Acción Antibacteriana in vitro del Taraxacun officinale frente al Acinetobacter baumannii / In vitro Antibacterial Activity of Taraxacum officinale Against Acinetobacter baumannii / Ação antibacteriana in vitro de Taraxacum officinale contra Acinetobacter baumannii

Acinetobacter baumannii es una bacteria oportunista que representa un desafío significativo en el ámbito clínico debido a su rápida diseminación, elevada mortalidad y altos niveles de resistencia a los antimicrobianos convencionales. Esto ha impulsado la búsqueda de alternativas terapéuticas eficaces para el manejo de infecciones causadas por este patógeno. Objetivo: Evaluar la actividad antibacteriana in vitro del extracto de Taraxacum officinale (diente de león) frente a cepas de Acinetobacter baumannii. Materiales y Métodos: Se utilizaron cultivos in vitro con medio Muller Hinton y agar nutritivo para la activación y propagación de la cepa de referencia A. baumannii ATCC BAA-1605. Se obtuvo un extracto etanólico de T. officinale y se evaluaron diferentes concentraciones del mismo. Resultados: El extracto de T. officinale no mostró actividad antibacteriana significativa frente a. baumannii, ya que no se observó la formación de halos de inhibición, incluyendo en la prueba con el control positivo de Ciprofloxacina. Estos hallazgos llevaron a aceptar la hipótesis nula y rechazar la hipótesis alternativa, lo que sugiere una escasa eficacia del extracto de la planta frente a esta bacteria. Conclusiones: Se resalta la necesidad de realizar investigaciones más exhaustivas para comprender mejor los mecanismos de acción y la eficacia del extracto de T. officinale, así como explorar su potencial aplicación clínica en el tratamiento de infecciones causadas por A. baumannii dado que esta bacteria presenta altos niveles de resistencia a los antimicrobianos convencionales

Acinetobacter baumannii is an opportunistic bacteria that represents a significant challenge in the clinical field due to its rapid dissemination, high mortality, and high levels of resistance to conventional antimicrobials. This has driven the search for effective therapeutic alternatives for the management of infections caused by this pathogen. Objective: To evaluate the in vitro antibacterial activity of the Taraxacum officinale (dandelion) extract against Acinetobacter baumannii strains. Materials and Methods: In vitro cultures with Muller Hinton medium and nutrient agar were used for the activation and propagation of the reference strain A. baumannii ATCC BAA-1605. An ethanolic extract of T. officinale was obtained, and different concentrations of the extract were evaluated. Results: The T. officinale extract did not show significant antibacterial activity against A. baumannii, as no formation of inhibition halos was observed, including in the test with the positive control of Ciprofloxacin. These findings led to accepting the null hypothesis and rejecting the alternative hypothesis, suggesting a poor efficacy of the plant extract against this bacterium. Conclusions: The need to conduct more extensive research to better understand the mechanisms of action and the efficacy of the T. officinale extract is highlighted, as well as to explore its potential clinical application in the treatment of infections caused by A. baumannii, as this bacterium presents high levels of resistance to conventional antimicrobials.

Acinetobacter baumannii é uma bactéria oportunista que representa um desafio significativo no campo clínico devido à sua rápida disseminação, elevada mortalidade e altos níveis de resistência a antimicrobianos convencionais. Isso tem impulsionado a busca por alternativas terapêuticas eficazes para o manejo de infecções causadas por esse patógeno. Objetivo: Avaliar a atividade antibacteriana in vitro do extrato de Taraxacum officinale (dente-de-leão) contra cepas de Acinetobacter baumannii. Materiais e Métodos: Culturas in vitro com meio Muller Hinton e ágar nutritivo foram utilizadas para a ativação e propagação da cepa de referência A. baumannii ATCC BAA-1605. Um extrato etanólico de T. officinale foi obtido e diferentes concentrações do extrato foram avaliadas. Resultados: O extrato de T. officinale não mostrou atividade antibacteriana significativa contra A. baumannii, uma vez que não foi observada a formação de halos de inibição, incluindo no teste com o controle positivo de Ciprofloxacina. Esses achados levaram à aceitação da hipótese nula e rejeição da hipótese alternativa, sugerindo uma eficácia limitada do extrato da planta contra essa bactéria. Conclusões: Destaca-se a necessidade de realizar pesquisas mais amplas para compreender melhor os mecanismos de ação e a eficácia do extrato de T. officinale, bem como explorar sua potencial aplicação clínica no tratamento de infecções causadas por A. baumannii, uma vez que essa bactéria apresenta altos níveis de resistência a antimicrobianos convencionais.

Screening for acetylcholinesterase inhibition, lipid peroxidation inhibition and antioxidant activity of medicinal plants from Morocco / Detección de inhibición de acetilcolinesterasa, inhibición de peroxidación de lípidos y actividad antioxidante de plantas medicinales de Marruecos

Acetylcholinesterase (AChE), hydrolyzes acetylcholine to choline and acetate, thereby terminating this neurotransmitter effect at cholinergic synapses. Therefore, AChE inhibition is used for counterbalance the cholinergic deficit in Alzheimer's disease (AD) patients. In the present work, in order to find new plant acetylcholinesterase inhibitors, the hydroalcoholic extracts from seventeen medicinal plant species were screened for their acetylcholinesterase inhibition activity, as well as total phenolic (TPC) and flavonoids contents (TFC) and antioxidant activity using ORAC (Oxygen Radical Absorbance Capacity) assay, and their ability to inhibit lipid peroxidation. The results revealed that Rumex acetosa, Taraxacum officinale and Hypericum perforatum extracts possessing the highest TPC and TFC, were the most effective in terms of ORAC antioxidant activity, and acetylcholinesterase inhibition, in addition to their ability to inhibit liposomes peroxidation, suggesting that those plant species may provide a substantial source of secondary metabolites, which act as natural antioxidants and acetylcholinesterase inhibitors, and may be beneficial in the treatment of AD.

La acetilcolinesterasa (AChE) hidroliza la acetilcolina se hidroliza en colina y acetato, terminando así este efecto neurotransmisor en las sinapsis colinérgicas. Por lo tanto, la inhibición de la AChE se utiliza para contrarrestar el déficit colinérgico en pacientes con enfermedad de Alzheimer (EA). En el presente trabajo, con el fin de encontrar nuevos inhibidores de la acetilcolinesterasa vegetal, se analizaron los extractos hidroalcohólicos de diecisiete especies de plantas medicinales para determinar su actividad inhibidora de la acetilcolinesterasa, así como el contenido total de fenólicos (TPC) y flavonoides (TFC) y la actividad antioxidante utilizando ORAC (Capacidad de absorbancia de radicales de oxígeno) y su capacidad para inhibir la peroxidación de lípidos. Los resultados revelaron que los extractos de Rumexacetosa, Taraxacum officinale e Hypericum perforatum que poseen los más altos TPC y TFC, fueron los más efectivos en términos de actividad antioxidante ORAC e inhibición de acetilcolinesterasa, además de su capacidad para inhibir la peroxidación de los liposomas, sugiriendo que esas especies de plantas puede proporcionar una fuente sustancial de metabolitos secundarios, que actúan como antioxidantes naturales e inhibidores de la acetilcolinesterasa, y puede ser beneficioso en el tratamiento de la EA.

Plantas alimentícias não convencionais: revisão / Non-conventional food plants: review / Plantas alimenticias no convencionales: revisión

As plantas alimentícias não convencionais (PANCs) são hortaliças nativas, normalmente encontradas em calçadas ou terrenos abandonados, sempre fizeram parte do cardápio dos antepassados. No entanto, com a modernização da agricultura e do êxodo rural, seu consumo foi esquecido de ser repassado para as gerações futuras. O objetivo deste estudo consistiu em realizar um levantamento bibliográfico sobre as plantas alimentícias não convencionais (PANCs), sua importância na alimentação e farmacológica. A metodologia consistiu na realização de levantamento bibliográfico, com as principais plantas utilizadas como alimento pelos antepassados sendo as plantas Pereskia aculeata Miller, Basella alba, Sonchus oleraceus, Stachys byzantina, Taraxacum Officinale, Xanthosoma sagittifolium, Dioscorea bulbifera, Physalis angulata, Acmella oleracea, Tropaeolum majus. Através deste estudo pode-se constatar que estas plantas são úteis, pois além de apresentar valor nutricional e a sua utilização na alimentação, também são utilizadas como como plantas medicinais, devido à presença de compostos ativos responsáveis pela ação biológica.

Unconventional food plants (PANCs) are native vegetables, usually found on sidewalks or abandoned land, have always been part of the ancestors' menu. Nonetheless, with the modernization of agriculture and the rural exodus, its consumption was forgotten to be passed on to future generations. The objective of this study was to carry out a bibliographic survey on unconventional food plants (PANCs), their importance in food and pharmacology. The methodology consisted of carrying out a bibliographic survey, with the main plants used as food by the ancestors being the plants Pereskia aculeata Miller, Basella alba, Sonchus oleraceus, Stachys byzantina, Taraxacum Officinale, Xanthosoma sagittifolium, Dioscorea bulbifera, Physalis angulata, Acmella oleracea, Tropaeolum majus. Through this study it can be seen that these plants are useful, because in addition to presenting nutritional value and their use in food, they are also used as medicinal plants, due to the presence of active compounds responsible for biological action.

Las plantas alimenticias no convencionales (PANC, por sus siglas en inglés) son vegetales nativos, que generalmente se encuentran en las aceras o en terrenos abandonados, y siempre han sido parte del menú de los antepasados. Sin embargo, con la modernización de la agricultura y el éxodo rural, su consumo quedó en el olvido para pasar a las generaciones futuras. El objetivo de este estudio fue realizar un levantamiento bibliográfico sobre las plantas alimenticias no convencionales (PANCs), su importancia en la alimentación y farmacología. La metodología consistió en realizar un levantamiento bibliográfico, siendo las principales plantas utilizadas como alimento por los ancestros las plantas Pereskia aculeata Miller, Basella alba, Sonchus oleraceus, Stachys byzantina, Taraxacum Officinale, Xanthosoma sagittifolium, Dioscorea bulbifera, Physalis angulata, Acmella oleracea , Tropaeolum mayor. A través de este estudio se puede apreciar que estas plantas son útiles, pues además de presentar valor nutritivo y su uso en la alimentación, también son utilizadas como plantas medicinales, debido a la presencia de compuestos activos responsables de la acción biológica.

Lipid Composition of Latex and Rubber Particles in Hevea brasiliensis and Taraxacum kok-saghyz.

Natural rubber is usually synthesized in the rubber particles present in the latex of rubber-producing plants such as the Pará rubber tree (Hevea brasiliensis) and rubber dandelion (Taraxacum kok-saghyz). Since the detailed lipid compositions of fresh latex and rubber particles of the plants are poorly known, the present study reports detailed compound lipid composition, focusing on phospholipids and galactolipids in the latex and rubber particles of the plants. In the fresh latex and rubber particles of both plants, phospholipids were much more dominant (85-99%) compared to galactolipids. Among the nine classes of phospholipids, phosphatidylcholines (PCs) were most abundant, at ~80%, in both plants. Among PCs, PC (36:4) and PC (34:2) were most abundant in the rubber tree and rubber dandelion, respectively. Two classes of galactolipids, monogalactosyl diacylglycerol and digalactosyl diacylglycerol, were detected as 12% and 1%, respectively, of total compound lipids in rubber tree, whereas their percentages in the rubber dandelion were negligible (< 1%). Overall, the compound lipid composition differed only slightly between the fresh latex and the rubber particles of both rubber plants. These results provide fundamental data on the lipid composition of rubber particles in two rubber-producing plants, which can serve as a basis for artificial rubber particle production in the future.

Toxicity evaluation of water extract of tissue-cultured Taraxacum formosanum by acute, subacute administration, and Ames test

BACKGROUND: Taraxacum species (commonly known as dandelion) used as herbal medicine have been reported to exhibit an antiproliferative effect on hepatoma cells and antitumor activity in non-small-cell lung cancer cells. Although several investigations have demonstrated the safety of Taraxacum officinale, the safety of tissue-cultured plants of T. formosanum has not been assessed so far. Therefore, the present study examines the safety of the water extract of the entire plant of tissue cultured T. formosanum based on acute and subacute toxicity tests in rats, as well as the Ames tests. RESULTS: No death or toxicity symptoms were observed in the acute and subacute tests. The results of the acute test revealed that the LD50 (50% of lethal dose) value of the T. formosanum water extract for rats exceeded 5 g/kg bw. No abnormal changes in the body weight, weekly food consumption, organ weight, or hematological, biochemical, and morphological parameters were observed in the subacute toxicity test. Thus, the no observed adverse effect level (NOAEL) of T. formosanum water extract was estimated to be higher than 2.0 g/kg. Finally, the results of the Ames test revealed that T. formosanum water extract was not genotoxic at any tested concentration to any of five Salmonella strains. CONCLUSIONS: The water extract of tissue-cultured T. formosanum was non-toxic to rats in acute and subacute tests and exhibited no genotoxicity to five Salmonella strains.

Kinetics and modeling of cell growth for potential anthocyanin induction in cultures of Taraxacum officinale G.H. Weber ex Wiggers (Dandelion) in vitro

Background: Taraxacum officinale G.H. Weber ex Wiggers is a wild plant used in folk medicine to treat several diseases owing to bioactive secondary metabolites present in its tissue. The accumulation of such molecules in plant cells can occur as a response against abiotic stress, but these metabolites are often deposited in low concentrations. For this reason, the use of a biotechnological approach to improve the yields of technologically interesting bioactive compounds such as anthocyanins is a compelling option. This work focuses on investigating the potential of in vitro T. officinale cultures as an anthocyanin source. Results: To demonstrate the suitability of anthocyanin induction and accumulation in calluses under specific conditions, anthocyanin was induced in the T. officinale callus. A specific medium of 5.5% sucrose supplemented with 6-benzylaminopurine /1-naphthaleneacetic acid in a 10:1 ratio was used to produce an anthocyanin yield of 1.23 mg g-1 fw. An in vitro dandelion callus line was established from this experiment. Five mathematical models were then used to objectively and predictably explain the growth of anthocyanin-induced calluses from T. officinale. Of these models, the Richards model offered the most suitable representation of anthocyanin callus growth in a solid medium and permitted the calculation of the corresponding kinetic parameters. Conclusions: The findings demonstrate the potential of an in vitro anthocyanin-induced callus line from T. officinale as an industrial anthocyanin source.

Indicators of environmental contamination by heavy metals in leaves of Taraxacum officinale in two zones of the metropolitan area of Mexico City.

The present study was designed to detect the effect of heavy metals in two zones of the Metropolitan Area of Mexico City (MAMC), the Centro de Ciencias de la Atmósfera (CCA), and the Altzomoni station in the Iztaccíhuatl-Popocatépetl National Park. Taraxacum officinale was selected as the indicator organism of responses to atmospheric contamination by heavy metals. Determinations of heavy metals were performed, and total mRNA was extracted to quantify the expression of microRNA398 (miR398), superoxide dismutase 2 (CSD2), and the amounts of free radicals using the bromide of 3-(4,5-dimethylthiazole-2-ilo)-2,5-diphenyltetrazole (MTT) salts reduction assay. Results from the Altzomoni station showed high concentrations of five heavy metals, especially Aluminum, while three heavy metals were identified in the CCA-UNAM zone, most importantly, Vanadium, both in the dry season; miR398 expression presented subtle changes but was greater in the leaves from the stations with higher concentrations of heavy metals. Observations included a significant expression of CSD2, mainly in the dry season in both study zones, where levels were significant with respect to controls (p < 0.05). Reduced MTT was also higher in the dry season than in the rainy season (p < 0.05). In conclusion, the increase in heavy metals on the leaves of Taraxacum officinale induces increased expression of the CSD2 gene and reduced MTT; thus, they can be used as indicators for biomonitoring heavy metal concentrations.

In vitro assessment of Argemone mexicana, Taraxacum officinale, Ruta chalepensis and Tagetes filifolia against Haemonchus contortus nematode eggs and infective (L3) larvae.

Argemone mexicana, Taraxacum officinale, Ruta chalepensis and Tagetes filifolia are plants with deworming potential. The purpose of this study was to evaluate methanolic extracts of aerial parts of these plants against Haemonchus contortus eggs and infective larvae (L3) and identify compounds responsible for the anthelmintic activity. In vitro probes were performed to identify the anthelmintic activity of plant extracts: egg hatching inhibition (EHI) and larvae mortality. Open column Chromatography was used to bio-guided fractionation of the extract, which shows the best anthelmintic effect. The lethal concentration to inhibit 50% of H. contortus egg hatching or larvae mortality (LC50) was calculated using a Probit analysis. Bio-guided procedure led to the recognition of an active fraction (TF11) mainly composed by 1) quercetagitrin, 2) methyl chlorogenate and chlorogenic acid. Quercetagitrin (1) and methyl chlorogenate (2) did not show an important EHI activity (3-14%) (p < 0.05); however, chlorogenic acid (3) showed 100% of EHI (LC50 248 µg/mL) (p < 0.05). Chlorogenic acid is responsible of the ovicidal activity and it seems that, this compound is reported for the first time with anthelmintic activity against a parasite of importance in sheep industry.

Cumulative effects of volcanic ash on the food preferences of two Orthopteran species.

Inert dusts are an early form of insecticide which is still in use. One of the most common inert dusts is volcanic ash. In order to study the reaction of rangeland grasshoppers, Dichroplus vittigerum (Acrididae) and a katydid, Burgilis mendosensis (Phaneropteridae), to the presence of volcanic ash in their food sources and how this reaction changed as a function of time, we conducted paired preference tests between clean leaves of their preferred host plant and leaves exposed to volcanic ash of different grain size. The behavioral response was measured as the rating on the Thurstonian preference scale of leaves with ash in relation to clean leaves. The results showed that the avoidance of volcanic ash increased as a function of time in both species. Both species studied are occasionally exposed to volcanic activity, and come from an area in which a volcanic eruption had recently occurred. As their populations did not decrease after the ash fall, we propose that some behavioral responses such as avoidance of places with ash, works as tolerance mechanism to inert dusts exposure.

Concentraciones de alcaloides, glucósidos cianogénicos, polifenoles y saponinas en plantas medicinales seleccionadas en Ecuador y su relación con la toxicidad aguda contra Artemia salina / Concentrations of alkaloids, cyanogenic glycosides, polyphenols and saponins in selected medicinal plants from Ecuador and their relationship with acute toxicity against Artemia salina

ResumenEntre los principales compuestos químicos sintetizados por las plantas, pero considerados no esenciales para su metabolismo básico, están los alcaloides, los polifenoles, los glucósidos cianogénicos y las saponinas que tienen diversas funciones en las plantas y reconocidas propiedades medicinales y farmacológicas. En esta investigación se determinaron las concentraciones de los mencionados metabolitos secundarios en los extractos de las hojas de las plantas medicinales Taraxacum officinale, Parthenium hysterophorus, Artemisia absinthium, Cnidoscolus aconitifolius y Piper carpunya y se relacionaron con la toxicidad aguda contra Artemia salina. En cada bioensayo con A. salina se usaron los extractos alcohólicos de las hojas de las plantas seleccionadas a diferentes concentraciones, calculándose la proporción de organismos muertos y los CL50. Las concentraciones de alcaloides, fenoles totales, taninos, glucósidos cianogénicos y saponinas fueron determinadas mediante métodos espectrofotométricos. Este es el primer reporte de cuantificación de metabolitos secundarios en las plantas analizadas provenientes de Ecuador. T. officinale presentó las mayores concentraciones de fenoles (22.30 ± 0.23 mg/g) y taninos (11.70 ± 0.10 mg/g), C aconitifolius de glucósidos cianogénicos (5.02 ± 0.37 µg/g) y P. hysterophorus de saponinas (6.12 ± 0.02 mg/g). Las plantas evaluadas presentaron actividades hemolíticas dependiendo de las concentraciones de saponinas. Los valores de taninos determinados estuvieron entre 0.20 ± 0.01 y 11.70 ± 0.10 mg/g, por lo que no son adversos para su consumo. Aunque los valores de glucósidos cianogénicos son permisibles, es necesario monitorear la presencia de estos compuestos químicos en las plantas para minimizar problemas de salud. Los CL50 obtenidos oscilaron entre los valores 3.37 µg/mL, extremadamente letal o tóxica, para P. carpunya y 274.34 µg/mL, altamente tóxica, para T. officinale. De los análisis de correlaciones realizados a los resultados, se observó que los alcaloides favorecen de manera significativa (p<0.001) a la toxicidad aguda contra A. salina, mientras que a mayor contenido de polifenoles dicha toxicidad disminuye significativamente (p<0.001) el nivel de toxicidad de las plantas. Del análisis de componentes principales, se demuestra que las saponinas están en sinergia con los polifenoles para disminuir la toxicidad, pero tienen un efecto antagónico con los alcaloides y los glucósidos cianogénicos, lo cual evidencia que estos metabolitos secundarios presentan variabilidades en los mecanismos de acción contra A. salina, como compuestos citotóxicos. Estos resultados demuestran que las saponinas y los polifenoles pueden ser letales para A. salina a bajas concentraciones, evidenciando que este bioensayo permite evaluar extractos vegetales que contengan bajas concentraciones de compuestos con altas polaridades. La correspondencia significativamente positiva entre citoxicidad y concentración de los alcaloides, confirmada con el bioensayo de Artemia salina, puede ser útil para hallar fuentes promisorias de compuestos antitumorales y para evaluar los límites tolerables que no afecten otras células benignas. El contenido de metabolitos secundarios hallados en las plantas analizadas les atribuye un gran valor farmacológico.

Abstract:Alkaloids, polyphenols, cyanogenic glycosides and saponins are among the main chemical compounds synthesized by plants but not considered essential for their basic metabolism. These compounds have different functions in plants, and have been recognized with medicinal and pharmacological properties. In this research, concentrations of the mentioned secondary metabolites were determined in the medicinal plants Artemisia absinthium, Cnidoscolus aconitifolius, Parthenium hysterophorus, Piper carpunya and Taraxacum officinale, from Ecuador, and related with cytotoxic effects against Artemia salina. Alcoholic and aqueous extracts from leaves of these selected plants were prepared at different concentrations. To assess cytotoxicity of these extracts, different bioassays with A. salina were undertaken, and the mortality rates and LC50 were obtained. Besides, concentrations of alkaloids, cyanogenic glycosides, phenols, tannins and saponins were determined by spectrophotometric methods; this constituted the first report of quantification of secondary metabolites in the selected plants from Ecuador. T. officinale had the highest concentration of total phenols (22.30 ± 0.23 mg/g) and tannins (11.70 ± 0.10 mg/g), C. aconitifolius of cyanogenic glycosides (5.02 ± 0.37 µg/g) and P. hysterophorus of saponins (6.12 ± 0.02 mg/g). Tannins values obtained were not adverse to their consumption. Alcoholic and aqueous extracts of selected plants had hemolytic activity depending on the concentration of saponins. Although the values of cyanogenic glycosides were permissible, it was necessary to monitor the presence of this metabolite in plants to minimize health problems. LC50 values ranged from extremely toxic (3.37 µg/mL) to highly toxic (274.34 μg/mL), in P. carpunya and T. officinale, respectively. From correlation analysis, it was observed that increase values of alkaloids concentrations had highly significant (p<0.001) acute toxicity against A. salina, while at a higher polyphenol concentration the level of plants cytotoxicity decreased significantly (p<0.001). The results of principal component analysis showed that saponins apparently were in synergy with polyphenols to decrease cytotoxicity, but antagonize with alkaloids and cyanogenic glycosides, indicating that these secondary metabolites present variability in the mechanisms of action against A. salina, as cytotoxic compounds. These results also demonstrate that polyphenols and saponins can be lethal at low concentrations, demonstrating the potential of brine shrimp bioassay as a model to evaluate plant extracts containing low concentrations of chemical compounds with high polarities. The significant positive correlation between cytotoxicity and concentration of alkaloids confirmed by the bioassay of brine shrimp can be useful to identify promising sources of antitumor compounds, and to evaluate tolerable limits not affecting other benign cells. Contents of secondary metabolites found in the selected plants confer them great pharmacologic values. Rev. Biol. Trop. 64 (3): 1171-1184. Epub 2016 September 01.

[Concentrations of alkaloids, cyanogenic glycosides, polyphenols and saponins in selected medicinal plants from Ecuador and their relationship with acute toxicity against Artemia salina]. / Concentraciones de alcaloides, glucósidos cianogénicos, polifenoles y saponinas en plantas medicinales seleccionadas en Ecuador y su relación con la toxicidad aguda contra Artemia salina.

Alkaloids, polyphenols, cyanogenic glycosides and saponins are among the main chemical compounds synthesized by plants but not considered essential for their basic metabolism. These compounds have different functions in plants, and have been recognized with medicinal and pharmacological properties. In this research, concentrations of the mentioned secondary metabolites were determined in the medicinal plants Artemisia absinthium, Cnidoscolus aconitifolius, Parthenium hysterophorus, Piper carpunya and Taraxacum officinale, from Ecuador, and related with cytotoxic effects against Artemia salina. Alcoholic and aqueous extracts from leaves of these selected plants were prepared at different concentrations. To assess cytotoxicity of these extracts, different bioassays with A. salina were undertaken, and the mortality rates and LC50 were obtained. Besides, concentrations of alkaloids, cyanogenic glycosides, phenols, tannins and saponins were determined by spectrophotometric methods; this constituted the first report of quantification of secondary metabolites in the selected plants from Ecuador. T. officinale had the highest concentration of total phenols (22.30 ± 0.23 mg/g) and tannins (11.70 ± 0.10 mg/g), C. aconitifolius of cyanogenic glycosides (5.02 ± 0.37 µg/g) and P. hysterophorus of saponins (6.12 ± 0.02 mg/g). Tannins values obtained were not adverse to their consumption. Alcoholic and aqueous extracts of selected plants had hemolytic activity depending on the concentration of saponins. Although the values of cyanogenic glycosides were permissible, it was necessary to monitor the presence of this metabolite in plants to minimize health problems. LC50 values ranged from extremely toxic (3.37 µg/mL) to highly toxic (274.34 µg/mL), in P. carpunya and T. officinale, respectively. From correlation analysis, it was observed that increase values of alkaloids concentrations had highly significant (p<0.001) acute toxicity against A. salina, while at a higher polyphenol concentration the level of plants cytotoxicity decreased significantly (p<0.001). The results of principal component analysis showed that saponins apparently were in synergy with polyphenols to decrease cytotoxicity, but antagonize with alkaloids and cyanogenic glycosides, indicating that these secondary metabolites present variability in the mechanisms of action against A. salina, as cytotoxic compounds. These results also demonstrate that polyphenols and saponins can be lethal at low concentrations, demonstrating the potential of brine shrimp bioassay as a model to evaluate plant extracts containing low concentrations of chemical compounds with high polarities. The significant positive correlation between cytotoxicity and concentration of alkaloids confirmed by the bioassay of brine shrimp can be useful to identify promising sources of antitumor compounds, and to evaluate tolerable limits not affecting other benign cells. Contents of secondary metabolites found in the selected plants confer them great pharmacologic values.

Calidad de hierbas medicinales por recolección directa / Quality of medicinal herbs by direct collection

La detección de insectos y el mal aspecto en las hierbas medicinales que se comercializan en la herboristería resulta una problemática cotidiana. Con el objetivo de contribuir con la mejora de la calidad final de estas hierbas, se colectaron a campo cuatro drogas vegetales de amplia utilización en la medicina tradicional. Se comparó su calidad con la de las provenientes de un acopiador y se realizó un minucioso examen para la detección e identificación de insectos, sus rastros o vestigios. Posteriormente, se ensayaron algunos métodos físicos para evitar la afectación de las hierbas por parte de esos insectos. Las características de calidad final de las hierbas provenientes de recolección propia resultaron superiores a las provenientes de un acopiador. Desde el punto de vista entomológico, se identificaron las principales especies contaminantes y se encontraron los mejores métodos y condiciones para evitar su proliferación.

Is physiological performance a good predictor for fitness? Insights from an invasive plant species.

Is physiological performance a suitable proxy of fitness in plants? Although, several studies have been conducted to measure some fitness-related traits and physiological performance, direct assessments are seldom found in the literature. Here, we assessed the physiology-fitness relationship using second-generation individuals of the invasive plant species Taraxacum officinale from 17 localities distributed in five continents. Specifically, we tested if i) the maximum quantum yield is a good predictor for seed-output ii) whether this physiology-fitness relationship can be modified by environmental heterogeneity, and iii) if this relationship has an adaptive consequence for T. officinale individuals from different localities. Overall, we found a significant positive relationship between the maximum quantum yield and fitness for all localities evaluated, but this relationship decreased in T. officinale individuals from localities with greater environmental heterogeneity. Finally, we found that those individuals from localities where environmental conditions are highly seasonal performed better under heterogeneous environmental conditions. Contrarily, under homogeneous controlled conditions, those individuals from localities with low environmental seasonality performed much better. In conclusion, our results suggest that the maximum quantum yield seem to be good predictors for plant fitness. We suggest that rapid measurements, such as those obtained from the maximum quantum yield, could provide a straightforward proxy of individual's fitness in changing environments.

Actividad antiviral contra el virus de la fiebre amarilla, cepa vacunal 17D, de extractos de hojas de Taraxacum officinale GH Weber ex Wiggers / Phytochemicaland antiviral activity against yellow fever virus, 17D vaccine strain, of extracts from leaves of Taraxacum officinale GH Weber ex Wiggers

Taraxacum officinale leaves were collected at two and 5 months of growth, for antiviral activity against flavivirus, using the 17D vaccine strain of yellow fever virus as a model. Using spectroscopy technique, a total of twelve (12) compounds were identified in the chloroform (C) and hexane (H) extracts of two and five months (2M and 5M) of recollection., The antiviral activity against the yellow fever 17D virus was evaluated with the plaque assay and the concentrations used (50 - 1,5 ug/mL) were no cytotoxic to Vero cells as determined using the MTT(3-(4,5-Dimetiltiazol-2yl)-2,4-difenilbromuro de tetrazolium) assay. The phytochemical composition of leaves growing for 5 months is different and more complex than leaves growing for 2 months. From the four extracts, only C5M inhibited the viral replication in a dose depend manner, with 100 percent viral inhibition at 50 ug/mL (p=0,0124) and the effective doses 50 (ED50: 10,2 +/- 8,7 ug/mL), meanwhile, ED50 of C2M extract was 93,5 +/- 23,5 ug/mL, thus, the extract C5M is 8 times more effective than extract C2M. The identified compounds in extract C5M were: Psi taraxasteryl acetate, cafeic acid, taraxasteryl acetate, taraxerol, taraxerilo acetate and Psi-taraxasterol. One of these compounds or the combinations of them is responsible for the reported high antiviral activity.

Las hojas de Taraxacum officinale fueron colectadas a dos y cinco meses de crecimiento, para determinar actividad antiviral contraflavivirus, utilizando como modelo el virus de fiebre amarilla cepa vacunal 17D. Se identificaron por métodos espectroscópicos, un total de doce (12) compuestos provenientes de los extractos de hexano (H) y cloroformo (C) a dos y cinco meses (2M y 5M) de recolección La actividad antiviral se determinó mediante un ensayo de placa y las concentraciones de extractos utilizadas (50-1,5 ug/mL) fueron no citotóxica en células Vero, determinadas por el método colorimétrico del MTT (3-(4,5-Dimetiltiazol-2yl)-2,4-difenilbromuro de tetrazolio). La composición fitoquímica de los extractos de 5 meses es distinta y más compleja que la de dos meses de crecimiento. De los cuatro extractos sólo el C5M inhibió la replicación del virus en una manera dosis dependiente, con una inhibición del 100 por ciento a 50 ug/mL (p=0,0124) y una dosis efectiva 50 (DE50) de 10,2 +/- 8,7 ug/mL, mientras que el DE50 del extracto C2M es de 93,5 +/- 23,5 ug/mL, lo que hace al extracto clorofórmico de 5 meses aproximadamente 8 veces más efectivo que el C2M. Los compuestos presentes en el extracto C5M son Psi taraxasterilo, ácido cafeíco, acetato de taraxasterilo, taraxerol, acetato de taraxerilo y Psi-taraxasterol. Uno o más de estos compuestos son responsables de alta actividad antiviral reportada.

Antioxidant properties of Taraxacum officinale fruit extract are involved in the protective effect against cellular death induced by sodium nitroprusside in brain of rats.

CONTEXT: Taraxacum officinale Weber (Asteraceae), known as dandelion, is used for medicinal purposes due to its choleretic, diuretic, antitumor, antioxidant, antiinflammatory, and hepatoprotective properties. OBJECTIVE: We sought to investigate the protective activity of T. officinale fruit extract against sodium nitroprusside (SNP)-induced decreased cellular viability and increased lipid peroxidation in the cortex, hippocampus, and striatum of rats in vitro. To explain the mechanism of the extract's antioxidant activity, its putative scavenger activities against NO, DPPH·, OH·, and H(2)O(2) were determined. METHODS: Slices of cortex, hippocampus, and striatum were treated with 50 µM SNP and T. officinale fruit ethanolic extract (1-20 µg/mL) to determine cellular viability by MTT reduction assay. Lipid peroxidation was measure in cortical, hippocampal and striatal slices incubates with SNP (5 µM) and T. officinale fruit extract (1-20 µg/mL). We also determined the scavenger activities of T. officinale fruit extract against NO·, DPPH·, OH·, and H(2)O(2), as well as its iron chelating capacity. RESULTS: The extract (1, 5, 10, and 20 µg/mL) protected against SNP-induced decreases in cellular viability and increases in lipid peroxidation in the cortex, hippocampus, and striatum of rats. The extract had scavenger activity against DPPH· and NO· at low concentrations and was able to protect against H(2)O(2) and Fe(2+)-induced deoxyribose oxidation. CONCLUSION: T. officinale fruit extract has antioxidant activity and protects brain slices against SNP-induced cellular death. Possible mechanisms of action include its scavenger activities against reactive oxygen species (ROS) and reactive nitrogen species (RNS), which are attributed to the presence of phenolic compounds in the extract.

Antioxidant properties of Taraxacum officinale leaf extract are involved in the protective effect against hepatoxicity induced by acetaminophen in mice.

Acetaminophen (APAP) hepatotoxicity has been related to several cases of hepatitis, cirrhosis, and hepatic transplant. As APAP hepatotoxicity is related to reactive oxygen species (ROS) formation and excessive oxidative stress, natural antioxidant compounds have been tested as an alternative therapy to diminish the hepatic dysfunction induced by APAP. Taraxacum officinale Weber (Family Asteraceae), commonly known as dandelion, is used for medicinal purposes because of its choleretic, diuretic, antioxidant, anti-inflammatory, and hepatoprotective properties. This study evaluated the hepatoprotective activity of T. officinale leaf extract against APAP-induced hepatotoxicity. T. officinale was able to decrease thiobarbituric acid-reactive substance levels induced by 200 mg/kg APAP (p.o.), as well as prevent the decrease in sulfhydryl levels caused by APAP treatment. Furthermore, histopathological alterations, as well as the increased levels of serum aspartate and alanine aminotransferases caused by APAP, were prevented by T. officinale (0.1 and 0.5 mg/mL). In addition, T. officinale extract also demonstrated antioxidant activity in vitro, as well as scavenger activity against 2,2-diphenyl-1-picrylhydrazyl and nitric oxide radicals. Our results clearly demonstrate the hepatoprotective effect of T. officinale against the toxicity induced by APAP. The possible mechanisms involved include its scavenger activities against ROS and reactive nitrogen species, which are attributed to the content of phenolic compounds in the extract.

Efectos de extractos vegetales sobre la absorción intestinal de glucosa y su capacitación vesículas de membrana apical de enterocitos / Effects of vegetables extracst on the intestinal absorption of glucose and its training for vecicles the membrane apical of enterocyte

En el presente trabajo se midió el efectos que los extractos acuosos de la hoja Bauhinia megalandra, momordica charantia y Taraxacum officinale, tienen sobre la absorción intestinal de glucosa, utilizando segmentos intestinales aislados. También se estudió el efecto que el extracto de B. megalandra tienen sobre la captación de [14C]- glucosa por vesículas de borde apical de enterocito por el método de la filtración rápida. La absorción intestinal de glucosa fue inhibida solamente por el extracto de B. megalandra, en una manera dependiente de la concentración y con un efecto aditivo al de la floricina. La captación de [14C]-glucosa por vesículas de borde apical enterocito fue drásticamente inhibida por la presencia del extracto de B. megalandra, siendo su efecto de una magnitud similar al de 1 mM floricina. El extracto de las hojas de B.megalandra inhibe la absorción intestinal de glucosa por bloquear en cotransportador Na+-glucosa

Taraxacum Officinalis de Weber / Taraxacum Officinalis of Weber

El proposito de este trabajo es estudias en su totalidad un medicamento de los mal llamados "chicos": su sinonimia, su origen, su composicion quimica, su historia, su comportamiento en la... (AU)