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Juazeiro do Norte, Brazil

Coutinho H.D.M.,Regional University of Cariri | Costa J.G.M.,Leao Sampaio College | Falcao-Silva V.S.,Federal University of Paraiba | Siqueira-Junior J.P.,Federal University of Paraiba | Lima E.O.,Federal University of Paraiba
Pharmaceutical Biology | Year: 2010

Context: Bacterial infectious agents represent a risk to populations, where they are responsible for the high morbidity and mortality. In combating these pathogens, our main line of defense is the use of antibiotics. However, the indiscriminate use of these drugs select resistant strains to these same drugs. Objective: In this study the ethanol extract of Hyptis martiusii Benth. (EEHM) (Lamiaceae) was tested for its antimicrobial activity against aminoglycoside multi-resistant Staphylococcus aureus (MRSA). Materials and methods: In this study, the ethanol extract of H. martiusii was prepared and tested with chlorpromazine for its antimicrobial activity using the microdilution method. Chlorpromazine and the ethanol extract were used alone and also in combination with aminoglycosides against a MRSA strain resistant to these antibiotics to determine the participation of efflux systems in resistance mechanisms. The FIC index was calculated and evaluated by the checkerboard method. Results: A potentiating effect between this extract and aminoglycosides was demonstrated. Similarly, a potentiating effect of chlorpromazine with kanamycin was detected, indicating the involvement of an efflux system in the resistance to this aminoglycoside. The checkerboard method with combinations of aminoglycosides and EEHM demonstrated additive effect with kanamycin and gentamicin. It is therefore suggested that extracts from H. martiusii could be used as a source of plant-derived natural products with resistance- modifying activity. Conclusion: This is the first report about the modifying antibiotic activity of Hyptis martiusii, constituting a new approach against bacterial resistance to antibiotics as aminoglycosides. © 2010 Informa Healthcare USA, Inc.

Coutinho H.D.M.,Health Science University | Costa J.G.M.,Leao Sampaio College | Lima E.O.,Federal University of Paraiba | Siqueira-Junior J.P.,Federal University of Paraiba
International Journal of Food Properties | Year: 2010

The antibacterial activity of ethanol extracts of Eugenia jambolana L. and E. uniflora L. (Myrtaceae) were evaluated by agar-well diffusion method and MICs by microdillution method. E. jambolana showed antibacterial activity against MRSA strains (MIC < 1024 μg/mL). E. uniflora did not show significant antibacterial activity (MIC > 1024 μg/mL). It is therefore suggested that extracts from E. jambolana could be used as an anti- Staphylococcus agent. When compared with Methicillin and Gentamicin, the extract was more effective against, being a promising antibacterial agent. Based on the author's knowledge, this is the first report about the antibacterial activity of leave ethanol extract from Eugenia jambolana. Copyright © Taylor and Francis Group, LLC.

Morais-Braga M.F.B.,Regional University of Cariri | Sales D.L.,Regional University of Cariri | Carneiro J.N.P.,Regional University of Cariri | Machado A.J.T.,Regional University of Cariri | And 11 more authors.
Microbial Pathogenesis | Year: 2016

The therapeutic combinations have been increasingly used against fungal resistance. Natural products have been evaluated in combination with pharmaceutical drugs in the search for new components able to work together in order to neutralize the multiple resistance mechanisms found in yeasts from the genus Candida. The aqueous and hydroethanolic extracts from Psidium brownianum Mart ex DC. and Psidium guajava L. species were evaluated for their potential to change the effect of commercial pharmaceutical drugs against Candida albicans and Candida tropicalis strains. The tests were performed according to the broth microdilution method. Plate readings were carried out by spectrophotometry, and the data generated the cell viability curve and IC50 of the extracts against the yeasts. A chemical analysis of all the extracts was performed for detection and characterization of the secondary metabolites. The total phenols were quantified in gallic acid eq/g of extract (GAE/g) and the phenolic composition of the extracts was determined by HPLC. Fluconazole and all extracts presented high Minimum Inhibitories Concentrations (MICs). However, when associated with the extracts at sub-inhibitory concentrations (MIC/16), fluconazole had its effect potentiated. A synergistic effect was observed in the combination of fluconazole with Psidium brownianum extracts against all Candida strains. However, for Psidium guajava extracts the synergistic effect was produced mainly against the Candida albicans LM77 and Candida tropicalis INCQS 400042 strains. The IC50 values of fluconazole ranged from 19.22 to 68.1 μg/mL when it was used alone, but from 2.2 to 45.4 μg/mL in the presence of the extracts. The qualitative chemical characterization demonstrated the presence of phenols, flavonoids and tannins among the secondary metabolites. The concentration of total phenols ranged from 49.25 to 80.77 GAE/g in the P. brownianum extracts and from 68.06 to 82.18 GAE/g in the P. guajava extracts. Our results indicated that both P. brownianum and P. guajava extracts are effective on potentiating the effect of fluconazole, and therefore, these plants have the potential for development of new effective drugs for treating fungal infections. © 2016 Elsevier Ltd.

Francisco E.B.,Regional University of Cariri | Matias E.F.,Regional University of Cariri | Oliveira D.R.,Regional University of Cariri | Ramos A.G.B.,Regional University of Cariri | And 10 more authors.
Journal of Medicinal Plant Research | Year: 2011

Croton campestris A. St.-Hill., known as Velame do campo (Euphorbiaceae), native of the Brazilian Northeastern region, is used in the popular medicine as decoction against several diseases as inflammations, hematological disturbances, flu and gastritis. The study analyzed the chemical composition and the antibacterial activity against bacterial strains of Escherichia coli and Staphylococcus aureus of the hydroalcoholic extract of the leaves of the C. campestris (HEFCC). The inhibition of the bacterial growth was demonstrated for the bacteria tested with MIC values ≥ 1024 μg/ml. When combined with aminoglycosides (gentamicin, kanamycin, amikacin and neomycin), the extract demonstrated synergistic effect. This result showed that HEFCC can be used as promisor font of new antimicrobial compounds for pathogenic diseases. © 2011 Academic Journals.

Coutinho H.D.M.,Regional University of Cariri | Costa J.G.M.,Regional University of Cariri | Costa J.G.M.,Leao Sampaio College | Lima E.O.,Federal University of Paraiba
Journal of Medicinal Food | Year: 2010

This is the first report about the modifying antibiotic activity of Eugenia uniflora L. and Eugenia jambolanum L. In this study the ethanol extract of E. uniflora and E. jambolanum was tested for their antimicrobial activity against strains of Escherichia coli. The growth of the two strains of E. coli bacteria tested was not inhibited in a clinically relevant form by the extract. The minimal inhibitory concentration was ≥1,024 μg/mL for both strains of E. coli assayed. Synergism between this extract and gentamicin was demonstrated. In the same extract synergism was observed between chlorpromazine and kanamycin and between amikacin and tobramycin, indicating the involvement of an efflux system in the resistance to these aminoglycosides. It is therefore suggested that extracts from E. uniflora L. and E. jambolanum L. could be used as a source of plant-derived natural products with modifying antibiotic activity to gentamicin. © Mary Ann Liebert, Inc.

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