Tatiana Lobo-Echeverri - Academia.edu (original) (raw)
Papers by Tatiana Lobo-Echeverri
Journal of Natural Products, Mar 15, 2005
Fractionation of the chloroform-soluble extract of the leaves and twigs of Calyptranthes pallens,... more Fractionation of the chloroform-soluble extract of the leaves and twigs of Calyptranthes pallens, collected from an experimental plot in a hardwood forest of southern Florida, using a hormone-dependent human prostate carcinoma (LNCaP) tumor cell line, led to the isolation of a phloroglucinol derivative with a novel carbon skeleton, pallenic acid (1), and a new triterpenoid, 3beta-hydroxy-18alpha,19alpha-urs-20-en-28-oic acid (2). The known compound methylene-bis-aspidinol (3) was selectively active against the human oral epidermoid carcinoma (KB) cell line. Several known compounds of the ellagic acid, lignan, phloroglucinol, sterol, and triterpene types were also obtained in the present investigation.
DOAJ (DOAJ: Directory of Open Access Journals), Nov 1, 2010
Vitae, Sep 1, 2010
Los envenenamientos causados por serpientes del género Bothrops constituyen un problema de salud ... more Los envenenamientos causados por serpientes del género Bothrops constituyen un problema de salud en algunos países tropicales, no solamente por la mortalidad sino por el alto porcentaje de incapacidades físicas que ocasionan. Las fosfolipasas A 2 (PLA 2) son componentes abundantes en los venenos bothrópicos y crotálicos, y se caracterizan por inducir daños irreversibles en el músculo. Considerando el aporte de las plantas en el tratamiento ofídico, este trabajo se enfocó en la búsqueda de inhibidores de las fosfolipasas, bien sea como alternativa terapéutica o como coadyuvante del tratamiento ofídico. De un tamizaje de 37 especies de plantas vasculares y briofitos contra las PLA 2 , se seleccionó la especie Murraya paniculata por su promisoria actividad preliminar. Se siguió con el fraccionamiento biodirigido por la evaluación de la actividad inhibitoria de la PLA 2 y de la fracción con mayor actividad inhibitoria, por medio de cromatografía de gases acoplada a masas se identificaron metabolitos responsables de la actividad, para proponer un modelo de inhibición enzima-sustrato. Los resultados de este proyecto pretenden contribuir en la búsqueda de moléculas inhibitorias de las PLA 2 en plantas vasculares, como la especie M. paniculata, que podrían llegar a ser una herramienta en el desarrollo de nuevos productos para mejorar el pronóstico del accidente ofídico.
Revista Productos Naturales
Se estima que los hongos fitopatógenos causan alrededor del 70% de las enfermedades que afectan l... more Se estima que los hongos fitopatógenos causan alrededor del 70% de las enfermedades que afectan los cultivos1. Anualmente, estos organismos son responsables de hasta la mitad de las pérdidas de la producción de alimentos a nivel mundial2...
Revista Productos Naturales
Stromanthe jacquinii (Marantaceae) es una de las especies cuyas hojas llamadas Biao/Bijao, son us... more Stromanthe jacquinii (Marantaceae) es una de las especies cuyas hojas llamadas Biao/Bijao, son usadas para envolver alimentos, aprovechando su dureza y capacidad aislante de la temperatura.
Revista Productos Naturales
Siendo Colombia un país mega-diverso, sus especies nativas han sido poco exploradas, como fuente ... more Siendo Colombia un país mega-diverso, sus especies nativas han sido poco exploradas, como fuente alterna de compuestos bioactivos, que ayuden a mitigar problemáticas causadas por productos sintéticos.
Revista Productos Naturales
La aplicación indiscriminada de agroquímicos sintéticos deteriora los ecosistemas naturales, amen... more La aplicación indiscriminada de agroquímicos sintéticos deteriora los ecosistemas naturales, amenaza la salud humana y la inocuidad alimentaria1. El aprovechamiento de compuestos, extractos o formulaciones provenientes de plantas bioactivas, constituye una estrategia con potencial para aminorar la dependencia a dichos productos2...
Los musgos no poseen las mismas barreras anatomicas que las plantas vasculares, por lo que se ha ... more Los musgos no poseen las mismas barreras anatomicas que las plantas vasculares, por lo que se ha sugerido que la acumulacion de ciertos compuestos, como flavonoides, tiene un rol fundamental en su defensa y adaptacion a condiciones causantes de estres oxidativo. Se evaluo la capacidad antioxidante de los extractos totales de seis especies de musgos por los metodos DPPH, ABTS y FRAP. De las especies evaluadas, Sphagnum sp. presento actividades significativas por los tres metodos, mientras que Leptodontium luteum y Dicranum frigidum presentaron actividad relevante en al menos uno de los metodos.
International Journal of Pest Management, 2021
Journal of Chemical Ecology, 2020
Plants of the Piperaceae family are studied for their diverse secondary metabolism with a vast ar... more Plants of the Piperaceae family are studied for their diverse secondary metabolism with a vast array of compounds that act as chemical defense agents against herbivores. Of all the agricultural pests, the management of insects is a highly significant challenge in the Neotropics, and ants of the Attini tribe pose a major problem. Due to their symbiotic association with the fungus Leucoagaricus gongylophorus (Möller) Singer (Agaricaceae), the species of Atta and Acromyrmex have exhaustive foraging activity which has intensified as deforestation and monoculture farming have increased. The control of leaf-cutting ants is still carried out with synthetic products with negative consequences to the environment and human health. In search for natural and sustainable alternatives to synthetic pesticides, Piper holtonii C. DC. was selected among other plant species after field observations of the foraging activity of Atta cephalotes, which revealed that P. holtonii was never chosen by ants. In vitro evaluation of an ethanol extract of the leaves of P. holtonii resulted in promising inhibitory activity (IC 50 102 ppm) against L. gongylophorus. Subsequently, bioassay-guided fractionation led to the isolation of the phenylpropanoid dillapiole, which was also detected in the essential oil. This compound demonstrated inhibition of the fungus with an IC 50 of 38 ppm. Considering the symbiotic relationship between the Attini ants and L. gongylophorus, the negative effect on the survival of one of the organisms will affect the survival of the other, so dillapiole or standardized essential oil extracts of P. holtonii containing this active principle could be a unique and useful source as a control agent for leaf cutting-ants.
Revista Colombiana de Entomología, 2018
Leaf cutter ants are considered to be a major pest in the Neotropics, due to the considerable eco... more Leaf cutter ants are considered to be a major pest in the Neotropics, due to the considerable economic losses they cause by cutting large amounts of plant material to cultivate their symbiotic fungus. Their control is mainly achieved through synthetic products with adverse consequences to the environment and human health. In search for alternatives, the ethanolic extracts of leaves of Capsicum baccatum and C. frutescens (Solanaceae), were evaluated against medium size leaf cutter ant Atta cephalotes, and its symbiotic fungus Leucoagaricus gongylophorus. The results were promising as both plant extracts exhibited a combination of insecticidal and antifungal activity when evaluated at concentrations of 0.10, 0.25, and 0.50 % w/v. Thus, C. baccatum was shown to be the most promising as an insecticidal while, C. frutescens presented a better antifungal activity at high concentrations. Since secondary metabolites present in plants are responsible for their bioactivity, preliminary phytoc...
International Journal of Pest Management, 2019
The symbiotic association of the leaf-cutter ants with the fungus Leucoagaricus gongylophorus imp... more The symbiotic association of the leaf-cutter ants with the fungus Leucoagaricus gongylophorus implies that the negative impact on the fungi will affect the survival of the ants. After a promising antifungal bioactivity, Carica papaya was studied leading to the bioassay-guided isolation of squalene, 4,5-dihydrohumulen, the flavanol-glycosides quercetin, kaempferol, and rutin, and the alkaloid carpaine. Carpaine and squalene were found to have a moderate individual activity, which increased when evaluated together. Based on the presence of these compounds, standardized extracts were formulated for field tests on nests of Acromyrmex octospinosus. All the nests treated were negatively affected evidencing a promising lead for the integrated management of leaf-cutter ants.
Toxins, 2019
Plant natural products can attenuate the myonecrosis caused by Bothrops snake venom and their pho... more Plant natural products can attenuate the myonecrosis caused by Bothrops snake venom and their phospholipases A2 (PLA2). In this study, we evaluated the effects of two fractions (F4 and F6) from Swietenia macrophylla and purified catechin on the muscle damage caused by a myotoxic PLA2 from Colombian Bothrops asper venom (BaColPLA2) in mice and by Bothrops marmoratus venom from Brazil in mouse phrenic nerve-diaphragm muscle (PND) preparations in vitro. Male mice were injected with PLA2 (50 µg) in the absence or presence of F4, F6, and catechin, in the gastrocnemius muscle and then killed 3, 7, 14, and 28 h later for histopathological analysis of myonecrosis, leukocyte infiltration, and the presence of collagen. Fractions F4 and F6 (500 µg) and catechin (90 µg) significantly reduced the extent of necrosis at all-time intervals. These two fractions and catechin also attenuated the leukocyte infiltration on day 3, as did catechin on day 14. There was medium-to-moderate collagen depositio...
Southwestern Entomologist, 2017
Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a Neotropical polyphagous moth that is an i... more Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a Neotropical polyphagous moth that is an important pest of maize, Zea mays L., in the Western Hemisphere. In the Americas, including Colombia, the insect also is a pest of rice, Oryza sativa L.; sorghum, Sorghum bicolor (L.) Moench; cotton, Gossypium hirsutum L.; and sugarcane, Saccharum officinarum L. The species in Colombia has diverged into strains in maize and rice as their most frequent hosts. Studies of reproductive isolation in Colombia showed that females of the corn strain rarely mated with males of the rice strain while females of the rice strain mated with both strains. Because behavioral isolation can be influenced by chemical composition of female sexual glands, we examined the volatile compounds for both strains, considering the time of extraction and male stimulation in production of metabolites. Altogether, 27 compounds were detected by gas chromatography coupled to mass spectrometry in the female sexual glands of both strains under laboratory conditions. The most relevant were the pheromones (Z)-9-tetradecenyl acetate and (Z)-7-dodecenyl acetate, among other volatiles reported for Lepidoptera. While 11 constituents were exclusive for the rice strain and eight for the corn strain, nine were common to both strains. A detrended correspondence analysis associated a group of compounds with each strain, while no significant differences were found in the abundance of compounds in common (T-test/Mann Whitney). In addition, the production of compounds was optimal after 3 hours of the scotophase for the corn strain and after 6 hours for the rice strain, while the presence of males was a positive influence in the production of compounds for females of both strains.
Revista Vitae, 2017
Background: The mahogany tree (Swietenia macrophylla King) is widely used in traditional medicine... more Background: The mahogany tree (Swietenia macrophylla King) is widely used in traditional medicine, especially its seeds, which are used in Malaysia, Indonesia and some countries of South America. Recently an active fraction of the leaf ethanolic extract (labelled "Sm13-16,23"), showed promising results against some toxins of South American pit vipers. Objectives: In this study the aim was to evaluate the acute oral toxicity of fraction Sm13-16,23 from the leaf ethanolic extract, using Swiss Webster mice. Methods: Fraction Sm13-16,23 was administered orally in a single dose to 2000 mg/kg and 300 mg/kg, clinical follow-up for 14 days was performed and then euthanasia, necropsy and histopathology of organs were performed. Results: Overall, there were not deaths recorded during the study period. Further not signs of toxicity in doses of 300mg/kg were observed, but at doses of 2000 mg/kg, histopathological lesions in the liver, as karyomegaly and binucleation were observed. Conclusions: Fraction Sm13-16, 23 does not produce toxicity lesion at doses of 300mg/kg, indicating that the acute oral toxicity risk is low.
Revista Vitae, 2016
Background: Some species of the Lauraceae family are known to produce secondary metabolites that ... more Background: Some species of the Lauraceae family are known to produce secondary metabolites that have antiplatelet properties. Studies on the leaves of Nectandra amazonum Nees. have shown antiaggregant activity but the bark of this species has not been studied. Objectives: To assess the antiplatelet effect of the ethanolic fraction obtained from the bark of Nectandra amazonum Nees. [N.V. "laurel amarillo", Lauraceae] applying the "Born" turbidimetric method. Methods: The screening test compared the effects of a fraction of N. amazonum (0.1 mg/mL), acetylsalicylic acid (ASA, 0.5 mM, as reference standard) and dimethylsulphoxide (DMSO, 0.1%, as control) on human platelets stimulated with adenosine diphosphate (ADP, 2 µM), epinephrine (EPI, 1 uM (one micromolar)), collagen (COLL, 1 µg/mL) and arachidonic acid (AA, 0.2 mg/mL). Subsequently, the study focused on determining the antiaggregant potency of the N. amazonum fraction through concentration-response curves (from 1 µg/mL to 0.4 mg/ mL), obtaining pIC 50 (-log IC 50) values against the platelet agonists. Results: Control platelets attained the highest percentage values of aggregation (96% AA, 89% EPI, 85% COLL, and 77% ADP). The N. amazonum fraction significantly reduced the aggregation effects (6% AA, 45% EPI, 10% COLL, 21% ADP), with values close to those obtained with ASA (17% AA, 21% EPI, 10% COLL, 20% ADP). According to concentration-response curves, the pIC 50 values of the ethanolic fraction indicated the following order of potency: AA, 4.90 > ADP, 4.51 > COLL, 4.33 > EPI, 3.85. Conclusions: These results suggest that the N. amazonum Nees. ethanolic fraction elicited antiplatelet effects mainly related to the inhibition of the arachidonic acid pathway.
Journal of Medicinal Plants Research, 2016
The genus Swietenia (Meliaceae) has a wide variety of secondary metabolites with reported antioxi... more The genus Swietenia (Meliaceae) has a wide variety of secondary metabolites with reported antioxidant activity, such as flavonoids and limonoids. In the present study, the antioxidant capacity, along with the phenol and flavonoid contents of the leaf extracts of three species of this genus: Swietenia mahagoni, Swietenia macrophylla, and Swietenia humilis were evaluated. The antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric reducing/antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) methods. The results showed that the three species had significant antioxidant activity and substantial contents of phenolic compounds and flavonoids. The species S. macrophylla was the most effective, and compounds with recognized antioxidant capability were detected by gas chromatography coupled with mass spectrometry (GC-MS). Catechin was the most abundant constituent in the active fractions, and was confirmed and quantified by high performance liquid chromatography (HPLC).
Vitae
Los envenenamientos causados por serpientes del género Bothrops constituyen un problema de salud ... more Los envenenamientos causados por serpientes del género Bothrops constituyen un problema de salud en algunos países tropicales, no solamente por la mortalidad sino por el alto porcentaje de incapacidades físicas que ocasionan. Las fosfolipasas A 2 (PLA 2) son componentes abundantes en los venenos bothrópicos y crotálicos, y se caracterizan por inducir daños irreversibles en el músculo. Considerando el aporte de las plantas en el tratamiento ofídico, este trabajo se enfocó en la búsqueda de inhibidores de las fosfolipasas, bien sea como alternativa terapéutica o como coadyuvante del tratamiento ofídico. De un tamizaje de 37 especies de plantas vasculares y briofitos contra las PLA 2 , se seleccionó la especie Murraya paniculata por su promisoria actividad preliminar. Se siguió con el fraccionamiento biodirigido por la evaluación de la actividad inhibitoria de la PLA 2 y de la fracción con mayor actividad inhibitoria, por medio de cromatografía de gases acoplada a masas se identificaron metabolitos responsables de la actividad, para proponer un modelo de inhibición enzima-sustrato. Los resultados de este proyecto pretenden contribuir en la búsqueda de moléculas inhibitorias de las PLA 2 en plantas vasculares, como la especie M. paniculata, que podrían llegar a ser una herramienta en el desarrollo de nuevos productos para mejorar el pronóstico del accidente ofídico.
Revista Brasileira de Farmacognosia, 2013
Activity-guided fractionation of an ethanol-soluble extract of the leaves of Swietenia macrophyll... more Activity-guided fractionation of an ethanol-soluble extract of the leaves of Swietenia macrophylla King, Meliaceae, led to several fractions. As a result, sample Sm13-16, 23 had the most promising activity against phospholipases A2 (PLA 2), Asp49 and Lys49 types. This fraction inhibited PLA 2 activity of the Asp49 PLA 2 , when aggregated substrate was used. On the other hand, this activity was weakly neutralized when monodispersed substrate was used. In addition, Sm13-16, 23 inhibited, in a dose dependent manner, the cytotoxicity, myotoxicity and edema induced by PLA 2s , as well as the anticoagulant activity of Asp49 PLA 2. Overall, this fraction exhibited a better inhibition of the toxic activities induced by the Lys49 PLA 2 than those caused by the Asp49 PLA 2. The spectral data of Sm13-16, 23 suggested the presence of aromatic compounds (UV λ max (nm) 655, 266, and 219; IR λ max KBr (cm-1):
Revista Brasileira de Farmacognosia, 2010
Veneno de cobra continua a ser um problema importante de saúde em muitos países da América Latina... more Veneno de cobra continua a ser um problema importante de saúde em muitos países da América Latina. Apesar dos avanços na terapia antiveneno, os efeitos locais causados por fosfolipases A 2 miotóxica (PLA 2) presentes no veneno, ainda persistem. Em busca de alternativas para antagonizar a atividade da PLA 2 do veneno de Bothrops asper, foram selecionados 36 extratos pertencentes a dezessete famílias de plantas vasculares e briófitas. Uma inibição significativa da atividade enzimática de PLA 2 presente no veneno de B. asper foi observada em onze extratos. Além disso, a atividade antioxidante dos extratos foi avaliada. Os resultados evidenciaram uma correlação estatisticamente significativa entre os extratos com ação inibitória contra a PLA 2 e aqueles com atividade antioxidante. Também, a quantidade de fenóis foi avaliada e foi encontrada uma relação entre a atividade biológica e a presença dessas substâncias. Nove extratos foram testados contra uma fração do veneno rico em PLA 2 básica (Fx-V B. asper), resultando em um efeito inibitório na atividade desta fração da PLA 2 na faixa de 30-80%. Esta atividade foi apoiada pela inibição que esses extratos apresentaram na citotoxicidade causada pelo Fx-V B. asper sobre mioblastos C2C12 de músculo esquelético de murino. Os resultados podem indicar a minimização dos esforços na busca de inibidores da PLA 2 , com foco nas amostras com propriedades antioxidantes conhecidas. Unitermos: fosfolipase A 2 , veneno de cobra, Bothrops asper, extratos de plantas, antioxidantes, DPPH.
Journal of Natural Products, Mar 15, 2005
Fractionation of the chloroform-soluble extract of the leaves and twigs of Calyptranthes pallens,... more Fractionation of the chloroform-soluble extract of the leaves and twigs of Calyptranthes pallens, collected from an experimental plot in a hardwood forest of southern Florida, using a hormone-dependent human prostate carcinoma (LNCaP) tumor cell line, led to the isolation of a phloroglucinol derivative with a novel carbon skeleton, pallenic acid (1), and a new triterpenoid, 3beta-hydroxy-18alpha,19alpha-urs-20-en-28-oic acid (2). The known compound methylene-bis-aspidinol (3) was selectively active against the human oral epidermoid carcinoma (KB) cell line. Several known compounds of the ellagic acid, lignan, phloroglucinol, sterol, and triterpene types were also obtained in the present investigation.
DOAJ (DOAJ: Directory of Open Access Journals), Nov 1, 2010
Vitae, Sep 1, 2010
Los envenenamientos causados por serpientes del género Bothrops constituyen un problema de salud ... more Los envenenamientos causados por serpientes del género Bothrops constituyen un problema de salud en algunos países tropicales, no solamente por la mortalidad sino por el alto porcentaje de incapacidades físicas que ocasionan. Las fosfolipasas A 2 (PLA 2) son componentes abundantes en los venenos bothrópicos y crotálicos, y se caracterizan por inducir daños irreversibles en el músculo. Considerando el aporte de las plantas en el tratamiento ofídico, este trabajo se enfocó en la búsqueda de inhibidores de las fosfolipasas, bien sea como alternativa terapéutica o como coadyuvante del tratamiento ofídico. De un tamizaje de 37 especies de plantas vasculares y briofitos contra las PLA 2 , se seleccionó la especie Murraya paniculata por su promisoria actividad preliminar. Se siguió con el fraccionamiento biodirigido por la evaluación de la actividad inhibitoria de la PLA 2 y de la fracción con mayor actividad inhibitoria, por medio de cromatografía de gases acoplada a masas se identificaron metabolitos responsables de la actividad, para proponer un modelo de inhibición enzima-sustrato. Los resultados de este proyecto pretenden contribuir en la búsqueda de moléculas inhibitorias de las PLA 2 en plantas vasculares, como la especie M. paniculata, que podrían llegar a ser una herramienta en el desarrollo de nuevos productos para mejorar el pronóstico del accidente ofídico.
Revista Productos Naturales
Se estima que los hongos fitopatógenos causan alrededor del 70% de las enfermedades que afectan l... more Se estima que los hongos fitopatógenos causan alrededor del 70% de las enfermedades que afectan los cultivos1. Anualmente, estos organismos son responsables de hasta la mitad de las pérdidas de la producción de alimentos a nivel mundial2...
Revista Productos Naturales
Stromanthe jacquinii (Marantaceae) es una de las especies cuyas hojas llamadas Biao/Bijao, son us... more Stromanthe jacquinii (Marantaceae) es una de las especies cuyas hojas llamadas Biao/Bijao, son usadas para envolver alimentos, aprovechando su dureza y capacidad aislante de la temperatura.
Revista Productos Naturales
Siendo Colombia un país mega-diverso, sus especies nativas han sido poco exploradas, como fuente ... more Siendo Colombia un país mega-diverso, sus especies nativas han sido poco exploradas, como fuente alterna de compuestos bioactivos, que ayuden a mitigar problemáticas causadas por productos sintéticos.
Revista Productos Naturales
La aplicación indiscriminada de agroquímicos sintéticos deteriora los ecosistemas naturales, amen... more La aplicación indiscriminada de agroquímicos sintéticos deteriora los ecosistemas naturales, amenaza la salud humana y la inocuidad alimentaria1. El aprovechamiento de compuestos, extractos o formulaciones provenientes de plantas bioactivas, constituye una estrategia con potencial para aminorar la dependencia a dichos productos2...
Los musgos no poseen las mismas barreras anatomicas que las plantas vasculares, por lo que se ha ... more Los musgos no poseen las mismas barreras anatomicas que las plantas vasculares, por lo que se ha sugerido que la acumulacion de ciertos compuestos, como flavonoides, tiene un rol fundamental en su defensa y adaptacion a condiciones causantes de estres oxidativo. Se evaluo la capacidad antioxidante de los extractos totales de seis especies de musgos por los metodos DPPH, ABTS y FRAP. De las especies evaluadas, Sphagnum sp. presento actividades significativas por los tres metodos, mientras que Leptodontium luteum y Dicranum frigidum presentaron actividad relevante en al menos uno de los metodos.
International Journal of Pest Management, 2021
Journal of Chemical Ecology, 2020
Plants of the Piperaceae family are studied for their diverse secondary metabolism with a vast ar... more Plants of the Piperaceae family are studied for their diverse secondary metabolism with a vast array of compounds that act as chemical defense agents against herbivores. Of all the agricultural pests, the management of insects is a highly significant challenge in the Neotropics, and ants of the Attini tribe pose a major problem. Due to their symbiotic association with the fungus Leucoagaricus gongylophorus (Möller) Singer (Agaricaceae), the species of Atta and Acromyrmex have exhaustive foraging activity which has intensified as deforestation and monoculture farming have increased. The control of leaf-cutting ants is still carried out with synthetic products with negative consequences to the environment and human health. In search for natural and sustainable alternatives to synthetic pesticides, Piper holtonii C. DC. was selected among other plant species after field observations of the foraging activity of Atta cephalotes, which revealed that P. holtonii was never chosen by ants. In vitro evaluation of an ethanol extract of the leaves of P. holtonii resulted in promising inhibitory activity (IC 50 102 ppm) against L. gongylophorus. Subsequently, bioassay-guided fractionation led to the isolation of the phenylpropanoid dillapiole, which was also detected in the essential oil. This compound demonstrated inhibition of the fungus with an IC 50 of 38 ppm. Considering the symbiotic relationship between the Attini ants and L. gongylophorus, the negative effect on the survival of one of the organisms will affect the survival of the other, so dillapiole or standardized essential oil extracts of P. holtonii containing this active principle could be a unique and useful source as a control agent for leaf cutting-ants.
Revista Colombiana de Entomología, 2018
Leaf cutter ants are considered to be a major pest in the Neotropics, due to the considerable eco... more Leaf cutter ants are considered to be a major pest in the Neotropics, due to the considerable economic losses they cause by cutting large amounts of plant material to cultivate their symbiotic fungus. Their control is mainly achieved through synthetic products with adverse consequences to the environment and human health. In search for alternatives, the ethanolic extracts of leaves of Capsicum baccatum and C. frutescens (Solanaceae), were evaluated against medium size leaf cutter ant Atta cephalotes, and its symbiotic fungus Leucoagaricus gongylophorus. The results were promising as both plant extracts exhibited a combination of insecticidal and antifungal activity when evaluated at concentrations of 0.10, 0.25, and 0.50 % w/v. Thus, C. baccatum was shown to be the most promising as an insecticidal while, C. frutescens presented a better antifungal activity at high concentrations. Since secondary metabolites present in plants are responsible for their bioactivity, preliminary phytoc...
International Journal of Pest Management, 2019
The symbiotic association of the leaf-cutter ants with the fungus Leucoagaricus gongylophorus imp... more The symbiotic association of the leaf-cutter ants with the fungus Leucoagaricus gongylophorus implies that the negative impact on the fungi will affect the survival of the ants. After a promising antifungal bioactivity, Carica papaya was studied leading to the bioassay-guided isolation of squalene, 4,5-dihydrohumulen, the flavanol-glycosides quercetin, kaempferol, and rutin, and the alkaloid carpaine. Carpaine and squalene were found to have a moderate individual activity, which increased when evaluated together. Based on the presence of these compounds, standardized extracts were formulated for field tests on nests of Acromyrmex octospinosus. All the nests treated were negatively affected evidencing a promising lead for the integrated management of leaf-cutter ants.
Toxins, 2019
Plant natural products can attenuate the myonecrosis caused by Bothrops snake venom and their pho... more Plant natural products can attenuate the myonecrosis caused by Bothrops snake venom and their phospholipases A2 (PLA2). In this study, we evaluated the effects of two fractions (F4 and F6) from Swietenia macrophylla and purified catechin on the muscle damage caused by a myotoxic PLA2 from Colombian Bothrops asper venom (BaColPLA2) in mice and by Bothrops marmoratus venom from Brazil in mouse phrenic nerve-diaphragm muscle (PND) preparations in vitro. Male mice were injected with PLA2 (50 µg) in the absence or presence of F4, F6, and catechin, in the gastrocnemius muscle and then killed 3, 7, 14, and 28 h later for histopathological analysis of myonecrosis, leukocyte infiltration, and the presence of collagen. Fractions F4 and F6 (500 µg) and catechin (90 µg) significantly reduced the extent of necrosis at all-time intervals. These two fractions and catechin also attenuated the leukocyte infiltration on day 3, as did catechin on day 14. There was medium-to-moderate collagen depositio...
Southwestern Entomologist, 2017
Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a Neotropical polyphagous moth that is an i... more Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a Neotropical polyphagous moth that is an important pest of maize, Zea mays L., in the Western Hemisphere. In the Americas, including Colombia, the insect also is a pest of rice, Oryza sativa L.; sorghum, Sorghum bicolor (L.) Moench; cotton, Gossypium hirsutum L.; and sugarcane, Saccharum officinarum L. The species in Colombia has diverged into strains in maize and rice as their most frequent hosts. Studies of reproductive isolation in Colombia showed that females of the corn strain rarely mated with males of the rice strain while females of the rice strain mated with both strains. Because behavioral isolation can be influenced by chemical composition of female sexual glands, we examined the volatile compounds for both strains, considering the time of extraction and male stimulation in production of metabolites. Altogether, 27 compounds were detected by gas chromatography coupled to mass spectrometry in the female sexual glands of both strains under laboratory conditions. The most relevant were the pheromones (Z)-9-tetradecenyl acetate and (Z)-7-dodecenyl acetate, among other volatiles reported for Lepidoptera. While 11 constituents were exclusive for the rice strain and eight for the corn strain, nine were common to both strains. A detrended correspondence analysis associated a group of compounds with each strain, while no significant differences were found in the abundance of compounds in common (T-test/Mann Whitney). In addition, the production of compounds was optimal after 3 hours of the scotophase for the corn strain and after 6 hours for the rice strain, while the presence of males was a positive influence in the production of compounds for females of both strains.
Revista Vitae, 2017
Background: The mahogany tree (Swietenia macrophylla King) is widely used in traditional medicine... more Background: The mahogany tree (Swietenia macrophylla King) is widely used in traditional medicine, especially its seeds, which are used in Malaysia, Indonesia and some countries of South America. Recently an active fraction of the leaf ethanolic extract (labelled "Sm13-16,23"), showed promising results against some toxins of South American pit vipers. Objectives: In this study the aim was to evaluate the acute oral toxicity of fraction Sm13-16,23 from the leaf ethanolic extract, using Swiss Webster mice. Methods: Fraction Sm13-16,23 was administered orally in a single dose to 2000 mg/kg and 300 mg/kg, clinical follow-up for 14 days was performed and then euthanasia, necropsy and histopathology of organs were performed. Results: Overall, there were not deaths recorded during the study period. Further not signs of toxicity in doses of 300mg/kg were observed, but at doses of 2000 mg/kg, histopathological lesions in the liver, as karyomegaly and binucleation were observed. Conclusions: Fraction Sm13-16, 23 does not produce toxicity lesion at doses of 300mg/kg, indicating that the acute oral toxicity risk is low.
Revista Vitae, 2016
Background: Some species of the Lauraceae family are known to produce secondary metabolites that ... more Background: Some species of the Lauraceae family are known to produce secondary metabolites that have antiplatelet properties. Studies on the leaves of Nectandra amazonum Nees. have shown antiaggregant activity but the bark of this species has not been studied. Objectives: To assess the antiplatelet effect of the ethanolic fraction obtained from the bark of Nectandra amazonum Nees. [N.V. "laurel amarillo", Lauraceae] applying the "Born" turbidimetric method. Methods: The screening test compared the effects of a fraction of N. amazonum (0.1 mg/mL), acetylsalicylic acid (ASA, 0.5 mM, as reference standard) and dimethylsulphoxide (DMSO, 0.1%, as control) on human platelets stimulated with adenosine diphosphate (ADP, 2 µM), epinephrine (EPI, 1 uM (one micromolar)), collagen (COLL, 1 µg/mL) and arachidonic acid (AA, 0.2 mg/mL). Subsequently, the study focused on determining the antiaggregant potency of the N. amazonum fraction through concentration-response curves (from 1 µg/mL to 0.4 mg/ mL), obtaining pIC 50 (-log IC 50) values against the platelet agonists. Results: Control platelets attained the highest percentage values of aggregation (96% AA, 89% EPI, 85% COLL, and 77% ADP). The N. amazonum fraction significantly reduced the aggregation effects (6% AA, 45% EPI, 10% COLL, 21% ADP), with values close to those obtained with ASA (17% AA, 21% EPI, 10% COLL, 20% ADP). According to concentration-response curves, the pIC 50 values of the ethanolic fraction indicated the following order of potency: AA, 4.90 > ADP, 4.51 > COLL, 4.33 > EPI, 3.85. Conclusions: These results suggest that the N. amazonum Nees. ethanolic fraction elicited antiplatelet effects mainly related to the inhibition of the arachidonic acid pathway.
Journal of Medicinal Plants Research, 2016
The genus Swietenia (Meliaceae) has a wide variety of secondary metabolites with reported antioxi... more The genus Swietenia (Meliaceae) has a wide variety of secondary metabolites with reported antioxidant activity, such as flavonoids and limonoids. In the present study, the antioxidant capacity, along with the phenol and flavonoid contents of the leaf extracts of three species of this genus: Swietenia mahagoni, Swietenia macrophylla, and Swietenia humilis were evaluated. The antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric reducing/antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) methods. The results showed that the three species had significant antioxidant activity and substantial contents of phenolic compounds and flavonoids. The species S. macrophylla was the most effective, and compounds with recognized antioxidant capability were detected by gas chromatography coupled with mass spectrometry (GC-MS). Catechin was the most abundant constituent in the active fractions, and was confirmed and quantified by high performance liquid chromatography (HPLC).
Vitae
Los envenenamientos causados por serpientes del género Bothrops constituyen un problema de salud ... more Los envenenamientos causados por serpientes del género Bothrops constituyen un problema de salud en algunos países tropicales, no solamente por la mortalidad sino por el alto porcentaje de incapacidades físicas que ocasionan. Las fosfolipasas A 2 (PLA 2) son componentes abundantes en los venenos bothrópicos y crotálicos, y se caracterizan por inducir daños irreversibles en el músculo. Considerando el aporte de las plantas en el tratamiento ofídico, este trabajo se enfocó en la búsqueda de inhibidores de las fosfolipasas, bien sea como alternativa terapéutica o como coadyuvante del tratamiento ofídico. De un tamizaje de 37 especies de plantas vasculares y briofitos contra las PLA 2 , se seleccionó la especie Murraya paniculata por su promisoria actividad preliminar. Se siguió con el fraccionamiento biodirigido por la evaluación de la actividad inhibitoria de la PLA 2 y de la fracción con mayor actividad inhibitoria, por medio de cromatografía de gases acoplada a masas se identificaron metabolitos responsables de la actividad, para proponer un modelo de inhibición enzima-sustrato. Los resultados de este proyecto pretenden contribuir en la búsqueda de moléculas inhibitorias de las PLA 2 en plantas vasculares, como la especie M. paniculata, que podrían llegar a ser una herramienta en el desarrollo de nuevos productos para mejorar el pronóstico del accidente ofídico.
Revista Brasileira de Farmacognosia, 2013
Activity-guided fractionation of an ethanol-soluble extract of the leaves of Swietenia macrophyll... more Activity-guided fractionation of an ethanol-soluble extract of the leaves of Swietenia macrophylla King, Meliaceae, led to several fractions. As a result, sample Sm13-16, 23 had the most promising activity against phospholipases A2 (PLA 2), Asp49 and Lys49 types. This fraction inhibited PLA 2 activity of the Asp49 PLA 2 , when aggregated substrate was used. On the other hand, this activity was weakly neutralized when monodispersed substrate was used. In addition, Sm13-16, 23 inhibited, in a dose dependent manner, the cytotoxicity, myotoxicity and edema induced by PLA 2s , as well as the anticoagulant activity of Asp49 PLA 2. Overall, this fraction exhibited a better inhibition of the toxic activities induced by the Lys49 PLA 2 than those caused by the Asp49 PLA 2. The spectral data of Sm13-16, 23 suggested the presence of aromatic compounds (UV λ max (nm) 655, 266, and 219; IR λ max KBr (cm-1):
Revista Brasileira de Farmacognosia, 2010
Veneno de cobra continua a ser um problema importante de saúde em muitos países da América Latina... more Veneno de cobra continua a ser um problema importante de saúde em muitos países da América Latina. Apesar dos avanços na terapia antiveneno, os efeitos locais causados por fosfolipases A 2 miotóxica (PLA 2) presentes no veneno, ainda persistem. Em busca de alternativas para antagonizar a atividade da PLA 2 do veneno de Bothrops asper, foram selecionados 36 extratos pertencentes a dezessete famílias de plantas vasculares e briófitas. Uma inibição significativa da atividade enzimática de PLA 2 presente no veneno de B. asper foi observada em onze extratos. Além disso, a atividade antioxidante dos extratos foi avaliada. Os resultados evidenciaram uma correlação estatisticamente significativa entre os extratos com ação inibitória contra a PLA 2 e aqueles com atividade antioxidante. Também, a quantidade de fenóis foi avaliada e foi encontrada uma relação entre a atividade biológica e a presença dessas substâncias. Nove extratos foram testados contra uma fração do veneno rico em PLA 2 básica (Fx-V B. asper), resultando em um efeito inibitório na atividade desta fração da PLA 2 na faixa de 30-80%. Esta atividade foi apoiada pela inibição que esses extratos apresentaram na citotoxicidade causada pelo Fx-V B. asper sobre mioblastos C2C12 de músculo esquelético de murino. Os resultados podem indicar a minimização dos esforços na busca de inibidores da PLA 2 , com foco nas amostras com propriedades antioxidantes conhecidas. Unitermos: fosfolipase A 2 , veneno de cobra, Bothrops asper, extratos de plantas, antioxidantes, DPPH.