Alcohols are a part of cellular metabolism, but their physiological roles are not well understood. We investigated the effects of short-chain alcohols on Daphnia pulex and model membranes mimicking the lipid composition of eukaryotic inner mitochondrial membranes. We also studied the synergistic effects of alcohols with the bee venom membrane-active peptide, melittin, which is structurally similar to endogenous membrane-active peptides. The alcohols, from ethanol to octanol, gradually decreased the heart rate and the mitochondrial ATP synthesis of daphnia; in contrast, in combination with melittin, which exerted no sizeable effect, they gradually increased both the heart rate and the ATP synthesis. Lipid packing and the order parameter of oriented films, monitored by EPR spectroscopy of the spin-labeled probe 5-doxylstrearic acid, revealed gradual alcohol-assisted bilayer to non-bilayer transitions in the presence of melittin; further, while the alcohols decreased, in combination with melittin they increased the order parameter of the film, which is attributed to the alcohol-facilitated association of melittin with the membrane. A 1H-NMR spectroscopy of the liposomes confirmed the enhanced induction of a non-bilayer lipid phase that formed around the melittin, without the permeabilization of the liposomal membrane. Our data suggest that short-chain alcohols, in combination with endogenous peptides, regulate protein functions via modulating the lipid polymorphism of membranes.
Skin penetration/permeation enhancers are compounds that improve (trans)dermal drug delivery. We designed hybrid terpene-amino acid enhancers by conjugating natural terpenes (citronellol, geraniol, nerol, farnesol, linalool, perillyl alcohol, menthol, borneol, carveol) or cinnamyl alcohol with 6-(dimethylamino)hexanoic acid through a biodegradable ester linker. The compounds were screened for their ability to increase the delivery of theophylline and hydrocortisone through and into human skin ex vivo. The citronellyl, bornyl and cinnamyl esters showed exceptional permeation-enhancing properties (enhancement ratios up to 82) while having low cellular toxicities. The barrier function of enhancer-treated skin (assessed by transepidermal water loss and electrical impedance) recovered within 24 h. Infrared spectroscopy suggested that these esters fluidized the stratum corneum lipids. Furthermore, the citronellyl ester increased the epidermal concentration of topically applied cidofovir, which is a potent antiviral and anticancer drug, by 15-fold. In conclusion, citronellyl 6-(dimethylamino)hexanoate is an outstanding enhancer with an advantageous combination of properties, which may improve the delivery of drugs that have a limited ability to cross biological barriers.
- MeSH
- alkoholy chemie farmakologie MeSH
- aplikace kožní MeSH
- buňky 3T3 MeSH
- chemie farmaceutická MeSH
- cidofovir aplikace a dávkování chemie farmakokinetika MeSH
- epidermis účinky léků metabolismus MeSH
- estery chemie farmakologie MeSH
- farmaceutické pomocné látky chemie farmakologie MeSH
- hydrokortison aplikace a dávkování chemie farmakokinetika MeSH
- keratinocyty MeSH
- lidé MeSH
- metabolismus lipidů účinky léků MeSH
- monoterpeny chemie MeSH
- myši MeSH
- permeabilita účinky léků MeSH
- perspiratio insensibilis účinky léků MeSH
- příprava léků metody MeSH
- terpeny chemie farmakologie MeSH
- testy akutní toxicity MeSH
- theofylin aplikace a dávkování chemie farmakokinetika MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
After cold shock, the Bacillus subtilis desaturase Des introduces double bonds into the fatty acids of existing membrane phospholipids. The synthesis of Des is regulated exclusively by the two-component system DesK/DesR; DesK serves as a sensor of the state of the membrane and triggers Des synthesis after a decrease in membrane fluidity. The aim of our work is to investigate the biophysical changes in the membrane that are able to affect the DesK signalling state. Using linear alcohols (ethanol, propanol, butanol, hexanol, octanol) and benzyl alcohol, we were able to suppress Des synthesis after a temperature downshift. The changes in the biophysical properties of the membrane caused by alcohol addition were followed using membrane fluorescent probes and differential scanning calorimetry. We found that the membrane fluidization induced by alcohols was reflected in an increased hydration at the lipid-water interface. This is associated with a decrease in DesK activity. The addition of alcohol mimics a temperature increase, which can be measured isothermically by fluorescence anisotropy. The effect of alcohols on the membrane periphery is in line with the concept of the mechanism by which two hydrophilic motifs located at opposite ends of the transmembrane region of DesK, which work as a molecular caliper, sense temperature-dependent variations in membrane properties.
- MeSH
- alkoholy farmakologie MeSH
- aminokyselinové motivy MeSH
- Bacillus subtilis metabolismus MeSH
- bakteriální proteiny metabolismus MeSH
- buněčná membrána účinky léků fyziologie MeSH
- desaturasy mastných kyselin biosyntéza genetika MeSH
- diferenciální skenovací kalorimetrie MeSH
- enzymová indukce účinky léků MeSH
- fluidita membrány účinky léků MeSH
- fluorescenční polarizace MeSH
- fosforylace MeSH
- hydrofobní a hydrofilní interakce MeSH
- mastné kyseliny metabolismus MeSH
- nízká teplota MeSH
- posttranslační úpravy proteinů * MeSH
- proteinkinasy metabolismus MeSH
- regulace genové exprese u bakterií účinky léků MeSH
- rekombinantní fúzní proteiny metabolismus MeSH
- reportérové geny MeSH
- signální transdukce účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
The effect of alcohols on cell membrane proteins has originally been assumed to be mediated by their primary action on membrane lipid matrix. Many studies carried out later on both animal and yeast cells have revealed that ethanol and other alcohols inhibit the functions of various membrane channels, receptors and solute transport proteins, and a direct interaction of alcohols with these membrane proteins has been proposed. Using our fluorescence diS-C3 (3) diagnostic assay for multidrug-resistance pump inhibitors in a set of isogenic yeast Pdr5p and Snq2p mutants, we found that n-alcohols (from ethanol to hexanol) variously affect the activity of both pumps. Beginning with propanol, these alcohols have an inhibitory effect that increases with increasing length of the alcohol acyl chain. While ethanol does not exert any inhibitory effect at any of the concentration used (up to 3%), hexanol exerts a strong inhibition at 0.1%. The alcohol-induced inhibition of MDR pumps was detected even in cells whose membrane functional and structural integrity were not compromised. This supports a notion that the inhibitory action does not necessarily involve only changes in the lipid matrix of the membrane but may entail a direct interaction of the alcohols with the pump proteins.
- MeSH
- ABC transportéry antagonisté a inhibitory genetika metabolismus MeSH
- adenosintrifosfát metabolismus MeSH
- alkoholy farmakologie MeSH
- fungální léková rezistence genetika MeSH
- ionty metabolismus MeSH
- mikrobiální testy citlivosti MeSH
- permeabilita buněčné membrány účinky léků MeSH
- Saccharomyces cerevisiae - proteiny antagonisté a inhibitory genetika metabolismus MeSH
- Saccharomyces cerevisiae účinky léků genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
