ANTIMICROBIAL PEPTIDE P34 INFLUENCES GENE EXPRESSION OF LISTERIA MONOCYTOGENES GROWING IN SOFT CHEESE

Objective: To evaluate whether antimicrobial substances produced by autochthonous lactic acid bacteria (LAB) from Minas Frescal cheese are able to enhance the activity of bacteriocin P34 against Listeria monocytogenes and investigate the influence of P34 in specific gene expression of this bacterium after the inoculation in Minas Frescal cheese.Methods: Bacillus sp. P34 and L. monocytogenes ATCC 7644 were used in this study. The antimicrobial peptide P34 was purified and applied (0, 800 or 6400 AU/ml) to cheese surface before inoculation with L. monocytogenes. Antimicrobial activity and synergism were detected using the agar diffusion technique. Expression levels of D-Alanine-D-alanyl carrier protein ligase (dltA), Putative phospholipid lysinylation (Imo 1695) and EIIABMan of mannose-specific PTS (mptA) mRNAs in bacteriocin-treated L. monocytogenes growing in Minas Frescal cheese were determined using real-time PCR.Results: The peptide P34 showed increased antilisterial activity when combined with culture supernatants of some selected LAB isolated from Minas Frescal cheese. The addition of peptide P34 to cheese caused a decrease of up to 3 log cycles in viable counts of artificially inoculated L. monocytogenes. The influence of peptide P34 on the expression of genes associated with components of the cell surface of L. monocytogenes was investigated by real-time PCR. A significant increase in the expression of the genes dltA, Imo 1695 and mptA was observed after 96 h in the presence of peptide P34.Conclusion: These results suggest that the peptide P34 influences the expression of genes involved in D-alanylation of teichoic acids and lipoteichoic acids and lysination of the cell membrane of phospholipids

DEVELOPMENT OF NANOEMULSION CONTAINING PELARGONIUM GRAVEOLENS OIL: CHARACTERIZATION AND STABILITY STUDY

Objective: To develop, characterize and evaluate the stability of nanoemulsions containing geranium oil (NEG) at different temperatures (4 °C, 25 °C and 45 °C) for 90 d.Methods: The quantification of oil in the nanostructure was performed by gas chromatography–mass spectrometry (GC-MS). The NEG was prepared in Ultra-Turrex and characterized by determining the particle size, polydispersity indices and pH. The thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) to evaluate the thermal stability of the compounds, the thermal events and morphological analyses of NEG, respectively.Results: The results allow us to suggest that the use the ultra-turrax method is a strategy good to NEG preparation. The stability of the NEG was strongly influenced by storage temperature, with droplet size increasing rapidly at higher temperatures (45 °C), which was attributed to coalescence near the phase inversion temperature. The NEG submitted the low temperatures (4±2 °C) remained with the same particle size value (164 nm). However, the citronellol and geraniol showed a significant reduction throughout the test even in these conditions of temperature. Thermogram of NEG shows the crystallization peak at the cooling cycle in-20.1 °C and a melting was observed at 1.5 °C. TEM images indicated that NEG was spherical and nanometric.Conclusion: The proposed Ultra-Turrax method is simple which prevents volatilization of GO for the production of NEG. The formulations presented good physicochemical characteristics and stability for 90 d was only achieved in 4 °C

Nanocapsules With Naringin And Naringenin Affect Hepatic and Renal Energy Metabolism Without Altering Serum Markers of Toxicity in Rats

Naringin and naringenin are flavonoids found in citrus fruits and have several health benefits, however these compounds are susceptible to degradation, limiting their therapeutic application. To solve this problem, an alternative is to incorporate them into nanocapsules. The aim of this work was to evaluate the toxicity of these nanocapsules against renal and hepatic serum markers and also on the activities of pyruvate kinase, Mg2+-ATPase, and creatine kinase. Nanocapsules containing naringin and naringenin, nanocapsules without the active compounds and the compounds in their free form were administered orally, once a day, for 28 days. After treatment, the serum levels of hepatic and renal markers were not altered, nor the activities of pyruvate kinase tissue, however, the treatment of nanocapsules with flavonoids increased the activities of mitochondrial creatine kinase in the kidney and hepatic Mg2+-ATPase. Thus, renal and hepatic serum markers, which are normally used as indicators of toxicity, did not change after the period of administration of the nanoparticles. However, the activities of important enzymes of the energy metabolism in these organs were affected. Our findings reinforce that nanomaterial testing for toxicity needs to go beyond traditional methods to ensure the safe use of nanoparticles for therapeutic purposes

NANOPARTÍCULA LIPÍDICA COM QUERCETINA NO TRATAMENTO DO CÂNCER DE PÂNCREAS: UMA REVISÃO DA LITERATURA

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