curcumin and Cystic-Fibrosis

Cystic fibrosis is one of the most common autosomal recessive genetic disorders in caucasians of Northern European descent, affecting approximately 30 000 children and adults living in the United States, today. Complications of this chronic disease result in deterioration of lung function and development of pancreatic abnormalities requiring pharmacological therapy and may include patients seeking complementary and alternative option for treatment. Health care professionals should be knowledgeable of these therapies to effectively provide education and drug therapy management. This article offers an overview of the most common complementary therapies in cystic fibrosis such as vitamin A, vitamin C, vitamin E, zinc, omega 3 fatty acids, docosahexaenoic acid (DHA), garlic, ginseng, and curcumin.

Topics: Antioxidants; Ascorbic Acid; Curcumin; Cystic Fibrosis; Dietary Supplements; Docosahexaenoic Acids; Fatty Acids, Omega-3; Garlic; Humans; Panax; Phytotherapy; Vitamin A; Vitamin E; Zinc

Cystic fibrosis (CF) is a common inherited fatal disease affecting 70,000 people worldwide, with a median predicted age of survival of approximately 38 years. The deletion of Phenylalanine in position 508 of the Cystic Fibrosis Transmembrane conductance Regulator (F508del-CFTR) is the most common mutation in CF patients: the deleted protein, not properly folded, is degraded. To date no commercial drugs are available. Low temperature, some osmolytes and conditions able to induce heat shock protein 70 (Hsp70) expression and heat shock cognate 70 (Hsc70) inhibition result in F508del-CFTR rescue, hence restoring its physiological function: this review sheds light on the correlation between these several evidences. Interestingly, all these approaches have a role in the cell stress response (CSR), a set of cell reactions to stress. In addition, unpredictably, F508del-CFTR rescue has to be considered in the frame of CSR: entities that induce - or are induced during - the CSR are, in general, also able to correct trafficking defect of CFTR. Specifically, the low temperature induces, by definition, a CSR; osmolytes, such as glycerol and trimethylamine N-oxide (TMAO), are products of the CSR; pharmacological correctors, such as Matrine and 4-phenylbutirric acid (4PBA), down-regulate the constitutive Hsc70 in favor of an up-regulation of the inducible chaperone Hsp70, another component of the CSR. The identification of a common mechanism of action for different types of correctors could drive the discovery of new active molecules in CF, overcoming methods clinically inapplicable, such as the low temperature.

Topics: Alkaloids; Animals; Cell Membrane; Cold Temperature; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; HSP70 Heat-Shock Proteins; Humans; Matrines; Models, Molecular; Molecular Targeted Therapy; Phenylbutyrates; Protein Interaction Domains and Motifs; Protein Transport; Quinolizines

Genistein and curcumin are major components of Asian foods, soybean and curry turmeric respectively. These compounds have been intensively investigated for their chemical and biological features conferring their anti-cancer activity. Genistein and curcumin have also been investigated for their potentiation effects on disease-associated CFTR mutants such as ΔF508 and G551D. Recently, we investigated the combined effect of genistein and curcumin on G551D-CFTR, which exhibits gating defects without abnormalities in protein synthesis or trafficking using the patch-clamp technique. We found that genistein and curcumin showed additive effects on their potentiation of G551D-CFTR in high concentration range and also, more importantly, showed a significant synergistic effect in their minimum concentration ranges. These results are consistent with the idea that multiple mechanisms are involved in the action of these CFTR potentiators. In this review, we revisit the pharmacology of genistein and curcumin on CFTR and also propose new pharmaceutical implications of combined use of these compounds in the development of drugs for CF pharmacotherapy.

Topics: Animals; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Drug Discovery; Drug Synergism; Genistein; Humans; Ion Channel Gating; Membrane Potentials; Models, Molecular; Molecular Structure; Molecular Targeted Therapy; Mutation; Patch-Clamp Techniques; Protein Conformation

Obstructive airway diseases including asthma, chronic obstructive pulmonary disease and cystic fibrosis present with dyspnea and variety of other symptoms. Physiologically, they are characterized by maximal expiratory flow limitation and pathologically, by inflammation of the airways and the lung parenchyma. Inflammation plays a major role in the gradual worsening of the lung function resulting in worsening symptoms. For many years, scientists focused their efforts in identifying various pathways involved in the chronic inflammation present in these diseases. Further, studies are underway to identify various molecular targets in these pathways for the purpose of developing novel therapeutic agents. Natural agents have been used for thousands of years in various cultures for the treatment of several medical conditions and have mostly proven to be safe. Recent in vivo and in vitro studies show potential anti-inflammatory role for some of the existing natural agents. This review provides an overview of the literature related to the anti-inflammatory effects of some of the natural agents which have potential value in the treatment of inflammatory lung diseases.

Topics: Ambroxol; Anti-Inflammatory Agents, Non-Steroidal; Curcumin; Cystic Fibrosis; Diet; Expectorants; Humans; Justicia; Lung Diseases, Obstructive; Phytotherapy; Picrorhiza; Pneumonia; Prostaglandins; Resveratrol; Stilbenes; Treatment Outcome; Tylophora

Cystic fibrosis (CF), the most-common lethal hereditary disease in the white population, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The mutation that is most frequently responsible for the disease, DeltaF508, causes misfolding and retention of the CFTR protein in the endoplasmic reticulum. This leads to a series of cellular dysfunctions and results in a multi-organ disease. In a recent report, Egan et al.(1) demonstrated that curcumin, a non-toxic natural product and major constituent of turmeric spice, corrected the CF defects in DeltaF508 CF mice. This paper aroused a lot of attention and hopes were raised that curcumin might produce similar effects in human, giving an efficient treatment for most CF patients. However, skepticism is growing since subsequent studies fail to reproduce these initial exciting results. Thus, although herbal medicines and dietary supplements can be desirable alternatives to classical pharmacological compounds, their efficacy needs careful evaluation both in vivo and ex vivo.

Topics: Animals; Clinical Trials as Topic; Cloning, Molecular; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Dietary Supplements; Humans; Mice; Mice, Inbred CFTR; Mice, Transgenic; Models, Biological; Protein Folding

The activation of mutant forms of the cystic fibrosis transmembrane conductance regulator (CFTR), particularly the most frequent mutant allele (DeltaF508), is a potential strategy for the treatment of the disease cystic fibrosis (CF). Therefore, it is of great interest that curcumin, a component of the spice turmeric, is reported to restore function to this allele, both in heterologous expression systems and in DeltaF508 CF mice. Although other laboratories have not been able to confirm the initial observations, activating DeltaF508 CFTR could have such important therapeutic implications that a thorough investigation of the potential of curcumin is warranted.

Topics: Animals; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Mice; Mice, Inbred CFTR; Models, Biological

Cystic fibrosis (CF) is a genetic disorder, which is caused by the CFTR protein defects. Along with CFTR dysfunction, inflammation plays a key role in the disease outcomes. Inflammation may develop due to the internal dysfunction of the CFTR protein or external factors. Curcumin affects the CFTR protein function primarily as a corrector and potentiator and secondary as an anti-inflammatory and antimicrobial agent. The present study aims to assess the impact of nano-curcumin on clinical and inflammatory markers in children with CF.. This prospective, double blind control trial will be conducted at the Akbar Children's Hospital in Mashhad, Iran. Children with CF will be enrolled based on the eligibility criteria. Placebo and curcumin with the maximum dose of 80 mg considering the body surface of the patients will be administrated for 3 months. The primary outcome is to evaluate inflammation based on serum interleukin-6, interleukin-10, and hs-CRP, stool calprotectin, and neutrophil count of nasopharyngeal swab. The secondary outcome involved clinical assessment via spirometry, anthropometrics, and quality of life. They will be assessed before and after 3 months.. Due to the multifarious effects of curcumin on CF disease, it could be proposed as a nutritional strategy in the treatment of cystic fibrosis.. Iranian Registry of Clinical Trials IRCT20200705048018N1 . Registered on July 10, 2020.

Topics: Child; Curcumin; Cystic Fibrosis; Humans; Iran; Prospective Studies; Quality of Life; Randomized Controlled Trials as Topic

The natural food supplements curcumin and genistein, and the drug ivacaftor were found effective as CFTR potentiators in the organoids of individuals carrying a S1251N gating mutation, possibly in a synergistic fashion. Based on these in vitro findings, we evaluated the clinical efficacy of a treatment with curcumin, genistein and ivacaftor, in different combinations.. In three multi-center trials people with CF carrying the S1251N mutation were treated for 8 weeks with curcumin+genistein, ivacaftor and ivacaftor+genistein. We evaluated change in lung function, sweat chloride concentration, CFQ-r, BMI and fecal elastase to determine the clinical effect. We evaluated the pharmacokinetic properties of the compounds by evaluating the concentration in plasma collected after treatment and the effect of the same plasma on the intestinal organoids.. A clear clinical effect of treatment with ivacaftor was observed, evidenced by a significant improvement in clinical parameters. In contrast we observed no clear clinical effect of curcumin and/or genistein, except for a small but significant reduction in sweat chloride and airway resistance. Plasma concentrations of the food supplements were low, as was the response of the organoids to this plasma.. We observed a clear clinical effect of treatment with ivacaftor, which is in line with the high responsiveness of the intestinal organoids to this drug. No clear clinical effect was observed of the treatment with curcumin and/or genistein, the low plasma concentration of these compounds emphasizes that pharmacokinetic properties of a compound have to be considered when in vitro experiments are performed.

Topics: Adolescent; Adult; Aminophenols; Child; Chloride Channel Agonists; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Female; Genistein; Humans; Male; Organoids; Quinolones

Sweat pH is an important indicator for diagnosing disease states, such as cystic fibrosis. However, conventional pH sensors are composed of large brittle mechanical parts and need additional instruments to read signals. These pH sensors have limitations for practical wearable applications. In this study, we propose wearable colorimetric sweat pH sensors based on curcumin and thermoplastic-polyurethane (C-TPU) electrospun-fibers to diagnose disease states by sweat pH monitoring. This sensor aids in pH monitoring by changing color in response to chemical structure variation from enol to di-keto form

Topics: Colorimetry; Curcumin; Cystic Fibrosis; Humans; Hydrogen-Ion Concentration; Sweat; Textiles; Wearable Electronic Devices

The pathogenic mechanism of cystic fibrosis (CF) includes the functional interaction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein with the epithelial sodium channel (ENaC). The reduction of ENaC activity may constitute a therapeutic option for CF. This hypothesis was evaluated using drugs that target the protease-dependent activation of the ENaC channel and the transcriptional activity of its coding genes. To this aim we used: camostat, a protease inhibitor; S-adenosyl methionine (SAM), showed to induce DNA hypermethylation; curcumin, known to produce chromatin condensation. SAM and camostat are drugs already clinically used in other pathologies, while curcumin is a common dietary compound. The experimental systems used were CF and non-CF immortalized human bronchial epithelial cell lines as well as human bronchial primary epithelial cells. ENaC activity and SCNN1A, SCNN1B and SCNN1G gene expression were analyzed, in addition to SCNN1B promoter methylation. In both immortalized and primary cells, the inhibition of extracellular peptidases and the epigenetic manipulations reduced ENaC activity. Notably, the reduction in primary cells was much more effective. The SCNN1B appeared to be the best target to reduce ENaC activity, in respect to SCNN1A and SCNN1G. Indeed, SAM treatment resulted to be effective in inducing hypermethylation of SCNN1B gene promoter and in lowering its expression. Importantly, CFTR expression was unaffected, or even upregulated, after treatments. These results open the possibility of CF patients' treatment by epigenetic targeting.

Topics: Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Down-Regulation; Epigenesis, Genetic; Epithelial Cells; Epithelial Sodium Channels; Humans; Respiratory Mucosa

Cystic fibrosis (CF), the most common lethal inherited disorder caused by mutation in the gene encoding the CF transmembrane regulator (CFTR), is characterized by chronic inflammation that ultimately leads to death from respiratory failure. In CF patients, up-regulation of toll-like receptor-2 (TLR2), a pattern recognition receptor that senses CF-pathogenic bacteria Staphylococcus aureus peptidoglycan (PGN), in airway epithelial cells is observed, and enhanced proinflammatory responses towards PGN may result in detrimental effects in CF patients. Here, we showed that curcumin, a well known anti-inflammatory agent derived from the curry spice turmeric, inhibits TLR2 expression in CF bronchial epithelial cell line, CFBE41o- cells. Strong suppression of TLR2 gene and protein expression was observed at more than 40 µM of curcumin treatment in CFBE41o- cells. Consistent with decreased expression of TLR2, PGN-dependent interleukin-8 (IL-8) gene up-regulation was markedly reduced by 40 µM of curcumin treatment. Strong reductions of TLR2 gene expression and function were also observed in primary human CF bronchial epithelial cells, but not in human non-CF primary cells. Interestingly, curcumin treatment decreased nuclear expression of transcription factor specificity protein 1 (SP1), a factor that is critical for increased basal TLR2 expression in CF cell line and primary cells. Finally, curcumin-dependent SP1 reduction was diminished by anti-oxidant N-acetylcystein (NAC) and proteasomal inhibitor MG-132, suggesting the crucial roles of oxidative and proteasomal degradation pathways. Taken together, our study shows that curcumin down-regulates TLR2 gene expression and function in CF bronchial epithelial cells possibly by accelerating SP1 degradation via an oxidative process.

Topics: Bronchi; Cell Line; Curcumin; Cystic Fibrosis; Down-Regulation; Enzyme Inhibitors; Epithelial Cells; Gene Expression Regulation; Humans; Oxidation-Reduction; Proteasome Endopeptidase Complex; Toll-Like Receptor 2

Small molecules that correct the folding defects and enhance surface localization of the F508del mutation in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) comprise an important therapeutic strategy for cystic fibrosis lung disease. However, compounds that rescue the F508del mutant protein to wild type (WT) levels have not been identified. In this report, we consider obstacles to obtaining robust and therapeutically relevant levels of F508del CFTR. For example, markedly diminished steady state amounts of F508del CFTR compared to WT CFTR are present in recombinant bronchial epithelial cell lines, even when much higher levels of mutant transcript are present. In human primary airway cells, the paucity of Band B F508del is even more pronounced, although F508del and WT mRNA concentrations are comparable. Therefore, to augment levels of "repairable" F508del CFTR and identify small molecules that then correct this pool, we developed compound library screening protocols based on automated protein detection. First, cell-based imaging measurements were used to semi-quantitatively estimate distribution of F508del CFTR by high content analysis of two-dimensional images. We evaluated ~2,000 known bioactive compounds from the NIH Roadmap Molecular Libraries Small Molecule Repository in a pilot screen and identified agents that increase the F508del protein pool. Second, we analyzed ~10,000 compounds representing diverse chemical scaffolds for effects on total CFTR expression using a multi-plate fluorescence protocol and describe compounds that promote F508del maturation. Together, our findings demonstrate proof of principle that agents identified in this fashion can augment the level of endoplasmic reticulum (ER) resident "Band B" F508del CFTR suitable for pharmacologic correction. As further evidence in support of this strategy, PYR-41-a compound that inhibits the E1 ubiquitin activating enzyme-was shown to synergistically enhance F508del rescue by C18, a small molecule corrector. Our combined results indicate that increasing the levels of ER-localized CFTR available for repair provides a novel route to correct F508del CFTR.

Topics: Alleles; Benzoates; Cells, Cultured; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Endoplasmic Reticulum; Furans; Gene Deletion; HEK293 Cells; HeLa Cells; High-Throughput Screening Assays; Humans; Hydroxamic Acids; Microscopy, Fluorescence; Protein Folding; Protein Structure, Tertiary; Pyrazoles; RNA, Messenger; Small Molecule Libraries; Ubiquitination; Vorinostat

The potentiator VX-770 (ivacaftor/KALYDECO™) targets defective gating of CFTR and has been approved for treatment of cystic fibrosis (CF) subjects carrying G551D, S1251N or one of 8 other mutations. Still, the current potentiator treatment does not normalize CFTR-dependent biomarkers, indicating the need for development of more effective potentiator strategies. We have recently pioneered a functional CFTR assay in primary rectal organoids and used this model to characterize interactions between VX-770, genistein and curcumin, the latter 2 being natural food components with established CFTR potentiation capacities. Results indicated that all possible combinations of VX-770, genistein and curcumin synergistically repaired CFTR-dependent forskolin-induced swelling of organoids with CFTR-S1251N or CFTR-G551D, even under suboptimal CFTR activation and compounds concentrations, conditions that may predominate in vivo. Genistein and curcumin also enhanced forskolin-induced swelling of F508del homozygous organoids that were treated with VX-770 and the prototypical CFTR corrector VX-809. These results indicate that VX-770, genistein and curcumin in double or triple combinations can synergize in restoring CFTR-dependent fluid secretion in primary CF cells and support the use of multiple potentiators for treatment of CF.

Topics: Aminophenols; Chloride Channel Agonists; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Drug Synergism; Drug Therapy, Combination; Enzyme Inhibitors; Genistein; Humans; Models, Theoretical; Molecular Targeted Therapy; Mutation; Organoids; Quinolones; Rectum

Curcumin potentiates cystic fibrosis transmembrane conductance regulator (CFTR) activation in an ATP-independent but phosphorylation-dependent manner. The underlying molecular mechanisms are unclear. Here, HEK-293T cells cultured in an Fe(3+)-containing medium were transiently transfected with CFTR constructs, and the role of the inhibitory Fe(3+) bridge between intracellular loop 3 and the regulatory domain of CFTR in this pathway was investigated. The results showed that ethylenediaminetetraacetic acid (EDTA) stimulated phosphorylation-dependent CFTR activation and the stimulation was suppressed by the deletion of the regulatory domain or the insertion of a C832A mutation that removes the Fe(3+)-binding interface. Furthermore, curcumin potentiation of CFTR was significantly weakened not only by Fe(3+)-insensitive mutations at the interface between the regulatory domain and intracellular loop 3 but also by N-ethylmaleimide or EDTA pretreatment that removes Fe(3+). More importantly, potentiation of CFTR was completely suppressed by sufficient Fe(3+). Finally, the insertion of Fe(3+)-insensitive H950R/S768R increased the curcumin-independent activity of ΔF508 but weakened its curcumin potentiation. Thus, Fe(3+) homeostasis in epithelia may play a critical role in regulating CFTR activity, and targeting Fe(3+)-chelating potentiators may direct new therapies for cystic fibrosis.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Chelating Agents; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Edetic Acid; Ferric Compounds; HEK293 Cells; Humans; Mutation; Phosphorylation

Topics: Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Genistein; Humans; Molecular Targeted Therapy; Mutation; S-Nitrosothiols

Aminoglycoside antibiotics and imipenem are reported to stimulate exopolysaccharide alginate production and cause an increased biofilm volume in Pseudomonas aeruginosa. Recently, some remarkable studies have been conducted on the effects of curcumin (Turmeric), which is the fenolic form of Curcuma longa plant, on virulence factors of P.aeruginosa. In this study, we aimed to investigate the effects of MIC and sub-MIC concentrations of imipenem, tobramycin, and curcumin on biofilm formation of P.aeruginosa strains. P.aeruginosa strains (n= 2) used in this study were isolated from deep oropharyngeal swab samples of two cystic fibrosis patients. Antimicrobial susceptibilities of the two strains to imipenem, tobramycin, and curcumin were investigated by broth microdilution method, and biofilm production was assessed by using crystal violet staining method. In our study, MIC values of imipenem, tobramycin and curcumin for strain-1 were 8 µg/ml, 8 µg/ml and 16 µg/ml, respectively, while those values were 4 µg/ml, 8 µg/ml and 16 µg/ml for strain-2. Biofilm optical density values of the strain-1 and strain-2 before being treated with the test substances were 0.937 and 0.313 (control: 0.090), respectively, Biofilm optical densities of the both strains showed an increase following treatment with MIC concentrations of imipenem and tobramycin. The treatment of the strains with MIC and sub-MIC concentrations of curcumin led to no significant increase in biofilm optical density. The data obtained in this study supported the promising inhibitory effect of curcumin on P.aeruginosa biofilms. However, further more comprehensive studies are required to provide satisfactory data about the use of curcumin to treat P.aeruginosa infections characterized by biofilm formation.

Topics: Anti-Bacterial Agents; Biofilms; Curcumin; Cystic Fibrosis; Humans; Imipenem; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas Infections; Tobramycin

The G551D mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) is a common cause of cystic fibrosis (CF). G551D-CFTR is characterized by an extremely low open probability despite its normal trafficking to the plasma membrane. Numerous small molecules have been shown to increase the activity of G551D-CFTR presumably by binding to the CFTR protein.. We investigated the effect of curcumin, genistein and their combined application on G551D-CFTR activity using the patch clamp technique.. Curcumin increased G551D-CFTR whole-cell and single-channel currents less than genistein did at their maximally effective concentrations. However, curcumin further increased the channel activity of G551D-CFTR that had been already maximally potentiated by genistein, up to ~50% of the WT-CFTR level. In addition, the combined application of genistein and curcumin over a lower concentration range synergistically rescued the gating defect of G551D-CFTR.. The additive effects between curcumin and genistein not only support the hypothesis that multiple mechanisms are involved in the action of CFTR potentiators, but also pose pharmaceutical implications in the development of drugs for CF pharmacotherapy.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; CHO Cells; Cricetinae; Cricetulus; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Drug Synergism; Genistein; Green Fluorescent Proteins; Humans; Ion Channel Gating; Membrane Potentials; Mutation, Missense; Patch-Clamp Techniques; Phytoestrogens; Transfection

Cystic fibrosis (CF) is a common life threatening genetic disease (incidence: approximately 1 in 2500 live births). CF is caused by mutations in CFTR, a chloride channel involved in epithelial secretion of fluid and electrolytes. The most common mutation entails the deletion of a phenylalanine in position 508 that causes protein misfolding and abnormal CFTR processing. The DeltaF508 mutation accounts for approximately 70% of all CF alleles, and about 90% of CF patients carry at least one copy of DeltaF508 CFTR. Curcumin, a natural constituent of Curcuma longa (turmeric spice), is a nontoxic low-affinity SERCA (sarco (endo)plasmic reticulum calcium ATPase) pump inhibitor thought to permit DeltaF508 CFTR escape from the ER. The compound has been shown to be capable of correcting the defect in cell lines and mice expressing DeltaF508 CFTR. In this work, poly lactic-co-glycolic acid (PLGA) nanoparticles encapsulating curcumin were synthesized and used to treat two different CF mouse strains in an effort to correct the defects associated with CF by improving bioavailability of the compound, which has previously been a challenge in treatment with curcumin. Our results suggest that oral administration of PLGA nanoparticles encapsulating curcumin enhances the effects of curcumin therapy in CF mice, as compared to delivery of nonencapsulated curcumin.

Topics: Administration, Oral; Animals; Biological Availability; Biological Transport, Active; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Enzyme Inhibitors; Humans; Lactic Acid; Mice; Mice, Inbred C57BL; Mice, Inbred CFTR; Microscopy, Electron, Scanning; Mutation; Nanoparticles; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Sarcoplasmic Reticulum Calcium-Transporting ATPases

Cystic fibrosis (CF) is caused by loss-of-function mutations in the CFTR chloride channel. Wild type and mutant CFTR channels can be activated by curcumin, a well tolerated dietary compound with some appeal as a prospective CF therapeutic. However, we show here that curcumin has the unexpected effect of cross-linking CFTR polypeptides into SDS-resistant oligomers. This effect occurred for CFTR channels in microsomes as well as in intact cells and at the same concentrations that are effective for promoting CFTR channel activity (5-50 mum). Both mature CFTR polypeptides at the cell surface and immature CFTR protein in the endoplasmic reticulum were cross-linked by curcumin, although the latter pool was more susceptible to this modification. Curcumin cross-linked two CF mutant channels (Delta F508 and G551D) as well as a variety of deletion constructs that lack the major cytoplasmic domains. In vitro cross-linking could be prevented by high concentrations of oxidant scavengers (i.e. reduced glutathione and sodium azide) indicating a possible oxidation reaction with the CFTR polypeptide. Importantly, cyclic derivatives of curcumin that lack the reactive beta diketone moiety had no cross-linking activity. One of these cyclic derivatives stimulated the activities of wild type CFTR channels, Delta 1198-CFTR channels, and G551D-CFTR channels in excised membrane patches. Like the parent compound, the cyclic derivative irreversibly activated CFTR channels in excised patches during prolonged exposure (>5 min). Our results raise a note of caution about secondary biochemical effects of reactive compounds like curcumin in the treatment of CF. Cyclic curcumin derivatives may have better therapeutic potential in this regard.

Topics: Cell Line; Cross-Linking Reagents; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Humans; Microsomes; Signal Transduction

Topics: Anti-Inflammatory Agents, Non-Steroidal; Curcumin; Cystic Fibrosis; Cytokines; Humans; Phytotherapy; Plant Extracts

Deletion of phenylalanine 508 (deltaF508) accounts for nearly 70% of all mutations that occur in the cystic fibrosis transmembrane conductance regulator (CFTR). The deltaF508 mutation is a class II processing mutation that results in very little or no mature CFTR protein reaching the apical membrane and thus no cAMP-mediated Cl- conductance. Therapeutic strategies have been developed to enhance processing of the defective deltaF508 CFTR molecule so that a functional cAMP-regulated Cl- channel targets to the apical membrane. Sarcoplasmic/endoplasmic reticulum calcium (SERCA) inhibitors, curcumin and thapsigargin, have been reported to effectively correct the CF ion transport defects observed in the deltaF508 CF mice. We investigated the effect of these compounds in human airway epithelial cells to determine if they could induce deltaF508 CFTR maturation, and Cl- secretion. We also used Baby Hamster Kidney cells, heterologously expressing deltaF508 CFTR, to determine if SERCA inhibitors could interfere with the interaction between calnexin and CFTR and thereby correct the deltaF508 CFTR misfolding defect. Finally, at the whole animal level, we tested the ability of curcumin and thapsigargin to (1) induce Cl- secretion and reduce hyperabsorption of Na+ in the nasal epithelia of the deltaF508 mouse in vivo, and (2) induce Cl- secretion in intestine (jejunum and distal colon) and the gallbladder of the deltaF508 CF mouse. We conclude that curcumin and thapsigargin failed to induce maturation of deltaF508 CFTR, or induce Cl- secretion, as measured by biochemical and electrophysiologic techniques in a variety of model systems ranging from cultured cells to in vivo studies.

Topics: Animals; Bronchi; Calcium-Transporting ATPases; Calnexin; Cells, Cultured; Chlorides; Cricetinae; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Gallbladder; Humans; Intestines; Ion Transport; Mice; Mice, Mutant Strains; Mutation; Protein Folding; Respiratory Mucosa; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Sodium; Thapsigargin

Topics: Alzheimer Disease; Antioxidants; Capsaicin; Cinnamomum zeylanicum; Curcumin; Cystic Fibrosis; Health Promotion; Humans; Hypercholesterolemia; Neoplasms; Phytotherapy; Plant Structures; Plants, Medicinal; Salvia officinalis; Spices

Topics: Complementary Therapies; Curcumin; Cystic Fibrosis; Humans; Information Dissemination; Mass Media; Peer Review, Research; Periodicals as Topic

Cystic fibrosis is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). The most common mutation, DeltaF508, results in the production of a misfolded CFTR protein that is retained in the endoplasmic reticulum and targeted for degradation. Curcumin is a nontoxic Ca-adenosine triphosphatase pump inhibitor that can be administered to humans safely. Oral administration of curcumin to homozygous DeltaF508 CFTR mice in doses comparable, on a weight-per-weight basis, to those well tolerated by humans corrected these animals' characteristic nasal potential difference defect. These effects were not observed in mice homozygous for a complete knockout of the CFTR gene. Curcumin also induced the functional appearance of DeltaF508 CFTR protein in the plasma membranes of transfected baby hamster kidney cells. Thus, curcumin treatment may be able to correct defects associated with the homozygous expression of DeltaF508 CFTR.

Topics: Animals; Calcium; Calnexin; Cell Line; Cell Membrane; Cricetinae; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Electrolytes; Endoplasmic Reticulum; Gene Targeting; Glycosylation; Humans; Intestinal Mucosa; Intestinal Obstruction; Isoproterenol; Membrane Potentials; Mice; Mice, Knockout; Mutation; Nasal Mucosa; Polyethylene Glycols; Protein Folding; Rectum; Transfection

Topics: Animals; Calcium-Transporting ATPases; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Disease Models, Animal; Endoplasmic Reticulum; Mice; Mice, Mutant Strains; Nasal Mucosa

Curcumin, the yellow colored component of the spice turmeric, has been reported to rescue defective DeltaF508-cystic fibrosis transmembrane conductance regulator (CFTR) cellular processing in homozygous mutant mice, restoring nasal potential differences and improving survival (Egan, M. E., Pearson, M., Weiner, S. A., Rajendran, V., Rubin, D., Glockner-Pagel, J., Canny, S., Du, K., Lukacs, G. L., and Caplan, M. J. (2004) Science 304, 600-602). Because of the implied potential use of curcumin or similar compounds in the therapy of cystic fibrosis caused by the DeltaF508 mutation, we tried to reproduce and extend the pre-clinical data of Egan et al. Fluorometric measurements of iodide influx in Fischer rat thyroid cells expressing DeltaF508-CFTR showed no effect of curcumin (1-40 microm) when added for up to 24 h prior to assay in cells grown at 37 degrees C. Controls, including 27 degrees C rescue and 4 mm phenylbutyrate at 37 degrees C, were strongly positive. Also, curcumin did not increase short circuit current in primary cultures of a human airway epithelium homozygous for DeltaF508-CFTR with a 27 degrees C rescue-positive control. Nasal potential differences in mice were measured in response to topical perfusion with serial solutions containing amiloride, low Cl-, and forskolin. Robust low Cl- and forskolin-induced hyperpolarization of 22 +/- 3 mV was found in wild type mice, with 2.1 +/- 0.4 mV hyperpolarization in DeltaF508 homozygous mutant mice. No significant increase in Cl-/forskolin hyperpolarization was seen in any of the 22 DeltaF508 mice studied using different curcumin preparations and administration regimens, including that used by Egan et al. Assay of serum curcumin by ethyl acetate extraction followed by liquid chromatography/mass spectrometry indicated a maximum serum concentration of 60 nm, well below that of 5-15 microm, where cellular effects by sarcoplasmic/endoplasmic reticulum calcium pump inhibition are proposed to occur. Our results do not support further evaluation of curcumin for cystic fibrosis therapy.

Topics: Administration, Oral; Amiloride; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Cycle; Cell Line; Cells, Cultured; Chlorine; Chromatography, High Pressure Liquid; Colforsin; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Epithelial Cells; Homozygote; Humans; Mice; Mutation; Perfusion; Phenylbutyrates; Rats; Rats, Inbred F344; Temperature; Thyroid Gland; Time Factors; Trachea; Transfection

Topics: Anti-Inflammatory Agents; Curcumin; Cystic Fibrosis; Humans

Topics: Animals; Calcium; Chloride Channels; Curcumin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Endoplasmic Reticulum; Enzyme Inhibitors; Humans; Mice; Mice, Knockout; Mutation

Topics: Clinical Trials as Topic; Curcumin; Cystic Fibrosis; Endoplasmic Reticulum; Enzyme Inhibitors; Humans; Treatment Outcome

It has been suggested that curcumin and other sarcoplasmic/endoplasmic reticulum Ca(2+)-pump inhibitors could correct the defect in the most common mutation (DeltaF508) in cystic fibrosis (CF), and restore normal chloride transport. In the present study, the effect of curcumin was tested on baby hamster kidney (BHK) cells transfected with DeltaF508-CFTR, a CF airway epithelial cell line (CFBE), and cells isolated from the nasal epithelium of CF-patient homozygous for the DeltaF508-mutation. Curcumin had a small effect on basal (non-CFTR-mediated) chloride efflux in CFBE and CF nasal epithelial cells, but did not increase the net cAMP-activated (CFTR-mediated) chloride efflux. Curcumin caused a small increase in net cAMP-activated chloride efflux from DeltaF508-CFTR BHK cells. Immunocytochemical analysis failed to show significant movement of DeltaF508-CFTR to the plasma membrane in DeltaF508-CFTR BHK cells or CFBE cells. It is concluded that it is unlikely that curcumin has a significant positive effect on CFTR-mediated chloride transport in airway epithelial cells.

Topics: Animals; Chlorides; Cricetinae; Curcumin; Cyclic AMP; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Enzyme Inhibitors; Fluorescent Antibody Technique; Humans; Immunohistochemistry; Respiratory Mucosa

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Curcumin; Cystic Fibrosis; Disease Models, Animal; Mice; Mice, Inbred CFTR