Modification of Antibiotic Activity by Fixed Oil of the Artocarpus heterophyllus Almond against Standard and Multidrug-Resistant Bacteria Strains

Artocarpus heterophyllus (jackfruit) is an evergreen tree distributed in tropical regions and is among the most studied species of the genus Artocarpus. The jackfruit almond has been highlighted in relation to phytochemical studies, biological properties, and application in the development of food products. This study aimed to analyze jackfruit fixed oil regarding chemical components, antibacterial property alone, and in association with antibiotics against standard and MDR bacteria strains. In the analysis of the oil by gas chromatography coupled to a flame ionization detector (GC-FID), a high content of saturated fatty acids (78.51%) was identified in relation to unsaturated fatty acids (17.07%). The main fatty acids identified were lauric acid (43.01%), myristic acid (11.10%), palmitic acid (6.95%), and oleic acid (15.32%). In the antibacterial analysis, broth microdilution assays were used. The oil presented minimum inhibitory concentration (MIC) ≥ 1024 μg/mL in antibacterial analysis for standard and MDR bacterial strains. The oil showed synergistic effects in the association with gentamicin, ofloxacin, and penicillin against MDR strains, with significant reductions in the MIC of antibiotics. The results suggest that the fixed oil of A. heterophyllus has fatty acids with the potential to synergistically modify antibiotic activity

Enhancing the Antifungal Efficacy of Fluconazole with a Diterpene: Abietic Acid as a Promising Adjuvant to Combat Antifungal Resistance in <i>Candida</i> spp.

The increasing antifungal resistance rates against conventional drugs reveal the urgent need to search for new therapeutic alternatives. In this context, natural bioactive compounds have a critical role in antifungal drug development. Since evidence demonstrates that abietic acid, a diterpene found in Pinus species, has significant antimicrobial properties, this study aimed to evaluate the antifungal activity of abietic acid against Candida spp and its ability to potentiate the activity of fluconazole. Abietic acid was tested both individually and in combination with fluconazole against Candida albicans (CA INCQS 40006), Candida krusei (CK INCQS 40095), and Candida tropicalis (CT INCQS 40042). The microdilution method was used to determine the IC50 and the cell viability curve. Minimum Fungicidal Concentration (MFC) was determined by subculture in a solid medium. The plasma membrane permeability was measured using a fluorescent SYTOX Green probe. While the IC50 of the drugs alone ranged between 1065 and 3255 μg/mL, the IC50 resulting from the combination of abietic acid and fluconazole ranged between 7563 and 160.1 μg/mL. Whether used in combination with fluconazole or isolated, abietic acid exhibited Minimum Fungicidal Concentration (MFC) values exceeding 1024 μg/mL against Candida albicans, Candida krusei and Candida tropicalis. However, it was observed that the antifungal effect of fluconazole was enhanced when used in combination with abietic acid against Candida albicans and Candida tropicalis. These findings suggest that while abietic acid alone has limited inherent antifungal activity, it can enhance the effectiveness of fluconazole, thereby reducing antifungal resistance

Thiazolidinedione and thiazole derivatives potentiate norfloxacin activity against NorA efflux pump over expression in Staphylococcus aureus 1199B strains

International audienc

Impacts of the Residual Trace Metals of Aquaculture in Net Cages on the Quality of Sediment

Anthropogenic pollution by trace metals in aquatic environments in semiarid zones is a critical area of investigation. The objective of this study was to investigate the concentration and spatial distribution of trace metals in surface sediments in the Ros&aacute;rio reservoir, which is affected by the intensive aquaculture of Til&aacute;pia-do-Nilo (Oreochromis niloticus). Sediment samples were collected in three different areas, postculture (PCTV), cultivation (CTV) and control (CTRL) in the dry season in 2019. The granulometric composition, organic matter and concentrations of Fe, Mn, Zn, Cu, Cr, Cd, Pb and Ni metals were determined. Multivariate statistics were used. Geochemical and ecotoxicological indices and a comparison with sediment quality guidelines (SQG) were used. The sediment was characterized by silty clay loam with an average organic matter of 18.76 &plusmn; 4.27. The analytical merit figures demonstrated accuracy (metal recoveries in certified standards) between 89 to 99% and high precision (RSD &lt; 5%). The concentration ranges for the metals were Fe: 0.11&ndash;0.85 (%), Mn: 14.46&ndash;86.91, Zn: 2.6&ndash;220.56, Cu: 26.89&ndash;98.75, Cr: 60.18&ndash;76.06, Cd: 0.38&ndash;0.59, Pb: 18.13&ndash;43.13, and Ni: 34.4&ndash;46.75, all in (mg/kg&minus;1). The highest concentration values were found in the CTV areas (Fe: 40 &plusmn; 0.22, Mn: 66.48 &plusmn; 19.11, Zn: 114.83 &plusmn; 59.75 and Cr: 70.85 &plusmn; 2.62) and PCTV (Cd: 0.53 &plusmn;0.04, Cu: 71.83 &plusmn; 21.20, Pb: 33.71 &plusmn; 4.34 and Ni: 44.60 &plusmn; 1.79). Pearson&rsquo;s correlation, hierarchical cluster analysis and principal component analysis confirmed the influence of fish farming on metals. Only Ni presented concentration values higher than the reference value established in the SQG. Thus, considering the probable geochemical and ecotoxicological effects, they comprise the two lowest levels of impact

Impacts of the Residual Trace Metals of Aquaculture in Net Cages on the Quality of Sediment

Anthropogenic pollution by trace metals in aquatic environments in semiarid zones is a critical area of investigation. The objective of this study was to investigate the concentration and spatial distribution of trace metals in surface sediments in the Rosário reservoir, which is affected by the intensive aquaculture of Tilápia-do-Nilo (Oreochromis niloticus). Sediment samples were collected in three different areas, postculture (PCTV), cultivation (CTV) and control (CTRL) in the dry season in 2019. The granulometric composition, organic matter and concentrations of Fe, Mn, Zn, Cu, Cr, Cd, Pb and Ni metals were determined. Multivariate statistics were used. Geochemical and ecotoxicological indices and a comparison with sediment quality guidelines (SQG) were used. The sediment was characterized by silty clay loam with an average organic matter of 18.76 ± 4.27. The analytical merit figures demonstrated accuracy (metal recoveries in certified standards) between 89 to 99% and high precision (RSD −1). The highest concentration values were found in the CTV areas (Fe: 40 ± 0.22, Mn: 66.48 ± 19.11, Zn: 114.83 ± 59.75 and Cr: 70.85 ± 2.62) and PCTV (Cd: 0.53 ± 0.04, Cu: 71.83 ± 21.20, Pb: 33.71 ± 4.34 and Ni: 44.60 ± 1.79). Pearson’s correlation, hierarchical cluster analysis and principal component analysis confirmed the influence of fish farming on metals. Only Ni presented concentration values higher than the reference value established in the SQG. Thus, considering the probable geochemical and ecotoxicological effects, they comprise the two lowest levels of impact

Efeito antibacteriano e anti-inflamatório tópico do extrato metanólico de Chenopodium ambrosioides L.

Made available in DSpace on 2017-06-01T19:34:42Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 3.pdf: 329832 bytes, checksum: cf16aaf2e8921755b13da01b30f9481c (MD5) Previous issue date: 8Universidade Estadual do Ceará. Fortaleza, CE, Brasil.Universidade Federal do Ceará. Fortaleza, CE, Brasil.Universidade Federal do Ceará. Fortaleza, CE, Brasil.Faculdade Leão Sampaio. Juazeiro do Norte, CE, Brasil.Faculdade Leão Sampaio. Juazeiro do Norte, CE, Brasil.Universidade Regional do Cariri. Crato, CE, Brasil.Universidade Regional do Cariri. Crato, CE, Brasil.Universidade Regional do Cariri. Crato, CE, Brasil.Universidade Regional do Cariri. Crato, CE, Brasil.Universidade Regional do Cariri. Crato, CE, Brasil.A utilização de plantas medicinais é uma prática comum nos países, fazendo parte da cultura popular como forma de tratamento de diferentes patologias. A planta Chenopodium ambrosioides L., conhecida popularmente como Mastruz, é utilizada na medicina popular no tratamento de bronquite crônica, tuberculose, contusões, hérnias e fraturas, tendo algumas atividades comprovadas cientificamente como ação vermífuga e antimicrobiana. Dessa forma, o presente estudo teve como objetivo avaliar o perfil químico e investigar a atividade antibacteriana, moduladora de antibióticos e antiedematogênica tópica e do extrato metanólico obtido das folhas de Chenopodium ambrosioides L. Na prospecção fitoquímica do extrato, foram verificados diferentes metabólitos que possuem várias atividades biológicas, e na dosagem dos fenóis totais foram verificados 21,0 mg/g equivalente de ácido gálico, sendo a quantificação de flavonoides encontrado um total de 135,4 mg/g de quercetina. Não houve atividade antibacteriana, porém detectou-se modulação quando o extrato foi associado aos aminoglicosídeos contra cepas de E. coli e Staphylococcus aureus. Nos testes para inflamação aguda, o extrato apresentou um potencial antiedematogênico. Nas concentrações de 25 e 50 mg/Kg. Diante dos resultados, pode-se correlacionar o conhecimento empírico das pessoas, às propriedades biológicas observadas nessa pesquisa, esta podendo ser importante para futura validação dessas propriedades etnomedicinais.The use of medicinal plants is a common practice in countries as part of popular culture as a treatment of different pathologies. The Chenopodium ambrosioides L. plant, popularly known as Mastruz, is used in folk medicine to treat chronic bronchitis, tuberculosis, bruises, fractures and hernias, and some activities scientifically proven as anthelmintic and antimicrobial action. Thus, this study aimed to evaluate the chemical profile and investigate the antibacterial activity, modulator of antibiotics and topical anti-inflammatory of methanol extract obtained from Chenopodium ambrosioides L. leaves. In the phytochemical extract prospecting, they were checked different metabolites that have multiple biological activity, and the dosage of total phenols were checked 21.0 mg / g gallic acid equivalent, and the quantification of flavonoids found a total of 135.4 mg / g quercetin. There was no antibacterial activity, but modulation was detected when the extract was associated with aminoglycosides against strains of E. coli and Staphylococcus aureus. In tests for acute inflammation, the extract showed an antiedematogenic potential at concentrations of 25 and 50 mg. Given the results, we can correlate the empirical knowledge of people; the biological properties observed in this study, this may be important for future validation of these ethnomedicinal properties

GC-MS Chemical Characterization and In Vitro Evaluation of Antioxidant and Toxic Effects Using <i>Drosophila melanogaster</i> Model of the Essential Oil of <i>Lantana montevidensis</i> (Spreng) Briq.

Background and objectives: Natural products such as essential oils with antioxidant potential can reduce the level of oxidative stress and prevent the oxidation of biomolecules. In the present study, we investigated the antioxidant potential of Lantana montevidensis leaf essential oil (EOLM) in chemical and biological models using Drosophila melanogaster. Materials and methods: in addition, the chemical components of the oil were identified and quantified by gas chromatography coupled to mass spectrometry (GC-MS), and the percentage compositions were obtained from electronic integration measurements using flame ionization detection (FID). Results: our results demonstrated that EOLM is rich in terpenes with Germacrene-D (31.27%) and &#946;-caryophyllene (28.15%) as the major components. EOLM (0.12&#8722;0.48 g/mL) was ineffective in scavenging DPPH radical, and chelating Fe(II), but showed reducing activity at 0.24 g/mL and 0.48 g/mL. In in vivo studies, exposure of D. melanogaster to EOLM (0.12&#8722;0.48 g/mL) for 5 h resulted in 10% mortality; no change in oxidative stress parameters such as total thiol, non-protein thiol, and malondialdehyde contents, in comparison to control (p &gt; 0.05). Conclusions: taken together, our results indicate EOLM may not be toxic at the concentrations tested, and thus may not be suitable for the development of new botanical insecticides, such as fumigants or spray-type control agents against Drosophila melanogaster

Antibacterial effect, efflux pump inhibitory (NorA, TetK and MepA) of Staphylococcus aureus and in silico prediction of α, β and δ-damascone compounds

Objective: The present study aimed to evaluate the antibacterial effect and inhibitory capacity against NorA, TetK and MepA efflux pump of Staphylococcus aureus multiresistant by in vitro and in silico approach of α, β and δ-damascone compounds. Results: The compounds α, β and δ-damascone showed a clinically relevant effect against S. aureus ATCC 6538 standard strain. A modulating effect was also observed in association with antibiotics against MDR strains. Regarding the inhibition of the efflux pump, the compounds showed a modulating effect with antibiotics, against SA-1199, SA-1199B, SA IS-58 and K2068. Only δ-damascone demonstrated an efflux pump inhibitory effect. Regarding ADME properties, α, β and δ-damascone showed similar physicochemical properties with good pharmacokinetic characteristics, such as lipophilicity, oral bioavailability and low toxicity. In addition, they exhibited the binding energy and Ligand Efficiency (LE) −81.17 (5.4), −77.48(-5.4) and −64.55 (-5.1), which shows good interactions with the critical residues of the MepA receptor. Conclusions: From the results it is concluded that the compounds α, β and δ-damascone do not have antibacterial activity, but show a modulating effect in association with antibiotics, as well as not showing direct activity on the efflux pump, but they do have a modulating effect with antibiotics and with EtBr (α and β-damascone)

Efflux Pump (QacA, QacB, and QacC) and β-Lactamase Inhibitors? An Evaluation of 1,8-Naphthyridines against <i>Staphylococcus aureus</i> Strains

The bacterial species Staphylococcus aureus presents a variety of resistance mechanisms, among which the expression of β-lactamases and efflux pumps stand out for providing a significant degree of resistance to clinically relevant antibiotics. The 1,8-naphthyridines are nitrogen heterocycles with a broad spectrum of biological activities and, as such, are promising research targets. However, the potential roles of these compounds on bacterial resistance management remain to be better investigated. Therefore, the present study evaluated the antibacterial activity of 1,8-naphthyridine sulfonamides, addressing their ability to act as inhibitors of β-lactamases and efflux pump (QacA/B and QacC) against the strains SA-K4414 and SA-K4100 of S. aureus. All substances were prepared at an initial concentration of 1024 μg/mL, and their minimum inhibitory concentrations (MIC) were determined by the broth microdilution method. Subsequently, their effects on β-lactamase- and efflux pump-mediated antibiotic resistance was evaluated from the reduction of the MIC of ethidium bromide (EtBr) and β-lactam antibiotics, respectively. The 1,8-naphthyridines did not present direct antibacterial activity against the strains SA-K4414 and SA-K4100 of S. aureus. On the other hand, when associated with antibiotics against both strains, the compounds reduced the MIC of EtBr and β-lactam antibiotics, suggesting that they may act by inhibiting β-lactamases and efflux pumps such as QacC and QacA/B. However, further research is required to elucidate the molecular mechanisms underlying these observed effects

Comparative Antibacterial and Efflux Pump Inhibitory Activity of Isolated Nerolidol, Farnesol, and α-Bisabolol Sesquiterpenes and Their Liposomal Nanoformulations

The efflux systems are considered important mechanisms of bacterial resistance due to their ability to extrude various antibiotics. Several naturally occurring compounds, such as sesquiterpenes, have demonstrated antibacterial activity and the ability to inhibit efflux pumps in resistant strains. Therefore, the objective of this research was to analyze the antibacterial and inhibitory activity of the efflux systems NorA, Tet(K), MsrA, and MepA by sesquiterpenes nerolidol, farnesol, and α-bisabolol, used either individually or in liposomal nanoformulation, against multi-resistant Staphylococcus aureus strains. The methodology consisted of in vitro testing of the ability of sesquiterpenes to reduce the Minimum Inhibitory Concentration (MIC) and enhance the action of antibiotics and ethidium bromide (EtBr) in broth microdilution assays. The following strains were used: S. aureus 1199B carrying the NorA efflux pump, resistant to norfloxacin; IS-58 strain carrying Tet(K), resistant to tetracyclines; RN4220 carrying MsrA, conferring resistance to erythromycin. For the EtBr fluorescence measurement test, K2068 carrying MepA was used. It was observed the individual sesquiterpenes exhibited better antibacterial activity as well as efflux pump inhibition. Farnesol showed the lowest MIC of 16.5 µg/mL against the S. aureus RN4220 strain. Isolated nerolidol stood out for reducing the MIC of EtBr to 5 µg/mL in the 1199B strain, yielding better results than the positive control CCCP, indicating strong evidence of NorA inhibition. The liposome formulations did not show promising results, except for liposome/farnesol, which reduced the MIC of EtBr against 1199B and RN4220. Further research is needed to evaluate the mechanisms of action involved in the inhibition of resistance mechanisms by the tested compounds