In Vitro and Intracellular Activities of Omadacycline against Legionella pneumophila.

Omadacycline is an aminomethylcycline antibiotic with in vitro activity against pathogens causing community-acquired bacterial pneumonia (CABP). This study investigated the activity of omadacycline against Legionella pneumophila strains isolated between 1995 and 2014 from nosocomial or community-acquired respiratory infections. Omadacycline exhibited extracellular activity similar to comparator antibiotics; intracellular penetrance was found by day 3 of omadacycline exposure. These results support the utility of omadacycline as an effective antibiotic for the treatment of CABP caused by L. pneumophila.

Levonadifloxacin (WCK 771) exerts potent intracellular activity against Staphylococcus aureus in THP-1 monocytes at clinically relevant concentrations.

Objective . Levonadifloxacin is a broad-spectrum anti-staphylococcal drug that is under development. We investigated the in vitro activity of levonadifloxacin against methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains phagocytized in THP-1 monocytes to evaluate its scope for treatment of intracellular staphylococcal infections.Methods. The microdilution minimum inhibitory concentrations (MICs) of levonadifloxacin, moxifloxacin, levofloxacin and ciprofloxacin against MSSA ATCC 25923 and MRSA ATCC 43300 strains at pH 7.4±0.1 (original medium pH) and 5.5±0.1 (phagosome pH environment) were determined by following Clinical and Laboratory Standards Institute (CLSI) guidelines. The activity of antibiotics was investigated by extracellular and intracellular time-kill studies at 1-16× MIC concentrations. A suspension of ~5× log10 c.f.u. ml-1 test organism in supplemented RPMI 1640 medium was employed to determine the extracellular activity, while test organism phagocytized at a 4 : 1 ratio of bacteria to THP-1 monocytes was employed to investigate the intracellular activity. At intervals of 0, 2, 6 and 24 h, colony-forming unit (c.f.u.) counts were performed in triplicate on inoculated brain heart infusion (BHI) agar plates for both methods.Results. At pH 7.4, the MIC of levonadifloxacin against both tested S. aureus strains was 2, 8 and 16 times lower than those of moxifloxacin, levofloxacin and ciprofloxacin, respectively. At pH 5.5, the MIC of levonadifloxacin was reduced by ≥8× against both tested S. aureus strains compared to its MIC at pH 7.4. In contrast, comparator quinolones showed a fourfold elevation in MIC at pH 5.5. In the study assessing the extracellular bactericidal effect, levonadifloxacin at 1× MIC manifested ≥4.5 log10 c.f.u. ml-1 killing for both S. aureus strains. Moxifloxacin and levofloxacin also showed bactericidal activity, while ciprofloxacin showed no killing. In intracellular conditions, levonadifloxacin manifested 1.0 log10 and 2.0 log10 killing for intracellular S. aureus ATCC 25923 and ATCC 43300, respectively. These killing effects were better overall than those of comparator quinolones.Conclusions. Within a clinically achievable concentration range, levonadifloxacin achieved a 90-99 % intracellular reduction of MSSA and MRSA strains phagocytized in THP-1 monocytes. Therefore, levonadifloxacin has the potential to be a therapeutic option for the management of intracellular methicillin- and quinolone-resistant staphylococcal infections.

Fluorocycline TP-271 Is Potent against Complicated Community-Acquired Bacterial Pneumonia Pathogens.

TP-271 is a novel, fully synthetic fluorocycline antibiotic in clinical development for the treatment of respiratory infections caused by susceptible and multidrug-resistant pathogens. TP-271 was active in MIC assays against key community respiratory Gram-positive and Gram-negative pathogens, including Streptococcus pneumoniae (MIC90 = 0.03 µg/ml), methicillin-sensitive Staphylococcus aureus (MSSA; MIC90 = 0.25 µg/ml), methicillin-resistant S. aureus (MRSA; MIC90 = 0.12 µg/ml), Streptococcus pyogenes (MIC90 = 0.03 µg/ml), Haemophilus influenzae (MIC90 = 0.12 µg/ml), and Moraxella catarrhalis (MIC90 ≤0.016 µg/ml). TP-271 showed activity (MIC90 = 0.12 µg/ml) against community-acquired MRSA expressing Panton-Valentine leukocidin (PVL). MIC90 values against Mycoplasma pneumoniae, Legionella pneumophila, and Chlamydia pneumoniae were 0.004, 1, and 4 µg/ml, respectively. TP-271 was efficacious in neutropenic and immunocompetent animal pneumonia models, generally showing, compared to the burden at the start of dosing, ~2 to 5 log10 CFU reductions against MRSA, S. pneumoniae, and H. influenzae infections when given intravenously (i.v.) and ~1 to 4 log10 CFU reductions when given orally (p.o.). TP-271 was potent against key community-acquired bacterial pneumonia (CABP) pathogens and was minimally affected, or unaffected, by tetracycline-specific resistance mechanisms and fluoroquinolone or macrolide drug resistance phenotypes. IMPORTANCE Rising resistance rates for macrolides, fluoroquinolones, and ß-lactams in the most common pathogens associated with community-acquired bacterial pneumonia (CABP) are of concern, especially for cases of moderate to severe infections in vulnerable populations such as the very young and the elderly. New antibiotics that are active against multidrug-resistant Streptococcus pneumoniae and Staphylococcus aureus are needed for use in the empirical treatment of the most severe forms of this disease. TP-271 is a promising new fluorocycline antibiotic demonstrating in vitro potency and nonclinical efficacy by intravenous and oral administration against the major pathogens associated with moderate to severe CABP.

What do we know about sulforaphane protection against photoaging?

Sulforaphane (SFN), a natural compound occurring in cruciferous vegetables, has been known for years as a chemopreventive agent against many types of cancer. Recently, it has been investigated as an antioxidant and anti-aging agent, and interesting conclusions have been made over the last decade. SFN demonstrated protective effects against ultraviolet (UV)-induced skin damage through several mechanisms of action, for example, decrease of reactive oxygen species production, inhibition of matrix metalloproteinase expression, and induction of phase 2 enzymes. SFN used as a protective agent against UV damage is a whole new matter, and it seems to be a very promising ingredient in upcoming anti-aging drugs and cosmetics.

Evaluation of Antiradical and Anti-Inflammatory Activities of Ethyl Acetate and Butanolic Subfractions of Agelanthus dodoneifolius (DC.) Polhill & Wiens (Loranthaceae) Using Equine Myeloperoxidase and Both PMA-Activated Neutrophils and HL-60 Cells.

The ethyl acetate and n-butanolic subfractions of Agelanthus dodoneifolius were investigated for their antioxidant and antimyeloperoxidase (MPO) activities. The reactive oxygen species (ROS) generation was assessed by lucigenin-enhanced chemiluminescence (CL) and dichlorofluorescein- (DCF-) induced fluorescence techniques from phorbol myristate acetate- (PMA-) stimulated equine neutrophils and human myeloid cell line HL-60, respectively. In parallel, the effects of the tested subfractions were evaluated on the total MPO release by stimulated neutrophils and on the specific MPO activity by means of immunological assays. The results showed the potent activity of the butanolic subfraction, at least in respect of the chemiluminescence test (IC50 = 0.3 ± 0.1 µg/mL) and the ELISA and SIEFED assays (IC50 = 2.8 ± 1.2 µg/mL and 1.3 ± 1.0 µg/mL), respectively. However, the ethyl acetate subfraction was found to be the most potent in the DCF assay as at the highest concentration, DCF fluorescence intensity decreases of about 50%. Moreover, we demonstrated that the ethyl acetate subfraction was rich in catechin (16.51%) while it was not easy to identify the main compounds in the butanolic subfraction using the UPLC-MS/MS technique. Nevertheless, taken together, our results provide evidence that Agelanthus dodoneifolius subfractions may represent potential sources of natural antioxidants and of antimyeloperoxidase compounds.

In vitro and intracellular activities of peptide deformylase inhibitor GSK1322322 against Legionella pneumophila isolates.

GSK1322322, a novel peptide deformylase inhibitor currently in development as an oral and intravenous agent for the treatment of hospitalized community-acquired bacterial pneumonia, showed poor in vitro activity against a panel of 50 Legionella pneumophila strains, with MICs ranging from 1 to 16 µg/ml and an MIC90 of 16 µg/ml, but very potent intracellular activity, with the minimum extracellular concentrations capable of inhibiting intracellular proliferation (MIECs) ranging from 0.12 to 2 µg/ml and 98% of the strains being inhibited by concentrations of ≤ 1 µg/ml.

Kilometer range filamentation.

We demonstrate for the first time the possibility to generate long plasma channels up to a distance of 1 km, using the terawatt femtosecond T&T laser facility. The plasma density was optimized by adjusting the chirp, the focusing and beam diameter. The interaction of filaments with transparent and opaque targets was studied.

Ophiobolin A, a sesterterpenoid fungal phytotoxin, displays higher in vitro growth-inhibitory effects in mammalian than in plant cells and displays in vivo antitumor activity.

Ophiobolin A, a sesterterpenoid produced by plant pathogenic fungi, was purified from the culture extract of Drechslera gigantea and tested for its growth-inhibitory activity in both plant and mammalian cells. Ophiobolin A induced cell death in Nicotiana tabacum L. cv. Bright Yellow 2 (TBY-2) cells at concentrations ≥10 µM, with the TBY-2 cells showing typical features of apoptosis-like cell death. At a concentration of 5 µM, ophiobolin A did not affect plant cell viability but prevented cell proliferation. When tested on eight cancer cell lines, concentrations <1 µM of ophiobolin A inhibited growth by 50% after 3 days of culture irrespective of their multidrug resistance (MDR) phenotypes and their resistance levels to pro-apoptotic stimuli. It is, thus, unlikely that ophiobolin A exerts these in vitro growth-inhibitory effects in cancer cells by activating pro-apoptotic processes. Highly proliferative human keratinocytes appeared more sensitive to the growth-inhibitory effects of ophiobolin A than slowly proliferating ones. Ophiobolin A also displayed significant antitumor activity at the level of mouse survival when assayed at 10 mg/kg in the B16F10 mouse melanoma model with lung pseudometastases. Ophiobolin A could, thus, represent a novel scaffold to combat cancer types that display various levels of resistance to pro-apoptotic stimuli and/or various MDR phenotypes.

Efficient spectral-step expansion of a filamenting laser pulse.

We report an efficient transfer of 800 nm energy into both the ultraviolet and the far infrared (IR) during the filamentation in air of an appropriately shaped laser pulse. The multiorder enhancement of the IR supercontinuum in the 3-5 µm atmospheric transmission windows was achieved thanks to spectral-step cascaded four-wave mixing occurring within the spectrum of the shaped femtosecond laser pulse. These results also point out the limit of the self-phase modulation model to explain the spectral broadening of a filamenting laser pulse.

Synthesis and plasma pharmacokinetics in CD-1 mice of a 18ß-glycyrrhetinic acid derivative displaying anti-cancer activity.

OBJECTIVES: The plasma pharmacokinetic profile in CD-1 mice of a novel 18ß-glycyrrhetinic acid (GA) derivative, which displays in vitro anti-cancer activity, was assessed. METHODS: This study involved an original one-step synthesis of N-(2-{3-[3,5-bis(trifluoromethyl)phenyl]ureido}ethyl)-glycyrrhetinamide, (2) a compound that displays marked anti-proteasome and anti-kinase activity. The bioselectivity profile of 2 on human normal NHDF fibroblasts vs human U373 glioblastoma cells was assessed. Maximal tolerated dose (MTD) profiling of 2 was carried out in CD1 mice, and its serum pharmacokinetics were profiled using an acute intravenous administration of 40 mg/kg body weight. KEY FINDINGS: Compound 2 displayed IC(50) in vitro growth inhibitory concentrations of 29 and 8 µm on NHDF fibroblasts and U373 glioblastoma cells, respectively, thus a bioselectivity index of ∼4. The intravenous pharmacokinetic parameters revealed that 2 was rapidly distributed (t(1/2dist) of ∼3 min) but slowly eliminated (t(1/2elim) = ∼77 min). CONCLUSIONS: This study describes an original and reliable nanoemulsion of a GA derivative with both anti-proteasome and anti-kinase properties and that should be further tested in vivo using various human xenograft or murine syngeneic tumour models with both single and chronic intravenous administration.

Measurement of the influence of flavonoids on DNA repair kinetics using the comet assay.

The complexity of DNA repair mechanisms infers that xenobiotics, derived from food and medicinal plants, may interfere in the process, activating or inhibiting repair. Different flavonoids were investigated, at the highest non-toxic concentration, for their capacity to modulate DNA repair 12, 24 and 48 h after a non-reactive oxygen species (ROS) treatment involving ethylmethanesulfonate (2mM; 2h). After 12h, DNA fragmentation is substantially increased by quercetin; this effect disappears at subsequent sampling times. At 24h, fragmentation is reduced in the presence of apigenin and slightly increased by sakuranetin. None of the flavonoids tested inhibited repair, which seems complete at 48 h. Ex vivo comet experiments were then performed to assess the excision capabilities of protein extracts obtained from flavonoid-treated cells. Quercetin increases non-specific endonuclease activity, apigenin and epicatechin increase the excision of damages and sakuranetin increases both non-specific and specific enzymatic activities. Combining direct repair and ex vivo experiments yields complementary data that may lead to characterizing mechanisms.

Laser guiding of Tesla coil high voltage discharges.

We have investigated the guiding and triggering of discharges from a Tesla coil type 280 kHz AC high voltage source using filaments created by a femtosecond Terawatt laser pulse. Without the laser the discharges were maximum 30 cm long. With the laser straight, guided discharges up to 110 cm length were detected. The discharge length was limited by the voltage amplitude of the Tesla coil.

Trivanillic polyphenols with anticancer cytostatic effects through the targeting of multiple kinases and intracellular Ca2+ release.

Cancer cells exhibit de-regulation of multiple cellular signalling pathways and treatments of various types of cancers with polyphenols are promising. We recently reported the synthesis of a series of 33 novel divanillic and trivanillic polyphenols that displayed anticancer activity, at least in vitro, through inhibiting various kinases. This study revealed that minor chemical modifications of a trivanillate scaffold could convert cytotoxic compounds into cytostatic ones. Compound 13c, a tri-chloro derivative of trivanillic ester, displayed marked inhibitory activities against FGF-, VEGF-, EGF- and Src-related kinases, all of which are implicated not only in angiogenesis but also in the biological aggressiveness of various cancer types. The pan-anti-kinase activity of 13c occurs at less than one-tenth of its mean IC(50) in vitro growth inhibitory concentrations towards a panel of 12 cancer cell lines. Of the 26 kinases for which 13c inhibited their activity by >75%, eight (Yes, Fyn, FGF-R1, EGFR, Btk, Mink, Ret and Itk) are implicated in control of the actin cytoskeleton organization to varying degrees. Compound 13c accordingly impaired the typical organization of the actin cytoskeleton in human U373 glioblastoma cells. The pan-anti-kinase activity and actin cytoskeleton organization impairment provoked by 13c concomitantly occurs with calcium homeostasis impairment but without provoking MDR phenotype activation. All of these anticancer properties enabled 13c to confer therapeutic benefits in vivo in a mouse melanoma pseudometastatic lung model. These data argue in favour of further chemically modifying trivanillates to produce novel and potent anticancer drugs.

A randomized controlled study to evaluate the depigmenting activity of L-ascorbic acid plus phytic acid-serum vs. placebo on solar lentigines.

BACKGROUND: Solar lentigines (SL) are benign signs of sun damage that many people find distressing. AIM: To assess the efficacy and safety of L-ascorbic acid 10% + phytic acid 2% for treating SL. PATIENTS/METHODS: A double-blind, vehicle-controlled trial in 30 healthy subjects with ≥2 SL. Subjects were randomly assigned to apply product to one side of the body and vehicle to the other twice daily for 3 months with follow-up of 2 months. RESULTS: The pigmentation index for product-treated SL was reduced (maximum reduction 1.3 at 3 months [M3]), while that for vehicle-treated lesions remained stable. These differences were statistically significant for M1-M4 (P ≤ 0.003). Dermoscopy detected significant intergroup differences in pigmentation at M5 (P=0.011). Colorimetry results indicated a statistically significant improvement in brightness (L*) between study drug and vehicle at M5. Fifteen subjects experienced 23 adverse events; six (mostly halo depigmentation) were judged possibly related to the study drug. There were six instances of mild-to-moderate intolerance in the study drug group and five in the vehicle-treated group. CONCLUSIONS: Study treatment was significantly more efficacious than vehicle in many respects and was well tolerated. Future, larger studies are needed to confirm these results and to compare the product with gold standard treatments.

N-(2-{3-[3,5-bis(trifluoromethyl)phenyl]ureido}ethyl)-glycyrrhetinamide (6b): a novel anticancer glycyrrhetinic acid derivative that targets the proteasome and displays anti-kinase activity.

18-ß-Glycyrrhetinic acid (GA; 1) and many of its derivatives are cytotoxic in cancer cells. The current study aims to characterize the anticancer effects of 17 novel 1 derivatives. On the basis of these studies, N-(2-{3-[3,5-bis(trifluoromethyl)phenyl]ureido}ethyl)-glycyrrhetinamide (6b) appeared to be the most potent compound, with IC(50)in vitro growth inhibitory concentrations in single-digit micromolarity in a panel of 8 cancer cell lines. Compound 6b is cytostatic and displays similar efficiency in apoptosis-sensitive versus apoptosis-resistant cancer cell lines through, at least partly, the inhibition of the activity of a cluster of a dozen kinases that are implicated in cancer cell proliferation and in the control of the actin cytoskeleton organization. Compound 6b also inhibits the activity of the 3 proteolytic units of the proteasome. Compound 6b thus represents an interesting hit from which future compounds could be derived to improve chemotherapeutic regimens that aim to combat cancers associated with poor prognoses.

Modulatory activities of Agelanthus dodoneifolius (Loranthaceae) extracts on stimulated equine neutrophils and myeloperoxidase activity.

Agelanthus dodoneifolius DC Danser (Loranthaceae) is used for the treatment of various diseases including asthma. The aqueous and hydroalcoholic extracts have been reported to have anti-inflammatory, spasmolytic and bronchorelaxant activities. The present study investigates the effects of the aqueous decoction and the diethyl ether, ethyl acetate and butanolic fractions of Agelanthus dodoneifolius DC Danser (Loranthaceae) on reactive oxygen species (ROS) production and myeloperoxidase (MPO) release by phorbol 12-myristate 13-acetate (PMA)-stimulated equine neutrophils and on purified equine MPO activity. ROS production and MPO release by the PMA-stimulated neutrophils were measured by the lucigenin-enhanced chemiluminescence and ELISA assays, respectively. Specific immunological extraction followed by enzymatic detection (SIEFED) was used to specifically measure the equine MPO activity. Identification and quantification of the individual and total phenolic and flavonoid compounds were performed using UPLC-MS/MS equipment and colorimetric methods involving Folin-Ciocalteu and AlCl3, respectively. All the tested extracts displayed dose-dependent inhibitory effects on the oxidant activities of neutrophils; a stronger effect was observed with the organic fractions than the aqueous decoction. These findings could be correlated with a high content of phenolic and flavonoid compounds. The results confirm the previously shown anti-inflammatory effect of Agelanthus dodoneifolius and its potential use for the treatment of neutrophil-dependent inflammatory diseases.

Quercetin inhibits a large panel of kinases implicated in cancer cell biology.

Flavonoids are polyphenolic secondary metabolites from plants that possess a common phenylbenzopyrone structure (C6-C3-C6). Depending upon variations in their heterocyclic C-ring, flavonoids are categorised into one of the following groups: flavones, flavonols, flavanones, flavanols, anthocyanidins, isoflavones or chalcones. Flavonols include, among others, the molecules quercetin, myricetin and kaempferol. The anticancer activity of flavonols was first attributed to their electron-donating ability, which comes from the presence of phenolic hydroxyl groups. However, an emerging view is that flavonoids, including quercetin, may also exert modulatory actions in cells by acting through the protein kinase and lipid kinase signalling pathways. Data from the current study showed that 2 µM quercetin, a low concentration that represents less than 10% of its IC50 growth-inhibitory concentration as calculated from the average of eight distinct cancer cell lines, decreased the activity of 16 kinases by more than 80%, including ABL1, Aurora-A, -B, -C, CLK1, FLT3, JAK3, MET, NEK4, NEK9, PAK3, PIM1, RET, FGF-R2, PDGF-Rα and -Rß. Many of these kinases are involved in the control of mitotic processes. Quantitative video microscopy analyses revealed that quercetin displayed strong anti-mitotic activity, leading to cell death. In conclusion, quercetin partly exerts its anticancer activity through the inhibition of the activity of a large set of kinases. Quercetin could be an interesting chemical scaffold from which to generate novel derivatives possessing various types of anti-kinase activities.

Evaluation of the anticancer activities of two fungal polycyclic ethanones, alternethanoxins A and B, and two of their derivatives.

Alternethanoxins A (1) and B (2) are fungal phytotoxins that are produced by Alternaria sonchi and have been recently characterized as new polycyclic ethanones. Triacetyl (3) and dimethyl (4) derivatives of compound 1 were evaluated together with alternethanoxins for their in vitro growth inhibitory activities in five human and one mouse cancer cell lines in comparison to the reference compound temozolomide (TMZ). Compounds 1-4 and TMZ displayed similar growth inhibitory activities, and these anticancer activities were equivalent in cancer cell lines that display certain levels of resistance to pro-apoptotic stimuli and those that are sensitive to pro-apoptotic stimuli. Of the six cancer cell lines under study, the human esophageal cancer cell line OE21 was the most sensitive to the four polycyclic ethanones. Computer-assisted phase-contrast microscopy (quantitative videomicroscopy) revealed that compounds 1, 2 and 4 displayed cytostatic rather than cytotoxic growth inhibitory effects, while compound 3 appeared to have cytotoxic effects. Thus, this study creates a stimulus for further structure-activity investigations with respect to the anticancer activities of compounds belonging to the alternethanoxin group. The observed toxicity does not seem to be affected by the stereochemistry of C-6 of the B ring, the presence of a hydroxy group at C-1 or the presence of a furan ring joining rings A and C in alternethanoxin B. The anticancer activity (cytostatic versus cytotoxic) of this type of compound could be affected by the chemical moieties present at the hydroxy groups at C-4 and C-6, as was observed for the cytostatic and cytotoxic activities of derivatives 4 and 3, respectively.

Novel lipophilic 7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid derivatives as potential antitumor agents: improved synthesis and in vitro evaluation.

A convenient route for the synthesis of some acyloxymethyl esters and carboxamides of levofloxacin (LV) with modulated lipophilicity is described. The synthesized compounds were evaluated in vitro for their growth inhibitory effect in five human cancer cell lines. The most efficient LV derivatives (ester 2e and amide 4d) displayed IC(50) values in the 0.2-2.2 µM range, while IC(50) values for parent LV ranged between 70 and 622 µM depending on the cell line. The esters displayed no in vivo toxicity up to 80 mg/kg when administered intraperitoneally. This study thus shows that LV analogs displayed antitumor efficacy, at least in vitro, a feature that appeared to be independent from the lipophilicity of the grafted substituent.

Amaryllidaceae alkaloids belonging to different structural subgroups display activity against apoptosis-resistant cancer cells.

Fifteen Amaryllidaceae alkaloids (1-15) were evaluated for their antiproliferative activities against six distinct cancer cell lines. Several of these natural products were found to have low micromolar antiproliferative potencies. The log P values of these compounds did not influence their observed activity. When active, the compounds displayed cytostatic, not cytotoxic activity, with the exception of pseudolycorine (3), which exhibited cytotoxic profiles. The active compounds showed similar efficacies toward cancer cells irrespective of whether the cell lines were responsive or resistant to proapoptotic stimuli. Altogether, the data from the present study revealed that lycorine (1), amarbellisine (6), haemanthamine (14), and haemanthidine (15) are potentially useful chemical scaffolds to generate further compounds to combat cancers associated with poor prognoses, especially those naturally resistant to apoptosis, such as glioblastoma, melanoma, non-small-cell lung, and metastatic cancers.