. The cells were incubated with XN and NA at various concentrations, either individually or in combination with each other. Cell proliferation was quantified using the sulforodamine B (SRB) assay. In addition, the IC50 values for niflumic acid and xanthohumol applied separately were determined by cell proliferation tests for the following human cancer cell lines: 5637 (urinary bladder carcinoma), A-431 (epidermoid carcinoma), UM-SCC-17A (head and neck squamous carcinoma), SK-MEL-3 (melanoma), MCC13 (Merkel cell cancer), and A172 (glioblastoma), in comparison with the mouse normal fibroblasts (BALB/3T3 clone A31). The results show that the two-compound combinations of XN and NA significantly decreased the proliferation of cancer cells in a dose-dependent manner, and the effects were stronger than the additive responses to XN and NA individually. The membrane studies revealed a synergistic effect on the membrane rigidity when using the mixture of XN and NA, which may explain the observed increase in anticancer activity for the combined XN and NA. Our results suggest that NSAIDs, such as niflumic acid, may be a promising strategy for co-application with xanthohumol as anticancer drugs. [ABSTRACT FROM AUTHOR]

Although niflumic acid (NA) is one of the most used non-steroidal anti-inflammatory drugs, it suffers from poor solubility, low bioavailability, and significant adverse effects. To address these limitations, the complexation of NA with cyclodextrins (CDs) is a promising strategy. However, complexing CDs with low molecular weight drugs like NA can lead to low CE. This study explores the development of inclusion complexes of NA with 2-hydroxypropyl-β-cyclodextrin (2HP-β-CD), including the effect of converting NA to its sodium salt (NAs) and adding hydroxypropyl methylcellulose (HPMC) on complex formation. Inclusion complexes were prepared using co-evaporation solvent and freeze-drying methods, and their CE and Ks were determined through a phase solubility study. The complexes were characterized using physicochemical analyses, including FT-IR, DSC, SEM, XRD, DLS, UV-Vis, 1H-NMR, and 1H-ROESY. The dissolution profiles of the complexes were also evaluated. The analyses confirmed complex formation for all systems, demonstrating drug–cyclodextrin interactions, amorphous drug states, morphological changes, and improved solubility and dissolution profiles. The NAs-2HP-β-CD-HPMC complex exhibited the highest CE and Ks values, a 1:1 host-guest molar ratio, and the best dissolution profile. The results indicate that the NAs-2HP-β-CD-HPMC complex has potential for delivering NA, which might enhance its therapeutic effectiveness and minimize side effects. [ABSTRACT FROM AUTHOR]

Although niflumic acid (NA) is one of the most used non-steroidal anti-inflammatory drugs, it suffers from poor solubility, low bioavailability, and significant adverse effects. To address these limitations, the complexation of NA with cyclodextrins (CDs) is a promising strategy. However, complexing CDs with low molecular weight drugs like NA can lead to low CE. This study explores the development of inclusion complexes of NA with 2-hydroxypropyl-β-cyclodextrin (2HP-β-CD), including the effect of converting NA to its sodium salt (NAs) and adding hydroxypropyl methylcellulose (HPMC) on complex formation. Inclusion complexes were prepared using co-evaporation solvent and freeze-drying methods, and their CE and Ks were determined through a phase solubility study. The complexes were characterized using physicochemical analyses, including FT-IR, DSC, SEM, XRD, DLS, UV-Vis, 1H-NMR, and 1H-ROESY. The dissolution profiles of the complexes were also evaluated. The analyses confirmed complex formation for all systems, demonstrating drug–cyclodextrin interactions, amorphous drug states, morphological changes, and improved solubility and dissolution profiles. The NAs-2HP-β-CD-HPMC complex exhibited the highest CE and Ks values, a 1:1 host-guest molar ratio, and the best dissolution profile. The results indicate that the NAs-2HP-β-CD-HPMC complex has potential for delivering NA, which might enhance its therapeutic effectiveness and minimize side effects.

This study aimed to quantify and explain inter-subject variability in morniflumate pharmacokinetics and identify effective covariates through population pharmacokinetics modeling. Models were constructed using bioequivalence pharmacokinetics results from healthy Korean males and individual physiological and biochemical parameters. Additionally, we incorporated previously reported pharmacokinetics results of niflumic acid, a major active metabolite of morniflumate, to extend the established population pharmacokinetics model and predict niflumic acid pharmacokinetics. Moreover, we used quantitative reports of leukotriene B4 (LTB4) synthesis inhibition in response to niflumic acid exposure to predict drug efficacy using Sigmoid Emax model. Population pharmacokinetics profiles of morniflumate were described using a multi-absorption (5-sequential) two-compartment model, and analysis of inter-individual variability suggested that volume of distribution in peripheral compartment was correlated with body mass index (BMI). Model simulation results showed that individuals with lower BMI had higher plasma concentrations of morniflumate and niflumic acid, resulting in increased and sustained inhibition of LTB4 synthesis. Under steady-state conditions, average plasma concentrations of morniflumate and niflumic acid were 2.66–2.68 times higher in group with a BMI of 17.36 kg/m2 compared to the group with a BMI of 28.41 kg/m2. Additionally, inhibition of LTB4 synthesis was 1.02 times higher in group with a BMI of 17.36 kg/m2 compared to group with a BMI of 28.41 kg/m2, and the fluctuation was significantly reduced from 6.06 to 0.01%. These findings suggest that the concentration of active metabolite in plasma following morniflumate exposure was lower in the obese group compared to the normal group, thus potentially reducing the drug's efficacy. [ABSTRACT FROM AUTHOR]

Loss-of-function mutations in the KCNA1(Kv1.1) gene cause episodic ataxia type 1 (EA1), a neurological disease characterized by cerebellar dysfunction, ataxic attacks, persistent myokymia with painful cramps in skeletal muscles, and epilepsy. Precision medicine for EA1 treatment is currently unfeasible, as no drug that can enhance the activity of Kv1.1-containing channels and offset the functional defects caused by KCNA1 mutations has been clinically approved. Here, we uncovered that niflumic acid (NFA), a currently prescribed analgesic and anti-inflammatory drug with an excellent safety profile in the clinic, potentiates the activity of Kv1.1 channels. NFA increased Kv1.1 current amplitudes by enhancing the channel open probability, causing a hyperpolarizing shift in the voltage dependence of both channel opening and gating charge movement, slowing the OFF-gating current decay. NFA exerted similar actions on both homomeric Kv1.2 and heteromeric Kv1.1/Kv1.2 channels, which are formed in most brain structures. We show that through its potentiating action, NFA mitigated the EA1 mutation-induced functional defects in Kv1.1 and restored cerebellar synaptic transmission, Purkinje cell availability, and precision of firing. In addition, NFA ameliorated the motor performance of a knock-in mouse model of EA1 and restored the neuromuscular transmission and climbing ability in Shaker (Kv1.1) mutant Drosophila melanogaster flies (Sh5). By virtue of its multiple actions, NFA has strong potential as an efficacious single-molecule-based therapeutic agent for EA1 and serves as a valuable model for drug discovery. [ABSTRACT FROM AUTHOR]

Background: Inflammation-provoked disorders including cancer are arbitrated by cyclooxygenase-2 (COX-2). Celecoxib and niflumic acid are among the potent and selective inhibitors of this enzyme while aspirin (acetylsalicylic acid) and sodium salicylate are its non-selective and lesser potent inhibitors. Despite these proven studies, the comparative structural study of these selective and non-selective molecules at atomistic scale in complex state with COX-2 that may answer this differential inhibitory behavior has not been accomplished spotlighting the imperative need of additional research in this area. Thus, this study was framed to provide a strong explanation for the enigma of higher inhibitory activity of celecoxib-niflumic acid duo in comparison to aspirin and sodium salicylate towards COX-2. Methods: A contemporary approach including advanced molecular docking against COX2, molecular dynamics of receptor-ligand complexes, simulation-trajectory-backed MMGBSA for different time points, radius of gyration (Rg) calculations, and e-pharmacophores approach was employed to attain a rational conclusion. Results: Our findings demonstrated the higher binding affinity of celecoxib and niflumic acid over aspirin and sodium salicylate against COX-2. Although both selective and non-selective COX-2 inhibitors manifested nearly the same stability in the active site of this enzyme but the e-pharmocophoric features found in the case of selective inhibitors scored over non-selective ones. Thus, our findings excluded the differential stability to be the cause of stronger potency of selective inhibitors but attributed their potency to greater number of complementary features present in these inhibitors against the active site of inflammation engendering COX-2. [ABSTRACT FROM AUTHOR]

Copyright of Farmacia is the property of Societatea de Stiinte Farmaceutice Romania and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Erzincan University Journal of Science & Technology is the property of Erzincan Binali Yildirim Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study focuses on the dry milling of biopharmaceutical classification system (BCS) class II molecules. These molecules have a limited bioavailability because of their low aqueous solubility, poor water wettability and low dissolution rate. In order to improve these properties, indomethacin (IND) and niflumic acid (NIF) were milled using two different types of equipment: Pulverisette 0® and CryoMill®. Milled samples were characterized and compared to commercial molecules. IND shows a modified solid state, like surface crystallinity reduction and an increase in water vapor adsorption from to 2- up to 5-fold due to milling processes. The obtained solubility data resulted in an improvement in solubility up to 1.2-fold and an increase in initial dissolution kinetics: 2% of dissolved drug for original crystals against 25% for milled samples. For NIF no crystallinity reduction, no change of surface properties and no solubility improvement after milling were noticed. In addition, milled particles seemed more agglomerated resulting in no changes in dissolution rate compared to the original drug. IND solubility and dissolution enhancement can be attributed to the modification of surface area, drug crystallinity reduction, and water sorption increase due to specific behavior related to the drug crystal disorder induced by milling process. [ABSTRACT FROM AUTHOR]

Myotonia congenita (MC) is an inherited rare disease characterized by impaired muscle relaxation after contraction, resulting in muscle stiffness. It is caused by loss-of-function mutations in the skeletal muscle chloride channel ClC-1, important for the stabilization of restingmembrane potential and for the repolarization phase of action potentials. Thanks to in vitro functional studies, the molecular mechanisms by which ClC-1 mutations alter chloride ion influx into the cell have been in part clarified, classifying them in "gating-defective" or "expression-defective" mutations. To date, the treatment of MC is only palliative because no direct ClC-1 activator is available. An ideal drug should be one which is able to correct biophysical defects of ClC-1 in the case of gating-defective mutations or a drug capable to recover ClC-1 protein expression on the plasma membrane for trafficking-defective ones. In this study, we tested the ability of niflumic acid (NFA), a commercial nonsteroidal antiinflammatory drug, to act as a pharmacological chaperone on traffickingdefective MC mutants (A531V, V947E). Wild-type (WT) or MC mutant ClC-1 channels were expressed in HEK293 cells and whole-cell chloride currents were recorded with the patch-clamp technique before and after NFA incubation. Membrane biotinylation assays and western blot were performed to support electrophysiological results. A531V and V947E mutations caused a decrease in chloride current density due to a reduction of ClC-1 total protein level and channel expression on the plasma membrane. The treatment of A531V and V947E-transfected cells with 50 µM NFA restored chloride currents, reaching levels similar to those of WT. Furthermore, no significant difference was observed in voltage dependence, suggesting that NFA increased protein membrane expression without altering the function of ClC-1. Indeed, biochemical experiments confirmed that V947E total protein expression and its plasma membrane distribution were recovered after NFA incubation, reaching protein levels similar to WT. Thus, the use of NFA as a pharmacological chaperone in trafficking defective ClC-1 channel mutations could represent a good strategy in the treatment of MC. Because of the favorable safety profile of this drug, our study may easily open the way for confirmatory human pilot studies aimed at verifying the antimyotonic activity of NFA in selected patients carrying specific ClC-1 channel mutations. [ABSTRACT FROM AUTHOR]

A metal-organic framework based on γ-cyclodextrin and K+ cations synthesized by antisolvent vapor diffusion method is proposed as a delivery system for niflumic acid, a non-steroidal anti-inflammatory agent with limited aqueous solubility. Methods of loading niflumic acid into the framework are discussed. The resulting composites are characterized via XRD, low-temperature nitrogen sorption/desorption, and IR spectroscopy. Encapsulation in a metal–organic framework has effect on the kinetics of niflumic acid release and its membrane permeability. [ABSTRACT FROM AUTHOR]

Myotonia congenita (MC) is an inherited rare disease characterized by impaired muscle relaxation after contraction, resulting in muscle stiffness. It is caused by loss-of-function mutations in the skeletal muscle chloride channel ClC-1, important for the stabilization of resting membrane potential and for the repolarization phase of action potentials. Thanks to in vitro functional studies, the molecular mechanisms by which ClC-1 mutations alter chloride ion influx into the cell have been in part clarified, classifying them in “gating-defective” or “expression-defective” mutations. To date, the treatment of MC is only palliative because no direct ClC-1 activator is available. An ideal drug should be one which is able to correct biophysical defects of ClC-1 in the case of gating-defective mutations or a drug capable to recover ClC-1 protein expression on the plasma membrane for trafficking-defective ones. In this study, we tested the ability of niflumic acid (NFA), a commercial nonsteroidal anti-inflammatory drug, to act as a pharmacological chaperone on trafficking-defective MC mutants (A531V, V947E). Wild-type (WT) or MC mutant ClC-1 channels were expressed in HEK293 cells and whole-cell chloride currents were recorded with the patch-clamp technique before and after NFA incubation. Membrane biotinylation assays and western blot were performed to support electrophysiological results. A531V and V947E mutations caused a decrease in chloride current density due to a reduction of ClC-1 total protein level and channel expression on the plasma membrane. The treatment of A531V and V947E-transfected cells with 50 µM NFA restored chloride currents, reaching levels similar to those of WT. Furthermore, no significant difference was observed in voltage dependence, suggesting that NFA increased protein membrane expression without altering the function of ClC-1. Indeed, biochemical experiments confirmed that V947E total protein expression and its plasma membrane distribution were recovered after NFA incubation, reaching protein levels similar to WT. Thus, the use of NFA as a pharmacological chaperone in trafficking defective ClC-1 channel mutations could represent a good strategy in the treatment of MC. Because of the favorable safety profile of this drug, our study may easily open the way for confirmatory human pilot studies aimed at verifying the antimyotonic activity of NFA in selected patients carrying specific ClC-1 channel mutations.

The primary objective of this study was to synthesize a novel hyper-crosslinked cellulosic adsorbent (CLC) by a straightforward one-pot esterification reaction using cellulose and sebacoyl chloride as crosslinker agent. Efficient crosslinking of cellulose was confirmed by FTIR, CPMAS 13C NMR, elemental analysis, TGA, SEM and BET surface area analysis. The CLC material with high content of ester groups was employed to remove paracetamol (PCT) and niflumic acid (NFA) from aqueous solutions in batch adsorption experiments. The mesoporous structure of CLC created upon crosslinking was found to be a determinant in the adsorption behavior of the drugs. Indeed, PCT and NFA adsorption isotherms onto CLC were S-shaped and were adjusted by the Gu–Zhu, Frumkin–Fowler–Guggenheim and Hill–de Boer models. From the GZ isotherm model, the results indicate a cooperative adsorption mechanism leading to the formation of aggregates containing 2.53 and 4.25 molecules of PCT and NFA, respectively. Furthermore, FFG and HdB models reflect that the lateral interactions are attractive in nature for both drugs. The experimental kinetic data were fitted to the pseudo-second-order and intraparticle diffusion models, and the obtained parameters were linked to the aggregates arrangement of the drugs. [ABSTRACT FROM AUTHOR]

The presence of contaminants of emerging concern (CEC), such as pharmaceuticals, in water sources is one of the main concerns nowadays due to their hazardous properties causing severe effects on human health and ecosystem biodiversity. Niflumic acid (NFA) is a widely used anti-inflammatory drug, and it is known for its non-biodegradability and resistance to chemical and biological degradation processes. In this work, a 10 wt.% TiO2/PVDF–TrFE nanocomposite membrane (NCM) was prepared by the solvent casting technique, fully characterized, and implemented on an up-scaled photocatalytic membrane reactor (PMR). The photocatalytic activity of the NCM was evaluated on NFA degradation under different experimental conditions, including NFA concentration, pH of the media, irradiation time and intensity. The NCM demonstrated a remarkable photocatalytic efficiency on NFA degradation, as efficiency of 91% was achieved after 6 h under solar irradiation at neutral pH. The NCM proved effective in long-term use, with maximum efficiency losses of 7%. An artificial neural network (ANN) model was designed to model NFA’s photocatalytic degradation behavior, demonstrating a good agreement between experimental and predicted data, with an R2 of 0.98. The relative significance of each experimental condition was evaluated, and the irradiation time proved to be the most significant parameter affecting the NFA degradation efficiency. The designed ANN model provides a reliable framework l for modeling the photocatalytic activity of TiO2/PVDF-TrFE and related NCM.

Background/Aims: In the human genome, more than 400 genes encode ion channels, which are ubiquitously expressed and often coexist and participate in almost all physiological processes. Therefore, ion channel blockers represent fundamental tools in discriminating the contribution of individual channel types to a physiological phenomenon. However, unspecific effects of these compounds may represent a confounding factor. Three commonly used chloride channel inhibitors, i.e. 4,4′-diisothiocyano-2,2′-stilbene-disulfonic acid (DIDS), 5-nitro-2-[(3-phenylpropyl) amino]benzoic acid (NPPB) and the anti-inflammatory drug niflumic acid were tested to identify the lowest concentration effective on Cl- channels and ineffective on K+ channels. Methods: The activity of the above mentioned compounds was tested by whole cell patch-clamp on the swelling-activated Cl- current ICl,swell and on the endogenous voltage-dependent, outwardly rectifying K+ selective current in human kidney cell lines (HEK 293/HEK 293 Phoenix). Results: Micromolar (1-10 µM) concentrations of DIDS and NPPB could not discriminate between the Cl- and K+ selective currents. Specifically, 1 µM DIDS only affected the K+ current and 10 µM NPPB equally affected the Cl- and K+ currents. Only relatively high (0.1-1 mM) concentrations of DIDS and prolonged (5 minutes) exposure to 0.1-1 mM NPPB preferentially suppressed the Cl- current. Niflumic acid preferentially inhibited the Cl- current, but also significantly affected the K+ current. The endogenous voltage-dependent, outwardly rectifying K+ selective current in HEK 293/HEK 293 Phoenix cells was shown to arise from the Kv 3.1 channel, which is extensively expressed in brain and is involved in neurological diseases. Conclusion: The results of the present study underscore that sensitivity of a given physiological phenomenon to the Cl- channel inhibitors NPPB, DIDS and niflumic acid may actually arise from an inhibition of Cl- channels but can also result from an inhibition of voltage-dependent K+ channels, including the Kv 3.1 channel. The use of niflumic acid as anti-inflammatory drug in patients with concomitant Kv 3.1 dysfunction may result contraindicated.

Any time the pharmaceutical industry develops a new drug, potential polymorphic events must be thoroughly described, because in a crystalline pharmaceutical solid, different arrangements of the same active pharmaceutical ingredient can yield to very different physicochemical properties that might be crucial for its efficacy, such as dissolution, solubility, or stability. Polymorphism in cocrystal formulation cannot be neglected, either. In this work, two different cocrystal polymorphs of the non-steroidal anti-inflammatory drug niflumic acid and caffeine are reported. They have been synthesized by mechanochemical methods and thoroughly characterized in solid-state by powder and single crystal X-ray diffraction respectively, as well as other techniques such as thermal analyses, infrared spectroscopy and computational methods. Both theoretical and experimental results are in agreement, confirming a conformational polymorphism. The polymorph NIF–CAF Form I exhibits improved solubility and dissolution rate compared to NIF–CAF Form II, although Form II is significantly more stable than Form I. The conditions needed to obtain these polymorphs and their transition have been carefully characterized, revealing an intricate system.

• V o -Ce 0.05 -CuO achieved efficient degradation of NFA with a good durability. • Synergetic effects of triple reaction centers improve conversion percentage of H 2 O 2 to OH. • Electrons from pollutants adsorbed at electron-deficient Cu centers transferred to V o and Ce. • Electron-rich V o centers and single Ce atom centers capture and reduce H 2 O 2 to OH. • OH, HO 2 /O 2 − and 1O 2 were the primary oxidants in HFLP with OH playing a dominant role. V o (oxygen vacancy)-Ce-CuO nanosheet catalysts were studied for degrading niflumic acid (NFA) by the heterogeneous Fenton-like process (HFLP). NFA removal percentage of optimal V o -Ce 0.05 -CuO reached 92% after 60 min of Fenton-like reactions and dropped only 0.28% after five times of recycles. Synergetic effects of triple reaction centers with electron-rich V o centers, single Ce atom centers, and electron-deficient Cu centers have been demonstrated for generating hydroxyl radicals (OH) by H 2 O 2 decomposition. The electrons from the organic pollutants adsorbed at the electron-deficient Cu centers could be transferred to V o and Ce via the internal bridge bond to balance the electron transfer. H 2 O 2 could directly obtain electrons from electron-rich V o and single Ce atom centers to produce OH with a high H 2 O 2 utilization efficiency instead of reducing metal ions by consuming H 2 O 2. For the first time, we demonstrate that triple reaction centers with single Ce atom could improve the conversion percentage of H 2 O 2 to OH with 71.1%. OH, HO 2 /O 2 − and 1O 2 were the primary oxidants in the HFLP, in which OH played the dominant role. [ABSTRACT FROM AUTHOR]

ClopHensor, a fluorescent fusion protein, is a dual function biosensor that has been utilized as a tool for the simultaneous measurement of intracellular chloride and pH in cells. ClopHensor has traditionally been used in conjunction with fluorescence microscopy for single cell measurements. Here, we present a promising multi-well format advancement for the use of ClopHensor as a potential high-throughput method capable of measuring fluorescence signal intensity across a well of confluent cells with highly reproducible results. Using this system, we gained mechanistic insight into an endogenous oxalate transporter in Chinese hamster ovary (CHO) cells expressing ClopHensor and the human chloride transporter, SLC26A3. SLC26A3, a known anion exchanger, has been proposed to play a role in colonic oxalate absorption in humans. Our attempt to study the role of SLC26A3 in oxalate transport revealed the presence of an endogenous oxalate transporter in CHO cells. This transporter was strongly inhibited by niflumate, and exhibited clear saturability. Use of ClopHensor in a multi-well cell assay allowed us to quickly demonstrate that the endogenous oxalate transporter was unable to exchange chloride for bicarbonate, unlike SLC26A3.

Although the role of adaptive immunity in fighting Pneumocystis infection is well known, the role of the innate, airway epithelium, responses remains largely unexplored. The concerted interaction of innate and adaptive responses is essential to successfully eradicate infection. Increased expression of goblet-cell-derived CLCA1 protein plus excess mucus in infant autopsy lungs and in murine models of primary Pneumocystis infection alert of innate immune system immunopathology associated to Pneumocystis infection. Nonetheless, whether blocking mucus-associated innate immune pathways decreases Pneumocystis -related immunopathology is unknown. Furthermore, current treatment of Pneumocystis pneumonia (PcP) relying on anti- Pneumocystis drugs plus steroids is not ideal because removes cellular immune responses against the fungal pathogen. In this study, we used the steroid-induced rat model of PcP to evaluate inflammation and mucus progression, and tested the effect of niflumic acid (NFA), a fenamate-type drug with potent CLCA1 blocker activity, in decreasing Pneumocystis -associated immunopathology. In this model, animals acquire Pneumocystis spontaneously and pneumonia develops owing to the steroids-induced immunodeficiency. Steroids led to decreased animal weight evidencing severe immunosuppression and to significant Pneumocystis -associated pulmonary edema as evidenced by wet-to-dry lung ratios that doubled those of uninfected animals. Inflammatory cuffing infiltrates were noticed first around lung blood vessels followed by bronchi, and both increased progressively. Similarly, airway epithelial and lumen mucus progressively increased. This occurred in parallel to increasing levels of MUC5AC and mCLCA3, the murine homolog of hCLCA1. Administration of NFA caused a significant decrease in total mucus, MUC5AC and mCLCA3 and also, in Pneumocystis -associated inflammation. Most relevant, NFA treatment improved survival at 8 weeks of steroids. Results suggest an important role of innate immune responses in immunopathology of steroid-induced PcP. They warrant evaluation of CLCA1 blockers as adjunctive therapy in this condition and describe a simple model to evaluate therapeutic interventions for steroid resistant mucus, a common condition in patients with chronic lung disease like asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis. [ABSTRACT FROM AUTHOR]

The nonsteroidal anti-inflammatory drug (NSAID) niflumic acid, a fenamate in structure, has many molecular targets, one of them being specific subtypes of the main inhibitory ligand-gated anion channel, the GABA A receptor. Here, we report on the effects of other fenamates and other classes of NSAIDs on brain picrotoxinin-sensitive GABA A receptors, using an autoradiographic assay with [35S]TBPS as a ligand on mouse brain sections. We found that the other fenamates studied (flufenamic acid, meclofenamic acid, mefenamic acid and tolfenamic acid) affected the autoradiographic signal at low micromolar concentrations in a facilitatory-like allosteric fashion, i.e., without having affinity to the [35S]TBPS binding site. Unlike niflumic acid that shows clear preference for inhibiting cerebellar granule cell layer GABA A receptors, the other fenamates showed little brain regional selectivity, indicating that their actions are not receptor-subtype selective. Of the non-fenamate NSAIDs studied at 100 μM concentration, diclofenac induced the greatest inhibition of the binding, which is not surprising as it has close structural similarity with the potent fenamate meclofenamic acid. Using two-electrode voltage-clamp assays on Xenopus oocytes, the effect of niflumic acid was found to be dependent on the β subunit variant and the presence of γ2 subunit in rat recombinant α1β and α1βγ2 GABA A receptors, with the β1 allowing the niflumic acid inhibition and β3 the stimulation of the receptor-mediated currents. In summary, the fenamate NSAIDs constitute an interesting class of compounds that could be used for development of potent GABA A receptor allosteric agonists with other targets to moderate inflammation, pain and associated anxiety/depression. [ABSTRACT FROM AUTHOR]

Graphical abstract New copper(II) complexes containing the non-steroidal anti-inflammatory drug niflumic acid as ligand have been synthesized and characterized. Cytotoxic effects of the complexes on tumoral human cell lines have also been evaluated. Highlights • Five new copper(II)-niflumate complexes have been synthesized and characterized. • Their structures have been determined by X-ray diffraction and DFT calculations. • Cytotoxic effects of the complexes on tumoral human cell lines have been evaluated. • The niflumate coordination mode affects cytotoxicity against the cell line HT-144. Abstract Five new copper(II) niflumate complexes, [Cu(en) 2 (nif) 2 ], 1 , [Cu(unsym- dmen)(nif) 2 ], 2 , [Cu(pn) 2 (nif) 2 ][Cu(pn) 2 (H 2 O) 2 ](nif) 2 3 , [Cu(β- pic) 2 (nif) 2 ], 4 , [Cu(γ- pic) 2 (nif) 2 ] 5 (where en = ethylenediamine, pn = propan-1,3-diamine, unsym-dmen = 1,1-dimethyl-ethylenediamine, β -pic = 3-methylpyridine, γ -pic = 4-methylpyridine, nif = niflumate) have been synthesized by using appropriate starting materials and methanol-water (4:1 v/v) as solvent. All the above synthesized complexes 1 – 5 have been characterized by spectroscopic methods (UV–Vis, FT-IR, and EPR). The structures of complexes 1 , 3 and 5 have been unambiguously determined by single crystal X-ray structure determination which clearly revealed that these complexes are mononuclear complexes. The structure of complex 4 has been optimized by DFT calculations. In all complexes 1 – 5 , niflumate ligand shows direct coordination to central copper(II) ion leading to covalent character of these complexes, although the complex 3 also contains cationic moiety [Cu(p n) 2 (nif) 2 ]2+ and two nifumate ions. The ability of all the complexes to show cytotoxicity against human cancer cell lines has also been evaluated. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to assess whether nanofibrous drug mats have potential as delivery systems for poorly water-soluble drugs. Amorphous nanofiber mats from a model poorly water-soluble active pharmaceutical ingredient (API), niflumic acid, together with the polymer excipient, polyvinyl pyrrolidine, were prepared by nozzle-free electrospinning. This technique offers a scalable way for drug formulation, and by increasing the surface area of the drug, the dissolution rate and therefore bioavailability of the API can be improved. In this study, both the amount of the dissolved active ingredient and the dissolution kinetics has been improved significantly when the nanofibrous mats were used in the drug formulation. A 15-fold increase in the dissolved amount of the produced amorphous niflumic acid nanofiber was observed compared to the dissolved amount of the raw drug within the first 15 min. Capsule formulation was made by mixing the electrospun nanofibers with a microcrystalline cellulose filler agent. When comparing the dissolution rate of the capsule formulation on the market with the nanofibrous capsules, a 14-fold increase was observed in the dissolved drug amount within the first 15 min. [ABSTRACT FROM AUTHOR]

[Display omitted] The Hippo pathway regulates organ size and tissue homeostasis by controlling cell proliferation and apoptosis. The YAP–TEAD transcription factor, the downstream effector of the Hippo pathway, regulates the expression of genes such as CTGF , Cyr61 , Axl and NF2. Aberrant Hippo activity has been identified in multiple types of cancers. Flufenamic acid (FA) was reported to bind in a liphophilic TEAD palmitic acid (PA) pocket, leading to reduction of the expression of Axl and NF2. Here, we show that the replacement of the trifluoromethyl moiety in FA by aromatic groups, directly connected to the scaffold or separated by a linker, leads to compounds with better affinity to TEAD. Co-crystallization studies show that these compounds bind similarly to FA, but deeper within the PA pocket. Our studies identified LM-41 and AF-2112 as two TEAD binders that strongly reduce the expression of CTGF , Cyr61 , Axl and NF2. LM-41 gave the strongest reduction of migration of human MDA-MB-231 breast cancer cells. [ABSTRACT FROM AUTHOR]

Background/Aims: Pendrin is a Cl-/I-/HCO3- exchanger playing a fundamental role in controlling blood pressure and airway function, therefore representing an attractive target for the treatment of hypertensive states and respiratory distresses. A review of the literature regarding the ability of some compounds (namely several known inhibitors of ion transport) to block pendrin activity revealed discordant findings. These incongruous findings may be due, in part, to the concentration of compound and/or the nature of the model system used in the study. Methods: Pendrin activity was evaluated by measuring pendrin-dependent iodide influx following overexpression of the transporter in a human kidney cell line, in the presence of selected test compounds or the respective vehicles. Results: Pendrin activity was significantly hampered by 0.1 mM 5-nitro-2-[(3-phenylpropyl)amino]benzoic acid (NPPB), niflumic acid and tenidap, but was resistant to 0.1 mM 4, 4′-diisothiocyano-2, 2′-stilbene-disulfonic acid (DIDS), furosemide and probenecid. Conclusions: The results of the present study indicate that clinically effective non-steroidal anti-inflammatory drugs (niflumic acid and tenidap) directly inhibit pendrin activity.

Mammalian brainstem hypoglossal motoneurones (HMs) receive powerful synaptic glycinergic inputs and are involved in a variety of motor functions, including respiration, chewing, sucking, swallowing, and phonation. During the early postnatal development, subunit composition of chloride-permeable glycine receptors (GlyRs) changes leading to a decrease of “fetal” alpha2 and elevation of “adult” alpha1 GlyR subunits. It has been recently demonstrated that niflumic acid (NFA), a member of the fenamate class of non-steroidal anti-inflammatory drugs, is an efficient subunits-specific blocker of GlyRs. At a heterologous expression of different GlyR subunits it has been shown that blocking potency of NFA is more than one order higher for alpha2 GlyRs than for receptors formed by alpha1 subunit. To reveal the action of NFA on the synaptic activity we analyzed here the effects of NFA on the glycinergic inhibitory post-synaptic currents in the HMs from mouse brainstem slices. In the whole-cell patch clamp configuration, the amplitude and the frequency of glycinergic synaptic currents from two age groups have been analyzed: “neonate” (P2–P4) and “juvenile” (P7–P12). Addition of NFA in the presence of antagonists of glutamate and GABA receptors caused a decrease in the mean amplitude and frequency of synaptic events. The degree of the inhibition induced by NFA decreased with the postnatal development, being higher on the motoneurons from “neonate” brainstem slices in comparison with the “juvenile” age group. Analysis of the pair-pulse facilitation suggests the post-synaptic origin of NFA action. These observations provide evidence on the developmental changes in the inhibition by NFA of glycinergic synaptic transmission, which reflects increase in the alpha1 and decrease in the alpha2 GlyR subunits expression in synapses to hypoglossal motoneurons during the early stages of postnatal life.

Mammalian brainstem hypoglossal motoneurones (HMs) receive powerful synaptic glycinergic inputs and are involved in a variety of motor functions, including respiration, chewing, sucking, swallowing, and phonation. During the early postnatal development, subunit composition of chloride-permeable glycine receptors (GlyRs) changes leading to a decrease of "fetal" alpha2 and elevation of "adult" alpha1 GlyR subunits. It has been recently demonstrated that niflumic acid (NFA), a member of the fenamate class of non-steroidal anti-inflammatory drugs, is an efficient subunits-specific blocker of GlyRs. At a heterologous expression of different GlyR subunits it has been shown that blocking potency of NFA is more than one order higher for alpha2 GlyRs than for receptors formed by alpha1 subunit. To reveal the action of NFA on the synaptic activity we analyzed here the effects of NFA on the glycinergic inhibitory post-synaptic currents in the HMs from mouse brainstem slices. In the whole-cell patch clamp configuration, the amplitude and the frequency of glycinergic synaptic currents from two age groups have been analyzed: "neonate" (P2–P4) and "juvenile" (P7–P12). Addition of NFA in the presence of antagonists of glutamate and GABA receptors caused a decrease in the mean amplitude and frequency of synaptic events. The degree of the inhibition induced by NFA decreased with the postnatal development, being higher on the motoneurons from "neonate" brainstem slices in comparison with the "juvenile" age group. Analysis of the pair-pulse facilitation suggests the post-synaptic origin of NFA action. These observations provide evidence on the developmental changes in the inhibition by NFA of glycinergic synaptic transmission, which reflects increase in the alpha1 and decrease in the alpha2 GlyR subunits expression in synapses to hypoglossal motoneurons during the early stages of postnatal life. [ABSTRACT FROM AUTHOR]

Background/Aims: In the human genome, more than 400 genes encode ion channels, which are ubiquitously expressed and often coexist and participate in almost all physiological processes. Therefore, ion channel blockers represent fundamental tools in discriminating the contribution of individual channel types to a physiological phenomenon. However, unspecific effects of these compounds may represent a confounding factor. Three commonly used chloride channel inhibitors, i.e. 4,4'-diisothiocyano-2,2'-stilbene-disulfonic acid (DIDS), 5-nitro- 2-[(3-phenylpropyl) amino]benzoic acid (NPPB) and the anti-inflammatory drug niflumic acid were tested to identify the lowest concentration effective on Cl- channels and ineffective on K+ channels. Methods: The activity of the above mentioned compounds was tested by whole cell patch-clamp on the swelling-activated Cl- current ICl, swell and on the endogenous voltagedependent, outwardly rectifying K+ selective current in human kidney cell lines (HEK 293/HEK 293 Phoenix). Results: Micromolar (1-10 μM) concentrations of DIDS and NPPB could not discriminate between the Cl- and K+ selective currents. Specifically, 1 µM DIDS only affected the K+ current and 10 μM NPPB equally affected the Cl- and K+ currents. Only relatively high (0.1-1 mM) concentrations of DIDS and prolonged (5 minutes) exposure to 0.1-1 mM NPPB preferentially suppressed the Cl- current. Niflumic acid preferentially inhibited the Cl- current, but also significantly affected the K+ current. The endogenous voltage-dependent, outwardly rectifying K+ selective current in HEK 293/HEK 293 Phoenix cells was shown to arise from the Kv 3.1 channel, which is extensively expressed in brain and is involved in neurological diseases. Conclusion: The results of the present study underscore that sensitivity of a given physiological phenomenon to the Cl- channel inhibitors NPPB, DIDS and niflumic acid may actually arise from an inhibition of Cl- channels but can also result from an inhibition of voltage-dependent K+ channels, including the Kv 3.1 channel. The use of niflumic acid as anti-inflammatory drug in patients with concomitant Kv 3.1 dysfunction may result contraindicated. [ABSTRACT FROM AUTHOR]

The objectives of this work were to study the degradation of the niflumic acid (NIF) with a new solar photocatalytic reactor using immobilized ZnO. The residence time distribution and the reactor efficiency for the NIF removal were studied. Two models for Retention Time Distribution (RTD) have been summarized and compared with the experimental data. Effects on the photocatalytic degradation process owing to various operating parameters conditions were also studied in continue flow. The repetitive operation performance indicates the good reproducibility of the new reactor for NIF degradation. Concerning the energy, the reactor was designed to ensure its energy autonomy through solar energy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation and evaluation of niflumic acid loaded Brij® integrated bilosomes. • Investigation of in vitro release profile and ex vivo skin permeability. • In vivo anti-osteoarthritic study using monosodium iodoacetate. • Histopathological investigation. Bilosomes are innovative vesicular carriers containing bile salt with a non-ionic surfactant. Being highly flexible, bilosomes can squeeze themselves through the skin carrying the drug to the action site and improving its skin penetration. The objective of this research was to encapsulate niflumic acid (NA), a non-steroidal anti-inflammatory drug into Brij® integrated bilosomes (BIBs) for effective treatment of osteoarthritis through transdermal delivery. BIBs were formulated using 100 mg of Span 20 with different amounts of sodium cholate (NaC), sodium taurocholate (NaTC), or sodium glycocholate (NaGC) as bile salt, with the addition of 5 mg of Brij-93 or Brij-35. BIBs were prepared utilizing ethanol injection method with the application of (31 × 22) complete factorial design using Design-Expert® software. The optimal BIBs formulation determined was (B5) which contains 5 mg of NaTC used as bile salt and 5 mg of Brij-93. B5 exhibited entrapment efficiency% = 95.21 ± 0.00%, particle size = 373.05 ± 0.07 nm, polydispersity index = 0.27 ± 0.01, and zeta potential = –32.00 ± 0.00 mV. It also had a high elasticity with a spherical shape. B5 gel displayed a sustained release profile with a significantly 2.3 folds' higher drug permeation percent across rat skin than that permeated from NA gel. Moreover, in vivo anti-osteoarthritic and histopathological studies assured the efficacy and safety of B5 gel and its superiority over NA gel. Generally, the outcomes confirmed the great efficacy of NA loaded BIBs for the topical treatment of osteoarthritis. [ABSTRACT FROM AUTHOR]

The reaction of ZnCl 2 with the non-steroidal anti-inflammatory drug niflumic acid (Hnif) resulted in the formation of complex [Zn(nif-O) 2 (MeOH) 4 ], 1 . When this reaction was performed in the presence of a N , N ′-donor heterocyclic ligand such as 2,2′-bipyridine (bipy), 2,2′-bipyridylamine (bipyam), 1,10-phenanthroline (phen) and 2,2′-dipyridylketone oxime (Hpko), the complexes [Zn(nif-O,O′)(bipy)Cl], 2 , [Zn(nif-O)(nif-O,O′) 2 (bipyam)], 3 , [Zn(nif-O,O′) 2 (phen)], 4 and [Zn(nif-O) 2 (Hpko- N , N ′) 2 ], 5 were formed, respectively. The complexes were characterized by physicochemical and spectroscopic techniques and X-ray crystallography (for complexes 1–3 ). The complexes can scavenge 1,1-diphenyl-picrylhydrazyl, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals, may inhibit soybean lipoxygenase and are more active compounds than free Hnif. The interaction of the complexes with serum albumins was monitored by fluorescence emission spectroscopy and the corresponding binding constants were calculated. The affinity of the complexes with calf-thymus DNA was investigated by UV–vis spectroscopy, viscosity measurements and fluorescence emission spectroscopy for the competitive studies of the complexes with ethidium bromide revealing their interaction probably via intercalation. [ABSTRACT FROM AUTHOR]

Niflumic acid (NFA) is a type of non-steroidal anti-inflammatory drug. Neuropathic pain is caused by a decrease in presynaptic inhibition mediated by γ-aminobutyric acid (GABA). In the present study, a whole-cell patch-clamp technique and intracellular recording were used to assess the effect of NFA on GABA-induced inward current in dorsal root ganglion (DRG) neurons of a chronic constriction injury (CCI) model. It was observed that 1-1,000 μmol/l GABA induced a concentration-dependent inward current in DRG neurons. Compared with pseudo-operated rats, the thermal withdrawal latency (TWL) of CCI rats significantly decreased (P<0.01); however, the TWLs of each NFA group (50 and 300 μmol/l) were significantly longer than that of the CCI group (P<0.01). In the CCI group, the response evoked by GABA (10-6-10-3 mol/l) was reduced in a concentration dependent manner compared with a normal control group (P<0.01), and the current amplitudes of CCI rats activated by the same concentrations of GABA (10-6-10-3 mol/l) were significantly decreased compared with the control group (P<0.05). The inward currents activated by 100 μmol/l GABA were suppressed by treatment with 1, 10 and 100 μmol/l NFA (5.32±3.51, 33.8±5.20, and 52.2±6.32%, respectively; P<0.05). The inverse potentials of GABA-induced currents were 9.87±1.32 and 9.64±1.24 mV with and without NFA, respectively (P<0.05). Pre-treatment with NFA exerted a strong inhibitory effect on the peak value of GABA-induced current, and the GABA-induced response was inhibited by the same concentrations of NFA (1, 10 and 100 μmol/l) in the control and CCI groups (P<0.05). The results suggest that NFA reduced the primary afferent depolarization (PAD) associated with neuropathic pain and mediated by the GABAA receptor. NFA may regulate neuropathic pain by inhibiting dorsal root reflexes, which are triggered PAD. [ABSTRACT FROM AUTHOR]

Niflumic acid (NFC) and surfactant 1-octane sulfonic acid sodium (OS) are intercalated into the gallery of NO 3 ̄ type layered europium hydroxide (NO 3 –LEuH) by ion-exchange method. The prepared products display XRD patterns with series of diffractions attributing to layered materials. The composites correspond to a bilayered vertical arrangement. The thermal stability of the composites are enhanced after intercalation. Tunable luminescence of the composites is realized through the synergistic effect of layered europium hydroxide (LEuH) layer and NFC with different states and different excitation wavelength. Facile one-pot delamination of the composites achieves when dispersed in formamide (FM), which contributes to a white emission. This work may be beneficial to the fabrication of multifunctional chromophore intercalated layered rare-earth hydroxides (LRHs) hybrids, which may have wide applications in white emission materials. [ABSTRACT FROM AUTHOR]

Stem cell transplantation presents a potentially curative strategy for genetic disorders of skeletal muscle, but this approach is limited by the deleterious effects of cell expansion in vitro and consequent poor engraftment efficiency. In an effort to overcome this limitation, we sought to identify molecular signals that enhance the myogenic activity of cultured muscle progenitors. Here, we report the development and application of a cross-species small-molecule screening platform employing zebrafish and mice, which enables rapid, direct evaluation of the effects of chemical compounds on the engraftment of transplanted muscle precursor cells. Using this system, we screened a library of bioactive lipids to discriminate those that could increase myogenic engraftment in vivo in zebrafish and mice. This effort identified two lipids, lysophosphatidic acid and niflumic acid, both linked to the activation of intracellular calcium-ion flux, which showed conserved, dose-dependent, and synergistic effects in promoting muscle engraftment across these vertebrate species. [Display omitted] • Cross-species discovery approach for examining chemical activity to enhance engraftment • LPA and NFA increase the engraftment efficiency of myogenic progenitor cells • Increase in intracellular Ca2+ induces the engraftment of myogenic progenitor cells • Engrafted skeletal muscle cells rescue zebrafish model of Duchenne muscular dystrophy Tavakoli et al. perform a cross-species in vivo screen to directly test chemicals for enhanced muscle progenitor cell engraftment. Their findings show that a short ex vivo pre-transplantation treatment with specific compounds is beneficial, improving the engraftment of myogenic progenitor cells and improving cell therapy as a treatment option for degenerative muscle disorders. [ABSTRACT FROM AUTHOR]

TRP channels have been discovered as a specialized group of somatosensory neurons involved in the detection of noxious stimuli. Desensitization of TRPV1 located on dorsal root and trigeminal ganglia exhibits analgesic effect and makes it potential therapeutic target for treatment of neuropathic pain. With this background, the present study was aimed to investigate the protective effect of niflumic acid, a TRPV1 modulator, on stavudine (STV)-induced neuropathic pain in rats. Stavudine (50 mg/kg) was administered intravenously via tail vein in rats to induce neuropathic pain. Various behavioral tests were performed to access neuropathic pain (hyperalgesia and allodynia) on 7th, 14th, 21st, and 28th days. Electrophysiology (motor nerve conduction velocity; MNCV) and biochemical estimations were conducted after 28th day. Niflumic acid (10, 15, and 20 mg/kg) was administered intraperitoneally and evaluated against behavioral, electrophysiological (MNCV), and biochemical alterations in stavudine-treated rats. Pregabalin (30 mg/kg) was taken as reference standard and administered intraperitoneally. Four weeks after stavudine injection, rats developed behavioral, electrophysiological (MNCV), and biochemical (oxidative, nitrosative stress, and inflammatory cytokines, TRPV1) alterations. Niflumic acid restored core and associated symptoms of peripheral neuropathy by suppressing oxidative-nitrosative stress, inflammatory cytokines (TNF-α, IL-1β) and TRPV1 level in stavudine-induced neuropathic pain in rats. Pharmacological efficacy of niflumic acid (20 mg/kg) was equivalent to pregabalin (30 mg/kg). In conclusion, niflumic acid attenuates STV-induced behavioral, electrophysiological and biochemical alterations by manipulating TRP channel activity in two manners: (1) direct antagonistic action against TRPV1 channels and (2) indirect inhibition of TRP channels by blocking oxidative and inflammatory surge. Therefore, NA can be developed as a potential pharmacotherapeutic adjunct for antiretroviral drug-induced neuropathy. [ABSTRACT FROM AUTHOR]

Background: Human Ca2+-activated Cl ion channel 1 (hCLCAl) is expressed in goblet cell hyperplasia in the airway of asthmatics, and murine CLCA3 is associated with antigen-sensitized and IL-13-induced goblet cell metaplasia in mice. However, the role of CLCA in goblet cell degranulation is not fully investigated. Niflumic acid (NFA), a relatively specific CLCA inhibitor, inhibits goblet cell metaplasia, but the effect of NFA on goblet cell degranulation has not been determined in an asthma model. Methods: Guinea pigs were sensitized with ovalbumin (OA) twice and then challenged with saline, OA, histamine, and one of the Ca2+-dependent secretagogues, UTP. The PAS/AB-stained mucus area in the tracheal epithelium was measured with a computer image analysis system, and the morphology of mucus granules was examined by transmission electron microscopy. In the in vitro experiment, goblet cells cultured with IL-13 at the air-liquid interface were stimulated with UTP in the presence or absence of NFA, and the MUC5AC level in cell lysates was measured by ELISA. Results: The mucus areas were smaller in the OA-, histamine-, and UTP-challenged animals than in the saline-challenged animals. NFA inhibited the decrease in mucus area and morphological changes in mucus granules. UTP caused swelling and exocytosis of mucus granules and MUC5AC secretion by cultured goblet cells, and NFA inhibited these changes. Conclusions: NFA inhibited the secretory response of mucus granules in an asthma model, suggesting that CLCA may be associated with goblet cell degranulation and that CLCA inhibitors may be useful for the treatment of hypersecretion in asthma.

[Display omitted] • Microwave synthesis of SD-CDs using 5- sulpho anthranilic acid and 1,5-diphenylycarbazide as precursors. • SD-CDs could detect levocetirizine and niflumic acid by fluorescence "turn-on-off" principle. • The developed detection method showed high sensitivity and selectivity. • The as-synthesized SD-CDs could detect drugs from pharmaceutical and biological samples. In this work, water soluble carbon dots (CDs) were synthesized by using 5- sulpho anthranilic acid (SAA) and 1,5-diphenylycarbazide (DPC) as precursors via microwave-assisted method and named as "SD-CDs". We studied the effect of SAA and DPC molar ratio (1:3, 2:2 and 3:1) for the preparation of blue fluorescent CDs, showing the best emission properties at molar 3:1 ratio of SAA and DPC. The as-prepared SD-CDs emit bright blue color under UV light at 365 nm, and exhibit emission peak at 392 nm when excited at 319 nm. The as-synthesized SD-CDs act as a fluorescent sensor for detection of levocetirizine and niflumic acid through the fluorescence "turn-on–off" mechanism. The developed probe exhibited good linearity in the concentrations (levocetirizine − 1.0–100 µM and niflumic acid − 0.5–100 µM) with detection limits of 3.92 nM and 0.19 µM for levocetirizine and niflumic acid, respectively. Importantly, the developed analytical method was successfully used for the detection of levocetirizine in tablets and niflumic acid in biofluids of human (serum, plasma and urine), showing good recoveries from 97 to 99 %. Thus, this SD-CDs-based fluorescence method has the potential for levocetirizine and niflumic acid assays in biological and pharmaceutical samples. [ABSTRACT FROM AUTHOR]

Niflumic acid (NFA) is a novel gap junction (GJ) inhibitor. The aim of the present study was to investigate the effect of NFA on GJ communication and the expression of connexin (Cx) in vascular smooth muscle cells (VSMCs) of mesenteric arterioles of spontaneously hypertensive rats (SHR). Whole-cell patch clamp recording demonstrated that NFA at 1x10-4 M significantly inhibited the inward current and its effect was reversible. The time for charging and discharging of cell membrane capacitance (Cinput) reduced from 9.73 to 0.48 ms (P<0.05; n=6). Pressure myograph measurement showed that NFA at 3x10-4 M fully neutralized the contraction caused by phenylephrine. The relaxation responses of normotensive control Wistar Kyoto (WKY) rats were significantly higher, compared with those of t he SHRs ( P<0.05; n=6). Western blot and reverse transcription-quantitative polymerase chain reaction analyses showed that the mRNA and protein expression levels of Cx43 of the third-level branch of mesenteric arterioles of the SHRs and WKY rats were higher, compared with those of the first-level branch. The mRNA and protein expression levels of Cx43 of the primary and third-level branches of the mesenteric arterioles in the SHRs were higher, compared with those in the WKY rats (P<0.05; n=6). The mRNA levels of Cx43 in the mesenteric arterioles were significantly downregulated by NFA in a concentration-dependent manner (P<0.01; n=6). The protein levels of Cx43 in primary cultured VSMCs isolated from the mesenteric arterioles were also significantly downregulated by NFA in a concentration-dependent manner (P<0.01; n=6). These results showed that the vasorelaxatory effects of GJ inhibitors were reduced in the SHRs, which was associated with a higher protein expression level of Cx43 in the mesenteric arterioles of the SHRs. NFA also relaxed the mesenteric arterioles by reducing the expression of Cx43, which decreased blood pressure. Therefore, regulation of the expression of GJs may be a therapeutic target for the treatment of hypertension. [ABSTRACT FROM AUTHOR]

Uterine arteries embolization (UAE) is a recent technique that aims, by means of particles injected percutaneously, to stifle fibroids (leiomyomas). This treatment is non-invasive, compared with uterine ablation, but generates pelvic pain for a few days. A strategy to reduce the post-embolization pain would be to use calibrated embolization microspheres preloaded with a non-steroidal inflammatory drug (NSAID). In this study, we first compared four drugs, all active at low concentration on cyclooxygenase-2, i.e. ketoprofen, sodium diclofenac, flurbiprofen and niflumic acid (NFA), for their capacity to be loaded on resorbable embolization microspheres (REM) 500–700 μm. NFA had the highest capacity of loading (5 mg/mL) on resorbable microspheres. Then, we evaluated in vitro the NFA release profiles from REM having various degradation times of one, two or five days. NFA release was biphasic, with an initial burst (about 60% of the loading) followed by a sustained release that correlated significantly to REM’s hydrolysis (rho = 0.761, p < 0.0001). For each group of beads, the size distribution was not modified by the loading of NFA and their delivery through microcatheter was not impaired by the drug. NFA eluted from REM inhibited the synthesis of prostaglandin E 2 from rabbit uterus explants. In summary, NFA is loadable on REM in significant amount and its delivery can be tuned according to the degradation rate of REM to provide an antalgic effect for a few days after UAE. [ABSTRACT FROM AUTHOR]

The ability of non-steroidal anti-inflammatory drugs (NSAIDs) to modulate γ-aminobutyrate (GABA)-activated currents via Ca2+-activated Cl- channels in rat dorsal root ganglion neurons (DRG), was examined in the present study. During the preparation of DRG neurons harvested from Sprague-Dawley rats, the whole-cell recording technique was used to record the effect of NSAIDs on GABA-activated inward currents, and the expression levels of the TMEM16A and TMEM16B subunits were revealed. In the event that DRG neurons were pre-incubated for 20 sec with niflumic acid (NFA) and 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) prior to the administration of GABA, the GABA-induced inward currents were diminished markedly in the majority of neurons examined (96.3%). The inward currents induced by 100 µmol/l GABA were attenuated by (0±0.09%; neurons = 4), (5.32±3.51%; n eurons = 6), (21.3±4.00%; neurons = 5), (33.8±5.20%; neurons = 17), (52.2±5.10%; neurons = 4) and (61.1±4.12%; neurons = 12) by 0.1, 1, 3, 10, 30 and 100 µmol/l NFA, respectively. The inward currents induced by 100 µmol/l GABA were attenuated by (13.8±6%; neurons = 6), (23.2±14.7%; neurons = 6) and (29.7±9.1%; neurons = 9) by 3, 10 and 30 µmol/l NPPB, respectively. NFA and NPPB dose-dependently inhibited GABA-activated currents with half maximal inhibitory concentration (IC50) values of 6.7 and 11 µmol/l, respectively. The inhibitory effect of 100 µmol/l NFA on the GABA-evoked inward current were also strongly inhibited by nitrendipine (NTDP; an L-type calcium channel blocker), 1,2-bis(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid tetrakis (a highly selective calcium chelating reagent), caffeine (a widely available Ca2+ consuming drug) and calcium-free extracellular fluid, in a concentration-dependent manner. Immunofluorescent staining indicated that TMEM16A and TMEM16B expression was widely distributed in DRG neurons. The results suggest that NSAIDs may be able to regulate Ca2+-activated chloride channels to reduce GABAA receptor-mediated inward currents in DRGs. [ABSTRACT FROM AUTHOR]

Background/Aims: Pendrin is a Cl-/I-/HCO3- exchanger playing a fundamental role in controlling blood pressure and airway function, therefore representing an attractive target for the treatment of hypertensive states and respiratory distresses. A review of the literature regarding the ability of some compounds (namely several known inhibitors of ion transport) to block pendrin activity revealed discordant findings. These incongruous findings may be due, in part, to the concentration of compound and/or the nature of the model system used in the study. Methods: Pendrin activity was evaluated by measuring pendrin-dependent iodide influx following overexpression of the transporter in a human kidney cell line, in the presence of selected test compounds or the respective vehicles. Results: Pendrin activity was significantly hampered by 0.1 mM 5-nitro-2-[(3-phenylpropyl)amino]benzoic acid (NPPB), niflumic acid and tenidap, but was resistant to 0.1 mM 4, 4′-diisothiocyano-2, 2′-stilbene-disulfonic acid (DIDS), furosemide and probenecid. Conclusions: The results of the present study indicate that clinically effective non-steroidal anti-inflammatory drugs (niflumic acid and tenidap) directly inhibit pendrin activity. [ABSTRACT FROM AUTHOR]

The aim of this paper is to design and characterize some drug delivery systems (DDS) based on collagen hydrolysates (H), niflumic acid as a non-steroidal anti-inflammatory model drug and two essential oils of Lavandula officinalis L. (LO) and Lavandula stoechas L. subsp. Stoechas (LS), for use in healing cutaneous wounds with post-lesion inflammatory response. The essential oils are characterized by GC-MS. The wettability capacity of collagen hydrolysate powders was assessed by contact angle measurement. Niflumic acid release was investigated using a modified Franz diffusion cell, and the diffusion coefficient, time-lag and drug flux were determined. The kinetic parameters were found to be influenced by different concentrations and types of essential oils. These therapeutical products, based on collagen hydrolysates and synergistic drug associations, could have potential biomedical application in wound healing treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • MoNCs were synthesized by using DC-Schiff base as a ligand. • Fluorescence turn-off–on" was developed for the detection of niflumic acid drug and ammonium persulfate. • Emission intensity of DCSB-MoNCs was quenched by niflumic acid and enhanced with ammonium persulfate. • The developed method exhibited lower detection limits for niflumic acid and ammonium persulfate. • DCSB-MoNCs acted as a sensor for detection of niflumic acid drug in biological samples. Herein, fluorescent molybdenum nanoclusters are synthesized by using Schiff base 2,3-dialdehyde starch-cysteine derivative as a ligand and 2,3-dialdehyde starch-cysteine Schiff base (DCSB) protected molybdenum nanoclusters (MoNCs) are named as "DCSB-MoNCs". The as-synthesized fluorescent DCSB-MoNCs were stable and exhibited blue fluorescence under excitation at 365 nm. The as-prepared DCSB-MoNCs were narrowly and homogeneously distributed with a mean size of 2.80 ± 1.10 nm. The fluorescence of DCSB-MoNCs is significantly quenched by niflumic acid through non-covalent interactions DC Schiff derivative. Upon the addition of ammonium persulfate (APS) to MoNCs, the non-covalent interactions are cleaved between DCSB-MoNCs and niflumic acid, resulting in restoration the fluorescence of DCSB-MoNCs. In this, niflumic acid acts as both analyte and quencher by using DCSB-MoNCs as a nanosensor, showing a good linear response in the range of 0.005–10 µM with a limit of detection (LOD) of 2.2 nM. Then, "turn off–on" mechanism was established for sensing of APS, exhibiting a wider linear response in the range of 25–55 µM. The developed nanoclusters were successfully applied to detect niflumic acid drug in biological samples (blood plasma and urine) and industrial wastewater. [ABSTRACT FROM AUTHOR]

Anoctamin 1 (Ano1, TMEM16A) is a Ca2+-activated Cl- channel (CACC) expressed in interstitial cells of Cajal (ICC). The mechanisms by which Ca2+ regulates Ano1 are incompletely understood. In the gastrointestinal tract, Ano1 is required for normal slow wave activity and is involved in regulating cell proliferation. Splice variants of Ano1 have varying electrophysiological properties and altered expression in disease states. Recently, we identified a transcript for human Ano1 containing a novel exon-exon "0"-upstream of and in frame with exon 1. The electrophysiological properties of this longer Ano1 isoform are unknown. Our aim was to determine the functional contribution of the newly identified exon to the Ca2+ sensitivity and electrophysiological properties of Ano1. Constructs with (+0) or without (-0) the newly identified exon were transfected into HEK293 cells. Voltage clamp electrophysiology was used to determine voltage- and time-dependent parameters of whole cell Cl- currents between isoforms with varying concentrations of intracellular Ca2+, extracellular anions, or Cl- channel inhibitors. We found that exon 0 did not change voltage sensitivity and had no impact on relative permeability of Ano1 to most anions. Ano1(+0) exhibited greater changes in current density but lesser changes in kinetics than (-0) in response to varying intracellular Ca2+. The CACC inhibitor niflumic acid inhibited current with greater efficacy and higher potency against Ano1(+0) compared to Ano1(-0). Likewise, the Ano1 inhibitor T16Ainh-A01 reduced Ano1(+0) more than Ano1(-0). In conclusion, human Ano1 containing exon 0 imparts its Cl- current with greater sensitivity to intracellular Ca2+ and CACC inhibitors. [ABSTRACT FROM AUTHOR]

Anoctamin 1 (Ano1, TMEM16A) is a Ca2+-activated Cl- channel (CACC) expressed in interstitial cells of Cajal (ICC). The mechanisms by which Ca2+ regulates Ano1 are incompletely understood. In the gastrointestinal tract, Ano1 is required for normal slow wave activity and is involved in regulating cell proliferation. Splice variants of Ano1 have varying electrophysiological properties and altered expression in disease states. Recently, we identified a transcript for human Ano1 containing a novel exon-exon "0"-upstream of and in frame with exon 1. The electrophysiological properties of this longer Ano1 isoform are unknown. Our aim was to determine the functional contribution of the newly identified exon to the Ca2+ sensitivity and electrophysiological properties of Ano1. Constructs with (+0) or without (-0) the newly identified exon were transfected into HEK293 cells. Voltage clamp electrophysiology was used to determine voltage- and time-dependent parameters of whole cell Cl- currents between isoforms with varying concentrations of intracellular Ca2+, extracellular anions, or Cl- channel inhibitors. We found that exon 0 did not change voltage sensitivity and had no impact on relative permeability of Ano1 to most anions. Ano1(+0) exhibited greater changes in current density but lesser changes in kinetics than (-0) in response to varying intracellular Ca2+. The CACC inhibitor niflumic acid inhibited current with greater efficacy and higher potency against Ano1(+0) compared to Ano1(-0). Likewise, the Ano1 inhibitor T16Ainh-A01 reduced Ano1(+0) more than Ano1(-0). In conclusion, human Ano1 containing exon 0 imparts its Cl- current with greater sensitivity to intracellular Ca2+ and CACC inhibitors. [ABSTRACT FROM AUTHOR]

The solubility data of two fluorinated and non-steroidal anti-inflammatory drugs, niflumic acid (CAS No. 4394-00-7) and celecoxib (CAS No. 169590-42-5), in supercritical carbon dioxide were measured with a semi-flow type phase equilibrium apparatus at temperatures ranging from 313.2 K to 353.2 K and pressures up to 31 MPa. At the highest extraction temperature and pressure, the solubilities are 2.09 × 10 −5 and 1.52 × 10 −5 in mole fraction for niflumic acid and celecoxib, respectively. The saturated solubility data were correlated with the Chrastil model, the Mendez-Santiago–Teja equation, and the Peng–Robinson equation of state. The Chrastil model fitted the experimental data to about within the experimental uncertainty. The correlated results of the Mendez-Santiago–Teja model confirmed the consistency of the solubility data over the entire experimental conditions. Incorporating with two-parameter van der Waals one-fluid mixing rules, the Peng–Robinson equation of state represents satisfactorily the gas–solid equilibrium behavior of niflumic acid and celecoxib in supercritical carbon dioxide. [ABSTRACT FROM AUTHOR]

CLC-K chloride channels and their subunit, barttin, are crucial for renal NaCl reabsorption and for inner ear endolymph production. Mutations in CLC-Kb and barttin cause Bartter syndrome. Here, we identified two adjacent residues, F256 and N257, that when mutated hugely alter in Xenopus oocytes CLC-Ka's biphasic response to niflumic acid, a drug belonging to the fenamate class, with F256A being potentiated 37-fold and N257A being potently blocked with a K D ~ 1 μM. These residues are localized in the same extracellular I–J loop which harbors a regulatory Ca 2 + binding site. This loop thus can represent an ideal and CLC-K specific target for extracellular ligands able to modulate channel activity. Furthermore, we demonstrated the involvement of the barttin subunit in the NFA potentiation. Indeed the F256A mutation confers onto CLC-K1 a transient potentiation induced by NFA which is found only when CLC-K1/F256A is co-expressed with barttin. Thus, in addition to the role of barttin in targeting and gating, the subunit participates in the pharmacological modulation of CLC-K channels and thus represents a further target for potential drugs. [ABSTRACT FROM AUTHOR]

Evaporative crystallization is widely applied in several industrial processes, including the pharmaceutical industry. Microwave irradiation can significantly speed up solvent evaporation in these crystallization processes, resulting in reduced particle size due to rapid crystallization. A single-mode microwave setup was used for evaporative crystallization of the model active pharmaceutical ingredient, niflumic acid, and the polymer, polyvinylpirrolidone (PVP). Production of crystals by microwave irradiation offers a modern way for drug formulation, and by reducing the particle size the dissolution rate and bioavailability of the active pharmaceutical ingredient can be enhanced. In this study, a 2.5-fold increase in the dissolution rate of the produced niflumic acid crystals was observed compared to the dissolution rate of the original drug in 120 min. When niflumic acid was produced together with the PVP in the microwave system, an amorphous solid dispersion was created with particles in the nano-size range, which showed a 5-fold increase in dissolution rate in 120 min compared to the dissolution of the crystalline niflumic acid samples created by the microwave irradiation in the absence of PVP. [ABSTRACT FROM AUTHOR]

Severe bronchospasm refractory to β-agonists continues to cause significant morbidity and mortality in asthmatic patients. We questioned whether chloride channels/transporters are novel targets for the relaxation of airway smooth muscle (ASM). We have screened a library of compounds, derivatives of anthranilic and indanyloxyacetic acid, that were originally developed to antagonize chloride channels in the kidney. We hypothesized that members of this library would be novel calciumactivated chloride channel blockers for the airway. The initial screen of this compound library identified 4 of 20 compounds that relaxed a tetraethylammonium chloride-induced contraction in guinea pig tracheal rings. The two most effective compounds, compounds 1 and 13, were further studied for their potential to either prevent the initiation of or relax the maintenance phase of an acetylcholine (ACh)-induced contraction or to potentiate β-agonist-mediated relaxation. Both relaxed an established ACh-induced contraction in human and guinea pig ex vivo ASM. In contrast, the prevention of an ACh-induced contraction required copretreatment with the sodium-potassium-chloride cotransporter blocker bumetanide. The combination of compound 13 and bumetanide also potentiated relaxation by the β-agonist isoproterenol in guinea pig tracheal rings. Compounds 1 and 13 hyperpolarized the plasma cell membrane of human ASM cells and blocked spontaneous transient inward currents, a measure of chloride currents in these cells. These functional and electrophysiological data suggest that modulating ASM chloride flux is a novel therapeutic target in asthma and other bronchoconstrictive diseases. [ABSTRACT FROM AUTHOR]

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to induce apoptosis in a variety of cancer cells. However, the precise mechanisms by which NSAIDs facilitate apoptosis in tumor cells are not clear. In the present study, we show that niflumic acid (NA), a member of the fenamates group of NSAIDs and Cl and Ca-activated Cl (CAC) channels blocker, induced apoptosis (by ~8 %, 24 h treatment) and potentiated (by 8-10 %) apoptotic effect of endoplasmic reticulum Ca mobilizer thapsigargin (Tg) in human erythroleukemic K562 cell line. The whole-cell patch clamp and Fluo-3 flow cytometric experiments confirmed an inhibitory effect of NA (100 and 300 µM) on store-operated (SOC) channels. We also found that NA-blocked CAC channels were activated by acute application of Tg (2 µM) in K562 cells. NA blockage of CAC channels was accompanied by activation of Ca-activated K (SK4) channels. The observed effects of NA were not connected with COX-2 inhibition since 100-nM NA (IC for COX-2 inhibition) did not induce either apoptosis or affect the channels activity. We conclude that inhibition of SOC channels plays a major role in NA-induced apoptosis. Increased apoptotic levels in Tg-treated K562 cells in the presence of NA may be due to the blockage of CAC and stimulation of SK4 channels in addition to SOC channels inhibition. [ABSTRACT FROM AUTHOR]

The maintenance of pluripotency of mesenchymal stromal cells (MSCs), their proliferation and initiation of differentiation may critically depend on functional expression of ion channels. Despite such a possibility, mechanisms of electrogenesis in MSCs remain poorly understood. In particular, little is known about a variety of ion channels active in resting MSCs or activated upon MSC stimulation. Here we aimed at uncovering ion channels operating in MSCs, including those being active at rest, using the patch clamp technique and inhibitory analysis. In trying to evaluate a contribution of anion channels in MSC resting potential, we employed a number of diverse inhibitors of anion channels and transporters, including niflumic acid (NFA). Basically, NFA caused hyperpolarization of MSCs that was accompanied by a marked increase in ion conductance of their plasma membranes. The blockage of Cl channels could not underlie such a NFA effect, given that cells dialyzed with a CsCl solution were weakly or negligibly sensitive to this blocker. This and other findings indicated that NFA affected the MSC ion permeability not by targeting Cl channels but by stimulating K channels. NFA-activated K current was TEA and diltiazem blockable, and K channels involved were potentiated from outside by solution acidification and Cu ions. Taken together, the data obtained implicated two-pore domain K channels of the TREK-2 subtype in mediating stimulatory effects of NFA on MSCs. The notable inference from our work is that TREK-2 channels should be expressed and functional virtually in every MSC, given that all cells examined by us ( n > 100) similarly responded to NFA by increasing their TREK-2-like K conductance. [ABSTRACT FROM AUTHOR]