Atividade antimicrobiana e efeito combinado sobre drogas antifúngicas e antibacterianas do fruto de Morinda citrifolia L

La aparición de microorganismos resistentes y la toxicidad asociada a los antimicrobianos aumenta la necesidad de investigar nuevos principios activos. Morinda citrifolia L., es una planta fructífera utilizada popularmente como antibacteriano y con otros diversos usos farmacológicos. Posee diversos metabolitos primarios y secundarios, principalmente flavonoides, triterpenoides y alcaloides. Este estudio tuvo como objetivo ensayar la potencial actividad antimicrobiana y moduladora de los extractos obtenidos de su fruta. Los extractos de las frutas fueron testados tanto para determinar el efecto antimicrobiano como también utilizándolo en combinación con agentes antibacterianos y antifúngicos contra microorganismos patógenos, por el método de microdilución en caldo. Se observó que la asociación entre antibióticos y extractos dió resultados clínicamente significativos en pruebas con bacterias Pseudomonas aeruginosa y Escherichia coli.The rising of the drug resistant microrganisms and the toxicity related with the antimicrobial drugs enhances the necessity about the search of new bioactive compounds. Morinda citrifolia L. is a fruit tree traditionally used as antibacterial and with several other pharmacological properties. This plant presents several phytocompounds as flavonoids, alkaloids and triterpenes. The objective of this work was assay the antimicrobial and modulatory potential of the fruit extract. The extract was assayed alone and associated with antibiotics and antifungals against pathogenic microrganisms using the microdilution assay. The results demonstrated that the association between extract and antimicrobial drugs resulted in a potentiation of the drug activity clinically relevant against Pseudomonas aeruginosa and Escherichia coli.The surveillance of resistant microrganisms and the toxicity related with antimicrobial drugs enhances the necessity of research about new remedies. Morinda citrifolia is a plant commonly used as antibacterial, analgesic, and several other bioactivities, presenting aminoacids, anthraquinones, flavonoids, sterols, triterpenes and alkaloids. The aim of this work was evaluate the antimicrobial and the antibiotic-modulatory effect of the fruit extract. The extract was assayed alone and in association with antibiotic and antifungal drugs against clinical isolates by microdilution method. The fruit extract of M. citrifolia demonstrate an interesting modulatory activity, enhancing the effect of the assayed antibiotics against P. aeroginosa and E. coli, but not against Candida strains

Analysis of bioactivities and chemical composition of Ziziphus joazeiro Mart. using HPLC–DAD

AbstractThe aim of this study was to evaluate the chemical profile and antioxidant, antimicrobial and antiparasitic activities of the hydroalcoholic extract of the leaves of Ziziphus joazeiro Mart. (HELZJ). The antioxidant DPPH and FRAP assays and chemical profile were determined by colorimetric methods and HPLC/DAD. The antiparasitic, antibiotic and antibiotic-modifying activity were evaluated by microdilution assays. The HPLC–DAD assay showed the presence of mostly tannins and flavonoids, such as caffeic acid and quercetin. The levels of polyphenols and flavonoids were 183.136mg/g extract and 7.37mg/g extract, respectively. DPPH and FRAP showed low antioxidant activity for the extract. The antibacterial and antifungal activities were not of clinical relevance, showing MIC>1024μg/mL. However, synergism was observed between HELZJ and the antibiotics amikacin and gentamicin, which resulted in decreased bacterial drug resistance. EHFZJ showed low toxicity in fibroblasts in vitro, while antiparasitic results against Trypnosoma cruzi, Leishmania braziliensis and Leishmania infantum were not clinically relevant. Thus, our results indicate that Z. joazeiro Mart. (HELZJ) could be a source of plant-derived natural products that could lead to the development of promising new antibiotic compounds for infectious diseases

Modulatory antimicrobial activity of Piper arboretum extracts (Zingiberaceae)

The side effects of certain antibiotics have been a recent dilemma in the medical arena. Due this fact, the necessity of natural product discovery could provide important indications against several pharmacological targets and combat many infectious agents. Piper arboreum Aub. (Piperaceae) has been used by Brazilian traditional communities against several illnesses including rheumatism, bronchitis, sexually transmitted diseases and complaints of the urinary tract. Medicinal plants are a source of several remedies used in clinical practice to combat microbial infections. In this study, ethanol extract and fractions of Piper arboreum leaves were used to assay antimicrobial and modulatory activity. The minimum inhibitory concentration (MIC) was determined using microdilution method of ethanol extract and fractions from the leaves of P. arboreum ranging between 8 and 1024 mgmL–1. The capacity of these natural products to enhance the activity of antibiotic and antifungal drugs was also assayed. In these tests, natural products were combined with drugs. The natural products assayed did not demonstrate any clinically relevant antimicrobial activity (MIC ³ 1024 mg mL–1). However, the modulation of antibiotic activity assay observed a synergistic activity of natural products combined with antifungal (such as nystatin and amphotericin B) and antibiotic drugs (such as amikacin, gentamicin and kanamycin). According to these results, these natural products can be an interesting alternative not only to combat infectious diseases caused by bacteria or fungi, but also to combat enhanced resistance of microorganisms to antibiotic and antifungal drugs

Cytoprotective Effect of Lygodium venustum Sw. (Lygodiaceae) against Mercurium Chloride Toxicity

Mercury is a very dangerous metal when humans come into contact with it, whether through the air or skin or by ingestion. The aim of this work was to investigate the possible effects of the ethanol extract and fractions of Lygodium venustum Sw. against mercurium chloride toxicity towards Escherichia coli strain ATCC25922. The polyphenols and flavonoids present in the extract and fractions were quantified in mg equivalent of gallic acid/g sample and mg equivalent of quercetin/g sample, respectively. The in vitro FRAP method demonstrated the antioxidant activity of the samples. The antibacterial activity of the natural products was evaluated by microdilution method and by assays to elucidate the possible cytoprotective action when combining the natural products samples and mercurium chloride, utilizing the extract and fractions at a subinhibitory concentration. The results obtained in this work indicate that the ethanol extract and fractions of L. venustum are an alternative source of natural products with cytoprotective action, where this protection is correlated with antioxidant and chelating activity, due to the presence of total phenols and flavonoids

Avaliação da atividade antibacteriana e moduladora de aminoglicosídeos do óleo essencial de Cymbopogon citratus (DC.) Stapf

Vários trabalhos vêm demonstrando a importância do estudo de produtos naturais como fonte alternativa para novos antimicrobianos ou que venham potencializar os já existentes. Neste contexto este trabalho teve como objetivo investigar a atividade antibacteriana e as possíveis interações entre o óleo essencial de Cymbopogon citratus combinados a aminoglicosídeos frente a linhagens padrões e multirresistentes de S. aureus, E. coli e de P. aeruginosa provenientes de isolados clínicos. Um ensaio de microdiluição foi realizado para verificar a atividade antibacteriana e as possíveis interacções entre o produto natural e os antibióticos, utilizando uma concentração sub-inibitória. Através dos resultados foi constatado a interferência sinérgica dos aminoglicosídeos quando associados com o óleo essencial em uma concentração de CIM/8, com redução das CIMs em até quatro pontos frente às linhagens de S. aureus 358, E. coli 27 e P. eruginosa- 143. Mas nenhuma atividade modificadora foi observada frente a P. aeruginosa 78 e P. aeruginosa 91. Através dos resultados pode-se concluir que o óleo essencial de Cymbopogon citratus pode ser uma fonte alternativa de produtos naturais com atividade antibacterianaVarios trabajos están demostrando la importancia del estudio de productos naturales como una fuente alternativa para nuevos antimicrobianos o que puedan mejorar los ya existentes. En este contexto, el objetivo de este trabajo fue investigar la actividad antibacteriana y las posibles interacciones entre el aceite esencial de Cymbopogon citratus aminoglucósido combinado frente de linajes y patrones de S. aureus multirresistente, E. coli y P. aeruginosa provenientes de aislamientos clínicos. Se realizó una prueba de microdilución para verificar la actividad antibacteriana y posibles interacciones entre el producto natural y antibióticos, usando una concentración sub-inibitória. A través de los resultados se observan interferencia sinérgica de los aminoglucósidos cuando se asocian con el aceite esencial en una concentración de CIM/8, con reducción de CIMs de hasta cuatro puntos contra las cepas de S. aureus 358, E. coli 27 y P. aeruginosa 143. Pero no se observó ninguna actividad modificadora contra P. aeruginosa 78 y P. aeruginosa 91. A través de los resultados se puede concluir que el aceite esencial de Cymbopogon citratus puede ser una fuente alternativa de productos naturales con actividad antibacterianaSeveral works demonstrated the importance of the study of natural products as an alternative source for new antimicrobial drugs or for modulators for these ones. In this point, the aim of this was to investigate the antibacterial activity and the possible interactions between the essential oil of Cymbopogon citratus alone and in association with aminoglycosides against standard and clinically isolated strains of multidrug-resistant bacteria such as S. aureus, E. coli and P. aeruginosa by microdilution method. The results indicated a synergism between the antibiotics and the essential oil with a subinhibitory concentration (MIC/8), reducing the minimal inhibitory concentration (MIC) sixteen times against the multidrug-resistant strains of S. aureus 358, E. coli 27 and P. aeruginosa 143, but none modulatory activity was observed against P. aeruginosa 78 and P. aeruginosa 91 strains. By our results, can be concluded that the essential oil of Cymbopogon citratus can be an interesting source of natural products with antibacterial and/or modulatory antibiotic activities

Atividade antimicrobiana e efeito combinado sobre drogas antifúngicas e antibacterianas do fruto de Morinda citrifolia L

La aparición de microorganismos resistentes y la toxicidad asociada a los antimicrobianos aumenta la necesidad de investigar nuevos principios activos. Morinda citrifolia L., es una planta fructífera utilizada popularmente como antibacteriano y con otros diversos usos farmacológicos. Posee diversos metabolitos primarios y secundarios, principalmente flavonoides, triterpenoides y alcaloides. Este estudio tuvo como objetivo ensayar la potencial actividad antimicrobiana y moduladora de los extractos obtenidos de su fruta. Los extractos de las frutas fueron testados tanto para determinar el efecto antimicrobiano como también utilizándolo en combinación con agentes antibacterianos y antifúngicos contra microorganismos patógenos, por el método de microdilución en caldo. Se observó que la asociación entre antibióticos y extractos dió resultados clínicamente significativos en pruebas con bacterias Pseudomonas aeruginosa y Escherichia coli

Menadione (vitamin K) enhances the antibiotic activity of drugs by cell membrane permeabilization mechanism

Menadione, vitamin K3, belongs to the class of lipid-soluble vitamins and lipophilic substances as menadione cause disturbances in the bacterial membrane, resulting in damage to the fundamental elements for the integrity of the membrane, thus allowing increased permeability. Accordingly, the aim of this study was to evaluate in vitro the antibiotic-modifying activity of menadione in multiresistant strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, with a gradual increase in its subinhibitory concentration. In addition, menadione was compared with cholesterol and ergosterol for similarity in mechanism of drug modulatory action. Antibiotic-modifying activity and antibacterial effect were determined by the broth microdilution assay. Menadione, cholesterol and ergosterol showed modulatory activity at clinically relevant concentrations, characterizing them as modifiers of bacterial drug resistance, since they lowered the MIC of the antibiotics tested. This is the first report of the antibacterial activity of menadione and its potentiation of aminoglycosides against multiresistant bacteria

Avaliação da atividade antibacteriana dos extratos metanólico e hexânico do caule folhado de Melissa Officinalis

Introducción: Melissa Officinalis L., de la familia Lamiaceae, es una hierba utilizada en la medicina popular. Es conocido en Brasil como erva cidreira, melisa, y melitéia cidrilha. Teniendo en cuenta que M. Officinalis L. se utiliza ampliamente en la medicina popular, entre ellos para uso antibacteriano, este trabajo tuvo como objetivo evaluar la actividad antibacteriana y modulador de extracto de metanol y hexano rodar el tallo de M. officinalis L. frente a las cepas de bacterias normas y las bacterias multirresistentes. Materiales y métodos: se analizó el extracto de metanol y hexano del tallo rodadura M. Officinalis L. para la actividad antibacteriana por una prueba de microdilución para la determinación de la Concentración Mínima Inhibitoria (mic) y la modulación de aminoglucósidos (gentamicina y amikacina). Resultados: en la evaluación de la mic los resultados obtenidos fueron ≥1024μg/ml con contra las bacterias (Escherichia coli y Staphylococcus aureus) en ambos extractos. El extracto de metanol mostró resultados significativos en combinación con efecto potenciador gentamicina contra E. coli y s. Aureus cuando se combina con amikacina, esta bacteria era antagonismo. Ya extracto de hexano dio lugar a una reducción de la mic de amikacina y gentamicina contra cepas de E. coli, que muestra el efecto antagónico con cepas de la cuenta de amikacina de S. Aureus. Conclusión: se concluye que el material vegetal influye en el comportamiento de los antimicrobianos, lo que hace este trabajo importante como parámetro para futuros estudios que puedan combatir la creciente resistencia de las bacterias.Introdução: Melissa officinalis, da família Lamiaceae, é uma erva comumente utilizada na medicina popular. É conhecida no Brasil como Melissa, erva cidreira, cidrilha e melitéia. Tendo em vista que M.officinalis L é largamente utilizada na medicina popular, dentre elas para uso antibacteriano, este trabalho teve como principal objetivo avaliar a atividade antibacteriana e modulatória de extratos metanólico e hexânico do caule folhado de M. officinalis L frente a cepas de bactérias padrões e multirresistentes. Materiais e métodos: Os extratosmetanólico e hexânico do caule folhado de M. officinalis L foram analisados para a atividade antibacteriana por meio de teste de microdiluição para determinação de concentração inibitória mínima (cim) e modulação de aminoglicosídeos (gentamicina e amicacina). Resultados: Na avaliação dacim foram obtidos resultados ≥1024μg/mLcontra as bactérias (Escherichia coli e Staphylococcus aureus) em ambos extratos. O extrato metanólico mostrou resultados relevantes em associação com gentamicina potencializando o efeito contra E. coli e S. aureus quando associado à amicacina, nesta bactéria houve antagonismo. Já o extrato hexânico, resultou em uma redução da cim de amicacina e gentamicina frente a linhagens de E. coli, mostrando efeito antagonista com a amicacina conta cepas de S. aureus. Conclusão: Conclui-se que o material vegetal influencia no comportamento dos antimicrobianos, tornando este trabalho importante como parâmetro para estudos mais aprofundados que possam combater a crescente resistência de bactérias patogênicas.Introduction: Melissa officinalis L., of the Lamiaceae family, is a herb commonly used on folkmedicine. In Brazil it is known as Melissa, erva cidreira, cidrilha and meliteia. Considering thatthe M. Officinalis L is widely used in folk medicine, as for antibacterial use, among others, themain objective of this work was to evaluate the antibacterial and modulating activity of methanolic and hexanic extracts of M. officinalis L against pattern and multidrug resistant bacterial strains. Materials and methods: The methanolic and hexanic extracts of the stem of puff pastry of M. officinalis L were analized to determine antibacterial activity by using the microdiluition for establishing the minimal inibitory concentration (MIC) and aminoglycosides (gentamicin and amikacin) modulation. Results: In the MIC evaluation, the results obtained were ≥1024μg/mL against bacteria (Escherichia coli and Staphylococcus aureus) in both extracts. The methanolic extract showed important results when associated with gentamicin, since it potentiates its effect against E. coli and S. aureus when associated with amikacin, where antagonism was found. As to the hexanic extract, it showed a MIC reduction of amikacin and gentamicin against S. aureus strains. Conclusion: It was concluded that the plant material influences the antimicrobial behavior, a fact that makes this study an important parameter to deeper studies to combat the increase of pathogenic multidrug-resistant bacteria

Enhancement of Antibiotic Activity by 1,8-Naphthyridine Derivatives against Multi-Resistant Bacterial Strains

The search for new antibacterial agents has become urgent due to the exponential growth of bacterial resistance to antibiotics. Nitrogen-containing heterocycles such as 1,8-naphthyridine derivatives have been shown to have excellent antimicrobial properties. Therefore, the purpose of this study was to evaluate the antibacterial and antibiotic-modulating activities of 1,8-naphthyridine derivatives against multi-resistant bacterial strains. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of the following compounds: 7-acetamido-1,8-naphthyridin-4(1H)-one and 3-trifluoromethyl-N-(5-chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide. The antibiotic-modulating activity was analyzed using subinhibitory concentrations (MIC/8) of these compounds in combination with norfloxacin, ofloxacin, and lomefloxacin. Multi-resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were used in both tests. Although the compounds had no direct antibacterial activity (MIC ≥ 1.024 µg/mL), they could decrease the MIC of these fluoroquinolones, indicating synergism was obtained from the association of the compounds. These results suggest the existence of a structure–activity relationship in this group of compounds with regard to the modulation of antibiotic activity. Therefore, we conclude that 1,8-naphthyridine derivatives potentiate the activity of fluoroquinolone antibiotics against multi-resistant bacterial strains, and thereby interesting candidates for the development of drugs against bacterial infections caused by multidrug resistant strains