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1.
Planta ; 252(6): 100, 2020 Nov 10.
Article in English | MEDLINE | ID: mdl-33170407

ABSTRACT

MAIN CONCLUSION: The biochemical characterization of glycolate oxidase in Ricinus communis hints to different physiological functions of the enzyme depending on the organ in which it is active. Enzymatic activities of the photorespiratory pathway are not restricted to green tissues but are present also in heterotrophic organs. High glycolate oxidase (GOX) activity was detected in the endosperm of Ricinus communis. Phylogenetic analysis of the Ricinus L-2-hydroxy acid oxidase (Rc(L)-2-HAOX) family indicated that Rc(L)-2-HAOX1 to Rc(L)-2-HAOX3 cluster with the group containing streptophyte long-chain 2-hydroxy acid oxidases, whereas Rc(L)-2-HAOX4 clusters with the group containing streptophyte GOX. Rc(L)-2-HAOX4 is the closest relative to the photorespiratory GOX genes of Arabidopsis. We obtained Rc(L)-2-HAOX4 as a recombinant protein and analyze its kinetic properties in comparison to the Arabidopsis photorespiratory GOX. We also analyzed the expression of all Rc(L)-2-HAOXs and conducted metabolite profiling of different Ricinus organs. Phylogenetic analysis indicates that Rc(L)-2-HAOX4 is the only GOX encoded in the Ricinus genome (RcGOX). RcGOX has properties resembling those of the photorespiratory GOX of Arabidopsis. We found that glycolate, the substrate of GOX, is highly abundant in non-green tissues, such as roots, embryo of germinating seeds and dry seeds. We propose that RcGOX fulfills different physiological functions depending on the organ in which it is active. In autotrophic organs it oxidizes glycolate into glyoxylate as part of the photorespiratory pathway. In fast growing heterotrophic organs, it is most probably involved in the production of serine to feed the folate pathway for special demands of those tissues.


Subject(s)
Alcohol Oxidoreductases , Genome, Plant , Photosynthesis , Ricinus , Alcohol Oxidoreductases/genetics , Genome, Plant/genetics , Photosynthesis/genetics , Phylogeny , Ricinus/classification , Ricinus/enzymology , Ricinus/genetics
2.
Appl Microbiol Biotechnol ; 104(13): 5985-5998, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32418125

ABSTRACT

Due to a high unresponsiveness to chemotherapy, biofilm formation is an important medical problem that frequently occurs during infection with many bacterial pathogens. In this study, the marine sponge-derived natural compounds 4,6-dibromo-2-(2',4'-dibromophenoxy)phenol and 3,4,6-tribromo-2-(2',4'-dibromophenoxy)phenol were found to exhibit broad antibacterial activity against medically relevant gram-positive and gram-negative pathogens. The compounds were not only bactericidal against both replicating and stationary phase-persistent planktonic cells of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa; they also killed biofilm-incorporated cells of both species while not affecting biofilm structural integrity. Moreover, these compounds were active against carbapenemase-producing Enterobacter sp. This simultaneous activity of compounds against different growth forms of both gram-positive and gram-negative bacteria is rare. Genome sequencing of spontaneous resistant mutants and proteome analysis suggest that resistance is mediated by downregulation of the bacterial EIIBC phosphotransferase components scrA and mtlA in MRSA likely leading to a lower uptake of the molecules. Due to their only moderate cytotoxicity against human cell lines, phenoxyphenols provide an interesting new scaffold for development of antimicrobial agents with activity against planktonic cells, persisters and biofilm-incoporated cells of ESKAPE pathogens. KEY POINTS: • Brominated phenoxyphenols kill actively replicating and biofilm-incorporated bacteria. • Phosphotransferase systems mediate uptake of brominated phenoxyphenols. • Downregulation of phosphotransferase systems mediate resistance.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Biofilms/drug effects , Biological Products/pharmacology , Phenols/pharmacology , Animals , Anti-Bacterial Agents/chemistry , Biofilms/growth & development , Biological Products/chemistry , Cell Line , Drug Resistance, Bacterial/drug effects , Drug Resistance, Bacterial/genetics , Humans , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Microbial Viability/drug effects , Mutation , Phenols/chemistry , Phosphoenolpyruvate Sugar Phosphotransferase System/genetics , Porifera/chemistry
3.
Mar Drugs ; 18(2)2020 Feb 23.
Article in English | MEDLINE | ID: mdl-32102178

ABSTRACT

Chemical investigation of secondary metabolites from the endophytic fungus Pseudopestalotiopsis theae led to the isolation of eighteen new polyketide derivatives, pestalotheols I-Q (1-9) and cytosporins O-W (15-23), together with eight known analogs (10-14 and 24-26). The structures of the new compounds were elucidated by HRMS and 1D and 2D NMR data, as well as by comparison with literature data. Modified Mosher's method was applied to determine the absolute configuration of some compounds. Compound 23 showed significant cytotoxicity against the mouse lymphoma cell line L5178Y with an IC50 value of 3.0 µM. Furthermore, compounds 22 and 23 showed moderate antibacterial activity against drug-resistant Acinetobacter baumannii (ATCC BAA-1605) in combination with sublethal colistin concentrations.


Subject(s)
Fungi/metabolism , Polyketides/chemistry , Polyketides/metabolism , Rhizophoraceae/microbiology , Endophytes , Fermentation , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Structure
4.
Bioorg Med Chem ; 27(23): 115151, 2019 12 01.
Article in English | MEDLINE | ID: mdl-31648878

ABSTRACT

Xanthoangelol is a geranylated chalcone isolated from fruits of Amorpha fructicosa that exhibits antibacterial effects at low micromolar concentration against Gram-positive bacterial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecium and Enterococcus faecalis. We demonstrate that Xanthoangelol treatment of Gram-positive bacteria affects bacterial membrane integrity and leads to a leakage of intracellular metabolites. This correlates with a rapid collapse of the membrane potential and results in a fast and strong bactericidal effect. Proteomic profiling of Xanthoangelol-treated cells revealed signatures of cell wall and/or membrane damage and oxidative stress. Xanthoangelol specifically disturbs the membrane of Gram-positive bacteria potentially by forming pores resulting in cell lysis. In contrast, Xanthoangelol treatment of human cells showed only mildly hemolytic and cytotoxic effects at higher concentrations. Therefore, geranylated chalcones such as Xanthoangelol are promising lead structures for new antimicrobials against drug-resistant gram-positive pathogens.


Subject(s)
Anti-Bacterial Agents/pharmacology , Chalcone/analogs & derivatives , Gram-Positive Bacteria/drug effects , Gram-Positive Bacterial Infections/drug therapy , Anti-Bacterial Agents/chemistry , Cell Line , Chalcone/chemistry , Chalcone/pharmacology , Fabaceae/chemistry , Gram-Positive Bacteria/metabolism , Gram-Positive Bacterial Infections/microbiology , Humans , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/metabolism , Staphylococcal Infections/drug therapy , Staphylococcal Infections/metabolism
5.
Appl Microbiol Biotechnol ; 102(7): 2949-2963, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29455386

ABSTRACT

The rise of multidrug resistance in bacteria rendering pathogens unresponsive to many clinical drugs is widely acknowledged and considered a critical global healthcare issue. There is broad consensus that novel antibacterial chemotherapeutic options are extremely urgently needed. However, the development pipeline of new antibacterial drug lead structures is poorly filled and not commensurate with the scale of the problem since the pharmaceutical industry has shown reduced interest in antibiotic development in the past decades due to high economic risks and low profit expectations. Therefore, academic research institutions have a special responsibility in finding novel treatment options for the future. In this mini review, we want to provide a broad overview of the different approaches and concepts that are currently pursued in this research field.


Subject(s)
Academies and Institutes/trends , Anti-Bacterial Agents , Drug Discovery , Drug Industry/trends
6.
Brain ; 139(Pt 12): 3217-3236, 2016 12.
Article in English | MEDLINE | ID: mdl-27679481

ABSTRACT

Abnormal accumulation and propagation of the neuronal protein α-synuclein has been hypothesized to underlie the pathogenesis of Parkinson's disease, dementia with Lewy bodies and multiple system atrophy. Here we report a de novo-developed compound (NPT100-18A) that reduces α-synuclein toxicity through a novel mechanism that involves displacing α-synuclein from the membrane. This compound interacts with a domain in the C-terminus of α-synuclein. The E83R mutation reduces the compound interaction with the 80-90 amino acid region of α-synuclein and prevents the effects of NPT100-18A. In vitro studies showed that NPT100-18A reduced the formation of wild-type α-synuclein oligomers in membranes, reduced the neuronal accumulation of α-synuclein, and decreased markers of cell toxicity. In vivo studies were conducted in three different α-synuclein transgenic rodent models. Treatment with NPT100-18A ameliorated motor deficits in mThy1 wild-type α-synuclein transgenic mice in a dose-dependent manner at two independent institutions. Neuropathological examination showed that NPT100-18A decreased the accumulation of proteinase K-resistant α-synuclein aggregates in the CNS and was accompanied by the normalization of neuronal and inflammatory markers. These results were confirmed in a mutant line of α-synuclein transgenic mice that is prone to generate oligomers. In vivo imaging studies of α-synuclein-GFP transgenic mice using two-photon microscopy showed that NPT100-18A reduced the cortical synaptic accumulation of α-synuclein within 1 h post-administration. Taken together, these studies support the notion that altering the interaction of α-synuclein with the membrane might be a feasible therapeutic approach for developing new disease-modifying treatments of Parkinson's disease and other synucleinopathies.


Subject(s)
Antiparkinson Agents/pharmacology , Behavior, Animal/drug effects , Drug Discovery , Parkinson Disease/drug therapy , alpha-Synuclein/drug effects , Animals , Disease Models, Animal , Dose-Response Relationship, Drug , Humans , Mice , Mice, Transgenic
7.
Stroke ; 47(1): 151-9, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26564102

ABSTRACT

BACKGROUND AND PURPOSE: The aim of this trial was to investigate whether stroke patients who receive Cerebrolysin show improved motor function in the upper extremities at day 90 compared with patients who receive a placebo. METHODS: This study was a prospective, randomized, double-blind, placebo-controlled, multicenter, parallel-group study. Patients were treated with Cerebrolysin (30 mL/d) or a placebo (saline) once daily for 21 days, beginning at 24 to 72 hours after stroke onset. The patients also participated in a standardized rehabilitation program for 21 days that was initiated within 72 hours after stroke onset. The primary end point was the Action Research Arm Test score on day 90. RESULTS: The nonparametric effect size on the Action Research Arm Test score on day 90 indicated a large superiority of Cerebrolysin compared with the placebo (Mann-Whitney estimator, 0.71; 95% confidence interval, 0.63-0.79; P<0.0001). The multivariate effect size on global status, as assessed using 12 different outcome scales, indicated a small-to-medium superiority of Cerebrolysin (Mann-Whitney estimator, 0.62; 95% confidence interval, 0.58-0.65; P<0.0001). The rate of premature discontinuation was <5% (3.8%). Cerebrolysin was safe and well tolerated. CONCLUSIONS: Cerebrolysin had a beneficial effect on function and global outcome in early rehabilitation patients after stroke. Its safety was comparable with that of the placebo, suggesting a favorable benefit/risk ratio. Because this study was exploratory and had a relatively small sample size, the results should be confirmed in a large-scale, randomized clinical trial. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrialsregister.eu. Unique identifier: 2007-000870-21.


Subject(s)
Amino Acids/therapeutic use , Neuroprotective Agents/therapeutic use , Recovery of Function , Stroke/diagnosis , Stroke/drug therapy , Aged , Amino Acids/pharmacology , Double-Blind Method , Female , Humans , Male , Middle Aged , Neuroprotective Agents/pharmacology , Prospective Studies , Recovery of Function/drug effects , Treatment Outcome
9.
BMC Neurosci ; 16: 85, 2015 Nov 26.
Article in English | MEDLINE | ID: mdl-26611895

ABSTRACT

BACKGROUND: Tauopathies are a group of neurodegenerative disorders with accumulation of three-repeat (3R) or four-repeat (4R) Tau. While 3R tau is found in Pick's disease and Alzheimer's disease (AD), 4R tau is more abundant in corticobasal degeneration, progressive supranuclear palsy, and AD. We have previously shown that Cerebrolysin™ (CBL), a neuropeptide mixture with neurotrophic effects, ameliorates the pathology in amyloid precursor protein transgenic (tg) mouse model of AD and 4R tau, however it is unclear if CBL ameliorates the deficits and neuropathology in the mouse model of Pick's disease over expressing 3R tau. RESULTS: Mice expressing 3R tau (L266V and G272V mutations) under the mThy-1 promoter were treated with CBL in two separate groups, the first was 3 months old (treated for 3 months, IP) and the second was 6 months old (treated for 3 months, IP) at the start of the treatment. We found that although the levels of total 3R tau were unchanged, CBL reduced the levels of hyper-phosphorylated tau in both groups of mice. This was accompanied by reduced neurodegenerative pathology in the neocortex and hippocampus in both groups and by improvements in the behavioral deficits in the nest-building test and water maze in the 3-6 month group. CONCLUSION: Taken together these results support the notion that CBL may be beneficial in other taupathy models by reducing the levels of aberrantly phosphorylated tau.


Subject(s)
Amino Acids/pharmacology , Neuroprotective Agents/pharmacology , Pick Disease of the Brain/drug therapy , Tauopathies/drug therapy , Aging/drug effects , Aging/metabolism , Aging/pathology , Animals , Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Disease Models, Animal , Glycogen Synthase Kinase 3/metabolism , Glycogen Synthase Kinase 3 beta , Hippocampus/drug effects , Hippocampus/metabolism , Hippocampus/pathology , Humans , Mice, Inbred C57BL , Mice, Transgenic , Mutation , Phosphorylation/drug effects , Pick Disease of the Brain/metabolism , Pick Disease of the Brain/pathology , Proto-Oncogene Proteins c-akt/metabolism , Tauopathies/metabolism , Tauopathies/pathology , tau Proteins/genetics , tau Proteins/metabolism
10.
Stroke ; 44(7): 1965-72, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23696546

ABSTRACT

BACKGROUND AND PURPOSE: Cerebrolysin, a mixture of neurotrophic peptides, enhances neurogenesis and improves neurological outcome in experimental neurodegenerative diseases and stroke. The Sonic hedgehog (Shh) signaling pathway stimulates neurogenesis after stroke. The present study tests whether the Shh pathway mediates cerebrolysin-induced neurogenesis and improves neurological outcome after stroke. METHODS: Rats subjected to embolic stroke were treated with cerebrolysin with or without cyclopamine. RESULTS: Using neural progenitor cells derived from the subventricular zone of the lateral ventricle of adult rats, we found that cerebrolysin significantly increased neural progenitor cells proliferation and their differentiation into neurons and myelinating oligodendrocytes, which were associated with upregulation of Shh and its receptors patched and smoothened. Blockage of the Shh signaling pathway with a pharmacological smoothened inhibitor, cyclopamine, abolished cerebrolysin-induced in vitro neurogenesis and oligodendrogenesis. In the ischemic rats, treatment with cerebrolysin starting 24 hours after stroke significantly increased neural progenitor cell proliferation in the subventricular zone and enhanced neurogenesis, oligodendrogenesis, and axonal remodeling in the peri-infarct area. Moreover, profound neurological function improvements were observed in rats treated with cerebrolysin from week 3 to week 5 after stroke onset compared with vehicle-treated rats. However, in vivo inhibition of the Shh pathway with cyclopamine completely reversed the effects of cerebrolysin on neurorestoration and functional recovery. CONCLUSIONS: These results demonstrate that the Shh pathway mediates cerebrolysin-enhanced neurogenesis and white matter remodeling and improves functional recovery in rats after stroke.


Subject(s)
Amino Acids/pharmacology , Antihypertensive Agents/pharmacology , Cell Proliferation/drug effects , Hedgehog Proteins/physiology , Infarction, Middle Cerebral Artery/drug therapy , Neuroprotective Agents/pharmacology , Receptors, Cell Surface/physiology , Signal Transduction/physiology , Amino Acids/administration & dosage , Animals , Antihypertensive Agents/administration & dosage , Cell Differentiation/drug effects , Disease Models, Animal , Infarction, Middle Cerebral Artery/physiopathology , Male , Neurogenesis/drug effects , Neurogenesis/physiology , Neuroprotective Agents/administration & dosage , Patched Receptors , Random Allocation , Rats , Rats, Wistar , Recovery of Function/physiology , Signal Transduction/drug effects
11.
Eur Radiol ; 23(2): 450-60, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22968781

ABSTRACT

OBJECTIVES: The insular cortex has an important role within the cerebral pain circuitry. The aim of this study was to measure metabolic alterations by MR spectroscopy due to experimentally induced trigeminal pain in the anterior/posterior and right/left insular subdivisions. METHODS: Sixteen male volunteers were investigated using magnetic resonance (MR) spectroscopy before, during and after experimentally induced dental pain. Biphasic bipolar electric current pulses of 1 ms duration were administered based on the subjectively determined pain threshold. Volunteers were instructed to rate every stimulus using a MR compatible rating scale. RESULTS: Due to the pain stimulation a significant absolute increase in glutamate (Glu, F = 6.1; P = 0.001), glutamine (Gln, F = 11.2; P = 0.001) as well as glutamate/glutamine (Glx, F = 17.7; P = 0.001) were observed, whereas myo-inositol (mI, F = 9.5;P = 0.001) showed a significant drop. Additionally, these metabolites showed a significant effect towards lateralisation, meaning that metabolic concentration differed either in left or right insular subdivision. Creatine demonstrated also an absolute significant decrease during stimulation (F = 2.8; P = 0.022) with a significant anterior-posterior difference (F = 40.7; P = 0.001). CONCLUSIONS: Results confirm that the insular cortex is a metabolically high active region in pain processing within the brain. Quantitative metabolic changes show that there is a distinct but locally diverse neurometabolic activity under acute pain. The known cytoarchitectonic subdivisions show different metabolic reactions and give new insights into pain-processing physiology.


Subject(s)
Cerebral Cortex/metabolism , Glutamic Acid/metabolism , Glutamine/metabolism , Magnetic Resonance Spectroscopy/methods , Toothache/metabolism , Acute Pain/diagnosis , Acute Pain/metabolism , Adult , Aspartic Acid/metabolism , Brain Chemistry/physiology , Humans , Inositol/metabolism , Male , Middle Aged , Pain Threshold , Prospective Studies , Sampling Studies , Sensitivity and Specificity , Toothache/diagnosis , Young Adult
12.
Eur Addict Res ; 19(4): 184-93, 2013.
Article in English | MEDLINE | ID: mdl-23257512

ABSTRACT

The aim of this study was to clarify whether addiction-specific neurometabolic reaction patterns occur in the insular cortex during acute nicotine withdrawal in tobacco smokers in comparison to nonsmokers. Fourteen male smokers and 10 male nonsmokers were included. Neurometabolites of the right and the left insular cortices were quantified by magnetic resonance spectroscopy (MRS) on a 3-Tesla scanner. Three separate MRS measurements were performed in each subject: among the smokers, the first measurement was done during normal smoking behavior, the second measurement during acute withdrawal (after 24 h of smoking abstinence), and the third shortly after administration of an oral nicotine substitute. Simultaneously, craving, withdrawal symptoms, and CO levels in exhaled air were determined during the three phases. The participants in the control group underwent the same MR protocol. In the smokers, during withdrawal, the insular cortex showed a significant increase in glutamine (Gln; p = 0.023) as well as a slight increase not reaching significance for glutamine/glutamate (Glx; p = 0.085) and a nonsignificant drop in myoinositol (mI; p = 0.381). These values tended to normalize after oral nicotine substitution treatment, even though differences were not significant: Gln (p = 0.225), Glx (p = 0.107) and mI (p = 0.810). Overall, the nonsmokers (control group) did not show any metabolic changes over all three phases (p > 0.05). In smokers, acute nicotine withdrawal produces a neurometabolic reaction pattern that is partly reversed by the administration of an oral nicotine substitute. The results are consistent with the expression of an addiction-specific neurometabolic shift in the brain and confirm the fact that the insular cortex seems to play a possible role in nicotine dependence.


Subject(s)
Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Functional Neuroimaging , Nicotine/administration & dosage , Smoking/metabolism , Substance Withdrawal Syndrome/metabolism , Tobacco Use Cessation Devices , Administration, Oral , Adult , Behavior, Addictive/metabolism , Carbon Monoxide/metabolism , Case-Control Studies , Glutamic Acid/metabolism , Glutamine/metabolism , Humans , Inositol/metabolism , Male , Middle Aged , Nicotine/adverse effects , Nicotine/pharmacology
13.
Lancet ; 375(9727): 1695-703, 2010 May 15.
Article in English | MEDLINE | ID: mdl-20472172

ABSTRACT

BACKGROUND: Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to treatment with intravenous rt-PA (alteplase) on therapeutic benefit and clinical risk by adding recent trial data to the analysis. METHODS: We added data from ECASS III (821 patients) and EPITHET (100 patients) to a pool of common data elements from six other trials of alteplase for acute stroke (2775 patients). We used multivariate logistic regression to assess the relation of stroke onset to start of treatment (OTT) with treatment on favourable 3-month outcome (defined as modified Rankin score 0-1), mortality, and occurrence and outcome of clinically relevant parenchymal haemorrhage. The presence of an arterial occlusion was inferred from the patient's symptoms and absence of haemorrhage or other causes of ischaemic stroke. Vascular imaging was not a requirement in the trials. All patients with confirmed OTT within 360 min were included in the analysis. FINDINGS: Treatment was started within 360 min of stroke onset in 3670 patients randomly allocated to alteplase (n=1850) or to placebo (n=1820). Odds of a favourable 3-month outcome increased as OTT decreased (p=0.0269) and no benefit of alteplase treatment was seen after around 270 min. Adjusted odds of a favourable 3-month outcome were 2.55 (95% CI 1.44-4.52) for 0-90 min, 1.64 (1.12-2.40) for 91-180 min, 1.34 (1.06-1.68) for 181-270 min, and 1.22 (0.92-1.61) for 271-360 min in favour of the alteplase group. Large parenchymal haemorrhage was seen in 96 (5.2%) of 1850 patients assigned to alteplase and 18 (1.0%) of 1820 controls, with no clear relation to OTT (p=0.4140). Adjusted odds of mortality increased with OTT (p=0.0444) and were 0.78 (0.41-1.48) for 0-90 min, 1.13 (0.70-1.82) for 91-180 min, 1.22 (0.87-1.71) for 181-270 min, and 1.49 (1.00-2.21) for 271-360 min. INTERPRETATION: Patients with ischaemic stroke selected by clinical symptoms and CT benefit from intravenous alteplase when treated up to 4.5 h. To increase benefit to a maximum, every effort should be taken to shorten delay in initiation of treatment. Beyond 4.5 h, risk might outweigh benefit. FUNDING: None.


Subject(s)
Fibrinolytic Agents/administration & dosage , Stroke/drug therapy , Tissue Plasminogen Activator/administration & dosage , Fibrinolytic Agents/adverse effects , Humans , Infusions, Intravenous , Injections, Intravenous , Intracranial Hemorrhages/chemically induced , Randomized Controlled Trials as Topic , Recombinant Proteins/administration & dosage , Time Factors , Tissue Plasminogen Activator/adverse effects , Treatment Outcome
14.
RSC Adv ; 10(12): 7232-7240, 2020 Feb 13.
Article in English | MEDLINE | ID: mdl-35493894

ABSTRACT

Didymellanosine (1), the first analogue of the decahydrofluorene-class of natural products bearing a 13-membered macrocyclic alkaloid conjugated with adenosine, and a new benzolactone derivative, ascolactone C (4) along with eight known compounds (2, 3, 5-10), were isolated from a solid rice fermentation of the endophytic fungus Didymella sp. IEA-3B.1 derived from the host plant Terminalia catappa. In addition, ascochitamine (11) was obtained when (NH4)2SO4 was added to rice medium and is reported here for the first time as a natural product. Didymellanosine (1) displayed strong activity against the murine lymphoma cell line L5178Y, Burkitt's lymphoma B cells (Ramos) and adult lymphoblastic leukemia T cells (Jurkat J16), with IC50 values of 2.0, 3.3 and 4.4 µM, respectively. When subjected to a NFκB inhibition assay, didymellanosine (1) moderately blocked NFκB activation in the triple-negative breast cancer cell line MDA-MB 231. In an antimicrobial assay, ascomylactam C (3) was the most active compound when tested against a panel of Gram-positive bacteria including drug-resistant strains with MICs of 3.1-6.3 µM, while 1 revealed weaker activity. Interestingly, both compounds were also found active against Gram-negative Acinetobacter baumannii with MICs of 3.1 µM, in the presence of a sublethal concentration (0.1 µM) of colistin.

15.
Sleep ; 32(5): 607-13, 2009 May.
Article in English | MEDLINE | ID: mdl-19480227

ABSTRACT

STUDY OBJECTIVES: Proton resonance spectroscopy (1H-MRS) allows noninvasive chemical tissue analysis in the living brain. As neuronal loss and gliosis have been described in narcolepsy, metabolites of primary interest are N-acetylaspartate (NAA), a marker of neuronal integrity and myo-Inositol (ml), a glial marker and second messenger involved in the regulation of intracellular calcium. One 1H-MRS study in narcolepsy found no metabolic changes in the pontomedullary junction. Another study showed a reduction in NAA/creatine-phosphocreatine (Cr) in the hypothalamus of narcolepsy patients with cataplexy. We aimed to test for metabolic changes in specific brain areas, "regions of interest," thought to be involved in emotional processing, sleep regulation and pathophysiology of narcolepsy: hypothalamus, pontomesencephalic junction and both amygdalae. DESIGN: We performed 1H-MRS using a 3T Philips Achieva whole body MR scanner. Single-voxel proton MR spectra were acquired and quantified with LCModel to determine metabolite concentration ratios. SETTING: The participants in the study were recruited at the outpatient clinic for sleep medicine, Department of Neurology and magnetic resonance spectroscopy was performed at the MRI facility, University Hospital Zurich. PARTICIPANTS: 1H-MRS was performed in fourteen narcolepsy patients with cataplexy, CSF hypocretin deficiency (10/10) and HLA-DQB1*0602 positivity (14/14) and 14 age, gender and body mass index matched controls. Patients were treatment naïve or off therapy for at least 14 days before scanning. MEASUREMENTS AND RESULTS: No differences were observed in the regions of interest for (total NAA)/Cr ratios. Myo-Inositol (ml)/Cr was significantly lower in the right amygdala of the patients, compared to controls (P < 0.042). Significant negative correlations only in the patients group were found between (total NAA)/Cr in hypothalamus and ml/Cr in the right amygdala (r = -0.89, P < 0.001), between ml/Cr in hypothalamus and (total NAA)/Cr in the right amygdala (r = -63, P < 0.05) and between ml/Cr in the left amygdala and total NAA)/Cr in the pontomesencephalic junction (r = -0.69, P < 0.05). CONCLUSION: Our findings suggest amygdala involvement and possible hypothalamo-amygdala dysfunction in narcolepsy.


Subject(s)
Amygdala/physiopathology , Cataplexy/physiopathology , Energy Metabolism/physiology , Hypothalamus/physiopathology , Magnetic Resonance Spectroscopy , Narcolepsy/physiopathology , Adult , Aspartic Acid/analogs & derivatives , Aspartic Acid/metabolism , Cataplexy/diagnosis , Creatine/metabolism , Dominance, Cerebral/physiology , Female , Humans , Inositol/metabolism , Male , Mesencephalon/physiopathology , Narcolepsy/diagnosis , Pons/physiopathology , Reference Values
16.
Eur J Med Chem ; 181: 111555, 2019 Nov 01.
Article in English | MEDLINE | ID: mdl-31382119

ABSTRACT

Thia analogs of fosmidomycin are potent inhibitors of the non-mevalonate isoprenoid biosynthesis enzyme 1-deoxy-d-xylulose 5-phosphate reductoisomerase (IspC, Dxr) of Plasmodium falciparum. Several new thioethers displayed antiplasmodial in vitro activity in the low nanomolar range, without apparent cytotoxic effects in HeLa cells. The (S)-(+)-enantiomer of a typical representative selectively inhibited IspC and the growth of P. falciparum in continuous culture. The inhibitor was stable at pH 7.6 and room temperature, and no racemization was observed under these conditions during a period of up to two days. Oxidation of selected thioethers to sulfones reduced antiplasmodial activity and the inhibitory activity against Escherichia coli, Mycobacterium tuberculosis and P. falciparum IspC orthologs.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antiprotozoal Agents/pharmacology , Escherichia coli/drug effects , Fosfomycin/analogs & derivatives , Mycobacterium tuberculosis/drug effects , Plasmodium falciparum/drug effects , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Antiprotozoal Agents/chemical synthesis , Antiprotozoal Agents/chemistry , Caco-2 Cells , Dose-Response Relationship, Drug , Escherichia coli/growth & development , Fosfomycin/chemical synthesis , Fosfomycin/chemistry , Fosfomycin/pharmacology , HeLa Cells , Humans , Microbial Sensitivity Tests , Molecular Structure , Mycobacterium tuberculosis/growth & development , Parasitic Sensitivity Tests , Plasmodium falciparum/growth & development , Structure-Activity Relationship
17.
J Vet Sci ; 19(4): 570-576, 2018 Jul 31.
Article in English | MEDLINE | ID: mdl-29486536

ABSTRACT

The objective of the present study was to describe two non-invasive methods for fat quantification in normal canine liver by using magnetic resonance imaging (MRI) and spectroscopy. Eleven adult beagle dogs were anesthetized and underwent magnetic resonance examination of the cranial abdomen by performing morphologic, modified Dixon (mDixon) dual gradient echo sequence, and proton magnetic resonance spectroscopy (1H MRS) imaging. In addition, ultrasonographic liver examination was performed, fine-needle liver aspirates and liver biopsies were obtained, and hepatic triglyceride content was assayed. Ultrasonographic, cytologic, and histologic examination results were unremarkable in all cases. The median hepatic fat fraction calculated was 2.1% (range, 1.3%-5.5%) using mDixon, 0.3% (range, 0.1%-1.0%) using 1H MRS, and 1.6% (range 1.0%-2.5%) based on triglyceride content. The hepatic fat fractions calculated using mDixon and 1H MRS imaging were highly correlated to that based on triglyceride content. A weak correlation between mDixon and 1H MRS imaging was detected. The results show that hepatic fat content can be estimated using non-invasive techniques (mDixon or 1H MRS) in healthy dogs. Further studies are warranted to evaluate the use of these techniques in dogs with varying hepatic fat content and different hepatic disorders.


Subject(s)
Adiposity , Animal Husbandry/methods , Liver/physiology , Magnetic Resonance Imaging/veterinary , Proton Magnetic Resonance Spectroscopy , Animals , Biopsy/veterinary , Dogs , Female , Male , Reference Values , Ultrasonography/veterinary
18.
Int J Stroke ; 12(6): 628-635, 2017 08.
Article in English | MEDLINE | ID: mdl-28382851

ABSTRACT

Background and aims In an effort to characterize the effects of Cerebrolysin for treatment of stroke that are essential for successful clinical translation, we have demonstrated that Cerebrolysin dose dependently enhanced neurological functional recovery in experimental stroke. Here, we conduct a prospective, randomized, placebo-controlled, blinded study to examine the therapeutic window of Cerebrolysin treatment of rats subjected to embolic stroke. Methods Male Wistar rats age 3-4 months (n = 100) were subjected to embolic middle cerebral artery occlusion. Animals were randomized to receive saline or Cerebrolysin daily for 10 consecutive days starting 4, 24, 48, and 72 h after middle cerebral artery occlusion. Neurological outcome was measured weekly with a battery of behavioral tests (adhesive removal test, modified neurological severity score (mNSS), and foot-fault test). Global test was employed to assess Cerebrolysin effect on neurological recovery with estimation of mean difference between Cerebrolysin and control-treated groups and its 95% confidence interval in the intent-to-treat population, where a negative value of the mean difference and 95% confidence interval < 0 indicated a significant treatment effect. All rats were sacrificed 28 days after middle cerebral artery occlusion and infarct volume was measured. Results Cerebrolysin treatment initiated within 48 h after middle cerebral artery occlusion onset significantly improved functional outcome; mean differences and 95% confidence interval were -11.6 (-17.7, -5.4) at 4 h, -7.1 (-13.5, -0.8) at 24 h, -8.4 (-14.2, -8.6) at 48 h, and -4.9 (-11.4, 1.5) at 72 h. There were no differences on infarct volume and mortality rate among groups. Conclusions With a clinically relevant rigorous experimental design, our data demonstrate that Cerebrolysin treatment effectively improves stroke recovery when administered up to 48 h after middle cerebral artery occlusion.


Subject(s)
Brain Ischemia/drug therapy , Infarction, Middle Cerebral Artery/drug therapy , Intracranial Thrombosis/complications , Neuroprotective Agents/therapeutic use , Stroke/drug therapy , Animals , Disease Models, Animal , Double-Blind Method , Infarction, Middle Cerebral Artery/etiology , Male , Rats, Wistar , Recovery of Function/drug effects , Stroke/etiology , Time Factors
19.
FEMS Microbiol Rev ; 4(3): 195-222, 1988 Sep.
Article in English | MEDLINE | ID: mdl-3078744

ABSTRACT

Enterobacterial common antigen (ECA) is a family-specific surface antigen shared by all members of the Enterobacteriaceae and is restricted to this family. It is found in freshly isolated wild-type strains as well as in laboratory strains like Escherichia coli K-12. The family specificity of ECA can be used for taxonomic and diagnostic purposes. ECA is located in the outer leaflet of the outer membrane. It is a glycophospholipid built up by an aminosugar heteropolymer linked to an L-glycerophosphatidyl residue. In a few rough mutants, in addition, the sugar chain can be bound to the complete lipopolysaccharide (LPS) core. Recently, for Shigella sonnei a lipid-free cyclic form of ECA was reported. The genetical determination of ECA is closely related to that of lipopolysaccharide. For biosynthesis of ECA and LPS partly the same sugar precursors and the same carrier lipid is used.


Subject(s)
Antigens, Bacterial/analysis , Enterobacteriaceae/immunology , Animals , Enterobacteriaceae/classification , Enterobacteriaceae/genetics , Enterobacteriaceae Infections/diagnosis , Genes, Bacterial , Humans
20.
Am J Vet Res ; 77(5): 452-62, 2016 May.
Article in English | MEDLINE | ID: mdl-27111012

ABSTRACT

OBJECTIVE To investigate metabolite concentrations of the brains of dogs with intracranial neoplasia or noninfectious meningoencephalitis by use of short echo time, single voxel proton magnetic resonance spectroscopy ((1)H MRS) at 3.0 T. ANIMALS 29 dogs with intracranial lesions (14 with neoplasia [3 oligodendromas, 3 glioblastomas multiformes, 3 astrocytomas, 2 lymphomas, and 3 meningiomas] and 15 is with noninfectious meningoencephalitis) and 10 healthy control dogs. PROCEDURES Short echo time, single voxel (1)H-MRS at 3.0 T was performed on neoplastic and noninfectious inflammatory intracranial lesions identified with conventional MRI. Metabolites of interest included N-acetyl aspartate (NAA), total choline, creatine, myoinositol, the glutamine-glutamate complex (Glx), glutathione, taurine, lactate, and lipids. Data were analyzed with postprocessing fitting algorithm software. Metabolite concentrations relative to brain water content were calculated and compared with results for the healthy control dogs, which had been previously evaluated with the same (1)H MRS technique. RESULTS NAA, creatine, and Glx concentrations were reduced in the brains of dogs with neoplasia and noninfectious meningoencephalitis, whereas choline concentration was increased. Concentrations of these metabolites differed significantly between dogs with neoplasia and dogs with noninfectious meningoencephalitis. Concentrations of NAA, creatine, and Glx were significantly lower in dogs with neoplasia, whereas the concentration of choline was significantly higher in dogs with neoplasia. Lipids were predominantly found in dogs with high-grade intra-axial neoplasia, meningioma, and necrotizing meningoencephalitis. A high concentration of taurine was found in 10 of 15 dogs with noninfectious meningoencephalitis. CONCLUSIONS AND CLINICAL RELEVANCE (1)H MRS provided additional metabolic information about intracranial neoplasia and noninfectious meningoencephalitis in dogs.


Subject(s)
Brain Neoplasms/veterinary , Dog Diseases/diagnostic imaging , Glioma/veterinary , Meningoencephalitis/veterinary , Animals , Aspartic Acid/analogs & derivatives , Aspartic Acid/metabolism , Brain Neoplasms/diagnostic imaging , Case-Control Studies , Creatine/metabolism , Dogs , Female , Glioma/diagnostic imaging , Glutamine/metabolism , Male , Meningoencephalitis/diagnostic imaging , Proton Magnetic Resonance Spectroscopy
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