benzofurans and Cystic-Fibrosis

Talniflumate, an anti-inflammatory molecule that was originally developed by Laboratorios Bago, is currently being developed by Genaera as a mucoregulator for the treatment of cystic fibrosis, chronic obstructive pulmonary disease and asthma. Phase I trials with talniflumate had been completed by August 2001, and phase II trials were underway in Ireland for the treatment of cystic fibrosis.

Topics: Animals; Anti-Inflammatory Agents; Asthma; Benzofurans; Chloride Channels; Clinical Trials as Topic; Cystic Fibrosis; Expectorants; Humans; Pulmonary Disease, Chronic Obstructive; Pyridines; Sinusitis; Structure-Activity Relationship

To evaluate the antibacterial and antibiofilm mechanisms of usnic acid (USN) against methicillin-resistant Staphylococcus aureus from cystic fibrosis patients.. The effects exerted by USN at subinhibitory concentrations on S. aureus Sa3 strain was evaluated by proteomic, real-time PCR and electron microscopy analyses.. Proteomic analysis showed that USN caused damage in peptidoglycan synthesis, as confirmed by microscopy. Real-time PCR analysis showed that antibiofilm activity of USN is mainly due to impaired adhesion to the host matrix binding proteins, and decreasing lipase and thermonuclease expression. Our data show that USN exerts anti-staphylococcal effects through multitarget inhibitory effects, thus confirming the rationale for considering it 'lead compound' for the treatment of cystic fibrosis infections.

Topics: Adhesins, Bacterial; Anti-Bacterial Agents; Bacterial Proteins; Benzofurans; Biofilms; Carrier Proteins; Cell Membrane; Cell Survival; Colony Count, Microbial; Cystic Fibrosis; DNA, Bacterial; Down-Regulation; Lipase; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Microbial Viability; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Peptidoglycan; Propidium; Protein Interaction Maps; Proteomics; Real-Time Polymerase Chain Reaction; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Staphylococcal Infections; Time Factors; Virulence

Three secondary metabolites of lichens - usnic acid, atranorin and fumarprotocetraric acid - were evaluated for their in vitro antibacterial and antibiofilm activities against three strains each of methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MRSA) from cystic fibrosis patients.. Antibacterial activity was assessed by broth microdilution, while antibiofilm activity was evaluated by spectrophotometry or viable count.. Usnic acid was significantly more active than atranorin against planktonic cells, while fumarprotocetraric acid exhibited no activity. Atranorin was the most effective in counteracting adhesion to polystyrene, although usnic acid was more active against MRSA. Usnic acid and atranorin showed comparable activity against biofilm formation, although atranorin was more active against MRSA. Usnic acid was significantly more active than atranorin against preformed biofilms.. Secondary metabolites of lichens may be considered to be 'lead compounds' for the development of novel molecules for the treatment of S. aureus infections in cystic fibrosis patients.

Topics: Anti-Bacterial Agents; Benzofurans; Biofilms; Biological Products; Colony Count, Microbial; Cystic Fibrosis; Fumarates; Humans; Hydroxybenzoates; Lichens; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Plant Extracts; Staphylococcal Infections

Intestinal disease in cystic fibrosis (CF) mice closely mirrors aspects of obstructive syndromes in CF patients. The pathogenesis involves accumulation of mucoid debris in the crypts that fuse with intestinal content to form obstructing mucofeculant impactions. Treatment involves modalities that increase the fluidity of the luminal content, such as osmotic laxatives and liquid diets. We investigated the effects of talniflumate (Lomucin, Genaera Corporation, Plymouth Meeting, PA), a compound that may be beneficial to treatment of CF intestinal disease based on three mechanisms of action: mucus synthesis inhibition by blockade of the murine calcium-activated chloride channel 3 (mCLCA3), nonsteroidal anti-inflammatory effects, and inhibition of Cl(-)/HCO (-)(3) exchanger(s) involved in intestinal NaCl absorption. Cohorts of CF mice were fed control diet or diets containing either talniflumate (0.4 mg/g chow) or ibuprofen (0.4 mg/g chow) for 21 days to assess survival. Talniflumate significantly increased CF mouse survival from 26 to 77%, whereas ibuprofen had no effect (22% survival). Oral talniflumate did not alter crypt goblet cell numbers or change intestinal expression of mCLCA3 but tended to decrease crypt mucoid impaction. Ussing chamber studies indicated that talniflumate slightly increased the basal short-circuit current of CF intestine, but the change was not sensitive to secretagogue stimulation or bumetanide inhibition. In contrast, intracellular pH measurements of intact intestinal villous epithelium indicated that talniflumate significantly inhibited apical membrane Cl(-)/HCO (-)(3) exchange by >50%. We conclude that oral talniflumate increases the survival of CF mice, possibly by the beneficial effects of decreasing small intestinal NaCl absorption through the inhibition of apical membrane Cl(-)/HCO (-)(3) exchanger(s).

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Benzofurans; Cell Count; Chloride Channels; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Disease Models, Animal; Hydrogen-Ion Concentration; Intestinal Mucosa; Intestinal Obstruction; Intestine, Small; Ion Transport; Mice; Mucins; Mucoproteins; Mutation; Pyridines

To determine whether epithelial ion transport abnormalities in cystic fibrosis (CF) might reflect abnormal regulation of intracellular Ca2+ levels, cytosolic free calcium (Cai2+) was measured using fura-2 or quin2 in suspensions of normal or CF nasal epithelial cells derived from primary cell culture. The basal Cai2+ level measured with fura-2 in CF nasal epithelia was 155 +/- 9 nM (n = 5), a value not significantly different from normal nasal epithelia (143 +/- 16 nM, n = 5). Total cell calcium was measured by atomic absorption spectroscopy and no differences were observed between CF (6.3 +/- 0.5 nmol/mg protein; n = 3) and normal (6.2 +/- 1.2 nmol/mg protein; n = 3) nasal epithelial cells. Placing Na+ loaded cells in a low (10 mM) extracellular Na+ solution resulted in a rapid increase in Cai2+ consistent with Ca2+ uptake via a plasmalemmal Na+-Ca2+ exchanger. The level of Cai2+ achieved by this low Na+ maneuver was not significantly different in CF cells compared to normal cells. Neither isoproterenol (10(-5) M) nor forskolin (10(-6) M) had any effect on Cai2+ in normal or CF nasal epithelial cells. Thus, it appears that differences in cell Cai2+, as measured by fluorescent chelators in suspensions of cultured cells, do not account for the abnormalities in basal or isoproterenol stimulated ion transport in CF tissues.

Topics: Adolescent; Adult; Aged; Aminoquinolines; Benzofurans; Calcium; Cells, Cultured; Child; Cyclic AMP; Cystic Fibrosis; Cytosol; Epithelium; Ethers; Female; Fluorescent Dyes; Fura-2; Humans; Ionomycin; Isoproterenol; Male; Middle Aged; Nasal Mucosa; Ouabain; Sodium; Spectrophotometry, Atomic