Search results for "Bacteria"
showing 10 items of 4919 documents
Anthemis wiedemanniana essential oil prevents LPS-induced production of NO in RAW 264.7 macrophages and exerts antiproliferative and antibacterial ac…
2012
Anthemis wiedemanniana is known in folk medicine for the treatment of microbial infections, cancer and also urinary and pulmonary problems. In this study, the chemical composition of the essential oil from A. wiedemanniana was evaluated and its antibacterial activity was tested against 10 bacterial strains. The oil was also tested for its potentiality to inhibit nitric oxide production in RAW 264.7 macrophages and for its cytotoxicity against four human cancer cell lines. A. wiedemanniana oil, rich of oxygenated monoterpenes (25.4%), showed a good antibacterial activity against Gram-positive bacteria and a good activity against the two Gram-negative bacteria, Escherichia coli and Proteus vu…
Antibacterial and anticoagulant activities of coumarins isolated from the flowers of Magydaris tomentosa (Desf.) DC (Apiaceae)
2007
The phytochemical investigation of the acetone and methanol extracts of the flowers of Magydaris tomentosa (Desf.) DC afforded six known coumarins as well as (+)-meranzin hydrate (7), not previously reported as a natural product. The antibacterial activity of umbelliprenin (1), osthol (2), imperatorin (3), citropten (4) and (+)-meranzin hydrate (7) was tested against Gram-positive and Gram-negative bacteria. All coumarins (1-7) isolated in this study inhibited growth of all bacterial strains tested (MIC between 16 and 256 μg/mL), the most active being imperatorin (3) (MICs between 32 and 128 μg/mL) and citropten (4) (MICs between 16 and 256 μg/mL). The anticoagulant activity of compounds 1-…
Chemical composition of the essential oil from Thapsia garganica L. (Apiaceae) grown wild in Sicily and its antimicrobial activity.
2015
In this study, the chemical composition of the essential oil from flowers and leaves of Thapsia garganica L. collected in Sicily was evaluated by GC and GC-MS. The main components of T. garganica flower oil (T.f.) were chamazulene (58.3%), humulene oxide II (9.0%), tricosane (8.2%) and pentacosane (8.2%). Also the oil from leaves (T.l.) was characterised by high content of chamazulene (49.2%). Other abundant metabolites were 1,4-dimethylazulene (18.5%), (E)-phytol (6.3%) and neophytadiene (5.1%). The comparison with other studied oils of genus Thapsia is discussed. Antimicrobial activity against several micro-organisms, including some ones infesting historical art craft, was also determined.
Selective Antimicrobial Effects of Curcumin@Halloysite Nanoformulation: A Caenorhabditis elegans Study
2019
Alterations in the normal gastrointestinal microbial community caused by unhealthy diet, environmental factors, and antibiotic overuse may severely affect human health and well-being. Novel antimicrobial drug formulations targeting pathogenic microflora while not affecting or even supporting symbiotic microflora are urgently needed. Here we report fabrication of a novel antimicrobial nanocontainer based on halloysite nanotubes loaded with curcumin and protected with a dextrin outer layer (HNTs+Curc/DX) and its effective use to suppress the overgrowth of pathogenic bacteria in Caenorhabditis elegans nematodes. Nanocontainers have been obtained using vacuum-facilitated loading of hydrophobic …
Antibacterial activity of Pleurotus species
2013
Basidiomycetes express promising antitumor, immune modulating, cardiovascular and hypercholesterolemia, antiviral, antibacterial and antiparasitic effects (Wasser & Weis, 1999; Reshetnikov et al., 2001; Wasser, 2002, Didukh et al., 2003). They are also well known for their safety and efficacy as functional foods and dietary supplements (Wasser & Akavia, 2008). The antibacterial and antiviral value of different genera of Basidiomycetes has been tested by different authors (Benedict & Brady, 1972; Donnelly et al., 1986; Gao et al., 2003;). In particular the antibacterial and antiparasitic therapeutic effects were investigated in the genera Flammulina P. Karst, Fomes (Fr.) Fr., Ganoderma P. Ka…
Antibacterial and white spot lesions preventive effect of an orthodontic resin modified with silver-nanoparticles
2021
Background To evaluate the antibacterial property of a modified orthodontic resin with different concentrations of silver-nanoparticles (AgNPs), and quantify its preventive effect on the formation of white spot lesions (WSLs). Material and Methods An orthodontic resin (Transbond XT) was modified with four concentrations of AgNPs (1%, 0.5%, 0.1%, and 0.05%), the orthodontic resin without AgNPs was used as control. Polymerized resin discs (n=80) were submitted to Agar diffusion test on Petri dishes inoculated with Streptococcus mutans and Lactobacillus acidophilus. In addition, resin discs of each group (n=40) were placed in 96-well plates with bacterial suspensions to evaluate the colony-for…
CHARACTERIZATION AND DEVELOPMENT OF DIFFERENT METHODS TO EXTEND THE SHELF LIFE OF FRESH-CUT FRUIT
2017
La frutta di IV gamma è un prodotto altamente deperibile, con una shelf-life molto corta (5-7 giorni) influenzata dalle numerose variabili che entrano in gioco accelerando la senescenza del prodotto. Il suo alto valore aggiunto può giustificare l’utilizzo di soluzioni di conservazione più o meno costose. I metodi attualmente esistenti sono numerosi, spaziano dal dipping in sostanze naturali o sintetiche, all’utilizzo di packaging attivi, all’impiego di atmosfere modificate, ecc. Queste metodiche di conservazione incidono in maniera diversa sui costi finali del prodotto ma soprattutto sulla conservazione dello stesso e sul mantenimento della sua qualità lungo tutto il periodo di shelf-life. …
Effect of an orthodontic resin modified with silver-nanoparticles on enamel color change
2021
Background: To evaluate the effect of an orthodontic resin modified with various concentrations of silver-nanoparticles (AgNPs) on enamel color. Material and Methods: Twenty lower premolars were collected and divided into four groups (n = 5) according to the concentration of AgNPs (0.05%, 0.1%, 0.5%, and 1% wt/wt). Additionally, a group bonded with a conventional resin was used as control (n=5). Previous to the bracket bonding, enamel color was measuring with a spectrophotometer. Specimens were stored for 6 months in deionized water. Brackets were debonded and color changes of enamel were calculated with the CIEDE 2000 formula (ΔE00). One-way ANOVA and Tukey test were used to assess the col…
Asymmetric synthesis and biological evaluation of 1,2,4-Oxadiazoles analogues of Linezolid
2014
Oxazolidinones are a class of antibacterial agents which displayed activity againist a variety of gram-positive pathogens and are highly potent against multidrug-resistant bacteria. Linezolid is the first oxazolidinone antibiotic approved for clinical use but linezolid resistance began to appear. 1,2,4 – Oxadiazoles are known bioactive heterocycles whose activity has been often associated to their bioisosterism with amide or ester functionalities [1]. As results of a research project on the molecular design of heterocycle – based antibacterials to contrast Multi-Drug Resistance (MDR) [2], we report the synthesis of 1,2,4 - Oxadiazole analogues of Linezolid. The synthesis has been achieved b…
Antibiotic Resistance of Gram Negatives isolates from loggerhead sea turtles (Caretta caretta) in the central Mediterranean Sea
2009
Previous studies on fish and marine mammals support the hypothesis that marine species harbor antibiotic resistance and therefore may serve as reservoirs for anti biotic-resistance genetic determinants. The aim of this study was to assess the resistance to antimicrobial agents of Gram negative strains isolated from loggerhead sea turtles (Caretta caretta). Oral and cloacal swabs from 19 live-stranded loggerhead sea turtles, with hooks fixed into the gut, were analyzed. The antimicrobial resistance of the isolates to 31 antibiotics was assessed using the disk-diffusion method. Conventional biochemical tests identified Citrobacter spp., Proteus spp., Enterobacter spp., Escherichia spp., Provi…