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Staphylococcus aureus frequently causes subclinical mastitis around the world with a high impact on the milk industry and public health. Essential oils (EO) are recognized antimicrobials that can be synergistic with antibiotics. The main objective of this study was to evaluate the essential oil (EO) of Melaleuca armillaris as an adjuvant of erythromycin (ERY) for the alternative treatment of bovine mastitis caused by S. aureus. The Minimum Inhibitory and Bactericidal Concentrations (MIC and MBC) of EO, ERY, and its combinations were established against S. aureus at different pHs (7.4, 6.5 and 5.0), emulating extra and intracellular conditions. Sensitive (N = 3) and resistant (N = 3) strains to ERY and S. aureus ATCC 29213 as control were used. Math models were applied to describe the antibacterial activity of EO and combinations EO-ERY. The EO was bactericidal against all the strains independently of the pH with a slight improvement in acid conditions. The synergism between EO and ERY was estimated by the Fractional Inhibitory Concentration Index (FIC) and by mathematical modeling of the bacterial killing data. Synergism was observed with ERY, where combinations had bactericidal activity also even with pH modification. M. armillaris EO is an interesting adjuvant for ERY, being a promissory option for further analysis of intracellular efficacy against S. aureus.
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Essential oils (EO) are a great antimicrobial resource against bacterial resistance in public health. Math models are useful in describing the growth, survival, and inactivation of microorganisms against antimicrobials. We evaluated the antimicrobial activity of Melaleuca armillaris EO obtained from plants placed in the province of Buenos Aires (Argentina) against Staphylococcus aureus. The minimum inhibitory and bactericidal concentrations were close and decreased, slightly acidifying the medium from pH 7.4 to 6.5 and 5.0. This result was also evidenced by applying a sigmoid model, where the time and EO concentration necessaries to achieve 50% of the maximum effect decreased when the medium was acidified. Moreover, at pH 7.4, applying the Gompertz model, we found that subinhibitory concentrations of EO decreased the growth rate and the maximum population density and increased the latency period concerning the control. Additionally, we established physicochemical parameters for quality control and standardization of M. armillaris EO. Mathematical modeling allowed us to estimate key parameters in the behavior of S. aureus and Melaleuca armillaris EO at different pH. This is interesting in situations where the pH changes are relevant, such as the control of intracellular infections in public health or the development of preservatives for the food industry.
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Staphylococcus aureus is the major subclinical mastitis-causing pathogen in dairy cows. In some European and Latin American countries, rifaximin (RIF) is a commonly used therapy at drying off. Phytotherapeutics are alternatives for the treatment of infectious diseases. Melaleuca armillaris essential oil (EO) has been reported as a good antimicrobial against S. aureus. The aim of this work was to investigate, in vitro, the combined effect of EO and RIF to identify a synergic interaction against S. aureus in order to obtain enough information for subsequent pharmacokinetic/pharmacodynamic studies. The minimum inhibitory concentrations (MIC) for RIF, EO, and combinations of these against S. aureus strains were determined at pH 7.4, 6.5, and 5.0, representing intracellular conditions where S. aureus is usually located. The fractional inhibitory concentration index (FIC) and the index of antibacterial activity (E) were evaluated. The MIC of EO at pH 7.4 was 25-12.5 µL/mL and decreased with the acidity of the medium. RIF presented a high antimicrobial activity (0.032 µg/mL) against S. aureus regardless of the pH conditions. Combining RIF with EO, we found a synergic effect. A mix of 0.004 µg/mL of RIF and 12.5 µL/mL of EO led to a virtual eradication effect against wild-type strains at pH 7.4. Media acidification improves the EO/RIF activity, so EO would be a good adjuvant for RIF to treat staphylococcal infections and decrease antimicrobial resistance.
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The essential oil composition of the aerial parts of Artemisia magellanica Sch. Bip. (Asteraceae), native to Patagonia, was analyzed by GC-FID-MS. This is the first report on the essential oil composition of A. magellanica. A total of 113 components were identified accounting for 95.6-95.7 % of the oil. The essential oil was characterized by a high percentage of γ-costol (21.0-43.5 %), selina-4,11-diene, (Z)-ß-ocimene, (E)-ß-farnesene, (Z)-en-yn-dicycloether and 23 different esters (28.7 %). In turn, Artemisia biennis, a species native to North America, which is considered by some authors to be conspecific with A. magellanica, yielded an essential oil that was rich in (Z)-ß-ocimene (34.7 %), (E)-ß-farnesene (40.0 %) and the acetylenes (Z)- and (E)-en-yn-dicycloethers (11.0 %). Thus, as A. biennis lacks the three main components present in A. magellanica, namely γ-costol, 2-methylbutyl 2-methylbutyrate and selina-4,11-diene, these compounds could be considered as potential chemical markers for A. magellanica since they are absent or only found as minor constituents in other members of the genus. The data presented herein is also useful for genus taxonomy.
Assuntos
Artemisia/química , Óleos Voláteis/isolamento & purificação , Estrutura Molecular , Óleos Voláteis/química , Especificidade da EspécieRESUMO
The emergence of resistance to antibiotics has been favored by abuse in the application of antimicrobials in human and animal medicine. Essential oils are a great resource to deal with this crisis. Melaleuca armillaris belongs to the family of Myrtaceae, rich in species with essential oils. Plant extracts has shown antimicrobial activity in many investigations. Cloxacillin (CLOX) is an antibiotic widely used in veterinary medicine against Staphylococcus aureus. Our aim was to assess pharmacodynamic interaction established by combining essential oil of M. armillaris (EO) with CLOX in search of a synergistic effect that maximizes the antibacterial activity against S. aureus. The EO was obtained by steam distillation and its composition was analyzed by a GC-FID-MS. The most abundant components in the EO were 1.8 cineole (72.3%), limonene (7.8%). and α-pinene (6%). We worked with wild type S. aureus strains (n = 3) isolated from Holstein cows, and S. aureus ATCC 29213 as the reference strain. The Minimum Inhibitory Concentration (MIC) of CLOX, EO and the combination was determined by microdilution in broth at pH 7.4; 6.5 and 5.0. The checkerboard method was applied to evaluate the interaction between CLOX and EO. The Fractional Inhibitory Concentration index (FIC) was established. From those combinations that yielded the lowest FIC values, we evaluated the index of antibacterial activity (E), established as the difference between the Log10 values of the number of viable bacteria at the initial (nt0) and at the end of the test (nt24). So, time-killing curves with CLOX and EO/CLOX combination at 0.5, 1, 2, 4, and 8 fold the MIC in broth at pH 7.4; 6.5 and 5.0 were prepared. We considered Bacteriostatic effect (E = 0) Bactericidal effect (E = -3) and Effect of virtual eradication of bacteria (E = -4). A clear synergic activity between the EO and the CLOX was demonstrated, which allows reducing the MIC of ß-lactam against S. aureus. This interaction was favored by acidification of the medium, where lower concentrations of CLOX achieved a bactericidal effect, close to virtual eradication, in the presence of small amounts of EO.
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ETHNOPHARMACOLOGY RELEVANCE: Blepharocalyx salicifolius (Kunth) O. Berg (Myrtaceae) is a tree native to Argentina and Uruguay that grows and is cultivated along the riverside of the Rio de la Plata. The leaves of this plant species, locally known as "anacahuita" are used in South America to prepare infusions for the empiric treatment of cough and bronchospasm, as well as diarrhoea and other intestinal disorders. Although previous phytochemical studies have been performed with the essential oil extracted from Blepharocalyx salicifolius, pharmacological evidence supporting its traditional use is still lacking. AIM OF THE STUDY: To experimentally evaluate the pharmacological properties of Blepharocalyx salicifolius based on its traditional use. The studies were performed with tincture (T-Bs) and essential oil (EO-Bs) prepared from its leaves, in isolated rat trachea, intestine and heart preparations. METHODS: The ex-vivo effects of T-Bs and EO-Bs were evaluated with the agonists carbachol (CCh) and calcium chloride (Ca2+) in the contractile concentration-response curves (CRC) of the isolated intestine. The muscle relaxant effect of EO-Bs was evaluated in the isolated trachea and compared with the effect achieved with papaverine as a positive control. The T-Bs and EO-Bs cardiac effects were analysed by perfusion of an isolated rat heart before a period of ischemia/reperfusion (stunning model). The antitussive effect of both T-Bs and EO-Bs was evaluated in mice exposed to ammonia using codeine as a positive control. RESULTS: Both T-Bs and EO-Bs induced a non-competitive inhibition of the CCh-CRC in the rat intestine, with IC50 values of 170.3 ± 48.5µg T-Bs/mL (n = 6) and 5.9 ± 1.6µg EO-Bs/mL (n = 6), respectively. EO-Bs also inhibited non-competitively the Ca2+-CRC, with IC50 value of 1.8 ± 0.3µg EO-Bs/mL (n = 8). A similar effect was obtained with the main active component of the EO-Bs 1,8-cineole. In isolated trachea, EO-Bs induced the relaxation of the CCh-contracted tissue (1.7 ± 0.2µg EO-Bs/mL, n = 11) up to a maximal relaxation that was 1.9 times higher than that of papaverine. In the isolated heart, EO-Bs induced a poor negative inotropic response, and did not improve the contractile and energetic recovery after ischemia and reperfusion. In the mouse cough model, EO-Bs (90mg/Kg) was as effective as codeine (30mg/Kg) in reducing cough frequency. CONCLUSIONS: The results indicate that the preparations from Blepharocalyx salicifolius leaves were effective as central antitussive, bronchodilating and antispasmodic agents, suggestive of a mechanism associated with the inhibition of Ca2+ influx into smooth muscle. The EO-Bs displayed only a poor ability to reduce cardiac inotropism, and was devoid of any cardioprotective properties. Thus, the present study validates the traditional use of this South American plant for asthma, cough and bronchospasm, shedding new light into its potency and putative mechanism of action.
Assuntos
Medicina Tradicional/métodos , Myrtaceae/química , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Animais , Antitussígenos/administração & dosagem , Antitussígenos/isolamento & purificação , Antitussígenos/farmacologia , Broncodilatadores/administração & dosagem , Broncodilatadores/isolamento & purificação , Broncodilatadores/farmacologia , Cálcio/metabolismo , Cardiotônicos/administração & dosagem , Cardiotônicos/isolamento & purificação , Cardiotônicos/farmacologia , Tosse/tratamento farmacológico , Modelos Animais de Doenças , Feminino , Concentração Inibidora 50 , Masculino , Camundongos , Óleos Voláteis/administração & dosagem , Óleos Voláteis/isolamento & purificação , Parassimpatolíticos/administração & dosagem , Parassimpatolíticos/isolamento & purificação , Parassimpatolíticos/farmacologia , Extratos Vegetais/administração & dosagem , Folhas de Planta , Ratos , Ratos Sprague-Dawley , América do SulRESUMO
Introducción: las plantas aromáticas y medicinales son una fuente potencial de componentes antioxidantes. La Patagonia Argentina presenta un ambiente diverso en especies nativas, las cuales deberían ser estudiadas en mayor profundidad debido a su potencial farmacéutico, así como para contribuir a fomentar su conservación. Objetivos: estudiar la actividad antioxidante de infusiones, tinturas y aceites esenciales de las siguientes especies nativas de la Patagonia Argentina: Acantholippia seriphioides (A. Gray) Moldenke, Adesmia boronioides Hook. f., Buddleja globosa Hope, Fabiana imbricata Ruiz & Pav., Solidago chilensis Meyen. Identificar los componentes volátiles presentes en los aceites esenciales. Métodos: se obtuvieron infusiones y tinturas por la guía de las normas de la Farmacopea Argentina VI edición. Los aceites esenciales se obtuvieron por hidrodestilación con un aparato tipo Clevenger. El análisis de los componentes volátiles se realizó mediante cromatografía de gases-espectrometría de masas. Los ensayos de actividad antioxidante se realizaron por el método del difenil-picrilhidrazilo. Resultados: las especies presentaron el siguiente orden de actividad antioxidante: B. globosa > S. chilensis ≥ F. imbricata ≥ A . seriphioides > A. boronioides. Las infusiones de B. globosa, S. chilensis y A. seriphioides, presentaron una actividad antioxidante similar a Camellia sinensis (L.) Kuntze ("té verde") y superior a Ginkgo biloba (L.) Mant (especies reconocidas por su alto contenido de antioxidantes). La actividad encontrada para el aceite esencial de A. seriphioides se deba a sus contenidos en timol y carvacrol. En cuanto a la actividad de S. chilensis podría adjudicarse a su alto porcentaje de limoneno. Conclusiones: este trabajo es el primero que estudia la actividad antioxidante de plantas medicinales y aromáticas en la región noroeste de la Patagonia Argentina; los resultados obtenidos demuestran que las especies estudiadas de dicha región son una fuente rica en compuestos antioxidantes y de potencial valor como suplemento dietario(AU)
Introduction: medicinal and aromatic plants have potential as sources of antioxidant compounds. There is a great diversity of native species in Patagonia Argentina. It is worthy to study them because of its pharmaceutical potential and to help promote conservation. Objectives: to analyze antioxidant activities of herbal teas, tinctures and essential oils of native species from Patagonia Argentina: Acantholippia seriphioides (A. Gray) Moldenke, Adesmia boronioides Hook. f., Buddleja globosa Hope, Fabiana imbricata Ruiz & Pav., Solidago chilensis Meyen. Identify essential oils compounds. Methods: infusions and tinctures were obtained according to Pharmacopoeia Argentina VIth edition. The essential oils were obtained by hydrodistillation in a Clevenger apparatus. Volatiles compounds were analyzed by gas chromatography-mass spectrometry. Antioxidant activity assays were performed by difenil-picrilhidrazilo method. Results: antioxidant activity order was: B. globosa > S. chilensis ≥ F. imbricata ≥ A. seriphioides > A. boronioides. Infusions of B. globosa, S. chilensis and A. seriphioides presented an antioxidant activity similar to Camellia sinensis (L.) Kuntze ("green tea") and higher than Ginkgo biloba (L.) Mant. The A. seriphioides essential oil activity was probably obeyed to thymol and carvacrol presence. S. chilensis activity could be owing to its high limonene content. Conclusions: this study is the first report about antioxidant activity of medicinal and aromatic plants in the northwest region of Patagonia Argentina. The results showed that analyzed species are a rich source of antioxidant compounds and have potential value as a dietary supplement(AU)
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Humanos , Fabiana imbricata/uso terapêutico , Preparações de Plantas/uso terapêutico , Solidago/efeitos dos fármacos , Buddleja/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas/métodosRESUMO
El tomillo silvestre es una planta aromática y medicinal de amplio uso en varias regiones de Argentina como medicinal y saborizante. Se estudiaron poblaciones de Acantholippia seriphioides en dos zonas de la meseta chubutense, los parajes El Pajarito y La Rueda. Las partes aéreas oreadas fueron extraídas por hidrodestilación y los aceites esenciales se analizaron por GC-FID-MS. Los rendimientos en promedio de aceites esenciales fueron de 5.2 ml/kg y 3.2 ml/kg, para La Rueda y El Pajarito respectivamente. Los tipos químicos encontrados fueron: ipsilon-terpineno/timol/carvacrol en La Rueda y mirtenol/geraniol/carvona en El Pajarito. El probable quimiotipo de este último sitio difiere marcadamente de los reportados en trabajos previos para esta especie y presenta además importante variabilidad cuantitativa, según el estado fenológico.
Tomillo silvestre is a widespread medicinal and aromatic plant with medicinal and flavoring uses in numerous regions of Argentina. Acantholippia seriphioides populations from two areas of the Chubuts plateau: El Pajarito and La Rueda, have been studied. The dried aerial parts were extracted by hydrodistillation and the essential oils were analyzed by GC/FID/MS. The average yields of oils were 5.2 ml/kg and 3.2 ml/kg for La Rueda and El Pajarito, respectively. The chemical profiles found were: ypsilon-terpinene/thymol/carvacrol in La Rueda and myrtenol/geraniol/carvone in El Pajarito. The feasible chemotype from the latter area is significantly different from those previously reported for this species, and it also showed an important quantitative variation according to the phenological stages.
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Óleos Voláteis/química , Terpenos/isolamento & purificação , Verbenaceae/química , Argentina , Cromatografia Gasosa/métodosRESUMO
Nineteen samples from the aerial parts in bloom of Acantholippia seriphioides (Verbenaceae) were collected in three provinces belonging to the Cuyo region of Argentina. The essential oils were obtained by hydrodistillation, yielding between 0.57 and 2.46 percent (v/w). On the basis of the 13 main compounds determined by GC-FID-MS, representing the 87.2 and 95.3 percent of the total identified, four chemotypes were determined: carvacrol, thymol, cis and trans-dihydrocarvone and linalool-geraniol. The co-occurrence of different chemotypes in a same population indicates that the sample collection must be carefully done with the aid of an in situ olfactory testing of the plants, since no morphological differences at first sight were observed among them. The results showed in this study suggest that the pattern of variations for this species exists throughout its natural distribution area...
Se colectaron 19 muestras de partes aéreas en floración de Acantholippia seriphioides (Verbenaceae) de tres provincias de la región de Cuyo de la Argentina. Los aceites esenciales fueron obtenidos por hidrodestilación, arrojando rendimientos entre 0.57 y 2.46 por ciento (v/p). A partir de la determinación por GC-FID-MS de los 13 compuestos principales, que representaban entre el 87.2 y 95.3 por ciento del total de los identificados, fueron determinados cuatro quimiotipos: carvacrol, timol, cis y trans-dihidrocarvona, y linalol-geraniol. La co-ocurrencia de diferentes quimiotipos en una misma población indica que la colecta debe ser realizada con la ayuda de un examen olfatorio in situ de la planta, ya que, a primera vista no se observan diferencias morfológicas entre ellas. Los resultados sugieren que el patrón de variación para esta especie existe en toda su área de distribución natural...
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Humanos , Óleos Voláteis/química , Extratos Vegetais/química , Verbenaceae , Argentina , Biodiversidade , Cromatografia Gasosa/métodos , Cromatografia Gasosa-Espectrometria de MassasRESUMO
ETHOPHARMACOLOGY RELEVANCE: Lippia alba (Mill.) N. E. Brown (Verbenaceae) is an aromatic species used in Central and South America as eupeptic for indigestion. In Argentina, it is used by the "criollos" from the Chaco province. There are several chemotypes which differ in the chemical composition of the essential oils. Nowadays, it is experimentally cultivated in some countries of the region, including Argentina. AIM OF THE STUDY: To compare the chemical composition and pharmacology of the essential oils from two chemotypes: "citral" (CEO) and "linalool" (LEO), in isolated rat duodenum and ileum. METHODS: Contractile concentration-response curves (CRC) of acetylcholine (ACh) and calcium in 40mM K(+)-medium (Ca(2+)-CRC) were done in isolated intestine portions, in the absence and presence of CEO or LEO at different concentrations. RESULTS: Likewise verapamil, CEO and LEO induced a non-competitive inhibition of the ACh-CRC, with IC50 of 7.0±0.3mg CEO/mL and 37.2±4.2mg LEO/mL. l-NAME, a NO-synthase blocker, increased the IC50 of CEO to 26.1±8.7mg CEO/mL. Likewise verapamil, CEO and LEO non-competitively inhibited the Ca(2+)-CRC, with IC50 of 6.3±1.7mg CEO/mL, 7.0±2.5mg LEO/mL and 0.24±0.04mg verapamil/mL (pIC50: 6.28). CEO was proved to possess limonene, neral, geranial and (-)-carvone as the major components, while LEO was rich in linalool. CONCLUSIONS: Results suggest that CEO has five times more potency than LEO to inhibit muscarinic contractions. The essential oils of both chemotypes interfered with the Ca(2+)-influx, but with an IC50 about 28 times higher than that of verapamil. Moreover, CEO partially stimulated the NO production. These results show the medicinal usefulness of both Lippia alba chemotypes, thus validating its traditional use, potency and mechanism of action.