The inhibition the Tet(K) efflux pump of tetracycline resistant Staphylococcus epidermidis by essential oils from three Salvia species.

UNLABELLED: The inhibition of efflux pumps is an attractive and powerful response to the emergence of bacteria resistant to antibiotics. Essential oils (EOs) from Salvia fruticosa, Salvia officinalis and Salvia sclarea reduce the minimal inhibition concentration of tetracycline, decrease efflux of antibiotic and decrease the expression of tet(K) gene in tetracycline resistant clinical isolates of Staphylococcus epidermidis. In all the cases S. fruticosa was the best one. By using checkerboard and time-killing methods, we found synergistic interactions of EOs with tetracycline. SIGNIFICANCE AND IMPACT OF THE STUDY: Our data from molecular and functional analyses of inhibitory effect of Salvia's essential oils, namely from S. fruticosa, on Tet(K) pump of Staphylococcus epidermidis and from modulatory studies may be the starting point for consecutive study of pharmacokinetic and pharmacodynamic parameters and their perspective use in combination therapy. Combination of antibiotic with efflux pump inhibitor would be expected to re-establish susceptibility of the bacteria to antibiotics that became no longer effective due to bacterial resistance through the efflux pumps. The inhibition of an efflux pump can potentially improve the clinical efficacy of an antibiotic and simultaneously decrease the selection of resistant mutants.

Genotoxic and antimutagenic activities of extracts from pseudocereals in the Salmonella mutagenicity assay.

Extracts of amaranth (Amaranthus L.), sorghum (Sorghum bicolor L.) and Japanese millet (Echinochloa frumentacea L.) were evaluated for mutagenicity in Salmonella typhimurium strains TA98, TA100 and TA102. All three pseudocereal extracts were also assessed for their antimutagenic properties against the direct mutagens 2-nitrofluorene (2NF) for strain TA98, 3-(5-nitro-2-furyl)acrylic acid (5NFAA) for TA100 and H(2)O(2) for TA102 strain and against the indirect mutagen aflatoxin B(1) (AFB(1)). No mutagenicity was induced by any of the pseudocereal extracts when tested at concentrations as high as 50mg/ml. All three extracts showed similar antimutagenicity against 5NFAA and no antimutagenicity against 2NF. The number of revertants induced by H(2)O(2) extract was inhibited in order amaranth>Japanese milet>sorghum. All extracts were effective in the inhibition of mutagenic activity of aflatoxin B(1). The total polyphenol content as well as the amount of the flavonoids and phenolic acids as main component of polyphenolics were also determined.

The mechanism of ciprofloxacin resistance in dihydrogen peroxide-induced mutants of Salmonella enterica subsp. enterica serovar typhimurium consists mainly in mutations in gyrA gene and less in mutations affecting ciprofloxacin uptake.

The effect of H(2)O(2) on the induction of ciprofloxacin (CFL) resistant mutants of Salmonella enterica subsp. enterica serovar Typhimurium was evaluated and determinants of CFL resistance in the mutants were analyzed. Factors associated with CFL resistance in H(2)O(2)-induced mutants included (i) mutations in gyrA gene, predominantly (63 %) Asp(87)-->Asn and less (37 %) Ser(83)-->Phe substitutions, (ii) mutations in the regulatory genes of MarRAB or SoxRS or in the individual structural genes of these operons. Such mutations are induced by H(2)O(2) in a much lower extent. Reduced OmpF expression simultaneously with enhanced efflux was detected only in one mutant strain and 20 % of mutant strains had increased CFL efflux from the cells.

Variability of the essential oil from three sorts of Echinacea MOENCH genus during ontogenesis.

Variability of the essential oil from three sorts of Echinacea MOENCH genus during ontogenesis The content and quality of the essential oil in relation to the main ontogenetic stages of plants were studied in three various sorts of Echinacea genus. The comparison included Echinacea purpurea, Echinacea atrorubens, and Echinacea pallida. The differences in the content of the oil in different parts of plants and the abundance of individual oil constituents in oils from the sorts under study at the optimum stage of ripeness for harvest were evaluated as well.

[A study of qualitative properties of the essential oil of Tanacetum vulgare L]. / Studium kvalitatívnych vlastností silice Tanacetum vulgare L.

The study examined the qualitative properties of the essential oil obtained from the flower heads of the species Tanacetum vulgare L. The composition of the essential oil was evaluated in plants from various localities, which differed in the altitude, temperature gradient, as well as soil-climate conditions. With the use of gas chromatography (GC/MS), 49 constituents of the essential oil were separated, out of which 35 was identified. The shares of the constituents in the essential oil differed in dependence on the locality. In the lowest-lying locality with a relatively large sunshine, the content of beta-tujons in the essential oil was the highest, whereas in the regions lying towards the north the content of the essential oil was decreased and the content of camphor was increased. In the northern most region an increased number of chemovars of the camphor-cineole type was observed. In conclusion, it must be said that different climatic and agrotechnical conditions, geographical origin and adaptation of the genotypes of Tanacetum vulgare to the growth conditions can be the causes of the found chemotypes in the localities under examination.

Cytotoxic and genotoxic effects of some substituted tetrazolo[1,5-c]quinazolines.

Nine substituted tetrazolo[1,5-c]quinazolines have been tested for cytotoxic effects and structure activity relationship on the murine cancer cell line B16 and four bacterial strains. The most cytotoxic activity had non-substituted in the aromatic ring or substituted by bromo- or chloro-group, and in the pyrimidine ring of quinazoline skeleton by phenyl or morpholine group, respectively. In the bacterium all tested quinazolines had a lower antibacterial effect than ampicillin. 9-bromo-5-morpholino-tetrazolo[1,5-c]quinazoline (BMTQ) at the highest concentration tested (30.0 micromol/l) had an acute cytostatic effect manifested by the total inhibition of the cell proliferation. Other concentrations caused a cytotoxicity proportional to the concentration used. The IC50 values were found to be less than 4 microg/ml, a limit put forward by the National Cancer Institute (NCI) for classification of the compound as a potential anticancer drug. BMTQ induced mutations in a dose-related manner, starting from 10 microg/plate in strains TA100 and TA102. Lesser but significant increases in revertant colonies were also obtained in strain TA98. The mutagenity was slightly enhanced by metabolic activation.

Novel oxindole derivatives and their biological activity.

The antifungal activity of fourteen novel derivatives of oxindole with side chain was studied using representatives of toxinogenic, phytopathogenic and dermatophytic filamentous fungi. Derivatives with exocyclic C=C bond in position C-3 exhibited a higher antifungal activity compared with derivatives with an exocyclic C-C bond in the same position. The strongest antifungal effects were shown by 3-(-2-thienoylmethylidene)-indol-2(3H)-ones.

[Cytotoxic and genotoxic activity of certain preservative agents in cosmetics]. / Cytotoxická a genotoxická aktivita vybraných konzervacných látok pre kozmetické prostriedky.

Cytotoxic effects of the preservative compounds for cosmetics JMAC TD, Bronopol, CA 24, and Euxyl K100 were studied. Bronopol demonstrated the highest cytotoxic effect on the proliferation of V79 and VH10 fibroblast cell lines--the IC100 values being 10 mg/l during the whole experiment. The preservatives CA 24 and Euxyl K100 showed 4-times and 5-times smaller cytotoxic activity than Bronopol IC100 = 42 or 50.3 mg/l). The preservative compounds on silver chloride ions JMAC TD manifested the lowest cytotoxicity of the preservatives tested (IC100 = 150 mg/l); 15-times smaller than Bronopol, 3.5-times smaller than CA 24 and 3-times smaller than Euxyl K100. The biocide JMAC TD did not exhibit mutagenic effects on the bacteria Salmonella typhimurium TA 98 and TA 100.

Antibacterial and mutagenic activities of new isothiocyanate derivatives.

Nine newly synthesized isothiocyanate derivatives were demonstrated to posses antibacterial and genotoxic activities in vitro. 4-Hydroxybutyl isothiocyanate exhibited a broad antibacterial effect, with MIC values of 762 mumol/L for Staphylococcus aureus and Escherichia coli. Ethyl 4-methylsulfoxidobutanoate had the highest antibacterial activity in Gram-positive bacteria, the MIC value being 425 mumol/L for S. aureus. The highest tested concentrations of ethyl 4-isothiocyanatobutanoate and 4-hydroxybutyl isothiocyanate produced a bacteriocidal effect in Gram-positive bacteria. The compounds showed no mutagenic effects on Salmonella typhimurium tester strains TA 98 and TA 100, either in the absence or in the presence of a metabolically active microsomal S9 fraction from rat liver using standard Ames test.

Biological activity of some 4-anilinoquinazolines: cytotoxic, genotoxic and antiprotease effects, induction of necrosis and changes of actin cytoskeleton.

Fourteen substituted 4-anilinoquinazolines have been tested for cytotoxic effect and structure activity relationships. The most active derivatives were substituted by chlorine or bromine group in the aromatic ring, in the pyrimidine ring by morpholine group and in the aniline skeleton by nitro group in position 4 or 2. Derivatives 6-bromo-2-(morpholin-1-yl)-4-(4'-nitroanilino)quinazoline, 6-bromo-2-morpholin-1-yl)-4-anilinoquinazoline, 2-(morpholin-1-yl)-4-(4'-bromoanilino)-quinazoline and 6-chloro-2-(morpholin-1-yl)-4-(4'-nitroanilino)quinazoline inhibited growth of tumor cell lines HeLa, B16 and L1210. Mutagenic data provided by Ames test showed, that the compounds 6-bromo-2-morpholin-1-yl)-4-anilinoquinazoline and 2-(morpholin-1-yl)- 4-(4'-bromoanilino)quinazoline did not exhibit the mutagenic effect, whereas the compounds 6-bromo-2-(morpholin-1-yl)-4-(4'-nitroanilino)quinazoline and 6-chloro-2-(morpholin-1-yl)-4-(4'-nitroanilino) quinazoline increased slightly the number of revertants of the strain TA 98 without metabolic activation. Concentration 26 micromol/L of 6-bromo-2-(morpholin-1-yl)-4-anilinoquinazoline induced necrosis of tumor cells B16. Concentration 5.2 micromol/l induced a significant increase of filamentous actin in the transformed HepG2 cells. Derivatives 6-bromo-2-(morpholin-1-yl)-4-(4'-nitroanilino)quinazoline, 6-bromo-2-morpholin-1-yl)-4-anilinoquinazoline, 2-(morpholin-1-yl)-4-(4'-bromoanilino)quinazoline and 6-chloro-2-(morpholin-1-yl)-4-(4'-nitroanilino)quinazoline exhibited antiprotease effect on plasmine. This results could be relevant for the anticancer properties of these compounds.