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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11852
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Item Antibacterial activity of 7-epiclusianone and Its novel copper metal complex on Streptococcus spp. isolated from bovine mastitis and their cytotoxicity in MAC-T cells(Molecules, 2017-05-17) Barros, Mariana de; Perciano, Pedro Griffo; Santos, Marcelo Henrique dos; Oliveira, Leandro Licursi De; Costa, Éderson D’Martin; Moreira, Maria Aparecida ScatamburloMastitis is an inflammation of mammary gland parenchyma that adversely affects bovine health and dairy production worldwide despite significant efforts to eradicate it. The aim of this work was to characterize the antimicrobial activity of 7-epiclusianone (7-epi), a compound extracted from the Rheedia brasiliensis fruit, its complex with copper against Streptococcus spp. isolated from bovine mastitis, and to assess their cytotoxicity to bovine mammary alveolar cells (MAC-T). The complex 7-epiclusianone-Cu (7-epi-Cu) was an amorphous green solid with optical activity. Its vibrational spectrum in the infrared region showed absorption bands in the high-frequency region, as well as bands that can be attributed to the unconjugated and conjugated stretching of the free ligand. The complex was anhydrous. One of the tested bacterial strains was not sensitive to the compounds, while the other three had MIC values of 7.8 µg mL−1 and minimum bactericidal concentration (MBC) values between 15.6 and 31.3 µg mL−1. These two compounds are bacteriostatic, did not cause damage to the cell wall and, at sub-inhibitory concentrations, did not induce bacterial adhesion. The compounds were not cytotoxic. Based on these results, 7-epi and 7-epi-Cu exhibited desirable antimicrobial properties and could potentially be used in bovine mastitis treatment.Item Synergism of plant compound with traditional antimicrobials against Streptococcus spp. Isolated from bovine mastitis(Frontiers in Microbiology, 2018-06) Maia, Natasha L.; Barros, Mariana de; Oliveira, Leandro L. de; Cardoso, Silvia A.; Santos, Marcelo H. dos; Pieri, Fabio A.; Ramalho, Teodorico C.; Cunha, Elaine F. F. da; Moreira, Maria A. S.Mastitis is an inflammation of the mammary gland that causes major losses in the dairy industry. Streptococcus spp. are among the main agents of this disease. Increased resistance to antibiotics is one of the causes of therapeutic failure. Plants, due to their broad chemodiversity, are an interesting source of new molecules with antibacterial activity. Using these compounds along with traditional antibiotics is a possible method for reversing resistance. The objective of this work was to determine the interactions between the activities of guttiferone-A and 7-epiclusianone, two active substances isolated from the fruits of Garcinia brasiliensis, and traditional antibiotics against Streptococcus spp. isolated from bovine mastitis and known to be resistant to them. First, the MIC for the antibiotics and bioactive compounds was determined, followed by their activities, alone and in combination. Then, their cytotoxicity was measured in bovine mammary epithelial cells. Finally, molecular docking simulations were performed to elucidate molecular details of the interactions between β-lactamase and the compounds binding to it (clavulanic acid, ampicillin, 7-epiclusianone, and guttiferone-A). The bacterial isolates were resistant to ampicillin and gentamicin. Both antibiotics showed predominantly synergistic antibacterial activities in combination with guttiferone-A or 7-epiclusianone. These two active substances were not cytotoxic at synergistic concentrations and both showed strong binding to β-lactamase, which may explain the reversal of ampicillin resistance. These substances are promising for the treatment of bovine mastitis.