RESUMEN En el trabajo se estudió un consorcio microbiano metanogénico de una mina de carbón de la cuenca de Bogotá en Colombia. Se establecieron cultivos de enriquecimiento de carbón ex situ para el crecimiento y la producción de gas de novo. El gas biogénico producido por los cultivos se analizó mediante cromatografía de gases con detectores de ionización de llama y conductividad térmica. Los cultivos se utilizaron para aislar estirpes microbianas y para generar bibliotecas del gene 16S rARN empleando de cebadores de bacteria y de arquea. El análisis de cromatografía de gases mostró producción de metano a 37 oC, pero no a 60 oC, donde el CO2 fue el componente principal del gas biogénico. El análisis de la secuencia del gen 16S rARN de estirpes microbianos y de las bibliotecas de clones, estableció que el consorcio microbiano metanogénico estuvo formado por especies de bacterias de los géneros Bacillus y Gracilibacter más la arquea del género Methanothermobacter. El consorcio microbiano metanogénico identificado es potencialmente responsable de la generación de gas biogénico en la mina de carbón La Ciscuda. Los resultados sugirieron que los metanógenos de este consorcio producían metano por vía hidrogenotrófica o de reducción de CO2.

ABSTRACT The work studied the methanogenic microbial consortium in a coal mine from the Bogotá basin in Colombia. Ex situ coal-enrichment cultures were established for in vitro growth and de novo gas production. Biogenic gas produced by cultures was analyzed by gas chromatography using thermal conductivity and flame ionization detectors. Cultures were used to isolate microbial specimens and to generate 16S rRNA gene libraries employing bacterial and archaeal primer sets. The gas chromatographic analysis showed methane production at 37 oC, but not at 60 oC, where CO2 was the major component of the biogenic gas. 16S rRNA gene sequence analysis of microbial isolates and clone libraries established that the methanogenic microbial consortium was formed by bacteria species from Bacillus and Gracilibacter genera plus archaea from the Methanothermobacter genus. This meth-anogenic microbial consortium was potentially responsible for biogenic gas generation in La Ciscuda coal mine. The results suggested that these methanogens produced methane by hydrogenotrophic or CO2 reduction pathways.

RESUMO: Esta pesquisa descreve um protocolo de micropropagação eficiente para Lippia origanoides (Verbenaceae). Sementes estéreis foram utilizadas para a obtenção de mudas germinadas em meio Murashige e Skoog (MS) suplementado com sacarose e ágar. Os segmentos nodais obtidos das mudas foram cultivados em meio MS, suplementado com diferentes concentrações de ácido giberélico (GA), benzilaminopurina (BAP) e ácido 1-naftalenacético (ANA) com BAP. Foram analisados a indução de calo, comprimento de brotação, número de brotação e comprimento de raiz. Os tratamentos mostraram alta porcentagem de formação de calo com 0,5 a 1,5 mg L-1 de BAP sozinho ou em combinação com ANA (0,1 mg L-1). O maior valor de número de brotações por segmento nodal foi obtido com 1,5 mg L-1 de BAP (4,3 ± 0,8). As mudas obtidas apresentaram melhor enraizamento in vitro na ausência de reguladores de crescimento vegetal (PGRs) e demonstraram taxa de aclimatação de 90%. Contudo, relata-se um protocolo para propagação in vitro e aclimatação de L. origanoides para quimiotipos A da Colômbia.

ABSTRACT: This research described an efficient micropropagation protocol for Lippia origanoides (Verbenaceae). Sterile seeds were used to obtain germinated seedlings in Murashige and Skoog medium (MS) supplemented with sucrose and agar. The nodal segments obtained from seedlings were grown on MS medium supplemented with different concentrations of gibberellic acid (GA), benzylaminopurine (BAP) and 1-naphthalenacetic acid (NAA) with BAP. The callus induction, shoots length, shoots number and root length, were analyzed. The treatments showed high percentage of callus formation at 0.5 to 1.5 mg L-1 of BAP alone or in combination with NAA (0.1 mg L-1). The highest value of shoot number per nodal segments was obtained at 1.5 mg L-1 of BAP (4.3 ± 0.8). The obtained plantlets were better rooted in vitro in the absence of plant growth regulators (PGRs) and they showed acclimatization rate of 90%. We reported a protocol for in vitro propagation and acclimatization of L. origanoides for A chemotypes from Colombia.

Novel and miniaturized technique, a dynamic sonication-assisted solvent extraction before the analysis by high performance liquid chromatography-ultraviolet visible (HPLC-UV-Vis) for isolation, identification and quantification of rutin and quercetin metabolites in alcoholic extracts from Bidens pilosa Linné, was developed. The results showed that the flowers have a greater quantity of both analytes than other parts of the plant (e.g., leaves, stem and roots), the results were corroborated by liquid chromatography-mass spectrometry (LC-MS). In addition, the developed extraction technique against traditional methods for metabolites extraction such as solid-liquid extraction, Soxhlet and rotating-disk sorptive extraction was compared. Under optimal conditions of extraction such as 0.3 mL min-1 of solvent flow, ethanol:water (1:1) as solvent type and 0.5 g of sample amount, it was possible to reach 85% of recovery percentage of target analytes and a limit of detection close to 0.1 µg g-1 with a linear range of 50-400 µg g-1 were also obtained. Finally, the antibacterial evaluation of the flower extract of Bidens pilosa Linné, obtained under above optimal conditions against Gram-positive bacteria, was performed. The higher values of the inhibition diameters when using 1000 mg L-1 and significant differences among Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes were observed. The tests were performed with different microorganisms inoculated from three different absorbance levels (0.05, 0.5 and 0.1 absorbances), at a lower absorbance of these microorganisms in the growth medium used for evaluating the inhibitory effect of the B. pilosa Linné extract, when using this extract at the concentrations of 500 and 1000 mg L-1, statistically higher inhibition diameters were noticed.

Resumen Introducción: la consulta de un particular que trajo un producto fitoterapéutico a base de caléndula cuyo consumo le causó fuertes reacciones adversas, originó esta investigación sobre la composición de este producto. Objetivo: caracterizar la composición química de muestras de lotes diferentes de un producto comercial denominado fitoterapéutico a base de caléndula (Calendula officinalis) (PFC) comercializado en Colombia. Metodología: se analizaron tabletas de ocho cajas del PFC de cuatro lotes diferentes de producción (2017 y 2018). Se llevó a cabo el análisis de espacio de cabeza (HS) de tabletas por microextracción en fase sólida (SPME), con una fibra PDMS/DVB (65 µm), expuesta al HS de la muestra durante 30 min a 50 °C. Las fracciones volátiles se analizaron por cromatografía de gases acoplada a espectrometría de masas (GC/MS). Los extractos de tabletas obtenidos con mezcla de metanol:agua (1:1, v/v) se analizaron por cromatografía líquida (LC) de alta (HPLC) y ultra-alta eficiencia (UHPLC), con detectores de arreglo de diodos (DAD) y espectrometría de masas de alta resolución (HRMS), respectivamente; la cuantificación de diclofenaco se hizo por calibración con patrón externo y por adición de estándar. Los espectros de masas de baja y alta resolución y patrones de fragmentación de las sustancias detectadas se estudiaron, usando GC/HRMS y LC/HRMS-Orbitrap. Resultados: en tabletas analizadas por HSSPME, se encontraron monoterpenoides y sesquiterpenoides de origen vegetal, ftalatos, residuos de solventes (2-cloroetanol, etilenglicol) y sustancias químicas intermediarias en la síntesis de diclofenaco (2,6-dicloroanilina y 2,6-cloro-N-fenil-bencenamina). En los cromatogramas, obtenidos por GC/MS de los extractos de tabletas obtenidos con diclorometano, se detectaron diclofenaco, sus impurezas A, B y C, los ésteres de diclofenaco y algunas otras impurezas. Diclofenaco en cantidad ca. 40 mg (7-8%) se cuantificó por HPLC en tabletas (> 70 analizadas) escogidas al azar de ocho cajas del PFC, adquirido en el mercado local de Bucaramanga (Colombia). Conclusión: en cada tableta analizada se determinaron alrededor de 40 mg del compuesto sintético diclofenaco (sustancia no declarada en la etiqueta del producto) y en ninguna se detectaron ésteres de los triterpenoides oleanano o faradiol, constituyentes del extracto de caléndula que poseen actividad antiinflamatoria; se encontraron algunos flavonoides comunes a muchas plantas, en cantidades mil veces menores que la de diclofenaco.

Abstract Introduction: The consultation of a person who brought a marigold-based phytotherapeutic product whose consumption caused strong adverse reactions, originated this investigation of the composition of this product. Objective: to characterize the chemical composition of samples of different lots of a commercial product called calendula-based phytotherapeutic product (Calendula officinalis) (PFC) commercialized in Colombia. Methodology: Tablets of eight packs of the phytotherapeutic product from four different production batches (2017 and 2018) were analyzed. Headspace analysis (HS) of tablets by solid phase microextraction (SPME) was carried out with a PDMS/ DVB fiber (65 µm), exposed to the HS of the sample for 30 min at 50 °C. Volatile fractions were analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Tablet extracts obtained with methanol:water mixture (1:1, v / v) were analyzed by liquid chromatography (LC) of high (HPLC) and ultra-high performance (UHPLC) with diode array (DAD) and high-resolution mass spectrometric (HRMS) detectors, respectively; diclofenac was quantified by external calibration and standard addition. Low- and high-resolution mass spectra (MS, HRMS) and fragmentation patterns of detected substances were studied, using GC/HRTOF-MS and LC/HRMS-Orbitrap. Results: in tablets analyzed by HS-SPME, monoterpenoids and sesquiterpenoids of plant origin, phthalates, solvent residues (2-chloroethanol, ethylene glycol) and intermediary chemicals in diclofenac synthesis (2,6-dichloroaniline and 2,6- chloro-N-phenyl-benzenamine) were found. In the chromatograms (GC/MS) of the extracts of tablets obtained with organic solvent (dichloromethane), diclofenac, its impurities A, B and C, diclofenac esters, and some other compounds were detected; diclofenac quantification by HPLC found amounts of ca. 40 mg (7 - 8%) in tablets (> 70 analyzed) chosen at random from eight packs of the calendula-based phytotherapeutic product, purchased in the local market in Bucaramanga (Colombia). Conclusion: each analyzed tablet contained around 40 mg of the synthetic compound diclofenac (substance not declared in the product’s label) and no tablet contained detectable amounts of esters of the triterpenoids oleanane or faradiol, which are calendula extract constituents that possess antiinflammatory activity; a few flavonoids that are common to many plants were found in amounts a thousand times smaller than that of diclofenac.

RESUMEN Colombia posee gran diversidad de plantas medicinales, pero pocas han sido objeto de investigación. En este trabajo se evaluó la actividad antiproliferativa de aceites esenciales obtenidos por hidrodestilación asistida por microondas. Se analizaron 15 muestras de 11 especies en ensayos del MTT en células cancerosas MCF-7, HeLa y HepG-2 y se incluyeron células normales humanas (HEK293) y de animales (Vero y B16F10) para evaluar selectividad. La composición química de muestras activas se determinó por cromatografía de gases acoplada a espectrometría de masas (GC-MS). Aceites esenciales de cuatro especies mostraron actividad antiproliferativa (CI50: 50 μg/mL) en células HeLa y/o MCF-7, en el siguiente rango (índice de selectividad en paréntesis): Pipercumanense H.B.K. (4,7) > Piper subflavum var. espejuelanum C.DC (3,9) > Salvia officinalis L. (3,6) > Piper eriopodom (Miq.) C. DC. (3,1). Ninguna muestra fue activa en células HepG-2. El análisis por CG-MS identificó β-cariofileno, a-copaeno, β-pineno, α-pineno y linalol como componentes mayoritarios. Los aceites esenciales activos pueden ser puntos de partida para desarrollo de medicamentos herbales para cuidado paliativo del cáncer.

ABSTRACT Colombia has a great diversity of medicinal plants, but few have been investigated. In this work, the antiproliferative activity of essential oils obtained by microwave-assisted hydrodistillation was evaluated. Fifteen samples from 11 species were analyzed in MTT assays in cancer cells MCF-7, HeLa and HepG-2, and normal human cells (HEK293) and animal cells (Vero and B16F10) were included to evaluate selectivity. The chemical composition of the active oils was determined by gas chromatography coupled to mass spectrometry (GC-MS). Essential oils from four species showed antiproliferative activity (IC50: <50 μg / mL) in HeLa and / or MCF-7 cells, in the following range (selectivity index in parenthesis): Piper cumanense H.B.K. (4.7) > Piper subflavum var. espejuelanum C. DC (3.9) > Salvia officinalis Linneo. (3.6) > Piper eriopodom (Miq.) C.DC. (31). The CG-MS analysis identified β-caryophyllene, a-copaene, β-pinene, a-pinene and linalool as major components. Active essential oils could serve as starting points to develop herbal medicines for cancer palliative care.

Abstract The search for new insecticides to control dengue fever, chikungunya, and Zika vectors has gained relevance in the past decades. The aim of the present study was to evaluate the larvicidal action of essential oils (EOs) from Thymus vulgaris, Salvia officinalis, Lippia origanoides, Eucalyptus globulus, Cymbopogon nardus, Cymbopogon martinii, Lippia alba, Pelargonium graveolens, Turnera diffusa, and Swinglea glutinosa on Aedes (Stegomyia) aegypti. The EOs were extracted by microwave-assisted hydrodistillation and characterized by gas chromatography/mass spectrometry (GC/MS). The chemical components of the EOs were identified by linear retention indices and mass spectra. Lethal concentrations (LC50 and LC95) were determined by probit analysis using larvae of Ae. aegypti between the third and the fourth instars. All EOs achieved larvicidal activity at LC50 values lower than 115 mg/L. The lowest LC50 value (45.73 mg/L) corresponded to T. vulgaris EO, whereas C. martinii EO showed the highest LC50 (LC50 = 114.65 mg/L). Some EO mixtures showed lower LC50 than oils used individually, such as the mixtures of L. origanoides + S. glutinosa (LC50 = 38.40 mg/L), T. diffusa + S. glutinosa (LC50 = 63.71 mg/L), and L. alba + S. glutinosa (LC50 = 48.87 mg/L). The main compounds of the EOs with highest larvicidal activity were thymol (42%) and p-cymene (26.4%).

Antecedentes: Conocer la tendencia de productos de plantas a causar toxicidad en humanos es parte de la investigación orientada al descubrimiento de un medicamento natural. Las pruebas en animales son relativamente costosas, de bajo rendimiento, asociadas a sufrimiento del animal y diferencias relativas a la especie hacen difícil inferir efectos en humanos. Las pruebas en célula viva son recomendadas. Objetivos: Estudiar la tendencia a toxicidad de aceites esenciales (AE) de plantas de Colombia usando un ensayo basado en célula. Métodos: Los AE de 18 especies distintas de plantas fueron estudiados. Se usó el ensayo del MTT en seis líneas celulares de humano y animal derivadas de tejido normal y canceroso, las cuales se trataron antes y después de la proliferación. Los AE se organizaron en el orden de una agrupación jerárquica con base en los valores de CC50 y la sumatoria de la jerarquía ponderada en el panel de células (∑JPi ) se usó como indicador de similitud. Cuanto mayor fue el valor de ∑JPi menor fue la tendencia a toxicidad. Resultados: Los AE con valores de CC50 200 µg/mL en al menos cinco condiciones experimentales presentaron valores de ∑JPi 6,0 sugiriendo baja tendencia a toxicidad y fueron en orden descendente (∑JPi en paréntesis): Calycolpus moritzianus (O.Berg) Burret (9,7) < Psidium sartorianum (O. Berg) Nied. (8,9) < Wedelia calycina (6,5) < Lippia micromera Schauer (6,2) ≈ Piper haltonii . (6,2). AE con valores de CC50 <100 µg/mL en cuatro o más condiciones experimentales presentaron valores ∑JPi <4.0 sugiriendo alta tendencia a toxicidad y fueron en orden ascendente: Tagetes caracasana Kunth (2,7 - 2,8) Chromolaena odorata (L.) R.M.King & H.Rob. (3,0) Ageratina aff. popayanensis (Hieron.) R.M.King & H.Rob. (3,1) Lantana colombiana López-Pal. (3,3) Turnera disffusa. (3,4). AE de Tagetes caracasana presentó actividad antiproliferante (CI50: 42,2 y 47,9 µg/mL) sobre células humanas de cáncer de cérvix. Conclusiones: El abordaje metodológico permitió identificar AE con baja y alta tendencia a toxicidad. Los resultados podrían tener valor para predecir actividad in vivo y priorizar muestras para futuras investigaciones.

Background: Part of the research process focused on discovering natural medicines is the study of products derived from plants, which may be toxic to humans. Animal-based test methods can be relatively expensive, low-throughput and associated with animal suffering, and differences in animal species may difficult to infer human health effects. Methods based on living cells are recommended. Objectives: To study the tendency to toxicity of essential oils (EOs) from plants of Colombia using a cell-based assay. Methods: EOs from different species (n = 18) of plants were included. The MTT assay was used on six human and animal cell lines derived from normal and cancerous organs, which were treated before and after proliferation. The EOs were arranged in the order of a hierarchical clustering based on their CC50 values, and the sum of weighted hierarchy across cell panel (∑iWH) was used as the similarity metric. The greater the value of ∑iWH lesser tendency to toxicity. Results: The EOs, which showed CC50 values 200 µg/mL in at least five experimental conditions presented ∑iWH values 5,0 suggesting lower tendency to toxicity, and they were in descending order (∑iWH in parentheses), as follows: Calycolpus moritzianus (O.Berg) Burret (9,7) < Psidium sartorianum (O. Berg) Nied. 1893 (8,9) < Wedelia calcycina (6,5) < Lippia micromera Schauer (6,2) ≈ Piper haltonii Jacq. (6,2) The EOs, which showed CC50 <100 µg/mL in four or more experimental conditions presented ∑iWH values <4.0 suggesting higher tendency to toxicity, and they were in ascending order, as follows: Tagetes caracasana Kunth (2,7 - 2,8) Chromolaena odorata (L.) R.M.King & H.Rob. (3,0) Ageratina aff. popayanensis (Hieron.) R.M.King & H.Rob. (3,1) Lantana colombiana López-Pal. (3,3) Turnera diffusa (3,4). EO from Tagetes caracasana Kunth presented relevant antiproliferative activity (CI50: <50.0 µg/mL) on cells from human cervical carcinoma. Conclusions: The methodological approach allows identifying EOs with lower and higher tendency to toxicity. Data generated may be valuable for predicting in vivo toxicity and for prioritizing samples for further studies.

Antecedentes: La mora contiene compuestos fenólicos que contribuyen a su capacidad antioxidante. El método más común para aislar estas sustancias es la extracción con solventes, que puede asistirse con ultrasonido para aumentar el contenido de analitos extraídos. Objetivos: Determinar las condiciones de tipo y concentración de solvente en agua, y de tiempo de extracción asistida con ultrasonido, con las cuales se obtiene el mayor contenido de compuestos fenólicos y el valor de capacidad antioxidante más alto en extractos de mora andina (Rubus glaucus Benth). Comparar la capacidad antioxidante de los extractos de mora con la de antioxidantes de referencia como el di-terc-butilhidroxitolueno (BHT) y el a-tocoferol. Métodos: Se hicieron tres diseños de experimentos de dos factores con tres niveles cada uno. Las variables fueron la concentración de acetona, etanol o metanol en agua y el tiempo de extracción asistida con ultrasonido. Los observables-respuesta fueron el contenido total de compuestos fenólicos, que se determinó utilizando el reactivo de Folin-Ciocalteu, y la capacidad antioxidante, determinada mediante el ensayo ORAC (capacidad de absorción de radicales de oxígeno). Se calculó el coeficiente de correlación entre las dos variables de respuesta. Se comparó la capacidad antioxidante de los extractos de mora, obtenidos bajo las condiciones inferidas como óptimas, con las del BHT y del a-tocoferol. Resultados: Los extractos adquiridos con soluciones acuosas de acetona al 31% (v/v), asistiendo la extracción con ultrasonido durante 100 min, mostraron los mayores contenidos de compuestos fenólicos (30 ± 1 mg ácido gálico/g mora seca), y los valores de capacidad antioxidante más altos (273 ± 6 mmol Trolox®/g mora seca). El coeficiente de correlación entre las dos variables de respuesta fue 0,92. Los extractos de mora presentaron mejor capacidad antioxidante que el BHT y el a-tocoferol. Conclusiones: Bajo las condiciones óptimas de extracción, con las soluciones acuosas de acetona se obtuvieron el mayor contenido de compuestos fenólicos y el valor de capacidad antioxidante más alto. Se observó una relación lineal entre las dos variables de respuesta. Los extractos de mora, obtenidos bajo las mejores condiciones halladas, presentaron mayor capacidad antioxidante en comparación con la de los compuestos de referencia analizados.

Background: Blackberry contains phenolic compounds that contribute to their antioxidant capacity. The most common method used to isolate these substances is the conventional solvent extraction, which can be assisted by ultrasound in order to increase the content of extracted analyte. Objectives: Determining the conditions of solvent type and concentration, and ultrasound-assisted extraction time, under which the highest content of phenolic compounds and antioxidant capacity are obtained, in Andean blackberry (Rubus glaucus Benth) extracts. To compare the antioxidant capacity of blackberry extracts with those of reference antioxidants, such as di-tert-butylhydroxytoluene (BHT) and a-tocopherol. Methods: Three experimental designs, of two factors with three levels, were done to provide the data for the analysis of variance. Variables were the acetone, ethanol or methanol concentration in water and the duration of ultrasound-assisted extraction. The response variables were the total content of phenolic compounds, which was determined with the Folin-Ciocalteu reagent and the antioxidant capacity, measured by ORAC (oxygen radical absorbance capacity) assay. The correlation coefficient between the two response variables was calculated. The blackberry extracts' antioxidant capacity, obtained under isolation conditions inferred as optimal was compared with those of BHT and a-tocopherol. Results: Extracts obtained with an aqueous solution of 31% acetone (v/v), performing ultrasound-assisted extraction for 100 min, showed the highest content of phenolic compounds (30 ± 1 mg gallic acid/g dry blackberry), and antioxidant capacity (273 ± 6 μmol Trolox®/g dry blackberry). The correlation coefficient between the total phenolic compounds content and antioxidant capacity was 0.92. Blackberry extracts presented higher antioxidant capacity than BHT and a-tocopherol. Conclusions: Under optimum conditions of extraction, the aqueous solutions of acetone afforded the highest content of phenolic compounds and highest antioxidant capacity value. There was a linear relationship between the two response variables analyzed. Blackberry extracts, under the improved conditions found, presented higher antioxidant capacity than the reference compounds analyzed.

Many Gram-negative pathogens have the ability to produce N-acylhomoserine lactones (AHLs) as signal molecules for quorum sensing (QS). This cell-cell communication system allows them to coordinate gene expression and regulate virulence. Strategies to inhibit QS are promising for the control of infectious diseases or antibiotic resistant bacterial pathogens. The aim of the present study was to evaluate the anti-quorum sensing (anti-QS) and antibacterial potential of five essential oils isolated from Lippia alba on the Tn-5 mutant of Chromobacterium violaceum CV026, and on the growth of the gram-positive bacteria S. aureus ATCC 25923. The anti-QS activity was detected through the inhibition of the QS-controlled violacein pigment production by the sensor bacteria. Results showed that two essential oils from L. alba, one containing the greatest geranial:neral and the other the highest limonene:carvone concentrations, were the most effective QS inhibitors. Both oils also had small effects on cell growth. Moreover, the geranial/neral chemotype oil also produced the maximum zone of growth inhibition against S. aureus ATCC 25923. These data suggest essential oils from L. alba have promising properties as QS modulators, and present antibacterial activity on S. aureus.

Con el fin de contribuir al conocimiento de su actividad a nivel celular, se evaluó el mecanismo de acción del aceite esencial de Eucalyptus citriodora (Fam. Myrtaceae) sobre la bioenergética mitocondrial, su efecto sobre la velocidad de consumo de oxígeno de mitocondrias energizadas (estados 3 y 4) y su coeficiente de control respiratorio (CCR). Además, se analizó la actividad de los complejos de la cadena respiratoria usando técnicas espectrofotométricas. Los resultados obtenidos indican que el aceite esencial de E. citriodora aumenta la velocidad del consumo de oxígeno en los estados 3 y 4, disminuye el CCR, desacopla la fosforilación oxidativa, aumenta la actividad de la citocromo c oxidasa y aumenta la actividad ATPasa en mitocondrias íntegras, a partir de la concentración de 10 µg/mL. Estos resultados sugieren que el aceite esencial o sus metabolitos afectan el funcionamiento normal del transporte de electrones de la cadena respiratoria y la síntesis de ATP.

In order to contribute to the knowledge of its activity at the cellular level, the mechanism of action of the essential oil of Eucalyptus citriodora (Fam. Myrtaceae) on mitochondrial bioenergetics, the rate of oxygen consumption of energized mitochondria (states was assessed 3 and 4), and respiratory control ratio (CCR) were evaluated. The activity of the respiratory chain complexes was analyzed using spectrophotometric techniques. The results indicate that the essential oil of E. citriodora increases the rate of oxygen consumption in states 3 and 4, reduces the CCR, uncouples oxidative phosphorylation, increases the activity of cytochrome c oxidase, and increases the ATPase activity in mitochondria intact at concentrations ≥ 10 mg/mL. These results suggest that the essential oil or its metabolites affect the normal operation of the electron transport in the respiratory chain and ATP synthesis.

Com o fim de contribuir ao conhecimento da sua atividade a nível celular, foi avaliado o mecanismo de ação do óleo essencial de Eucalyptus citriodora (Fam. Myrtaceae) sobre a bioenergética mitocondrial, o efeito sobre a taxa de consumo de oxigênio de mitocôndrias energizadas (estados 3 e 4) e o coeficiente de controle respiratório (CCR). Usando técnicas espectrofotométricas, foi analisada a atividade dos complexos da cadeia respiratória. Os resultados obtidos indicam que o óleo essencial de E. citriodora aumenta a velocidade do consumo de oxigênio nos estados 3 e 4, reduz o CCR, desacopla a fosforilação oxidativa, aumenta a atividade da citocromo c oxidase e aumenta a atividade ATPase em mitocôndrias intatas, a partir da concentração de 10 µg / mL. Estes resultados sugerem que o óleo essencial ou seus metabolitos afetam o funcionamento normal do transporte de elétrons na cadeia respiratória e na síntese de ATP.

Se obtuvieron extractos de hojas y tallos de salvia (Salvia officinalis, Fam. Labiatae) y romero (Rosmarinus officinalis, Fam. Labiatae) y de hojas de guayaba (Psidium guajava Fam. Myrtaceae), empleando CO2 en estado supercrítico. Se obtuvieron modelos polinómicos para relacionar el rendimiento de extractos con las condiciones de su obtención. La composición de la fracción volátil de los extractos se determinó por medio de GC-MS. Se midieron la capacidad antioxidante (ORAC) de los extractos y el grado de protección que ofrecen al agregarse a una base cosmética sometida a oxidación lipídica por acción de la radiación UV. El extracto de romero mostró el mayor porcentaje de inhibición de la oxidación lipídica (88%), seguido por el de salvia (76%) y el de hojas de guayaba (43%). Los extractos de romero y salvia exhibieron una capacidad antioxidante alta (1,9 µmol Trolox®/mg), similar a la del BHT y la vitamina E (2,8 y 3,0 µmol Trolox®/mg), mayor que la del extracto de hojas de guayaba (0,7 µmol Trolox®/mg).

Extracts from stems and leaves of sage (Salvia officinalis, Labiatae Fam.) and rosemary (Rosmarinus officinalis, Labiatae Fam.) and from guava leaves (Psidium guajava, Myrtaceae Fam.), were obtained using supercritical CO2. Polynomic models were formulated to relate yield with extraction conditions. The compositions of the volatile fractions of these extracts were determined using GC-MS. Their antioxidant capacity (ORAC) and the protection resultant from their addition to a cosmetic base subjected to lipid peroxidation as a result of its exposure to UV radiation were also measured. The extract from rosemary imparted the highest lipid peroxidation inhibition (88%), followed by those obtained from sage (76%) and guava leaves (43%). Rosemary and sage extracts exhibited a high antioxidant capacity (1,9 µmol Trolox®/mg), similar to those of BHT and vitamin E (2,8 and 3,0 µmol Trolox®/mg), respectively, and higher than that of the guava leaves extract (0,7 µmol Trolox®/mg).

In this work, the toxicity and genotoxicity of organic solvents (acetone, carbon tetrachloride, dichloromethane, dimethylsulfoxide, ethanol, ether and methanol) were studied using the SOS chromotest. The influence of these solvents on the direct genotoxicity induced by the mutagens mitomycin C (MMC) and 4-nitroquinoline-1-oxide (4-NQO) were also investigated. None of the solvents were genotoxic in Escherichia coli PQ37. However, based on the inhibition of protein synthesis assessed by constitutive alkaline phosphatase activity, some solvents (carbon tetrachloride, dimethylsulfoxide, ethanol and ether) were toxic and incompatible with the SOS chromotest. Solvents that were neither toxic nor genotoxic to E. coli (acetone, dichloromethane and methanol) significantly reduced the genotoxicity of MMC and 4-NQO. When these solvents were used to dissolve vitamin E they increased the antigenotoxic activity of this compound, possibly through additive or synergistic effects. The relevance of these results is discussed in relation to antigenotoxic studies. These data indicate the need for careful selection of an appropriate diluent for the SOS chromotest since some solvents can modulate genotoxicity and antigenotoxicity.

The present work evaluated the chemical composition and the DNA protective effect of the essential oils (EOs) from Lippia alba against bleomycin-induced genotoxicity. EO constituents were determined by Gas Chromatography/Mass Spectrometric (GC-MS) analysis. The major compounds encountered being citral (33% geranial and 25% neral), geraniol (7%) and trans-β-caryophyllene (7%) for L. alba specimen COL512077, and carvone (38%), limonene (33%) and bicyclosesquiphellandrene (8%) for the other, COL512078. The genotoxicity and antigenotoxicity of EO and the compounds citral, carvone and limonene, were assayed using the SOS Chromotest in Escherichia coli. The EOs were not genotoxic in the SOS chromotest, but one of the major compound (limonene) showed genotoxicity at doses between 97 and 1549 mM. Both EOs protected bacterial cells against bleomycin-induced genotoxicity. Antigenotoxicity in the two L. alba chemotypes was related to the major compounds, citral and carvone, respectively. The results were discussed in relation to the chemopreventive potential of L. alba EOs and its major compounds.

Se determinó por cromatografía de gases acoplada a espectrometría de masas (GC-MS) la composición química de aceites esenciales (AE), aislados por hidrodestilación asistida por la radiación de microondas (MWHD), de las especies vegetales aromáticas Artemisia dracunculus, Foeniculum vulgare, Illicium verum, Lippia micromera, Lippia origanoides, Ocimum spp., Plectranthus amboinicus, Tagetes filifolia, Tagetes lucida y Thymus vulgaris. Los valores de capacidades antioxidantes in vitro de estos aceites esenciales, se obtuvieron usando los ensayos de decoloración del catión-radical ABTS+• (metodologías convencional y con dilución en microplacas) y la oxidación del ácido linoleico, inducida por O2 y Fe+2. El potencial inhibitorio de ABTS+• fue más alto para los aceites esenciales que contienen fenoles (carvacrol y timol), que para los aceites esenciales ricos en éteres (trans-anetol y estragol). La actividad antioxidante mediante el ensayo ABTS+• modificado en orden decreciente fue: AE Plectranthus amboinicus ≥ AE Lippia origanoides >> AE Thymus vulgaris > AE Lippia micromera >>> AE Tagetes lucida (flores) > AE Ocimum sp. > AE Tagetes lucida (hojas) > AE Illicium verum > AE Tagetes filifolia (Cenivam) > AE Foeniculum vulgare. Salud UIS 2009; 41: 287-294

Gas chromatography coupled to mass spectrometry (GC-MS) was used to determine the chemical composition of essential oils (EO) isolated by microwave-radiation-assisted hydrodistillation (MWHD) of Artemisia dracunculus, Foeniculum vulgare, Illicium verum, Lippia micromera, Lippia origanoides, Ocimum sp., Plectranthus amboinicus, Tagetes filifolia, Tagetes lucida and Thymus vulgaris. in vitro antioxidant capacity values using ABTS+• discoloration assays (traditional and microplate methods) and the linoleic acid oxidation (with O2 and Fe+2) of these essential oils were obtained. Essential oils with phenols (carvacrol and thymol) high content showed higher total antioxidant capacity values than the essential oils rich in ether compounds (estragole and trans-anethole). The antioxidant capacity using by modified ABTS+• assay in decreasing order was as follows: EO Plectranthus amboinicus ≥ EO Lippia origanoides >> EO Thymus vulgaris > EO Lippia micromera >>> EO Tagetes lucida (flowers) > EO Ocimum sp. > EO Tagetes lucida (leaf) > EO Illicium verum > EO Tagetes filifolia (Cenivam) > EO Foeniculum vulgare. Salud UIS 2009; 41: 287-294.