989 resultados para antimicrobial activities
Resumo:
The current in vitro study was designed to investigate the anti-inflammatory, cytotoxic and antioxidant activities of boesenbergin A (BA), a chalcone derivative of known structure isolated from Boesenbergia rotunda. Human hepatocellular carcinoma (HepG2), colon adenocarcinoma (HT-29), non-small cell lung cancer (A549), prostate adenocarcinoma (PC3), and normal hepatic cells (WRL-68) were used to evaluate the cytotoxicity of BA using the MTT assay. The antioxidant activity of BA was assessed by the ORAC assay and compared to quercetin as a standard reference antioxidant. ORAC results are reported as the equivalent concentration of Trolox that produces the same level of antioxidant activity as the sample tested at 20 µg/mL. The toxic effect of BA on different cell types, reported as IC50, yielded 20.22 ± 3.15, 10.69 ± 2.64, 20.31 ± 1.34, 94.10 ± 1.19, and 9.324 ± 0.24 µg/mL for A549, PC3, HepG2, HT-29, and WRL-68, respectively. BA displayed considerable antioxidant activity, when the results of ORAC assay were reported as Trolox equivalents. BA (20 µg/mL) and quercetin (5 µg/mL) were equivalent to a Trolox concentration of 11.91 ± 0.23 and 160.32 ± 2.75 µM, respectively. Moreover, the anti-inflammatory activity of BA was significant at 12.5 to 50 µM and without any significant cytotoxicity for the murine macrophage cell line RAW 264.7 at 50 µM. The significant biological activities observed in this study indicated that BA may be one of the agents responsible for the reported biological activities of B. rotunda crude extract.
Resumo:
Neutrophils play an important role in periodontitis by producing nitric oxide (NO) and antimicrobial peptides, molecules with microbicidal activity via oxygen-dependent and -independent mechanisms, respectively. It is unknown whether variation in the production of antimicrobial peptides such as LL-37, human neutrophil peptides (HNP) 1-3, and NO by neutrophils influences the pathogenesis of periodontal diseases. We compared the production of these peptides and NO by lipopolysaccharide (LPS)-stimulated neutrophils isolated from healthy subjects and from patients with periodontitis. Peripheral blood neutrophils were cultured with or without Aggregatibacter actinomycetemcomitans-LPS (Aa-LPS), Porphyromonas gingivalis-LPS (Pg-LPS) and Escherichia coli-LPS (Ec-LPS). qRT-PCR was used to determine quantities of HNP 1-3 and LL-37 mRNA in neutrophils. Amounts of HNP 1-3 and LL-37 proteins in the cell culture supernatants were also determined by ELISA. In addition, NO levels in neutrophil culture supernatants were quantitated by the Griess reaction. Neutrophils from periodontitis patients cultured with Aa-LPS, Pg-LPS and Ec-LPS expressed higher HNP 1-3 mRNA than neutrophils from healthy subjects. LL-37 mRNA expression was higher in neutrophils from patients stimulated with Aa-LPS. Neutrophils from periodontitis patients produced significantly higher LL-37 protein levels than neutrophils from healthy subjects when stimulated with Pg-LPS and Ec-LPS, but no difference was observed in HNP 1-3 production. Neutrophils from periodontitis patients cultured or not with Pg-LPS and Ec-LPS produced significantly lower NO levels than neutrophils from healthy subjects. The significant differences in the production of LL-37 and NO between neutrophils from healthy and periodontitis subjects indicate that production of these molecules might influence individual susceptibility to important periodontal pathogens.
Resumo:
This study evaluated the sedative and anesthetic effects of the essential oils (EO) of Hyptis mutabilis (Rich.) Briq. and their isolated components on silver catfish (Rhamdia quelen). Quantitative chemical differences between the EOs obtained from leaves and inflorescences were verified, and a new chemotype rich in globulol was described. Although there were no significant differences in the time of induction for sedation and anesthesia between the EOs, only the leaf EO at 344 mg/L anesthetized all fish without side effects. Fractionation of the leaf EO was carried out by column chromatography. The isolated compounds [(+)-1-terpinen-4-ol and (-)-globulol] showed different activity from that detected for the leaf EO in proportional concentrations and similar sedation to a eugenol control at 10 mg/L. However, fish exposed to 1-terpinen-4-ol (3 and 10 mg/L) did not remain sedated for 30 min. Anesthesia was obtained with 83-190 mg/L globulol, but animals showed loss of mucus during induction and mortality at these concentrations. Synergism of the depressor effects was detected with the association of globulol and benzodiazepine (BDZ), compared with either drug alone. Fish exposed to BDZ or globulol+BDZ association showed faster recovery from anesthesia in water containing flumazenil, but the same did not occur with globulol. In conclusion, the use of globulol in aquaculture procedures should be considered only at sedative concentrations of 10 and 20 mg/L, and its mechanism of action seems not to involve the GABAA-BDZ system.
Resumo:
The aim of this research was to investigate the antiproliferative and anticholinesterase activities of 11 extracts from 5 Annonaceae species in vitro. Antiproliferative activity was assessed using 10 human cancer cell lines. Thin-layer chromatography and a microplate assay were used to screen the extracts for acetylcholinesterase (AchE) inhibitors using Ellman's reagent. The chemical compositions of the active extracts were investigated using high performance liquid chromatography. Eleven extracts obtained from five Annonaceae plant species were active and were particularly effective against the UA251, NCI-470 lung, HT-29, NCI/ADR, and K-562 cell lines with growth inhibition (GI50) values of 0.04-0.06, 0.02-0.50, 0.01-0.12, 0.10-0.27, and 0.02-0.04 µg/mL, respectively. In addition, the Annona crassiflora and A. coriacea seed extracts were the most active among the tested extracts and the most effective against the tumor cell lines, with GI50 values below 8.90 µg/mL. The A. cacans extract displayed the lowest activity. Based on the microplate assay, the percent AchE inhibition of the extracts ranged from 12 to 52%, and the A. coriacea seed extract resulted in the greatest inhibition (52%). Caffeic acid, sinapic acid, and rutin were present at higher concentrations in the A. crassiflora seed samples. The A. coriacea seeds contained ferulic and sinapic acid. Overall, the results indicated that A. crassiflora and A. coriacea extracts have antiproliferative and anticholinesterase properties, which opens up new possibilities for alternative pharmacotherapy drugs.
Resumo:
This paper reports on the in vitro antibacterial and in vivo anti-inflammatory properties of a hydroethanolic extract of the aerial parts of Gochnatia pulchra (HEGP). It also describes the antibacterial activity of HEGP fractions and of the isolated compounds genkwanin, scutellarin, apigenin, and 3,5-O-dicaffeoylquinic acid, as evaluated by a broth microdilution method. While HEGP and its fractions did not provide promising results, the isolated compounds exhibited pronounced antibacterial activity. The most sensitive microorganism was Streptococcus pyogenes, with minimum inhibitory concentration (MIC) values of 100, 50 and 25 µg/mL for genkwanin and the flavonoids apigenin and scutellarin, respectively. Genkwanin produced an MIC value of 25 µg/mL against Enterococcus faecalis. A paw edema model in rats and a pleurisy inflammation model in mice aided investigation of the anti-inflammatory effects of HEGP. This study also evaluated the ability of HEGP to modulate carrageenan-induced interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) production. Orally administered HEGP (250 and 500 mg/kg) inhibited carrageenan-induced paw edema. Regarding carrageenan-induced pleurisy, HEGP at 50, 100, and 250 mg/kg diminished leukocyte migration by 71.43%, 69.24%, and 73.34% (P<0.05), respectively. HEGP suppressed IL-1β and MCP-1 production by 55% and 50% at 50 mg/kg (P<0.05) and 60% and 25% at 100 mg/kg (P<0.05), respectively. HEGP abated TNF-α production by macrophages by 6.6%, 33.3%, and 53.3% at 100, 250, and 500 mg/kg (P<0.05), respectively. HEGP probably exerts anti-inflammatory effects by inhibiting production of the pro-inflammatory cytokines TNF-α, IL-1β, and MCP-1.
Resumo:
Cocos nucifera (L.) (Arecaceae) is commonly called the “coconut tree” and is the most naturally widespread fruit plant on Earth. Throughout history, humans have used medicinal plants therapeutically, and minerals, plants, and animals have traditionally been the main sources of drugs. The constituents of C. nucifera have some biological effects, such as antihelminthic, anti-inflammatory, antinociceptive, antioxidant, antifungal, antimicrobial, and antitumor activities. Our objective in the present study was to review the phytochemical profile, pharmacological activities, and toxicology of C. nucifera to guide future preclinical and clinical studies using this plant. This systematic review consisted of searches performed using scientific databases such as Scopus, Science Direct, PubMed, SciVerse, and Scientific Electronic Library Online. Some uses of the plant were partially confirmed by previous studies demonstrating analgesic, antiarthritic, antibacterial, antipyretic, antihelminthic, antidiarrheal, and hypoglycemic activities. In addition, other properties such as antihypertensive, anti-inflammatory, antimicrobial, antioxidant, cardioprotective, antiseizure, cytotoxicity, hepatoprotective, vasodilation, nephroprotective, and anti-osteoporosis effects were also reported. Because each part of C. nucifera has different constituents, the pharmacological effects of the plant vary according to the part of the plant evaluated.
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This master’s thesis was made in order to gain answers to the question of how the integration of the marketing communications and the decision making related to it in a geographically dispersed service organization could be improved in a situation where an organization has gone through a merger. The effects of the organizational design dimensions towards the integration of the marketing communications and the decision making related to it was the main focus. A case study as a research strategy offered a perfect frames for an exploratory study and the data collection was conducted by semi-structured interviews and observing. The main finding proved that from the chosen design dimensions, decentralization, coordination and power, could be found specific factors that in a geographically dispersed organization are affecting the integration of the marketing communications negatively. The effects can be seen mostly in the decision making processes, roles and in the division of responsibility, which are affecting the other dimensions and by this, the integration. In a post-merger situation, the coordination dimension and especially the information asymmetry and the information flow seem to have a largest affect towards the integration of the marketing communications. An asymmetric information distribution with the lack of business and marketing education resulted in low self-assurance and at the end in fragmented management and to the inability to set targets and make independent decisions. As conclusions it can be stated, that with the organizational design dimensions can the effects of a merger towards the integration process of the marketing communications to be evaluated.
Resumo:
Origanum vulgare L. (oregano), Lamiaceae, essential oil has a variety of biological properties and its antimicrobial activity has received a renewed interest for use in food conservation. The aim of this study was to evaluate the interference of heating on the antimicrobial activity and chemical composition of O. vulgare essential oil. The antimicrobial activity of the essential oil kept at room temperature and exposed to different heating temperatures (60, 80, 100 and 120 °C during 1 hour) was evaluated by observing antimicrobial effectiveness at absolute concentration and determining MIC values by the solid medium diffusion procedure. The essential oil chemical composition analysis was performed by GC-MS. O. vulgare essential oil showed interesting antimicrobial activity on all assayed microbial strains (Candida albicans, C.krusei, C. tropicalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica, Salmonella enterica, Serratia marcencens), noted by large growth inhibition zones (30-42 mm). Heating treatment showed no significant interference (p < 0.05) on the essential oil antimicrobial activity, noted by the development of microbial growth inhibition zones with similar or close diameters when evaluating the essential oil kept at room temperature and after exposure to different thermal treatments. MIC values oscillated between 10and 40 µL.mL-1 (20µL.mL-1 for most strains). However, no significant difference (p < 0.05) was noted among the MIC values found for the essential oil aliquots exposed to different temperatures. Moreover, heating did not significantly (p < 0.05) affect the chemical composition of O. vulgare essential oil. Monoterpenes, terpenic compounds and sesquiterpenes were found in the essential oil, with carvacrol (68.06-70.27%) and p-cymene (12.85-15.81%) being the compounds found in the highest amounts. These results showed the thermal stability and intense antimicrobial properties of O. vulgare essential oil and support its possible concomitant use with heating temperatures in order to reach microbial safety in foods.
Resumo:
In this work, the essential oils of S. officinalis, S. sclarea, S. lavandulifolia and S. triloba were chemically analyzed by gas chromatography coupled to a mass spectrometry detector (GC/MSD), and their antimicrobial activity was tested against 10 microorganisms using the disk diffusion method and the Minimum Inhibitory Concentration (MIC) technique. The following major compounds were identified in the essential oils: α - and β-thujone, camphor and 1,8-cineole, except in S. sclarea, where linalool, linalyl acetate and α-terpineol were the major constituents. The antimicrobial activity showed significant differences (p < 0.05) only when obtained by the MIC method. Gram-positive microorganisms presented larger sensitivity for the essential oils. The lowest MIC was observed when Staphylococcus aureus was exposed to 2.31 mg.mL-1 of S. lavandulifolia essential oil, while the highest MIC value was obtained when Shigella flexneri was exposed to 9.25 mg.mL-1 of the same essential oil, thus demonstrating that this essential oil may be effective as a bacteriostatic agent against Gram-positive microorganisms.
Resumo:
Several essential oils of condiment and medicinal plants possess proven antimicrobial activity and are of important interest for the food industry. Therefore, the Minimum Inhibitory Concentrations (MIC) of those oils should be determined for various bacteria. MIC varies according to the oil used, the major compounds, and the physiology of the bacterium under study. In the present study, the essential oils of the plants Thymus vulgaris (time), Cymbopogon citratus (lemongrass) and Laurus nobilis (bay) were chemically quantified, and the MIC was determined on the bacteria Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Listeria monocytogenes ATCC 19117, Salmonella enterica Enteritidis S64, and Pseudomonas aeruginosa ATCC 27853. The essential oil of C. citratus demonstrated bacterial activity at all concentrations tested and against all of the bacteria tested. The majority of essential oil compounds were geranial and neral. The major constituent of T. vulgaris was 1.8-cineol and of L. nobilis was linalool, which presented lower antibacterial activity, followed by 1.8-cineol. The Gram-negative bacteria demonstrated higher resistance to the use of the essential oils tested in this study. E. coli was the least sensitive and was inhibited only by the oils of C. citratus and L. nobilis.
Resumo:
Several studies have shown the antimicrobial and antioxidant properties of turmeric (Curcuma longa), widely used in food industry as a colorant, among other functions. The aim of this study was to determine the antioxidant and antimicrobial properties of turmeric essential oil against pathogenic bacteria and to study the influence of the addition of ascorbic acid on the prevention of polyphenols oxidation. The commercial turmeric essential oil alone did not show bactericidal activity against the microorganisms studied, Listeria monocytogenes and Salmonella typhimurium, but when combined with ascorbic acid, it showed significant antibacterial activity. The highest antimicrobial activity of turmeric essential oil against Salmonella typhimurium was 15.0 ± 1.41 mm at the concentration of 2.30 mg.mL-1 of essential oil and 2.0 mg.mL-1 of ascorbic acid. With regard to Listeria monocytogenes, the largest zone of inhibition (13.7 ± 0.58 mm) was obtained at the same concentrations. The essential oil showed antioxidant activity of EC50 = 2094.172 µg.mL-1 for the DPPH radical scavenging method and 29% under the concentration of 1.667 mg.mL-1 for the β-carotene bleaching method.
Resumo:
Foodborne disease caused by microorganisms is a problem of public health. Minas soft cheese is a national product manufactured using simple technology; it has high level of acceptance in the country making its production an important economic activity. Many microorganisms may be present in foods including the bacterium Escherichia coli (E. coli). Overall, E. coli is a harmless commensal bacterium; however, some strains may have a pathogenic potential. Several outbreaks of foodborne diseases associated with consumption of contaminated cheese have been reported, and the presence of pathogenic strains of E. coli has increased. The objective of this study was to isolate, evaluate the antimicrobial susceptibility, and characterize, by Multiplex PCR, the pathogenic E. coli strains isolated from Minas cheese commercialized in Rio de Janeiro. Thirty samples were analyzed and five strains of E. coli (EPEC) were identified. The assessment of antimicrobial susceptibility revealed 40% of the isolates resistant to ampicillin and 40% with intermediate resistance to ampicillin-sulbactam combination. These findings are a warning signal to health authorities since Minas cheese is a ready to eat food product, and therefore should not pose health risks to the population.
Resumo:
Uruguayan artisan cheese is elaborated with raw milk and non-commercial starters. The associated native microbiota may include lactic acid bacteria and also potentially pathogenic bacteria. Lactic acid bacteria were isolated from artisan cheese, raw milk, and non-commercial starter cultures, and their potential bacteriocin production was assessed. A culture collection of 509 isolates was obtained, and five isolates were bacteriocin-producers and were identified as Enterococcus durans,Lactobacillus casei, and Lactococcus lactis. No evidence of potential virulence factors were found in E. durans strains. These are promising results in terms of using these native strains for cheese manufacture and to obtain safe products.
Resumo:
Kombucha is a health-promoting fermented beverage worldwide. The present study compared the free-radical scavenging abilities and total reducing power (TRP) of kombucha prepared from low-cost green tea (LGTK), black tea (BTK), and tea powder (TPK). LGTK had the highest scavenging abilities against 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion and hydroxyl radicals, while BTK showed the highest TRP. Changes in content of probiotics in LGTK were investigated during storage as well. The number of acetic acid bacteria decreased moderately up to 10 days of storage. The number of lactic acid bacteria (LAB) decreased significantly, and their survival rate was only 0.98% at the 8th day of storage.