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1.
Sci Rep ; 14(1): 8237, 2024 04 08.
Article in English | MEDLINE | ID: mdl-38589450

ABSTRACT

Coffee professionals have long known that the "roast profile," i.e., the temperature versus time inside the roaster, strongly affects the flavor and quality of the coffee. A particularly important attribute of brewed coffee is the perceived sourness, which is known to be strongly correlated to the total titratable acidity (TA). Most prior work has focused on laboratory-scale roasters with little control over the roast profile, so the relationship between roast profile in a commercial-scale roaster and the corresponding development of TA to date remains unclear. Here we investigate roast profiles of the same total duration but very different dynamics inside a 5-kg commercial drum roaster, and we show that the TA invariably peaks during first crack and then decays to its original value by second crack. Although the dynamics of the TA development varied with roast profile, the peak TA surprisingly exhibited almost no statistically significant differences among roast profiles. Our results provide insight on how to manipulate and achieve desired sourness during roasting.


Subject(s)
Coffea , Hot Temperature , Temperature , Time
2.
Br J Biomed Sci ; 81: 12148, 2024.
Article in English | MEDLINE | ID: mdl-38501148

ABSTRACT

Introduction: Active learning is a useful tool to enhance student engagement and support learning in diverse educational situations. We aimed to assess the efficacy of an active learning approach within a large interprofessional first year Medical Cell Biology module taken by six healthcare programmes across the School of Biomedical Sciences at Ulster University, United Kingdom. Materials and methods: An active learning approach was developed for weekly formative assessment using Smartwork to design a weekly interactive multiple-choice quiz to reinforce key concepts specifically for each lecture. We tracked and assessed student performance in the module overall and in each element of course work and exam for 2 years prior to and following the introduction of an active learning strategy to engage and support learning for students from all academic backgrounds and abilities. Results: Full engagement with active learning was significantly associated with an increased overall module performance as well as a significantly increased performance in each element of class test (No engagement vs. Full engagement, p < 0.001), exam (No Engagement vs. Full engagement, p < 0.05) and coursework (No engagement vs. Full engagement, p < 0.001) within this overall total (No Engagement vs. Full engagement, p < 0.01). Partial engagement with active learning was associated significantly improved class test (No engagement vs. partially engaged, p < 0.001) and coursework (No engagement vs. partially engaged, p < 0.05) performance. While a trend toward increased performance in exam and overall module mark was observed, these were not significant. Discussion: Active learning is a useful tool to support student learning across a range of healthcare programmes taken by students with differing backgrounds and academic abilities in an interprofessional and widening participation setting. Student engagement in active learning was highlighted as a key contributory factor to enhanced student performance in all aspects of assessment.


Subject(s)
Problem-Based Learning , Students , Humans , United Kingdom
3.
Int J Biol Macromol ; 264(Pt 1): 130500, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38428770

ABSTRACT

BACKGROUND: Endotoxemia is a severe and dangerous clinical syndrome that results in elevated morbidity, especially in intensive care units. Neonates are particularly susceptible to endotoxemia due to their immature immune systems. There are few effective treatments for neonatal endotoxemia. One group of compounds with potential in the treatment of neonatal inflammatory diseases such as endotoxemia is the flavonoids, mainly due to their antioxidant and anti-inflammatory properties. Among these, naringenin (NGN) is a citrus flavonoid which has already been reported to have anti-inflammatory, antioxidant, anti-nociceptive and anti-cancer effects. Unfortunately, its clinical application is limited by its low solubility and bioavailability. However, cyclodextrins (CDs) have been widely used to improve the solubility of nonpolar drugs and enhance the bioavailability of these natural products. OBJECTIVE: We, therefore, aimed to investigate the effects of NGN non-complexed and complexed with hydroxypropyl-ß-cyclodextrin (HPßCD) on neonatal endotoxemia injuries in a rodent model and describe the probable molecular mechanisms involved in NGN activities. METHOD: We used exposure to a bacterial lipopolysaccharide (LPS) to induce neonatal endotoxemia in the mice. RESULTS: It was found that NGN (100 mg/kg i.p.) exposure during the neonatal period reduced leukocyte migration and decreased pro-inflammatory cytokine (TNF-α, IL-1ß and IL-6) levels in the lungs, heart, kidneys or cerebral cortex. In addition, NGN upregulated IL-10 production in the lungs and kidneys of neonate mice. The administration of NGN also enhanced antioxidant enzyme catalase and SOD activity, reduced lipid peroxidation and protein carbonylation and increased the reduced sulfhydryl groups in an organ-dependent manner, attenuating the oxidative damage caused by LPS exposure. NGN decreased ERK1/2, p38MAPK and COX-2 activation in the lungs of neonate mice. Moreover, NGN complexed with HPßCD was able to increase the animal survival rate. CONCLUSION: NGN attenuated inflammatory and oxidative damage in the lungs, heart and kidneys caused by neonatal endotoxemia through the MAPK signaling pathways regulation. Our results show that NGN has beneficial effects against neonatal endotoxemia and could be useful in the treatment of neonatal inflammatory injuries.


Subject(s)
Citrus , Endotoxemia , Flavanones , Mice , Animals , Flavonoids/therapeutic use , 2-Hydroxypropyl-beta-cyclodextrin/pharmacology , Antioxidants/pharmacology , Antioxidants/therapeutic use , Endotoxemia/chemically induced , Endotoxemia/drug therapy , Lipopolysaccharides/therapeutic use , Anti-Inflammatory Agents/pharmacology
4.
Epigenetics ; 18(1): 2216005, 2023 12.
Article in English | MEDLINE | ID: mdl-37246786

ABSTRACT

While epigenetic mechanisms such as DNA methylation and histone modification are known to be important for gene suppression, relatively little is still understood about the interplay between these systems. The UHRF1 protein can interact with both DNA methylation and repressive chromatin marks, but its primary function in humans has been unclear. To determine what that was, we first established stable UHRF1 knockdowns (KD) in normal, immortalized human fibroblasts using targeting shRNA, since CRISPR knockouts (KO) were lethal. Although these showed a loss of DNA methylation across the whole genome, transcriptional changes were dominated by the activation of genes involved in innate immune signalling, consistent with the presence of viral RNA from retrotransposable elements (REs). We confirmed using mechanistic approaches that 1) REs were demethylated and transcriptionally activated; 2) this was accompanied by activation of interferons and interferon-stimulated genes and 3) the pathway was conserved across other adult cell types. Restoring UHRF1 in either transient or stable KD systems could abrogate RE reactivation and the interferon response. Notably, UHRF1 itself could also re-impose RE suppression independent of DNA methylation, but not if the protein contained point mutations affecting histone 3 with trimethylated lysine 9 (H3K9me3) binding. Our results therefore show for the first time that UHRF1 can act as a key regulator of retrotransposon silencing independent of DNA methylation.


Subject(s)
DNA Methylation , RNA, Viral , Humans , RNA, Viral/metabolism , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism , CCAAT-Enhancer-Binding Proteins/genetics , CCAAT-Enhancer-Binding Proteins/metabolism , Immunity, Innate/genetics , Interferons/metabolism
5.
Microb Pathog ; 177: 106058, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36878333

ABSTRACT

The increase in antibiotic resistance rates has attracted the interest of researchers for antibacterial compounds capable of potentiating the activity of conventional antibiotics. Coumarin derivatives have been reported to develop effective antibacterials with possible new mechanisms of action for treating infectious diseases caused by bacteria with a profile of drug resistance. In this context, the aim of the present study we have now prepared one variety of new synthetic coumarins evaluating the pharmacokinetic and chemical similarity in silico, their antimicrobial activity against Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), and potential for the modulation of antibiotic resistance against Staphylococcus aureus (SA10) and Escherichia coli (EC06) clinical isolate bacteria by in vitro assay. The antibacterial activity and antibiotic-enhancing properties were evaluated by the broth microdilution method and pharmacokinetically characterized according to the Lipinsk rule of 5 and had their similarity analyzed in databases such as ChemBL and CAS SciFinder. The results demonstrated that only compound C13 showed significant antibacterial activity (MIC ≤256 µg/mL), and all other coumarins did not display relevant antibacterial activity (MIC ≥1024 µg/mL). However, they did modulate the antibiotics activities to norfloxacin and gentamicin, except, compound C11 to norfloxacin against Staphylococcus aureus (SA10). The in silico properties prediction and drug-likeness results demonstrated that all coumarins presented a good drug-likeness score with no violations and promising in silico pharmacokinetic profiles showing that they have the potential to be developed into an oral drug. The results indicate that the coumarin derivatives showed good in vitro antibacterial activity. These new coumarin derivatives also demonstrated the capacity to modulate antibiotic resistance with potential synergy action for current antimicrobials assayed, as antibiotic adjuvants, to reduce the emergence of antimicrobial resistance.


Subject(s)
Staphylococcal Infections , Staphylococcus aureus , Humans , Norfloxacin/pharmacology , Escherichia coli , Coumarins/pharmacology , Coumarins/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Staphylococcal Infections/drug therapy , Bacteria , Microbial Sensitivity Tests
6.
Nutr Bull ; 48(2): 267-277, 2023 06.
Article in English | MEDLINE | ID: mdl-36807740

ABSTRACT

Suboptimal status of folate and/or interrelated B vitamins (B12 , B6 and riboflavin) can perturb one-carbon metabolism and adversely affect brain development in early life and brain function in later life. Human studies show that maternal folate status during pregnancy is associated with cognitive development in the child, whilst optimal B vitamin status may help to prevent cognitive dysfunction in later life. The biological mechanisms explaining these relationships are not clear but may involve folate-related DNA methylation of epigenetically controlled genes related to brain development and function. A better understanding of the mechanisms linking these B vitamins and the epigenome with brain health at critical stages of the lifecycle is necessary to support evidence-based health improvement strategies. The EpiBrain project, a transnational collaboration involving partners in the United Kingdom, Canada and Spain, is investigating the nutrition-epigenome-brain relationship, particularly focussing on folate-related epigenetic effects in relation to brain health outcomes. We are conducting new epigenetics analysis on bio-banked samples from existing well-characterised cohorts and randomised trials conducted in pregnancy and later life. Dietary, nutrient biomarker and epigenetic data will be linked with brain outcomes in children and older adults. In addition, we will investigate the nutrition-epigenome-brain relationship in B vitamin intervention trial participants using magnetoencephalography, a state-of-the-art neuroimaging modality to assess neuronal functioning. The project outcomes will provide an improved understanding of the role of folate and related B vitamins in brain health, and the epigenetic mechanisms involved. The results are expected to provide scientific substantiation to support nutritional strategies for better brain health across the lifecycle.


Subject(s)
Folic Acid , Vitamin B Complex , Child , Female , Pregnancy , Humans , Aged , Folic Acid/therapeutic use , Vitamin B Complex/pharmacology , Brain/diagnostic imaging , Diet , Vitamin A/pharmacology , Vitamin K/pharmacology , Epigenesis, Genetic
7.
Nat Prod Res ; 37(22): 3844-3850, 2023.
Article in English | MEDLINE | ID: mdl-36469681

ABSTRACT

In the present study, the volatile components and cytotoxic, antibacterial, antioxidant, and antiprotozoal activities of the essential oil obtained from the leaves of Eugenia stipitata McVaugh (Myrtaceae) grown in the Brazilian Northeast region (Araripe) were investigated. The essential oil was obtained by hydrodistillation. The leaves of E. stipitata provided an oil yield of 0.13 ± 0.01% (w/w). The volatile compounds in the essential oil of E. stipitata were analysed using gas chromatography, and the volatile chemical composition was mainly composed of ß-eudesmol (15.28%), γ-eudesmol (10.85%), elemol (10.21%) and caryophyllene oxide (6.65%). The essential oil of E. stipitata was highly selective against Leishmania braziliensis and L. infantum promastigotes. The essential oil exhibited good antibacterial activity. E. stipitata essential oil showed low free-radical scavenging activity. Our results suggest that the E. stipitata essential oil is a relevant source of the primary compounds required for the development of antibacterial and antiprotozoal drugs.

8.
Biotechnol Rep (Amst) ; 35: e00756, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35942239

ABSTRACT

Hyptis martiusii Benth. also known as "cidreira brava", has some activities verified in the literature, such as antiulcerogenic, antimicrobial and antiedematogenic. This study aimed to verify the anti-inflammatory and antinociceptive effect of the leaves essential oil. For the evaluation of the anti-inflammatory activity of OEHM (100 mg/kg/p.o.), models paw edema induced by dextran and histamine, peritonitis and vascular permeability were used. Regarding the anti-nociceptive activity of the OEHM, abdominal contortion tests by acetic acid, formalin, hot plate (50.75 and 100 mg/kg/p.o.), open field and mechanical plantar hyper-nociception (100 mg/kg/p.o.) were carried out. OEHM (100 mg/kg) showed anti-inflammatory activity, being able to remarkably deducing the paw edema induced by dextran and histamine, the total number of cell leukocytes/neutrophils in peritonitis, and exudate in vascular permeability. In antinociceptive activity, the OEHM did not promote significant effect in central nervous system in the open field assay, remarkably reduced abdominal contortions (50, 75 and 100 mg/kg), the time in the formalin assay and the mechanical hyper-nociception (100 mg/kg); however, only doses between 75 and 100 mg/kg were capable of ameliorating the reponse latency time. Regarding the probable mechanism of action, the antinociceptive activity includes the participation in the activation of opioid, TRPV1, and α2-noradrenergic systems. In short, data obtained here reveal that OEHM has anti-inflammatory and antinociceptive activity, implying that its action may be involved in the mechanism of inhibition or liberation of pro-inflammatory mediators involved in pain and inflammation.

9.
Diagnostics (Basel) ; 12(1)2022 Jan 10.
Article in English | MEDLINE | ID: mdl-35054323

ABSTRACT

Cardiovascular magnetic resonance (CMR) is used to investigate suspected acute myocarditis, however most supporting data is retrospective and few studies have included parametric mapping. We aimed to investigate the utility of contemporary multiparametric CMR in a large prospective cohort of patients with suspected acute myocarditis, the impact of real-world variations in practice, the relationship between clinical characteristics and CMR findings and factors predicting outcome. 540 consecutive patients we recruited. The 113 patients diagnosed with myocarditis on CMR performed within 40 days of presentation were followed-up for 674 (504-915) days. 39 patients underwent follow-up CMR at 189 (166-209) days. CMR provided a positive diagnosis in 72% of patients, including myocarditis (40%) and myocardial infarction (11%). In multivariable analysis, male sex and shorter presentation-to-scan interval were associated with a diagnosis of myocarditis. Presentation with heart failure (HF) was associated with lower left ventricular ejection fraction (LVEF), higher LGE burden and higher extracellular volume fraction. Lower baseline LVEF predicted follow-up LV dysfunction. Multiparametric CMR has a high diagnostic yield in suspected acute myocarditis. CMR should be performed early and include parametric mapping. Patients presenting with HF and reduced LVEF require closer follow-up while those with normal CMR may not require it.

10.
Eur J Med Chem ; 230: 114105, 2022 Feb 15.
Article in English | MEDLINE | ID: mdl-35065413

ABSTRACT

There is a pressing need for new drugs against tuberculosis (TB) to combat the growing resistance to current antituberculars. Herein a novel strategy is described for hit generation against promising TB targets involving X-ray crystallographic screening in combination with phenotypic screening. This combined approach (XP Screen) affords both a validation of target engagement as well as determination of in cellulo activity. The utility of this method is illustrated by way of an XP Screen against CYP121A1, a cytochrome P450 enzyme from Mycobacterium tuberculosis (Mtb) championed as a validated drug discovery target. A focused screening set was synthesized and tested by such means, with several members of the set showing promising activity against Mtb strain H37Rv. One compound was observed as an X-ray hit against CYP121A1 and showed improved activity against Mtb strain H37Rv under multiple assay conditions (pan-assay activity). Data obtained during X-ray crystallographic screening were utilized in a structure-based campaign to design a limited number of analogues (less than twenty), many of which also showed pan-assay activity against Mtb strain H37Rv. These included the benzo[b][1,4]oxazine derivative (MIC90 6.25 µM), a novel hit compound suitable as a starting point for a more involved hit to lead candidate medicinal chemistry campaign.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis , Antitubercular Agents/pharmacology , Drug Design , Humans , Tuberculosis/drug therapy , X-Rays
11.
Molecules ; 26(24)2021 Dec 17.
Article in English | MEDLINE | ID: mdl-34946747

ABSTRACT

The increase in antibiotic resistance and the emergence of new bacterial infections have intensified the research for natural products from plants with associated therapy. This study aimed to verify the antibacterial and antioxidant activity of crude extracts of the genus Plectranthus species, being the first report on the modulation of aminoglycosides antibiotic activity by Plectranthus amboinicus extracts. The chemical composition was obtained by chemical prospecting and High-Performance Liquid Chromatography with diode arrangement detector (HPLC/DAD). The antibacterial activities of the extracts alone or in association with aminoglycosides were analyzed using the microdilution test. The antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The phytochemical prospection allowed the flavonoids, saponins, tannins and triterpenoids to be identified. Quercetin, rutin, gallic acid, chlorogenic acid, caffeic acid, catechin, kaempferol, glycosylated kaempferol, quercitrin, and isoquercitrin were identified and quantified. The principal component analysis (PCA) observed the influence of flavonoids and phenolic acids from Plectranthus species on studied activities. Phytochemical tests with the extracts indicated, especially, the presence of flavonoids, confirmed by quantitative analysis by HPLC. The results revealed antibacterial activities, and synergistic effects combined with aminoglycosides, as well as antioxidant potential, especially for P. ornatus species, with IC50 of 32.21 µg/mL. Multivariate analyzes show that the inclusion of data from the antioxidant and antibacterial activity suggests that the antioxidant effect of these species presents a significant contribution to the synergistic effect of phytoconstituents, especially based on the flavonoid contents. The results of this study suggest the antibacterial activity of Plectranthus extracts, as well as their potential in modifying the resistance of the analyzed aminoglycosides.


Subject(s)
Anti-Bacterial Agents/chemistry , Antioxidants/chemistry , Chemometrics , Plant Extracts/chemistry , Plectranthus/chemistry
13.
Sci Rep ; 11(1): 1274, 2021 01 14.
Article in English | MEDLINE | ID: mdl-33446675

ABSTRACT

General control non-repressible 5 (GCN5)-related N-acetyltransferases (GNATs) catalyse the acetylation of a diverse range of substrates, thereby orchestrating a variety of biological processes within prokaryotes and eukaryotes. GNAT enzymes can catalyze the transfer of an acetyl group from acetyl coenzyme A to substrates such as aminoglycoside antibiotics, amino acids, polyamines, peptides, vitamins, catecholamines, and large macromolecules including proteins. Although GNATs generally exhibit low to moderate sequence identity, they share a conserved catalytic fold and conserved structural motifs. In this current study we characterize the high-resolution X-ray crystallographic structure of a GNAT enzyme bound with acetyl-CoA from Elizabethkingia anophelis, an important multi-drug resistant bacterium. The tertiary structure is comprised of six α-helices and nine ß-strands, and is similar with other GNATs. We identify a new and uncharacterized GNAT dimer interface, which is conserved in at least two other unpublished GNAT structures. This suggests that GNAT enzymes can form at least five different types of dimers, in addition to a range of other oligomers including trimer, tetramer, hexamer, and dodecamer assemblies. The high-resolution structure presented in this study is suitable for future in-silico docking and structure-activity relationship studies.


Subject(s)
Acetyl Coenzyme A/metabolism , Acetyltransferases/metabolism , Bacterial Proteins/metabolism , Flavobacteriaceae/metabolism , Acetyltransferases/chemistry , Bacterial Proteins/chemistry , Crystallography, X-Ray , Flavobacteriaceae/chemistry , Models, Molecular , Protein Binding , Protein Conformation , Protein Multimerization
14.
J Ethnopharmacol ; 265: 113338, 2021 Jan 30.
Article in English | MEDLINE | ID: mdl-32920137

ABSTRACT

Medicinal plants remain an invaluable source for therapeutics of diseases that affect humanity. Sideritis bilgeriana (Lamiaceae) is medicinal plant used in Turkey folk medicine to reduce inflammation and pain, but few studies scientific corroborates its medicinal use so creating a gap between popular use and scientific evidence. Thus, we aimed to evaluate the pharmacological effects of the methanolic extract of S. bilgeriana (MESB) in rodents nociception models and also performed its phytochemical analysis. Firstly, a screening was carried out that enabled the identification of the presence of phenolic compounds and flavonoids. In view of this, a chromatographic method by HPLC-DAD-UV was developed that made it possible to identify chlorogenic acid and its quantification in MESB. MESB-treated mice (MESB 50, 100 and 200 mg/kg, p.o.) reduced mechanical hyperalgesia and myeloperoxidase activity (p < 0.01), and also showed a reduced pain behavior in capsaicin test. In the carrageenan-induced pleurisy test, MESB (100 mg/kg p.o.) significantly reduced the leukocyte (polymorphonuclear) count in the pleural cavity and equally decreased the TNF-α and IL-1ß levels (p < 0.001). In the PSNL model, mechanical hyperalgesia was reduced on the first evaluation day and during the 7 days of evaluation compared to the vehicle group (p < 0.001). Thermal hyperalgesia was also reduced 1 h after treatment compared to the vehicle group (p < 0.001) and reversed the loss of force initially displayed by the animals, thus inferring an analgesic effect in the muscle strength test. Analysis of the marrow of these animals showed a decrease in the level of pro-inflammatory cytokine IL-6 (p < 0.001) and factor NF-κB, in relation to the control group (p < 0.05). Moreover, the MESB treatment produced no noticeable side effects, no disturb in motor performance and no signs of gastric or hepatic injury. Together, the results suggests that MESB could be useful to management of inflammation and neuropathic pain mainly by the management of pro-inflammatory mediators (NF-κB, TNF-α, IL-1ß and IL-6), so reinforcing its use in popular medicine and corroborating the need for further chemical and pharmacological studies for the species.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Plant Extracts/pharmacology , Sideritis/chemistry , Analgesics/isolation & purification , Analgesics/pharmacology , Animals , Anti-Inflammatory Agents/isolation & purification , Chromatography, High Pressure Liquid , Dose-Response Relationship, Drug , Humans , Inflammation/drug therapy , Inflammation/pathology , Inflammation Mediators/metabolism , Mice , Neuralgia/drug therapy , Plant Extracts/analysis
15.
Environ Geochem Health ; 43(6): 2433-2442, 2021 Jun.
Article in English | MEDLINE | ID: mdl-32488795

ABSTRACT

Human activities, especially in industry, have contributed to soil contamination with heavy or toxic metals. The objective of this study was to determine the chelating effect and antioxidant activity of pyrogallol, as well as to evaluate its cytoprotective activity in prokaryotic and eukaryotic models, animal and plant, respectively, against toxic mercury chloride action. Antioxidant activity was determined by DPPH where pyrogallol showed considerable action, chelating even iron ions. For the microbiologic activity assays, microdilution was performed to obtain the minimal inhibitory concentration, minimum bactericidal and minimum fungicide concentration, from which the sub-inhibitory concentrations were determined. The product did not conferred cytoprotection to the tested bacteria and fungi. To evaluate plant cytoprotection, Lactuta sativa seeds were used together with the product at a sub-allelopathic concentration with different HgCl2 concentrations. In this case, the tannin conferred cytoprotection to the plant model, allowing the best growth and development of caulicles and radicles, thus preserving tissues necessary for plant survival. From the results, it is observable that pyrogallol possesses cytoprotective action in the eukaryotic plant model, this action being useful as an alternative which favors the growth of plants in contaminated areas, as the recovering of crop fields or reforestation projects.


Subject(s)
Lactuca/drug effects , Mercuric Chloride/toxicity , Pyrogallol/pharmacology , Spectroscopy, Fourier Transform Infrared/methods , Allelopathy , Antioxidants/chemistry , Antioxidants/pharmacology , Chelating Agents/chemistry , Chelating Agents/pharmacology , Germination/drug effects , Iron Chelating Agents/chemistry , Iron Chelating Agents/pharmacology , Mercuric Chloride/chemistry , Microbial Sensitivity Tests , Pyrogallol/chemistry , Seeds/drug effects , Soil Pollutants/toxicity
16.
Membranes (Basel) ; 10(6)2020 Jun 25.
Article in English | MEDLINE | ID: mdl-32630491

ABSTRACT

Resistance to antibiotics has made diseases that previously healed easily become more difficult to treat. Staphylococcus aureus is an important cause of hospital-acquired infections and multi-drug resistant. NorA efflux pump, present in bacteria S. aureus, is synthesized by the expression of the norA gene. Menadione, also known as vitamin K3, is one of the synthetic forms of vitamin K. Therefore, the aim of this study is to verify the menadione effect on efflux inhibition through NorA pump gene expression inhibition and assess the effects of menadione in bacterial membrane. The effect of menadione as an efflux pump inhibitor (EPI) was evaluated by the microdilution method, fluorimetry, electron microscopy, and by RT-qPCR to evaluate gene expression. In the molecular docking, association with menadione induces increased fluorescence intensity. Menadione was observed (100% of the clusters) interacting with residues ILE12, ILE15, PHE16, ILE19, PHE47, GLN51, ALA105, and MET109 from NorA. The results showed the norA gene had its expression significantly diminished in the presence of menadione. The simulation showed that several menadione molecules were able to go through the bilayer and allow the entry of water molecules into the hydrophobic regions of the bilayer. When present within membranes, menadione may have caused membrane structural changes resulting in a decline of the signaling pathways involved in norA expression. Menadione demonstrated to be an efflux pump inhibitor with dual mechanism: affecting the efflux pump by direct interaction with protein NorA and indirectly inhibiting the norA gene expression, possibly by affecting regulators present in the membrane altered by menadione.

18.
Antibiotics (Basel) ; 9(5)2020 May 12.
Article in English | MEDLINE | ID: mdl-32408576

ABSTRACT

Considering the evidence that essential oils, as well as safrole, could modulate bacterial growth in different resistant strains, this study aims to characterize the phytochemical profile and evaluate the antibacterial and antibiotic-modulating properties of the essential oil Ocotea odorífera (EOOO) and safrole against efflux pump (EP)-carrying strains. The EOOO was extracted by hydrodistillation, and the phytochemical analysis was performed by gas chromatography coupled to mass spectrometry (GC-MS). The antibacterial and antibiotic-modulating activities of the EOOO and safrole against resistant strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were analyzed through the broth microdilution method. The EP-inhibiting potential of safrole in association with ethidium bromide or antibiotics was evaluated using the S. aureus 1199B and K2068 strains, which carry genes encoding efflux proteins associated with antibiotic resistance to norfloxacin and ciprofloxacin, respectively. A reduction in the MIC of ethidium bromide or antibiotics was used as a parameter of EP inhibition. The phytochemical analysis identified 16 different compounds in the EOOO including safrole as the principal constituent. While the EOOO and safrole exerted clinically relevant antibacterial effects against S. aureus only, they potentiated the antibacterial activity of norfloxacin against all strains evaluated by our study. The ethidium bromide and antibiotic assays using the strains of S. aureus SA1119B and K2068, as well as molecular docking analysis, indicated that safrole inhibits the NorA and MepA efflux pumps in S. aureus. In conclusion, Ocotea odorifera and safrole presented promising antibacterial and antibiotic-enhancing properties, which should be explored in the development of drugs to combat antibacterial resistance, especially in strains bearing genes encoding efflux proteins.

19.
J Ethnopharmacol ; 258: 112938, 2020 Aug 10.
Article in English | MEDLINE | ID: mdl-32387232

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Miconia albicans (Sw) Triana (Melastomataceae), a medicinal plant widely used by practitioners of folk medicine in the northeast of Brazil, has been used to treat chronic inflammatory disorders, such as rheumatoid arthritis (RA) and other joint conditions. Oddly, there is little research on the species. AIM OF THE STUDY: We aimed to evaluate the anti-arthritic and anti-inflammatory profile of the ethanolic leaf extract of M. albicans (EEMA), as well as to perform dereplication and quantification by HPLC-DAD-ESI-/MS/MS. MATERIALS AND METHODS: The compounds present in the extracts were identified by HPLC-DAD-ESI-MS/MS. The possible anti-inflammatory effect of EEMA (50 and 100 mg/kg, p.o) was evaluated using the pleurisy model induced by carrageenan and its action on IL-1ß and TNF-α levels was also evaluated. The RA model was induced through the intra-articular injection of complete Freund's adjuvant (CFA). RESULTS: HPLC-DAD-ESI-MS/MS analysis identified 23 compounds, with glycoside flavonoids mainly derived from quercetin, and rutin being the main compounds. EEMA significantly reduced (p < 0.001) leukocyte migration in the pleurisy model and reduced TNF-α and IL-1ß levels in pleural lavage (p < 0.001). In the CFA animal model, EEMA significantly reduced the nociceptive and hyperalgesic behaviors demonstrated by the rearing test (p < 0.01 or p < 0.05) and decreased mechanical hyperalgesia (p < 0.001). EEMA produced a significant improvement in mobility in the open-field test (only at the higher dose, p < 0.05). EEMA significantly (p < 0.01) increased hindpaw grip strength. The diameter of CFA-induced ipsilateral knee edema was significantly reduced (p < 0.001) by EEMA, which was related to reduced levels of IL-6 and TNF-α in the joint knee (p < 0.01). No indication of hepatic injury after chronic treatment was found. CONCLUSION: Taken together, these results contribute to the chemical and pharmacological knowledge of M. albicans and demonstrated that this medicinal plant appears to be able to mitigate deleterious symptoms of RA, which supports its use in folk medicine.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Arthritis, Experimental/drug therapy , Melastomataceae/chemistry , Plant Extracts/pharmacology , Animals , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/isolation & purification , Arthritis, Experimental/physiopathology , Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/physiopathology , Chromatography, High Pressure Liquid , Dose-Response Relationship, Drug , Ethanol/chemistry , Interleukin-1beta/metabolism , Interleukin-6/metabolism , Male , Mice , Plant Extracts/administration & dosage , Plant Extracts/chemistry , Tandem Mass Spectrometry , Tumor Necrosis Factor-alpha/metabolism
20.
Pharmaceuticals (Basel) ; 13(4)2020 Apr 13.
Article in English | MEDLINE | ID: mdl-32295048

ABSTRACT

The present study was aimed to synthesize silver nanoparticles (AgNPs) from the aqueous extracts of Odontosoria chinensis (L.) J. Sm. and the synthesized AgNPs were examined for their biopotentials. The Odontosoria chinensis extracts were added to 1 mM AgNO3 solution with different ratios viz., 0.5: 9.5, 1:9, 1.5: 8.5 and 2: 8 ratios for the reduction of Ag ions. After reduction, the AgNPs of Odontosoria chinensis were analyzed spectroscopically for further confirmation. The synthesized AgNPs of Odontosoria chinensis were characterized by pH, ultra violet-visible spectroscopy (UV-Vis), Fourier transform-infra red spectroscopy (FT-IR), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDAX) and X-Ray diffraction (XRD). The time taken for the complete reduction of Silver (Ag) in solution to nanoparticle was 10 min. The O. chinensis aqueous extracts mediated silver nanoparticles showed a broad peak with distinct absorption at around 400-420 nm and confirmed the silver nanoparticle formation. FT-IR results also confirmed the existence of organic materials in the silver nanoparticles of O. chinensis. The EDX spectra of AgNPs of O. chinenesis revealed the occurrence of a strong Ag peak. The synthesis of AgNPs of O. chinenesis was confirmed with the existence of a peak at 46.228°. The toxic potential of AgNPs of O. chinenesis showed varied percentage mortality with the LC50 values of 134.68 µL/ 50 mL and 76.5 µL/50 mL, respectively. The anti-inflammatory and anti-diabetic activities of aqueous and AgNPs of O. chinenesis were statistically significant at p < 0.05 level. Conclusion: The results demonstrated the toxicity, anti-diabetic and anti-inflammatory potential of the studied AgNPs. The synthesized nanoparticles of Odontosoria chinensis could be tested as an alternative to anticancer, anti-diabetic and anti-inflammatory drugs.

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