Mammea B/BA Isolated From the Seeds of Mammea americana L. (Calophyllaceae) is a Potent Inhibitor of Methicillin-Resistant Staphylococcus aureus.

Staphylococcus aureus remains a pathogen of high concern in public health programs worldwide due to antibiotic resistance and emergence of highly virulent strains. Many phytochemicals have demonstrated activity against S. aureus and other Gram-positive bacteria, but the minimum inhibitory concentration (MIC) values comparable to commonly used antibiotics are needed. In the present study, bio-guided fractionation of the ethanol extract of seeds of Mammea americana L. (Calophyllaceae) throughout the antibacterial activity, against S. aureus strains that are sensitive and resistant to methicillin, led to the isolation of four coumarins identified as mammea B/BA, mammea B/BC, mammea A/AA cyclo D and mammea A/AA cyclo F, and a mixture of mammea B/BA cyclo F plus mammea B/BD cyclo F. The extract inhibited the growth of S. aureus with MIC values of 2-4 µg/ml and Mammea B/BA (MaBBA) presented MIC values in a range between 0.5 and 1.0 µg/ml in six methicillin-sensitive strains and eight methicillin-resistant strains evaluated. We consider MaBBA the most potent of all mammea coumarins reported to date, according to the literature review carried out at the time of writing of this article. Toxicity assessment in vivo against the nematode Caenorhabditis elegans and in vitro against human fibroblasts of the extract and the compound MaBBA indicated that both had low toxicity.

Indole alkaloids inhibit zika and chikungunya virus infection in different cell lines.

BACKGROUND: In recent years, an increase in the occurrence of illnesses caused by two clinically- important arboviruses has been reported: Zika virus (ZIKV) and Chikungunya virus (CHIKV). There is no licensed antiviral treatment for either of the two abovementioned viruses. Bearing in mind that the antiviral effect of indole alkaloids has been reported for other arboviral models, the present study proposed to evaluate the antiviral in vitro and in silico effects of four indole alkaloids on infections by these two viruses in different cell lines. METHODS: The antiviral effects of voacangine (VOAC), voacangine-7-hydroxyindolenine (VOAC-OH), rupicoline and 3-oxo voacangine (OXO-VOAC) were evaluated in Vero, U937 and A549 cells using different experimental strategies (Pre, Trans, Post and combined treatment). Viral infection was quantified by different methodologies, including infectious viral particles by plating, viral genome by RT-qPCR, and viral protein by cell ELISA. Moreover, molecular docking was used to evaluate the possible interactions between structural and nonstructural viral proteins and the compounds. The results obtained from the antiviral strategies for each experimental condition were compared in all cases with the untreated controls. Statistically significant differences were identified using a parametric Student's t-test. In all cases, p values below 0.05 (p < 0.05) were considered statistically significant. RESULTS: In the pre-treatment strategy in Vero cells, VOAC and VOAC-OH inhibited both viral models and OXO-VOAC inhibited only ZIKV; in U937 cells infected with CHIKV/Col, only VOAC-OH inhibited infection, but none of the compounds had activity in A549 cells; in U937 cells and A549 cells infected with ZIKV/Col, the three compounds that were effective in Vero cells also had antiviral activity. In the trans-treatment strategy, only VOAC-OH was virucidal against ZIKV/Col. In the post-treatment strategy, only rupicoline was effective in the CHIKV/Col model in Vero and A549 cells, whereas VOAC and VOAC-OH inhibited ZIKV infection in all three cell lines. In the combined strategy, VOAC, VOAC-OH and rupicoline inhibited CHIKV/Col and ZIKV/Col, but only rupicoline improved the antiviral effect of ZIKV/Col-infected cultures with respect to the individual strategies. Molecular docking showed that all the compounds had favorable binding energies with the structural proteins E2 and NSP2 (CHIKV) and E and NS5 (ZIKV). CONCLUSIONS: The present study demonstrates that indole alkaloids are promising antiviral drugs in the process of ZIKV and CHIKV infection; however, the mechanisms of action evaluated in this study would indicate that the effect is different in each viral model and, in turn, dependent on the cell line.

The Antiviral and Virucidal Activities of Voacangine and Structural Analogs Extracted from Tabernaemontana cymosa Depend on the Dengue Virus Strain.

Currently, no specific licensed antiviral exists for treating the illness caused by dengue virus (DENV). Therefore, the search for compounds of natural origin with antiviral activity is an important area of research. In the present study, three compounds were isolated and identified from seeds of Tabernaemontana cymosa plants. The in vitro antiviral effect of those compounds and voacangine against different DENV strains was assessed using different experimental approaches: compounds added before the infection (Pre), at the same time with the virus (Trans), after the infection (Post) or compounds present in all moments of the experiment (Pre-Trans-Post, Combined treatment). In silico studies (docking and molecular dynamics) were also performed to explain the possible antiviral mechanisms. The identified compounds were three structural analogs of voacangine (voacangine-7-hydroxyindolenine, rupicoline and 3-oxo-voacangine). In the Pre-treatment, only voacangine-7-hydroxyindolenine and rupicoline inhibited the infection caused by the DENV-2/NG strain (16.4% and 29.6% infection, respectively). In the Trans-treatment approach, voacangine, voacangine-7-hydroxyindolenine and rupicoline inhibited the infection in both DENV-2/NG (11.2%, 80.4% and 75.7% infection, respectively) and DENV-2/16681 infection models (73.7%, 74.0% and 75.3% infection, respectively). The latter strain was also inhibited by 3-oxo-voacangine (82.8% infection). Moreover, voacangine (most effective virucidal agent) was also effective against one strain of DENV-1 (DENV-1/WestPac/74) and against the third strain of DENV-2 (DENV-2/S16803) (48.5% and 32.4% infection, respectively). Conversely, no inhibition was observed in the post-treatment approach. The last approach (combined) showed that voacangine, voacangine-7-hydroxyindolenine and rupicoline inhibited over 90% of infections (3.5%, 6.9% and 3.5% infection, respectively) of both strains (DENV-2/NG and DENV-2/16681). The free energy of binding obtained with an in silico approach was favorable for the E protein and compounds, which ranged between -5.1 and -6.3 kcal/mol. Finally, the complex formed between DENV-2 E protein and the best virucidal compound was stable for 50 ns. Our results show that the antiviral effect of indole alkaloids derived from T. cymose depends on the serotype and the virus strain.

Molecular Human Targets of Bioactive Alkaloid-Type Compounds from Tabernaemontana cymose Jacq.

Alkaloids are a group of secondary metabolites that have been widely studied for the discovery of new drugs due to their properties on the central nervous system and their anti-inflammatory, antioxidant and anti-cancer activities. Molecular docking was performed for 10 indole alkaloids identified in the ethanol extract of Tabernaemontana cymosa Jacq. with 951 human targets involved in different diseases. The results were analyzed through the KEGG and STRING databases, finding the most relevant physiological associations for alkaloids. The molecule 5-oxocoronaridine proved to be the most active molecule against human proteins (binding energy affinity average = -9.2 kcal/mol) and the analysis of the interactions between the affected proteins pointed to the PI3K/ Akt/mTOR signaling pathway as the main target. The above indicates that indole alkaloids from T. cymosa constitute a promising source for the search and development of new treatments against different types of cancer.

In vitro and in silico anti-dengue activity of compounds obtained from Psidium guajava through bioprospecting.

BACKGROUND: For decades, bioprospecting has proven to be useful for the identification of compounds with pharmacological potential. Considering the great diversity of Colombian plants and the serious worldwide public health problem of dengue-a disease caused by the dengue virus (DENV)-in the present study, we evaluated the anti-DENV effects of 12 ethanolic extracts derived from plants collected in the Colombian Caribbean coast, and 5 fractions and 5 compounds derived from Psidium guajava. METHODS: The cytotoxicity and antiviral effect of 12 ethanolic extracts derived from plants collected in the Colombian Caribbean coast was evaluated in epithelial VERO cells. Five fractions were obtained by open column chromatography from the ethanolic extract with the highest selectivity index (SI) (derived from P. guajava, SI: 128.2). From the fraction with the highest selectivity (Pg-YP-I-22C, SI: 35.5), five compounds were identified by one- and two-dimensional nuclear magnetic resonance spectroscopy. The antiviral effect in vitro of the fractions and compounds was evaluated by different experimental strategies (Pre- and post-treatment) using non-toxic concentrations calculated by MTT method. The DENV inhibition was evaluated by plate focus assay. The results were analyzed by means of statistical analysis using Student's t-test. Finally the antiviral effect in Silico was evaluated by molecular docking. RESULTS: In vitro evaluation of these compounds showed that three of them (gallic acid, quercetin, and catechin) were promising antivirals as they inhibit the production of infectious viral particles via different experimental strategies, with the best antiviral being catechin (100% inhibition with a pre-treatment strategy and 91.8% with a post-treatment strategy). When testing the interactions of these compounds with the viral envelope protein in silico by docking, only naringin and hesperidin had better scores than the theoretical threshold of - 7.0 kcal/mol (- 8.0 kcal/mol and - 8.2 kcal/mol, respectively). All ligands tested except gallic acid showed higher affinity to the NS5 protein than the theoretical threshold. CONCLUSION: Even though bioprospecting has recently been replaced by more targeted tools for identifying compounds with pharmacological potential, our results show it is still useful for this purpose. Additionally, combining in vitro and in silico evaluations allowed us to identify promising antivirals as well as their possible mechanisms of action.

Antiviral effect of compounds derived from the seeds of Mammea americana and Tabernaemontana cymosa on Dengue and Chikungunya virus infections.

BACKGROUND: The transmission of Dengue virus (DENV) and Chikungunya virus (CHIKV) has increased worldwide, due in part to the lack of a specific antiviral treatment. For this reason, the search for compounds with antiviral potential, either as licensed drugs or in natural products, is a research priority. The objective of this study was to identify some of the compounds that are present in Mammea americana (M. americana) and Tabernaemontana cymosa (T. cymosa) plants and, subsequently, to evaluate their cytotoxicity in VERO cells and their potential antiviral effects on DENV and CHIKV infections in those same cells. METHODS: Dry ethanolic extracts of M. americana and T. cymosa seeds were subjected to open column chromatographic fractionation, leading to the identification of four compounds: two coumarins, derived from M. americana; and lupeol acetate and voacangine derived from T. cymosa.. The cytotoxicity of each compound was subsequently assessed by the MTT method (at concentrations from 400 to 6.25 µg/mL). Pre- and post-treatment antiviral assays were performed at non-toxic concentrations; the resulting DENV inhibition was evaluated by Real-Time PCR, and the CHIKV inhibition was tested by the plating method. The results were analyzed by means of statistical analysis. RESULTS: The compounds showed low toxicity at concentrations ≤ 200 µg/mL. The compounds coumarin A and coumarin B, which are derived from the M. americana plant, significantly inhibited infection with both viruses during the implementation of the two experimental strategies employed here (post-treatment with inhibition percentages greater than 50%, p < 0.01; and pre-treatment with percentages of inhibition greater than 40%, p < 0.01). However, the lupeol acetate and voacangine compounds, which were derived from the T. cymosa plant, only significantly inhibited the DENV infection during the post-treatment strategy (at inhibition percentages greater than 70%, p < 0.01). CONCLUSION: In vitro, the coumarins are capable of inhibiting infection by DENV and CHIKV (with inhibition percentages above 50% in different experimental strategies), which could indicate that these two compounds are potential antivirals for treating Dengue and Chikungunya fever. Additionally, lupeol acetate and voacangine efficiently inhibit infection with DENV, also turning them into promising antivirals for Dengue fever.

Tamizaje fitoquímico preliminar de especies de plantas promisorias de la costa atlántica colombiana / Preliminary phytochemical screening of promising plant species of the Colombian Atlantic coast

Introducción: Colombia es el segundo país con mayor biodiversidad del mundo, posee 10 % del recurso vegetal mundial representado en 50 000 especies vegetales, de las cuales la costa norte colombiana posee cerca de 3 400. Esta región se caracteriza por mantener una rica tradición de uso de este recurso natural para tratar sus problemas de salud. Objetivo: realizar el estudio químico sobre 45 extractos etanólicos de 39 especies vegetales, que son utilizadas en la medicina tradicional de la costa atlántica colombiana, con el propósito de contribuir al conocimiento con base científica, de los metabolitos secundarios presentes en estas plantas. Métodos: se recolectaron cada uno de los órganos de las especies; la droga fresca fue sometida a extracciones sucesivas con etanol 98 % y en los extractos se identificaron los diferentes grupos de metabolitos secundarios presentes. Resultados: en los diferentes extractos etanólicos se detectó una alta diversidad de metabolitos secundarios, con predominio de los flavonoides, derivados antracénicos, triterpenos, compuestos cardiotónicos y alcaloides. Por primera vez se reportaron estudios químicos para las especies Sarcostemma clausum (Jacq) Schult., Diospyros inconstans Jacq., Sterculia apetala (Jacq.) H. Karst., Ceratopteris pteridoides Hooker., Cecropia peltata L., Cordia dentata Poir. y Gustavia superba (Kunth) O. Berg. Conclusiones: se evidenció presencia de flavonoides como fitoconstituyentes más abundantes en las especies seleccionadas. Los resultados constituyen un apoyo para continuar con los estudios químicos y farmacológicos de estas especies.

Introduction: Colombia is the second country with the highest biodiversity in the world, about 10 % of the world's plant resources are represented by 50,000 species of plants, and the north Colombian´s coast has about 3,400 of these species. This region is characterized by maintaining a rich tradition of use of this natural resource to treat several primary health problems. Objective: to conduct a phytochemical study of 45 ethanol extracts of 39 plants, which are used in traditional medicine in the Colombian Atlantic coast, with the aim of contributing to science-based knowledge of secondary metabolites present in these plants. Methods: different organs from each species were collected, fresh drug was subjected to successive extractions with 98 % ethanol and were identified in the extracts different groups of secondary metabolites present in each plants. Results: in the different ethanol extracts was detected high diversity of secondary metabolites; flavonoids, anthracene derivatives, triterpenes, cardiotonic compounds and alkaloids were predominantly present in each extracts. This studies were reported for first time the phytochemical study for species such as Sarcostemma clausum (Jacq) Schult., Diospyros inconstans Jacq., Sterculia apetala (Jacq.) Karst., Ceratopteris pteridoides Hooker., Cecropia peltata L., Cordia dentata Poir. and Gustavia superba (Kunth) O. Berg. Conclusions: there was evidence the presence of flavonoids as phytoconstituents most abundant in the species selected. The results provide support for further chemical and pharmacological studies of these species.

Actividad antiinflamatoria, antioxidante y antibacteriana de dos especies del género Tabebuia / Antiinflammatory, antioxidant and antibacterial activity of two species of Tabebuia genus

Introducción: Tabebuia rosea (Bertol.) A. DC. y Tabebuia ochracea (Cham.) Standl., que pertenecen a la familia Bignoniaceae, son utilizadas en la medicina popular por su potencial farmacológico como antiinflamatorio y antibacteriano, lo que ha motivado su estudio químico y biológico. Objetivos: determinar la actividad antiinflamatoria, antioxidante y antibacteriana de extractos totales etanólicos y fracciones en éter, diclorometano, acetato de etilo y etanol, obtenidas a partir de la corteza interna de Tabebuia rosea y Tabebuia ochracea. Métodos: el material vegetal se extrajo por maceración con etanol y se fraccionó mediante procedimientos de partición líquido/líquido. La actividad antiinflamatoria se evaluó utilizando el modelo murino in vivo de edema auricular inducido por 13-acetato de 12-orto-tetradecanoilforbol, mientras que la actividad antioxidante y antibacteriana se determinó in vitro, utilizando el método de captación del radical 2,2-difenil-1-picrilhidrazilo y métodos de difusión en agar, respectivamente.Resultados: los extractos etanólicos de la corteza de Tabebuia rosea y Tabebuia ochracea, así como algunas de sus fracciones, mostraron significativa actividad antiinflamatoria y antioxidante; en términos generales Tabebuia rosea resultó más activa como antiinflamatoria, mientras que en cuanto a la actividad antioxidante Tabebuia ochracea mostró ser más potente. Ambas especies de Tabebuia presentaron importante actividad antibacteriana frente a Staphylococcus aureus ATCC25923. Conclusiones: se demostró actividad antiinflamatoria, captadora de radicales libres 2,2-difenil-1-picrilhidrazilo y antibacteriana, en extractos totales y fracciones obtenidas de Tabebuia rosea y Tabebuia ochracea. Este constituye el primer reporte que valida el uso popular dado a estas especies como antiinflamatorio y antibacteriano, en la costa norte colombiana.

Introduction: Tabebuia rosea (Bertol.) A. DC. and Tabebuia ochracea (Cham.) Standl., belonging to the Bignoniaceae family, are widely used in folk medicine because of their antiinflammatory and antibacterial potentialities, all of which has prompted the chemical and biological study of these species. Objectives: to evaluate the antiinflammatory, antioxidant and antibacterial activity of the total ethanolic extracts and fractions obtained from the inner bark of Tabebuia rosea and Tabebuia ochracea by using ether, dichloromethane, ethyl acetate and ethanol. Methods: plant material was extracted through maceration with ethanol and fractionated through liquid-liquid partition method. The evaluation of antiinflammatory action used the 12-O-tetradecanoylphorbol-13-acetate induced ear edema in mice, whereas the antioxidant and antibacterial activities were determined in vitro, using the 2,22 -diphenyl-1-picrylhydrazyl radical scavenging method and agar well diffusion method, respectively. Results: ethanol extracts from Tabebuia rosea and Tabebuia ochracea inner bark, as well as some of their fractions showed significant antiinflammatory and antioxidant activity, being generally Tabebuia rosea more active as antiinflammatory. Regarding the antioxidant activity Tabebuia ochracea proved to be more potent. Both Tabebuia species revealed significant antibacterial activity against Staphylococcus aureus ATCC 25923. Conclusions: it was proven that total extracts and fractions obtained from Tabebuia rosea and Tabebuia ochracea had antiinflammatory, free radical DPPH scavenging capacity, and antibacterial activity. This is the first report which validates the popular use of these species as antiinflammatory and antibacterial agents in the north coast of Colombia.

Actividad larvicida de extractos etanólicos de Tabernaemontana cymosa y Trichilia hirta sobre larvas de estadio III y IV de Aedes aegypti (Diptera: Culicidae) / Larvicidal activity of ethanol extracts of Tabernaemontana cymosa and Trichilia hirta against III and IV stage larvae of Aedes aegypti (Diptera: Culicidae)

Introducción: el mosquito Aedes aegypti es el principal vector de los virus del dengue y la fiebre amarilla. Una de las formas actuales para combatir estas enfermedades es el control del vector. Sin embargo, los problemas causados por los insecticidas sintéticos y la resistencia adquirida por los mosquitos, hacen cada vez más difícil esta lucha. Las plantas constituyen una fuente alternativa al uso de insecticidas sintéticos. Objetivos: evaluar la actividad larvicida para el mosquito Aedes aegypti, de los extractos etanólicos y fracciones activas, de diferentes órganos vegetales de las especies Trichilia hirta L. y Tabernaemontana cymosa Jacq. Métodos: en este estudio se utilizaron larvas de Aedes aegypti en estadios III y IV. Los extractos etanólicos totales se obtuvieron por maceración del material vegetal seco y molido, durante una semana y posterior secado a presión reducida con un rotoevaporador. La obtención de fracciones y subfracciones, se realizó por cromatografía de columna abierta, usando solventes de diferentes polaridades. La actividad larvicida se evaluó bajo protocolos recomendados por la Organización Mundial de la Salud. Resultados: los extractos etanólicos de corteza de Trichilia hirta y flores, corteza y hojas de Tabernaemontana cymosa, no mostraron actividad larvicida. El extracto de semillas de Trichilia hirta mostró una actividad moderada con una CL50 y CL90 de 219,2 y 331,4 mg/L respectivamente. El extracto etanólico de semillas de Tabernaemontana cymosa, la fracción F008 y la subfracción F011, mostraron una buena actividad larvicida con CL50 de 35,1; 20,9, y 14,98 mg/L, respectivamente. Conclusiones: según los resultados, se consideró como promisorio el extracto de semillas de Tabernaemontana cymosa para la obtención de metabolitos secundarios con actividad larvicida.

Introduction: Aedes aegypti is the main vector of dengue and yellow fever. One way to combat these diseases today is the vector control. However, the problems caused by synthetic insecticides and the acquired resistance by mosquitoes, turn this control into a more difficult struggle every day. The plants offer an alternative source to the use of synthetic insecticides. Objectives: the objective of this study was to evaluate the larvicidal activity of the ethanol extracts and active fractions of different organs of Trichilia hirta L. and Tabernaemontana cymosa Jacq. Methods: in this study, Aedes aegypti larvae in III and IV stages were used. The total ethanol extracts were obtained by maceration of dried and ground plant material for a week and then dried at reduced pressure. The fractionation was performed by open column chromatography with the use of different polarity solvents. The larvicidal activity was assessed following protocols recommended by the World Health Organization. Results: the ethanol extracts from Trichilia hirta bark and flowers, and Tabernaemontana cymosa bark and leaves showed no larvicidal activity. The Trichilia hirta seed extract showed a moderate activity with an LC50 and LC90 of 219.2 and 331.4 mg/L respectively. The ethanol extract from Tabernaemontana cymosa seeds, the fraction F008 and the subfraction F011, showed good larvicidal activity with LC50 of 35.1, 20.9, and 14.98 mg/L, respectively. Conclusions: according to the results obtained in this study, the extract from Tabernaemontana cymosa seeds could be considered as a potential source of secondary metabolites with larvicidal activity.

In vitro antimalarial activity of fractions and constituents isolated from Tabebuia billbergii / Actividad antimalárica in vitro de fracciones y constituyentes aislados de Tabebuia billbergii

Introduction: in vitro antimalarial activity of naphthoquinones (1-5), isolated from Tabebuia billbergii (Bureau & K. Schum.) Standl., was investigated. Tabebuia billbergii, commonly known as guayacán, is a plant traditionally used in the Amazon in numerous conditions like bacterial and fungal infections, fever, syphilis, malaria, trypanosomiasis, as well as stomach and bladder disorders, and tumours. Objective: to study the dichloromethane extracts of both the trunk and the inner bark of Tabebuia billbergii and to demonstrate the antimalarial activity of some of its bioactive components. Methods: some bioactive components were evaluated for the antimalarial activity against Plasmodium berghei, by using the inhibition of the differentiation cycle of the parasite measure by the ³H-hypoxanthine incorporation and compared to that obtained for chloroquine. Results: conventional chromatographic techniques and bioassay-guided fractionation (Artemia salina) allowed isolating from the active fractions one naphthoquinone (lapachol) and four naphtho-furan-4,9-diones. These compounds proved to have an important antiplasmodial effect, with very encouraging IC50's, especially when compared to the results shown by Chloroquine in the same experiment. In addition, two triterpenes, β-sitosterol and stigmasterol, were obtained from the bark. Conclusions: the activity-guided fractionation (A. salina) of dichloromethane extracts of the trunk and the inner bark of Tabebuia billbergii led to the isolation and the identification of five quinonoid compounds with antiplasmodial effect. The significant inhibitory activity in vitro against Plasmodium berghei observed for compound 2-acetyl-naphtho-[2,3b]-furan-4,9-dione allow us to present them as a potential antimalarial compound.

Introducción: se evaluó la actividad antimalárica in vitro de una serie de naftoquinonas (1-5), aisladas de Tabebuia billbergii (Bureau & K. Schum.) Standl., que es conocida comúnmente como guayacán, una planta utilizada tradicionalmente en la Amazonía en numerosos problemas de salud como infecciones bacterianas y fúngicas, fiebre, sífilis, paludismo, tripanosomiasis, así como en problemas estomacales, tumores y trastornos de la vejiga. Objetivo: estudiar los extractos en diclorometano tanto del tronco como la corteza interna de Tabebuia billbergii y evaluar la actividad antimalárica de algunos de sus componentes bioactivos. Métodos: la actividad antimalárica contra Plasmodium berghei se evaluó en algunos componentes bioactivos, por la inhibición del ciclo de la diferenciación de la medida de los parásitos mediante la incorporación de 3H-hipoxantina y se comparó con la obtenida para la cloroquina. Resultados: a través de técnicas cromatográficas convencionales y el fraccionamiento guiado por bioensayo (Artemia salina) se aislaron de las fracciones activas, una naftoquinona (lapachol) y 4 nafto-furan-4,9-dionas. Estos compuestos presentaron un efecto antiplasmodial importante, con buenos valores de IC50, especialmente cuando se compara con los resultados mostrados por la cloroquina en el mismo experimento. Además, se obtuvieron de la corteza 2 triterpenos, β-sitosterol y estigmasterol. Conclusiones: el fraccionamiento guiado por Artemia salina de los extractos en diclorometano del tronco y la corteza interna de Tabebuia billbergii, condujo al aislamiento y la identificación de 5 compuestos de naturaleza quinoidal con efecto antiplasmódicol. La actividad in vitro contra Plasmodium berghei observada para el compuesto 2-acetil-nafto-[2,3 b]-furan-4,9-diona, permite proponerlo como un potencial compuesto antimalárico.

Química y biología del extracto etanólico del epicarpio de Crescentia cujete L. (totumo) / Chemistry and biology of ethanol extract from the epicarp of Crescentia cujete L. (totumo)

Introducción: el árbol de Crescentia cujete L. (Bignonaceae), conocido en Colombia como totumo, es una especie característica de climas tropicales. Su rasgo más distintivo es el fruto, el cual es una calabaza esférica con cáscara dura y leñosa, y una pulpa gelatinosa con numerosas semillas. Objetivo: realizar el estudio químico y biológico sobre el extracto etanólico del epicarpio de Crescentia cujete L. Métodos: se recolectó el material vegetal y se obtuvo el extracto etanólico total. Luego se realizó el tamizaje preliminar fitoquímico, los ensayos físico-químicos directos sobre el material vegetal, la cuantificación de metales pesados y, finalmente, el estudio biológico frente a larvas de Aedes aegypti L. (Culicidae) en estadios III y IV, larvas de Artemia salina Leach. (Artemiidae) y células apicales de raíces de Allium cepa L. (Amaryllidaceae). Resultados: se identificó la presencia de tres grupos de metabólitos secundarios: flavonoides, esteroides y triterpenos. Asimismo, se cuantificó el contenido de agua y cenizas en base seca, y se determinaron las concentraciones de algunos metales pesados como cadmio, cromo, mercurio y plomo. En el estudio biológico se puso de manifiesto que el extracto no presenta toxicidad aguda en ninguno de los sistemas biológicos ensayados, a las concentraciones y tiempos de experimentación. Conclusiones: la información obtenida en la presente investigación, constituye un recurso importante para la comunidad científica porque proporciona elementos relacionados con la naturaleza química y el comportamiento biológico del epicarpio del totumo, antes no reportados.

Introduction: Crescentia cujete L. (Bignonaceae) tree known in Colombia as totumo, is a characteristic species of tropical climates. Its most distinctive feature is the fruit, which is a spherical pumpkin with hard and woody peel, and a gelatinous pulp having a lot of seeds. Objective: to conduct the chemical and biological ethanol extract of Crescentia cujete L. epicarp. Methods: vegetal material was harvested and the total ethanol extract was obtained. Then, preliminary phytochemical screening, direct physical and chemical tests on vegetal material, the quantification of heavy metals and finally the biological study against Aedes aegypti L. (Culicidae) larvae in stages III and IV, Artemia salina Leach. (Artemiidae) larvae and apical cells of Allium cepa L. (Amaryllidaceae) roots. Results: the presence of three groups of secondary metabolites, that is, flavonoids, steroids and triterpenes were identified. Likewise, the water and ash content on dry basis was quantified as well as the levels of concentration of some heavy metals such as cadmium, chromium, mercury and lead were estimated. The biological study revealed that the extract did not show acute toxicity either in any of the tested biological systems or at the concentrations and the time of experimentation. Conclusions: the information obtained in this research is an important resource for the scientific community and provides elements associated to the chemical nature and the biological behavior of the totumo ´s epicarp not contained in previous reports.

Folk medicine in the northern coast of Colombia: an overview.

BACKGROUND: Traditional remedies are an integral part of Colombian culture. Here we present the results of a three-year study of ethnopharmacology and folk-medicine use among the population of the Atlantic Coast of Colombia, specifically in department of Bolívar. We collected information related to different herbal medicinal uses of the local flora in the treatment of the most common human diseases and health disorders in the area, and determined the relative importance of the species surveyed. METHODS: Data on the use of medicinal plants were collected using structured interviews and through observations and conversations with local communities. A total of 1225 participants were interviewed. RESULTS: Approximately 30 uses were reported for plants in traditional medicine. The plant species with the highest fidelity level (Fl) were Crescentia cujete L. (flu), Eucalyptus globulus Labill. (flu and cough), Euphorbia tithymaloides L. (inflammation), Gliricidia_sepium_(Jacq.) Kunth (pruritic ailments), Heliotropium indicum L. (intestinal parasites) Malachra alceifolia Jacq. (inflammation), Matricaria chamomilla L. (colic) Mentha sativa L. (nervousness), Momordica charantia L. (intestinal parasites), Origanum vulgare L. (earache), Plantago major L. (inflammation) and Terminalia catappa L. (inflammation). The most frequent ailments reported were skin affections, inflammation of the respiratory tract, and gastro-intestinal disorders. The majority of the remedies were prepared from freshly collected plant material from the wild and from a single species only. The preparation of remedies included boiling infusions, extraction of fresh or dry whole plants, leaves, flowers, roots, fruits, and seeds. The parts of the plants most frequently used were the leaves. In this study were identified 39 plant species, which belong to 26 families. There was a high degree of consensus from informants on the medical indications of the different species. CONCLUSIONS: This study presents new research efforts and perspectives on the search for new drugs based on local uses of medicinal plants. It also sheds light on the dependence of rural communities in Colombia on medicinal plants.