Withanolide E sensitizes renal carcinoma cells to TRAIL-induced apoptosis by increasing cFLIP degradation.

Withanolide E, a steroidal lactone from Physalis peruviana, was found to be highly active for sensitizing renal carcinoma cells and a number of other human cancer cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis. Withanolide E, the most potent and least toxic of five TRAIL-sensitizing withanolides identified, enhanced death receptor-mediated apoptotic signaling by a rapid decline in the levels of cFLIP proteins. Other mechanisms by which TRAIL sensitizers have been reported to work: generation of reactive oxygen species (ROS), changes in pro-and antiapoptotic protein expression, death receptor upregulation, activation of intrinsic (mitochondrial) apoptotic pathways, ER stress, and proteasomal inhibition proved to be irrelevant to withanolide E activity. Loss of cFLIP proteins was not due to changes in expression, but rather destabilization and/or aggregation, suggesting impairment of chaperone proteins leading to degradation. Indeed, withanolide E treatment altered the stability of a number of HSP90 client proteins, but with greater apparent specificity than the well-known HSP90 inhibitor geldanamycin. As cFLIP has been reported to be an HSP90 client, this provides a potentially novel mechanism for sensitizing cells to TRAIL. Sensitization of human renal carcinoma cells to TRAIL-induced apoptosis by withanolide E and its lack of toxicity were confirmed in animal studies. Owing to its novel activity, withanolide E is a promising reagent for the analysis of mechanisms of TRAIL resistance, for understanding HSP90 function, and for further therapeutic development. In marked contrast to bortezomib, among the best currently available TRAIL sensitizers, withanolide E's more specific mechanism of action suggests minimal toxic side effects.

[Identification of Legionella spp. by means of cultural and molecular methods in a public hospital]. / Isolamento di Legionella spp. mediante metodi colturali e tecniche molecolari in matrici ambientali prelevate in una struttura ospedaliera pubblica.

An epidemiologic study on the isolation of Legionella spp from the sanitary water of a public Hospital in Cagliari (Italy) has been performed. The aim of the study was the comparison between the isolation of various Legionella spp from different hospital sources and the real hazard of Legionella infection of the inpatients. Two test methods were used for Legionella detection: a) the culture on selective media, that has the disadvantage of being quite time-consuming and of isolating also other bacterial species. Furthermore, the culture method often fails the isolation of vital but not culturable bacteria (VBNC); b) the PCR molecular method, which is rapid and precise and recognizes also VBNC cells. The most relevant result of this work was that, in spite of the isolation of a considerable number of Legionella spp (even Legionella pneumophila), no case of infection was detected in the Hospital during the period of the study.

New trends in development of antimycobacterial compounds.

The resurgence of tuberculosis and the surge of multidrug-resistant clinical isolates of Mycobacterium tuberculosis have reaffirmed tuberculosis as a primary public health concern. In this review we describe some new findings on the pharmacological status of fluoroquinolones derivatives (Gatifloxacin, Moxifloxacin and Sitafloxacin), new macrolides (Clarithromycin, Azithromycin and Roxithromycin), new rifamycin derivatives (Rifapentin, Rifabutin and Rifalazil) and new oxazolidinones (Linezolid and PNU 100480). We describe also other type of agents that are being developed as antimycobacterial drugs. Some of these are under clinical investigation, while others are considered to be promising candidates for future development. Among them, nitroimidazopyrans, new ketolides, Isoxyl (ISO), pyrroles derived from BM 212, Mefloquine and Diarylquinoline R207910 are discussed. We also describe the mechanism of drug resistance in mycobacteria, as well as new potential targets.

[The synthesis and antiviral activity of glycyrrhizic acid conjugates with alpha-D-glucosamine and some glycosylamines]. / Sintez kon''iugatov glitsirrizinovoi kisloty s al'fa-D-gliukozaminom i nekotorymi glikozilaminami i ikh protivovirusnaia aktivnost'.

Glycyrrhizic acid and its 30-methyl ester were conjugated with 2-amino-1,3,4,6-tetra-O-acetyl-2-deoxy-alpha-D-glucopyranose, 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl amine, 2,3,4-tri-O-acetyl-apha-L-arabinopyranosyl amine, 2-acetamido-2-deoxy-beta-D-glucopyranosyl amine, and beta-D-galactopyranosyl amine using N,N'-dicyclohexylcarbodiimide and its mixtures with N-hydroxybenzotriazole. Structures of the conjugates were confirmed by IR, UV, 1H, and 13C NMR spectroscopy. The glycoconjugate with the residues of 2-acetamido-2-deoxy-beta-D-glucopyranosyl amine in the carbohydrate part of its molecule exhibited antiviral activity (ID50 4 microg/ml) toward the herpes simplex type 1 virus (HSV-1) in the VERO cell culture. Two compounds demonstrated anti-HIV-1 activity (50-70% inhibition of p24) in a culture of MT-4 cells at concentrations of 0.5-20 microg/ml. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 3; see also http://www.maik.ru.

Rapid detection of Listeria monocytogenes in foods, by a combination of PCR and DNA probe.

Listeria monocytogenes is a frequent contaminant of water and foods. Its rapid detection is needed before some foods can be prepared for marketing. In this work L. monocytogenes has been searched for in foods, by a combination of polymerase chain reaction (PCR) and a DNA probe. Both PCR and the probe were prepared for recognizing a specific region of the internalin gene, which is responsible for the production of one of the most important pathogenic factors of Listeria. The combined use of PCR and the DNA probe was used for the detection of L. monocytogenes in over 180 environmental and food samples. Several detection methods were compared in this study, namely conventional culture methods; direct PCR; PCR after an enrichment step; a DNA probe alone; a DNA probe after enrichment and another commercially available gene-probe. Finally PCR and the DNA probe were used in series on all the samples collected. When the DNA probe was associated with the PCR, specific and accurate detection of listeria in the samples could be obtained in about a working-day. The present molecular method showed some advantages in terms of rapidity and specificity in comparison to the other aforementioned tests. In addition, it resulted as being easy to handle, even for non-specialized personnel in small diagnostic microbiology laboratories.

Antioxidant activity of extracts from plants growing in Sardinia.

The present work was carried out to study the effect of some plant methanol extracts and essential oils on lipid peroxidation in simple in vitro systems. The tested extracts were obtained from four plants, commonly known in the Mediterranean area, indigenous to Sardinia: Artemisia arborescens L., Calycotome villosa L., Daphne gnidium L. or naturalized in the island, Eucalyptus globulus Labill. The activity of the extracts was investigated during both autoxidation and iron or EDTA-mediated oxidation of linoleic acid at 37 degrees C in the absence of solvent, and compared with that of BHT, alpha-tocopherol and EDTA. During linoleic acid autoxidation all the extracts were active, showing an antioxidant activity in the order: BHT >alpha- tocopherol >Daphne gnidium (methanol extract) >Eucalyptus globulus (essential oil) >Calycotome villosa (essential oil) >Artemisia arborescens (essential oil and methanol extract) >Calycotome villosa (methanol extract). None showed any prooxidant activity. During the iron-catalysed oxidation of linoleic acid the oils were not active, while all the methanol extracts showed some efficiency in preventing the oxidation process. All the extracts were also tested on cell cultures to investigate their cytotoxic activity or their ability to inhibit the growth of some pathogenic microorganisms.

Antimicrobial evaluation of coumarins and flavonoids from the stems of Daphne gnidium L.

The antimicrobial activity of stems methanol extract from Daphne gnidium L. collected from Sardinia (Italy) was evaluated against 6 strains of standard and clinical isolated gram (+/-) bacteria. The antimicrobial effect on two strains of fungi was also tested. The extract in toto exhibited antibacterial activity against Bacillus lentus and Escherichia coli, but was inactive against fungi. Four coumarins (daphnetin, daphnin, acetylumbelliferone, daphnoretin) and seven flavonoids (luteolin, orientin, isoorientin, apigenin-7-O-glucoside, genkwanin, 5-O-beta-D-primeverosyl genkwanine, 2,5,7,4'-tetrahydroxyisoflavanol) present in the plant extract were also investigated against the same strains of bacteria and fungi assayed for the crude extract. The most active compounds were daphnetin, genkwanin, and 2,5,7,4'-tetrahydroxyisoflavanol.

Chemical composition and cytotoxic and antimicrobial activity of Calycotome villosa (Poiret) link leaves.

The chemical composition of the essential oil and methanol extract of Calycotome villosa (Poiret) Link leaves collected in Sardinia (Italy) has been studied by analytical and spectroscopic methods. Falcarinol and some alcohols, terpenes, furan derivatives, and paraffins have been isolated from the essential oil. Thirteen alkaloids and falcarinol have been identified in the chloroform fraction of the basic methanol extract. Six flavonoids and four anthraquinones have been isolated in the chloroform fraction after acidification of the basic methanol extract. The cytotoxic and antimicrobial activities have also been evaluated. The essential oil, the methanol extract in toto, and the fraction of the basic extract showed strong cytotoxicity, whereas the fraction of the acid extract showed lower cytotoxicity. Furthermore, this fraction showed good antibacterial activity against Staphylococcus aureus, Bacillus lentus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Providencia rettgeri, and Morganella morganii. It can therefore be stated that this plant's cytotoxicity is prevalently due to falcarinol.

Enhancement of anti-herpetic activity of glycyrrhizic acid by physiological proteins.

Some enzymes present in biological fluids, such as lysozyme (LYS) and lactoferrin (LAC), are known to possess antibacterial and antiviral activity, against herpesviruses in particular. It will be shown in this paper that their combination with a natural triterpene, namely glycyrrhizic acid (GLA), gives significant results in enhancing the antagonistic activity on HSV1 in in vitro assays. Data elaboration was carried out by calculation of the FIC index (fractional inhibitory concentration) for each combination of the three compounds and by a three-dimensional evaluation of the inhibiting combinatory effects, which indicated the percentage of the synergistic action. A FIC index equal to or below 0.5 demonstrated a significant synergistic effect between two substances. Considering each single compound, the 50% inhibiting doses on viral replication (ID50) were 252+/-53 microg/ml for LAC, 497+/-165 microg/ml for LYS and 740+/-125 microg/ml for GLA. The combination of LAC and GLA showed a clear synergistic effect, with a FIC index of 0.08 and a potentiating activity which, for some doses, was up to 1.5 log10 of difference (from about 5.5x10(6) to 10(5) pfu/ml). The combinations of GLA and LYS, and LYS and LAC showed a less significant synergistic activity. These findings led to the conclusion that some physiological proteins, even at concentrations usually present in some body fluids, may enhance the anti-herpetic activity of a natural compound such as GLA.

New pyrrole derivatives as antimycobacterial agents analogs of BM212.

During the course of our investigations in the field of azole antimicrobial agents, we have identified BM212 a pyrrole derivative with good in vitro activity against mycobacteria and candidae. These findings prompted us to prepare new pyrrole derivatives 2-6 in the hope of increasing the activity. The microbiological data showed interesting in vitro activity against Mycobacterium tuberculosis and atypical mycobacteria.

High-level production of heterologous protein by engineered yeasts grown in cottage cheese whey.

Cottage cheese whey is a cheese industry by-product still rich in proteins and lactose. Its recycling is seldom cost-effective. In this work we show that the lactose-utilizing yeast Kluyveromyces lactis, engineered for production of recombinant human lysozyme, can be grown in cottage cheese whey, resulting in high-level production of the heterologous protein (125 microg/ml).

Production of lysozyme-enriched biomass from cheese industry by-products.

Cheese whey and cottage cheese whey are by-products of the milk and cheese industry, resulting from the production of cheese and cottage cheese (ricotta) from milk. They are still rich in organic substances and cannot be discarded into the environment without proper treatment. Whey and cottage cheese whey were used as culture media for some strains of the yeast Kluyveromyces lactis, transformed with the human lysozyme gene. It was found that the yeast strains grew well in both media and produced a considerable amount of recombinant protein. Production kinetics showed that the human lysozyme was produced in a greater amount within 36 h of fermentation (125 micrograms ml-1 vs 25 micrograms ml-1 in the control) than in the synthetic commercial media used for strain preparation and characterization. The recombinant protein produced was actually shown to be the human lysozyme, using renaturing SDS-PAGE and Western blot techniques. While producing recombinant protein, the Kluyveromyces strain cleared the cottage cheese whey of most organic substances and produced a considerable amount (almost 3%) of lysozyme-enriched useful biomass.

Antimycobacterial activity of new ortho-, meta- and para-toluidine derivatives.

Novel toluidine derivatives are described. Some of them showed an interesting in vitro activity against Mycobacterium tuberculosis, M. smegmatis, M. marinum, M. gordonae, and M. avium. Some of them were more active than Streptomycin and Isoniazid, which were used as controls, against M. avium and M. gordonae. In particular, we confirm the good activity of biphenyl derivatives.

Bactericidal activities of the pyrrole derivative BM212 against multidrug-resistant and intramacrophagic Mycobacterium tuberculosis strains.

The pyrrole derivative BM212 [1, 5-diaryl-2-methyl-3-(4-methylpiperazin-1-yl)methyl-pyrrole] was shown to possess strong inhibitory activity against both Mycobacterium tuberculosis and some nontuberculosis mycobacteria. BM212 was inhibitory to drug-resistant mycobacteria and also exerted bactericidal activity against intracellular bacilli residing in the U937 human histiocytic lymphoma cell line.

A rapid method for screening large numbers of environmental microorganisms for antiviral activity.

A new method for screening microbial colonies endowed with antiviral activity is described. It is based on close contact between microbial agar cultures and agar-covered virus-infected-cell monolayers and allows the screening of large numbers of colonies in just a few months.

N-[4-(1,1'-biphenyl)methyl]-4-(4-thiomorpholinylmethyl) benzenamines as non-oxazolidinone analogues of antimycobacterial U-100480.

Thiomorpholine analogues of U-100480 with the biphenylmethyl group replacing the acetamidomethyloxazolidinone moiety have been synthesized and tested as antimycobacterial agents together with various related derivatives. Some biphenyl derivatives were endowed with high activity against Mycobacterium tuberculosis and other non-tuberculous mycobacteria.

Pyrrolnitrin and related pyrroles endowed with antibacterial activities against Mycobacterium tuberculosis.

During development of nitroheterocycles with potential antimycobacterial activities we have tested against Mycobacterium tuberculosis a number of pyrroles strictly related to pyrrolnitrin, an antifungal antibiotic isolated from Streptomyces pyrrocinia. Some of the tested arylpyrrole derivatives and pyrrolnitrin have shown appreciable inhibiting activity against M. tuberculosis and M. avium. SAR studies well correlate antimycobacterial potency with the presence of halogens in the phenyl ring and a nitro group at position 3 of pyrrole.

Studies on the distribution of high-level gentamicin-resistant Enterococcus faecalis using ribotyping and restriction analysis of the 16S-23S rRNA intergenic spacer sequences.

Twenty-five high-level gentamicin resistant (HLGR) Enterococcus faecalis strains were isolated from three different University laboratories in Italy. The resistant strains were variously distributed in the three centers with percentages of prevalence ranging from about 3% up to 14%. Almost all strains shared high-level resistance to streptomycin (23 out of 25). Ribotyping and restriction analysis of the 16S-23S rRNA intergenic spacer sequences were used to genetically differentiate the various strains and to study their spreading in the university hospitals serviced by the three laboratories. At least three ribotypes were identified, which showed a peculiar distribution in the various centers. Only the ribotype B was isolated from the University of Padua. In Cagliari, most strains belonged to ribotype A (4/6), whereas in Genoa there was an equal distribution of the ribotypes A and B. A clonal spreading of some HLGR strains is suggested by these findings. The restriction analysis of the 16S-23S rRNA intergenic-spacer sequences gave comparable results with classical ribotyping and, in addition, was quicker and easier to perform than the latter.

Genotypic differentiation of Gardnerella vaginalis by amplified ribosomal DNA restriction analysis (ARDRA).

In total 34 strains of Gardnerella vaginalis were analyzed with various molecular techniques in order to find the possibility of dividing this single species into different genotypes. Classical ribotyping, PCR-ribotyping and restriction analysis of 16S-23S rRNA intergenic spacer sequences were all unsuccessful in genotype differentiation of these bacteria. Only amplified ribosomal DNA restriction analysis (ARDRA) was suitable in recognizing different G. vaginalis genotypes. At least 3-4 genotypes were identified with different restriction enzymes, some of which showed a prevalent distribution in certain of the centers from which they were collected. Although in this study no correlation was found between bacterial vaginosis and any of the genotypes identified, the ARDRA method could prove to be a useful tool for studying the etiopathology and epidemiology of G. vaginalis.