Anti-Escherichia coli effect of Hibiscus sabdariffa L. in a meat model

Abstract Hibiscus sabdariffa L. is used in traditional medicine because of its bioactive properties, such as antioxidant and antibacterial. Escherichia coli is a Gram-negative bacteria and as an indicator of contamination in food. The aim of this work was to evaluate the anti-Escherichia coli effect and the change in pH on the control of aerobic mesophilic microorganisms, using hydroethanolic extract of H. sabdariffa L. in different concentrations in a meat model, verifying its potential as food additive for microbiological stability on ground beef during cooling storage. For the preparation of the treatments, the meat experimental units were elaborated with different concentrations of the vegetal extract (5, 10, 15 and 20%), ground beef and contaminated with E. coli. For pH evaluation, the meat experimental units were added different percentages of hydroethanolic extract. The H. sabdariffa L. antibacterial action reduced two logarithmic levels in practically all treatments. The best pH result was obtained in the meat containing 30% of the extract. The hydroethanolic extracts of Hibiscus sabdariffa L. showed anti-Escherichia coli activity in the presence of refrigerated ground beef. Analyzing the pH results and the count of aerobic mesophilic bacteria, it is possible this extract to be used as a natural food additive.

Atividade desinfetante anti-Staphylococcus aureus meticilina resistentes e compostos flavonóides em Achyrocline satureioides Lam. (macela) / Actividad desinfectante anti-Staphylococcus aureus meticilina resistentes y compuestos flavonoides en Achyrocline satureioides Lam. (macela) / Disinfectant activity against methicillin-resistant Staphylococcus aureus and flavonoid compounds in Achyrocline satureioides Lam. (macela)

Introdução: os Staphylococcus aureus resistentes a meticilina (MRSA) estão envolvidos nas infecções nosocomiais, na comunidade, nos animais de companhia e nos animais para produção de alimentos, estando a desinfecção e a antissepsia entre os procedimentos adotados como medidas de controle. O fenômeno de resistência bem como a necessidade de insumos de higiene para uso em sistemas de criação animal baseados no modelo agroecológico motivaram o desenvolvimento do trabalho com Achyrocline satureioides (Lam.) DC.- Asteraceae (macela). Objetivos: testar atividade anti-MRSA de extrações da planta, e quantificar a presença de flavonóides. Método: os extratos decoto e hidroetanólico foram elaborados na proporção 5 g dos capítulos florais secos para 100 mL de solvente (concentração 50 mg/mL). A ação antibacteriana foi determinada pelo teste europeu de suspensão quantitativa para avaliar a atividade de desinfetantes e antissépticos, frente o padrão Staphylococcus aureus ATCC 6538 e 51 isolados MRSA, nas densidades populacionais iniciais de 106, 105 e 10 4 UFC/mL. Para quantificação de flavonóides foi usada cromatografia a líquido de alta eficiência. Resultados: frente a cepa padrão e aos 51 isolados, o decocto demonstrou maior atividade bactericida a partir das 8 h, inativando todos até às 24 h. Frente amostra de 21 isolados, na densidade populacional 106 UFC/mL o extrato hidroetanólico em quatro horas de contato já havia inativado 85,7 por ciento deles, tendo o restante sofrido redução populacional. Na densidade 104 UFC/mL 71 por ciento estavam inativados com uma hora de contato, e todos às 4 h. No decocto foram quantificadas, na média das concentrações em mg/100 mL, os metabólitos quercetina (66,96), luteolina (22,65) e 3-O -metilquercetina (81,42). Conclusão: as evidências observadas sugerem o potencial das soluções, principalmente o extrato hidroetanólico, para uso de modo direto sobre as fontes de infecção em procedimentos de desinfecção, de descontaminação ou de antissepsia, ou ainda em formulações que lhe sirvam de veículo(AU)

Introducción: Staphylococcus aureus resistentes a meticilina (MRSA) están involucrados en las infecciones nosocomiales, en la comunidad, en los animales de compañía y en los animales para la producción de alimentos, estando la desinfección y antisepsia entre las medidas para su control. El fenómeno de la resistencia y la necesidad de insumos de higiene para la ganadería agroecológica han motivado el trabajo con Achyrocline satureioides (Lam.) DC. - Asteraceae (Macela). Objetivo: evaluar la actividad anti-MRSA de extractos de la planta y cuantificar la presencia de flavonoides. Métodos: por el método de suspensión de evaluación cuantitativa de la acción bactericida de desinfectantes y antisépticos químicos, la decocción y el extracto hidroetanólico, en la proporción 5 g de los capítulos florales secos en 100 mL de solvente, fueron confrontados con el patrón Staphylococcus aureus ATCC 6538 y 51 MRSA en las densidades poblacionales iniciales de 106, 105 y 104 UFC/mL. Para la cuantificación de flavonoides se utilizó cromatografía líquida de alta eficacia. Resultados: frente a la cepa estándar y a los 51 aislados, la decocción demostró mayor actividad a partir de las 8 h, inactivando todos hasta 24 h. Frente a la muestra de 21 aislados, a la densidad poblacional 106 UFC/mL en cuatro horas de contacto el extracto hidroetanólico inactivó el 85,7 por ciento de ellos. A la densidad 104 UFC/mL 71 percent fueron inactivados en una hora de contacto, y todos hasta las 4 h. En la decocción se cuantificaron (concentraciones promedio en mg/100 mL) los metabolitos quercetina (66,96), luteolina (22,65) y 3-O-metilquercetina (81,42). Conclusión: las evidencias observadas sugieren el potencial de las soluciones, principalmente el extracto hidroetanólico para el uso de modo directo sobre las fuentes de infección en procedimientos de desinfección, de descontaminación o de antisepsia, o también en formulaciones que le sirvan de vehículo(AU)

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is present in nosocomial infections, in the community, in pets and in farm animals. Disinfection and antisepsis are among its control measures. The phenomenon of resistance and the need of hygiene products for agroecological cattle raising have aroused our interest in the species Achyrocline satureioides (Lam.) DC. - Asteraceae (macela). Objective: Evaluate the anti-MRSA activity of extracts from the plant and quantify the content of flavonoids. Methods: The methods used were quantitative suspension for evaluation of bactericidal activity of chemical disinfectants and antiseptics, decoction and hydroethanolic extract in a proportion of 5 g of dry floral capitula in 100 ml solvent, and confrontation with the pattern Staphylococcus aureus ATCC 6538 and 51 MRSA in initial population densities of 106, 105 and 104 UFC/ml. Quantification of flavonoids was based on high performance liquid chromatography. Results: The decoction displayed greater activity against the standard strain and the 51 isolates as of 8 h, inactivating all by 24 h. Against the sample of 21 isolates, at a population density of 106 UFC/ml in four hours of contact, the hydroethanolic extract inactivated 85.7 percent of them. At a density of 104 UFC/ml, 71 percent were inactivated in one hour of contact, and all by 4 h. The metabolites quercetin (66.96), luteolin (22,65) and 3-O-methylquercetin (81,42) were quantified in the decoction (average concentrations in mg / 100 ml). Conclusion: The evidence observed points to the potential of the solutions, mainly the hydroethanolic extract, for direct use against infection sources in disinfection, decontamination or antisepsis procedures, as well as in formulations serving as vehicles(AU)

Atividade desinfetante anti-Staphylococcus aureus meticilina resistentes e compostos flavonóides em Achyrocline satureioides Lam. (macela) / Disinfectant activity against methicillin-resistant Staphylococcus aureus and flavonoid compounds in Achyrocline satureioides Lam. (macela)

Introdução: os Staphylococcus aureus resistentes a meticilina (MRSA) estão envolvidos nas infecções nosocomiais, na comunidade, nos animais de companhia e nos animais para produção de alimentos, estando a desinfecção e a antissepsia entre os procedimentos adotados como medidas de controle. O fenômeno de resistência bem como a necessidade de insumos de higiene para uso em sistemas de criação animal baseados no modelo agroecológico motivaram o desenvolvimento do trabalho com Achyrocline satureioides (Lam.) DC.- Asteraceae (macela). Objetivos: testar atividade anti-MRSA de extrações da planta, e quantificar a presença de flavonóides. Método: os extratos decoto e hidroetanólico foram elaborados na proporção 5 g dos capítulos florais secos para 100 mL de solvente (concentração 50 mg/mL). A ação antibacteriana foi determinada pelo teste europeu de suspensão quantitativa para avaliar a atividade de desinfetantes e antissépticos, frente o padrão Staphylococcus aureus ATCC 6538 e 51 isolados MRSA, nas densidades populacionais iniciais de 106, 105 e 10 4 UFC/mL. Para quantificação de flavonóides foi usada cromatografia a líquido de alta eficiência. Resultados: frente a cepa padrão e aos 51 isolados, o decocto demonstrou maior atividade bactericida a partir das 8 h, inativando todos até às 24 h. Frente amostra de 21 isolados...(AU)

Introducción: Staphylococcus aureus resistentes a meticilina (MRSA) están involucrados en las infecciones nosocomiales, en la comunidad, en los animales de compañía y en los animales para la producción de alimentos, estando la desinfección y antisepsia entre las medidas para su control. El fenómeno de la resistencia y la necesidad de insumos de higiene para la ganadería agroecológica han motivado el trabajo con Achyrocline satureioides (Lam.) DC. - Asteraceae (Macela). Objetivo: evaluar la actividad anti-MRSA de extractos de la planta y cuantificar la presencia de flavonoides. Métodos: por el método de suspensión de evaluación cuantitativa de la acción bactericida de desinfectantes y antisépticos químicos, la decocción y el extracto hidroetanólico, en la proporción 5 g de los capítulos florales secos en 100 mL de solvente, fueron confrontados con el patrón Staphylococcus aureus ATCC 6538 y 51 MRSA en las densidades poblacionales iniciales de 106, 105 y 104 UFC/mL. Para la cuantificación de flavonoides se utilizó cromatografía líquida de alta eficacia. Resultados: frente a la cepa estándar y a los 51 aislados, la decocción demostró mayor actividad a partir de las 8 h, inactivando todos hasta 24 h. Frente a la muestra de 21 aislados, a la densidad poblacional 106 UFC/mL en cuatro horas de contacto el extracto hidroetanólico inactivó el 85,7 por ciento de ellos. A la densidad 104 UFC/mL 71 por ciento fueron inactivados en una hora de contacto, y todos hasta las 4 h. En la decocción se cuantificaron (concentraciones promedio en mg/100 mL) los metabolitos quercetina (66,96), luteolina (22,65) y 3-O-metilquercetina (81,42). Conclusión: las evidencias observadas sugieren el potencial de las soluciones, principalmente el extracto hidroetanólico para el uso de modo directo sobre las fuentes de infección en procedimientos de desinfección, de descontaminación o de antisepsia, o también en formulaciones que le sirvan de vehículo(AU)

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is present in nosocomial infections, in the community, in pets and in farm animals. Disinfection and antisepsis are among its control measures. The phenomenon of resistance and the need of hygiene products for agroecological cattle raising have aroused our interest in the species Achyrocline satureioides (Lam.) DC. - Asteraceae (macela). Objective: Evaluate the anti-MRSA activity of extracts from the plant and quantify the content of flavonoids. Methods: The methods used were quantitative suspension for evaluation of bactericidal activity of chemical disinfectants and antiseptics, decoction and hydroethanolic extract in a proportion of 5 g of dry floral capitula in 100 ml solvent, and confrontation with the pattern Staphylococcus aureus ATCC 6538 and 51 MRSA in initial population densities of 106, 105 and 104 UFC/ml. Quantification of flavonoids was based on high performance liquid chromatography. Results: The decoction displayed greater activity against the standard strain and the 51 isolates as of 8 h, inactivating all by 24 h. Against the sample of 21 isolates, at a population density of 106 UFC/ml in four hours of contact, the hydroethanolic extract inactivated 85.7 percent of them. At a density of 104 UFC/ml, 71 percent were inactivated in one hour of contact, and all by 4 h. The metabolites quercetin (66.96), luteolin (22,65) and 3-O-methylquercetin (81,42) were quantified in the decoction (average concentrations in mg / 100 ml). Conclusion: The evidence observed points to the potential of the solutions, mainly the hydroethanolic extract, for direct use against infection sources in disinfection, decontamination or antisepsis procedures, as well as in formulations serving as vehicles(AU)

The effects of Brazilian propolis on etiological agents of mastitis and the viability of bovine mammary gland explants.

The objective of this study was to evaluate in vitro the antimicrobial activity of Brazilian propolis from Urupema, São Joaquim, and Agua Doce (Santa Catarina State) and green propolis from Minas Gerais State, and the effects of propolis on bovine mammary gland explant viability. The propolis samples differed in flavonoid content and antioxidant activity. Green propolis showed the highest content of flavonoids, followed by the sample from São Joaquim. The propolis from Urupema showed the lowest flavonoid content along with the lowest antioxidant activity. The total phenolics were similar across all studied samples. Despite phytochemical differences, the propolis samples from Minas Gerais, São Joaquim, and Urupema presented the same level of antimicrobial activity against Staphylococcus aureus strains. The reduction in S. aureus growth was, on average, 1.5 and 4 log10 times at 200 and 500 µg/mL, respectively. At concentrations of 1,000 µg/mL, all propolis reduced bacterial growth to zero. On the other hand, when the propolis were tested against strains of Escherichia coli, the samples presented weak antimicrobial activity. Mammary explants were maintained in culture for 96h without a loss in viability, demonstrating the applicability of the model in evaluating the toxicity of propolis. The origin and chemical composition of the propolis had an effect on mammary explant viability. We encountered inhibitory concentrations of 272.4, 171.8, 63.85, and 13.26 µg/mL for the propolis from Água Doce, Urupema, São Joaquim, and Mina Gerais, respectively. A clear association between greater antimicrobial activity and toxicity for mammary explants was observed. Of all propolis tested, the Urupema sample was noteworthy, as it showed antimicrobial activity at less toxic concentrations than the other samples, reducing bacterial growth to an average of 9.3 × 10(2) cfu/mL after 6h of contact using 200 µg/mL of extract. The results demonstrate the potential for Brazilian propolis in the treatment of mastitis, although effectiveness is dependent on geographical origin and concentration. The results from the mammary gland explant assays are promising for the investigation of other natural products with antimicrobial and anti-inflammatory properties that can be used in the intramammary treatment of subclinical mastitis and during dry cow therapy.

Acaricidal activity of Calea serrata (Asteraceae) on Boophilus microplus and Rhipicephalus sanguineus.

Calea serrata (Asteraceae) is an endemic Southern Brazilian plant species used for religious and medicinal purposes. Previous study revealed the presence of chromenes, a class of natural compounds that possess insecticidal properties. This study reports the effect of the hexane extract from the aerial parts of this plant on egg hatchability, egg production and mortality rates of newly hatched larvae of the cattle tick Boophilus microplus. Larvae of Rhipicephalus sanguineus, the brown dog tick, received the same treatment. The extract was toxic to the eggs of B. microplus and to the larvae of both B. microplus and R. sanguineus.

Antifungal activity of some coumarins obtained from species of Pterocaulon (Asteraceae).

Fractionation of antifungal hexane extracts of the aerial parts of three Pterocaulon spp., Pterocaulon alopecuroides, Pterocaulon balansae and Pterocaulon polystachyum (Asteraceae) from South Brazil traditionally used to treat animal mycoses, afforded the coumarins 5-methoxy-6,7-methylenedioxycoumarin, 7-(2',3'-epoxy-3'-methylbutyloxy)-6-methoxycoumarin, 6,7-methylenedioxycoumarin (ayapin), along with a mixture of 6-hydroxy-7-(3'-methylbutyl-2'-en-oxy)-coumarin (prenyletin) and 6-methoxy-7-(3'-methylbutyl-2'-en-oxy)-coumarin (prenyletin-methyl-ether). Among the different components of the active extracts, only the mixture of prenyletin and prenyletin-methyl-ether isolated from Pterocaulon polystachyum showed activity against Cryptococcus neoformans, Microsporum gypseum, Trichophyton rubrum and Trichophyton mentagrophytes. Nevertheless their MIC values were higher than the MIC of the original extracts, suggesting that the mixture but not only one compound would be the responsible for the activity detected in these Pterocaulon species.

Ethnoveterinary medicine in the search for antimicrobial agents: antifungal activity of some species of Pterocaulon (Asteraceae).

Based on informal interview, ethnoveterinary information about plants used in the treatment of skin diseases were obtained. Plants from the genus Pterocaulon (Asteraceae) known as "quitoco" are used to treat problems popularly diagnosed as "mycoses", which can have both fungic and bacterial etiology. In order to validate this traditional practice, the crude methanolic extracts and fractions from the aerial parts of three species of Pterocaulon (Pterocaulon alopecuroides (Lam.) D.C., Pterocaulon balansae Chodat. and Pterocaulon polystachyum D.C.) grown in southern Brazil were analyzed for the in vitro antifungal activity against a panel of standardized and clinical opportunistic pathogenic yeasts and filamentous fungi including dermatophytes by the agar dilution method. The crude methanolic extract of Pterocaulon alopecuroides was the most active followed by the extract of Pterocaulon polystachyum. Pterocaulon balansae crude methanolic extract was the less active but its lipophilic fractions showed remarkable activity mainly against the dermatophytes.