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1.
Microbiol Spectr ; : e0148424, 2024 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-39373473

RESUMEN

In Gram-negative bacteria, the outer membrane (OM) is asymmetric, with lipopolysaccharides (LPS) in the outer leaflet and glycerophospholipids (GPLs) in the inner leaflet. The asymmetry is maintained by the Mla system (MlaA-MlaBCDEF), which contributes to lipid homeostasis by removing mislocalized GPLs from the outer leaflet of the OM. Here, we ascribed how Pseudomonas aeruginosa ATCC 27853 coordinately regulates pathways to provide defense against the threats posed by the deletion of mlaA. Especially, we explored (i) the effects on membrane lipid composition including LPS, GPLs, and lysophospholipids, (ii) the biophysical properties of the OM such as stiffness and fluidity, and (iii) the impact of these changes on permeability, antibiotic susceptibility, and membrane vesicles (MVs) generation. Deletion of mlaA induced an increase in total GPLs and a decrease in LPS level while also triggering alterations in lipid A structures (arabinosylation and palmitoylation), likely to be induced by a two-component system (PhoPQ-PmrAB). Altered lipid composition may serve a physiological purpose in regulating the mechanobiological and functional properties of P. aeruginosa. We demonstrated an increase in cell stiffness without alteration of turgor pressure and inner membrane (IM) fluidity in ∆mlaA. In addition, membrane vesiculation increased without any change in OM/IM permeability. An amphiphilic aminoglycoside derivative (3',6-dinonyl neamine) that targets P. aeruginosa membranes induced an opposite effect on ∆mlaA strain with a trend toward a return to the situation observed for the WT strain. Efforts dedicated to understanding the crosstalk between the OM lipid composition, and the mechanical behavior of bacterial envelope, is one needed step for designing new targets or new drugs to fight P. aeruginosa infections.IMPORTANCEPseudomonas aeruginosa is a Gram-negative bacterium responsible for severe hospital-acquired infections. The outer membrane (OM) of Gram-negative bacteria acts as an effective barrier against toxic compounds, and therefore, compromising this structure could increase sensitivity to antibiotics. The OM is asymmetric with the highly packed lipopolysaccharide monolayer at the outer leaflet and glycerophospholipids at the inner leaflet. OM asymmetry is maintained by the Mla pathway resulting in the retrograde transport of glycerophospholipids from the OM to the inner membrane. In this study, we show that deleting mlaA, the membrane component of Mla system located at the OM, affects the mechanical and functional properties of P. aeruginosa cell envelope. Our results provide insights into the role of MlaA, involved in the Mla transport pathway in P. aeruginosa.

2.
Ann Pharm Fr ; 78(2): 179-188, 2020 Mar.
Artículo en Francés | MEDLINE | ID: mdl-32037029

RESUMEN

OBJECTIVE: In order to improve the contribution of medicines from traditional pharmacopoeia to health care, African countries like Burkina Faso have adopted for several years, policies and regulations organizing their distribution. This study aims to analyze the situation of the wholesale and retail sale of herbal medicines imported by the official pharmaceutical facilities. METHOD: This is a retrospective study involving all 18 drug wholesalers and 115 pharmacies in the city of Ouagadougou (Burkina Faso). It consisted of a collection of sales data of herbal medicines from 2013 to 2016 and interviews of the pharmacists responsible for the facilities surveyed. RESULTS: All the pharmacies surveyed obtain their supplies from national wholesalers, but eleven of them do so directly from manufacturers or non-wholesalers. Only 40% (44/111) of herbal medicines distributed by wholesalers and pharmacies had valid marketing authorizations. Also, although the average growth rates of annual sales by wholesalers and private pharmacies, respectively 23.67% and 11.94%, are significant, the turnover generated from their sale remains low. CONCLUSION: Supporting local producers with appropriate funding and adequate promotion of herbal medicines is still needed to boost the share of the national herbal medicines market.


Asunto(s)
Industria Farmacéutica/estadística & datos numéricos , Fitoterapia/estadística & datos numéricos , Preparaciones de Plantas/provisión & distribución , Plantas Medicinales , Burkina Faso , Industria Farmacéutica/tendencias , Promoción de la Salud , Humanos , Medicinas Tradicionales Africanas , Farmacéuticos , Fitoterapia/tendencias , Estudios Retrospectivos
3.
Sci Rep ; 9(1): 16498, 2019 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-31712605

RESUMEN

Many plants require animal pollinators for successful reproduction; these plants provide pollinator resources in pollen and nectar (rewards) and attract pollinators by specific cues (signals). In a seeming contradiction, some plants produce toxins such as alkaloids in their pollen and nectar, protecting their resources from ineffective pollinators. We investigated signals and rewards in the toxic, protandrous bee-pollinated plant Aconitum napellus, hypothesizing that male-phase flower reproductive success is pollinator-limited, which should favour higher levels of signals (odours) and rewards (nectar and pollen) compared with female-phase flowers. Furthermore, we expected insect visitors to forage only for nectar, due to the toxicity of pollen. We demonstrated that male-phase flowers emitted more volatile molecules and produced higher volumes of nectar than female-phase flowers. Alkaloids in pollen functioned as chemical defences, and were more diverse and more concentrated compared to the alkaloids in nectar. Visitors actively collected little pollen for larval food but consumed more of the less-toxic nectar. Toxic pollen remaining on the bee bodies promoted pollen transfer efficiency, facilitating pollination.


Asunto(s)
Aconitum/fisiología , Flores/fisiología , Fenómenos Fisiológicos de las Plantas , Polen , Polinización , Reproducción , Alcaloides , Animales , Evolución Biológica , Néctar de las Plantas/química , Polen/química
4.
Oncogene ; 35(30): 3976-85, 2016 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-26686091

RESUMEN

Photosensitizers (PS) are ideally devoid of any activity in the absence of photoactivation, and rely on molecular oxygen for the formation of singlet oxygen ((1)O2) to produce cellular damage. Off-targets and tumor hypoxia therefore represent obstacles for the use of PS for cancer photodynamic therapy. Herein, we describe the characterization of OR141, a benzophenazine compound identified through a phenotypic screening for its capacity to be strictly activated by light and to kill a large variety of tumor cells under both normoxia and hypoxia. This new class of PS unraveled an unsuspected common mechanism of action for PS that involves the combined inhibition of the mammalian target of rapamycin (mTOR) signaling pathway and proteasomal deubiquitinases (DUBs) USP14 and UCH37. Oxidation of mTOR and other endoplasmic reticulum (ER)-associated proteins drives the early formation of high molecular weight (MW) complexes of multimeric proteins, the concomitant blockade of DUBs preventing their degradation and precipitating cell death. Furthermore, we validated the antitumor effects of OR141 in vivo and documented its highly selective accumulation in the ER, further increasing the ER stress resulting from (1)O2 generation upon light activation.


Asunto(s)
Enzimas Desubicuitinizantes/antagonistas & inhibidores , Retículo Endoplásmico/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Oxígeno/farmacología , Fotoquimioterapia , Fármacos Fotosensibilizantes/farmacología , Animales , Hipoxia de la Célula , Línea Celular Tumoral , Humanos , Ratones , Neoplasias/metabolismo , Oxidación-Reducción , Complejo de la Endopetidasa Proteasomal/metabolismo , Serina-Treonina Quinasas TOR/fisiología
5.
Anal Chim Acta ; 877: 41-50, 2015 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-26002209

RESUMEN

Mallotus and Phyllanthus genera, both containing several species commonly used as traditional medicines around the world, are the subjects of this discrimination and classification study. The objective of this study was to compare different discrimination and classification techniques to distinguish the two genera (Mallotus and Phyllanthus) on the one hand, and the six species (Mallotus apelta, Mallotus paniculatus, Phyllanthus emblica, Phyllanthus reticulatus, Phyllanthus urinaria L. and Phyllanthus amarus), on the other. Fingerprints of 36 samples from the 6 species were developed using reversed-phase high-performance liquid chromatography with ultraviolet detection (RP-HPLC-UV). After fingerprint data pretreatment, first an exploratory data analysis was performed using Principal Component Analysis (PCA), revealing two outlying samples, which were excluded from the calibration set used to develop the discrimination and classification models. Models were built by means of Linear Discriminant Analysis (LDA), Quadratic Discriminant Analysis (QDA), Classification and Regression Trees (CART) and Soft Independent Modeling of Class Analogy (SIMCA). Application of the models on the total data set (outliers included) confirmed a possible labeling issue for the outliers. LDA, QDA and CART, independently of the pretreatment, or SIMCA after "normalization and column centering (N_CC)" or after "Standard Normal Variate transformation and column centering (SNV_CC)" were found best to discriminate the two genera, while LDA after column centering (CC), N_CC or SNV_CC; QDA after SNV_CC; and SIMCA after N_CC or after SNV_CC best distinguished between the 6 species. As classification technique, SIMCA after N_CC or after SNV_CC results in the best overall sensitivity and specificity.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Mallotus (Planta)/química , Phyllanthus/química , Plantas Medicinales/química , Análisis Discriminante , Mallotus (Planta)/clasificación , Phyllanthus/clasificación , Extractos Vegetales/química , Extractos Vegetales/clasificación , Plantas Medicinales/clasificación , Análisis de Regresión
6.
Talanta ; 117: 94-101, 2013 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-24209316

RESUMEN

The purpose of the research was to develop and validate a rapid quantification method able to screen many samples of yam bean seeds to determine the content of two toxic polyphenols, namely pachyrrhizine and rotenone. The analytical procedure described is based on the use of an internal standard (dihydrorotenone) and is divided in three steps: microwave assisted extraction, purification by solid phase extraction and assay by ultra high performance liquid chromatography (UHPLC). Each step was included in the validation protocol and the accuracy profiles methodology was used to fully validate the method. The method was fully validated between 0.25 mg and 5 mg pachyrrhizin per gram of seeds and between 0.58 mg/g and 4 mg/g for rotenone. More than one hundred samples from different accessions, locations of growth and harvest dates were screened. Pachyrrhizine concentrations ranged from 3.29 mg/g to lower than 0.25 mg/g while rotenone concentrations ranged from 3.53 mg/g to lower than 0.58 mg/g. This screening along with principal component analysis (PCA) and discriminant analysis (DA) analyses allowed the selection of the more interesting genotypes in terms of low concentrations of these two toxic polyphenols.


Asunto(s)
Pachyrhizus/química , Polifenoles/análisis , Rotenona/análisis , Semillas/química , Cromatografía Líquida de Alta Presión/métodos , Análisis Discriminante , Genotipo , Límite de Detección , Microondas , Pachyrhizus/genética , Análisis de Componente Principal , Estándares de Referencia , Rotenona/análogos & derivados , Semillas/genética , Extracción en Fase Sólida , Factores de Tiempo
7.
Phytomedicine ; 20(3-4): 270-4, 2013 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-23312849

RESUMEN

Keetia leucantha is a West African tree used in traditional medicine to treat several diseases among which parasitic infections. The dichloromethane extract of leaves was previously shown to possess growth-inhibitory activities on Plasmodium falciparum, Trypanosoma brucei brucei and Leishmania mexicana mexicana with low or no cytotoxicity (>100 µg/ml on human normal fibroblasts) (Bero et al. 2009, 2011). In continuation of our investigations on the antitrypanosomal compounds from this dichloromethane extract, we analyzed by GC-FID and GC-MS the essential oil of its leaves obtained by hydrodistillation and the major triterpenic acids in this extract by LC-MS. Twenty-seven compounds were identified in the oil whose percentages were calculated using the normalization method. The essential oil, seven of its constituents and the three triterpenic acids were evaluated for their antitrypanosomal activity on Trypanosoma brucei brucei bloodstream forms (Tbb BSF) and procyclic forms (Tbb PF) to identify an activity on the glycolytic process of trypanosomes. The oil showed an IC(50) of 20.9 µg/ml on Tbb BSF and no activity was observed on Tbb PF. The best antitrypanosomal activity was observed for ursolic acid with IC(50) of 2.5 and 6.5 µg/ml respectively on Tbb BSF and Tbb PF. The inhibitory activity on a glycolytic enzyme of T. brucei, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), was also evaluated for betulinic acid, olenaolic acid, ursolic acid, phytol, α-ionone and ß-ionone. The three triterpenic acids and ß-ionone showed inhibitory activities on GAPDH with oleanolic acid being the most active with an inhibition of 72.63% at 20 µg/ml. This paper reports for the first time the composition and antitrypanosomal activity of the essential oil of Keetia leucantha. Several of its constituents and three triterpenic acids present in the dichloromethane leaves extract showed a higher antitrypanosomal activity on bloodstream forms of Tbb as compared to procyclic forms, namely geranyl acetone, phytol, α-ionone, ß-ionone, ursolic acid, oleanolic acid and betulinic acid. The four last compounds were proven to be inhibitors of trypanosomal GAPDH, which may in part explain these antitrypanosomal activities.


Asunto(s)
Gliceraldehído-3-Fosfato Deshidrogenasas/antagonistas & inhibidores , Aceites Volátiles/química , Rubiaceae/química , Tripanocidas/aislamiento & purificación , Trypanosoma brucei brucei/enzimología , Pruebas de Sensibilidad Parasitaria , Fitoterapia , Extractos Vegetales/química , Hojas de la Planta/química , Plantas Medicinales/química
8.
Artículo en Inglés | MEDLINE | ID: mdl-23176815

RESUMEN

The Mallotus genus comprises numerous species used as traditional medicines in oriental countries and provides scientists a broad basis in the search for pharmacologically active constituents. In this paper, the cytotoxicity of 39 Mallotus extracts, different in species, part of the plant used, origin, and harvest season, is evaluated combining cytotoxicity assays with fingerprint technology and data handling tools. At first, the antiproliferative activity of the plant extracts is analyzed both on a non-cancerous cell line (WI-38--human lung fibroblast) and on a cancerous cell line (HeLa human cervix carcinoma). The results are linked to a data set of high-performance liquid chromatographic fingerprint profiles of the samples using multivariate calibration techniques. The regression coefficients of the multivariate model are then evaluated to indicate those peaks potentially responsible for the cytotoxic activity of the Mallotus extracts. In a final step, the cytotoxic extracts are analyzed by HPLC-MS and the indicated peaks identified.


Asunto(s)
Mallotus (Planta)/química , Extractos Vegetales/análisis , Extractos Vegetales/toxicidad , Línea Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión/métodos , Evaluación Preclínica de Medicamentos , Humanos , Mallotus (Planta)/clasificación , Espectrometría de Masas/métodos , Análisis Multivariante , Estaciones del Año
9.
Artículo en Inglés | MEDLINE | ID: mdl-23026226

RESUMEN

The aim of this work is to develop the first validated UHPLC-PDA method for major anthocyanins quantification in Euterpe oleracea fruits after fast extraction procedures and samples preparation. The separation was performed on HSS C18 column (1.8 µm) using a gradient elution with acetonitrile and 5% formic acid in a total run time of only 17 min. Total error and accuracy profiles were used as criteria for the validation process. Calibration in the matrix was found to be more accurate than calibration without matrix. Trueness (<6.76% relative bias), repeatability (<4.6% RSD), intermediate precision (<5.3% RSD), selectivity, response function and linearity for major anthocyanins, cyanidin-3-glucoside and cyanidin-3-rutinoside, were evaluated. The concentration range validated was 1-48 µg/mL for both compounds. In addition two cyanidin-di-O-glycosides were detected for the fist time in this fruit. We also showed that a first extraction of the fruits with ethyl acetate removes the lipophilic compounds and allows an easier extraction by methanol and quantification of anthocyanins in this extract.


Asunto(s)
Antocianinas/análisis , Arecaceae/química , Cromatografía Líquida de Alta Presión/métodos , Frutas/química , Calibración , Modelos Lineales , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
10.
Artículo en Inglés | MEDLINE | ID: mdl-22795556

RESUMEN

The genera of Mallotus and Phyllanthus contain several species that are commonly used as traditional medicines in oriental countries. Some species show interesting pharmaceutical activities, such as an antioxidant activity. To produce clinically useful medicines or food supplements (nutraceuticals) from these herbs, the species should be identified and a thorough quality control should be implemented. Nowadays, the integration of chromatographic and chemometric approaches allows a high-throughput identification and activity prediction of medicinal plants. In this study, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were applied and compared to distinguish Mallotus and Phyllanthus species. Moreover, peaks from their chromatographic fingerprints, which were responsible for their antioxidant activity were assigned. For the latter purpose, the relevant information was extracted from the chromatographic fingerprints using linear multivariate calibration techniques, i.e., Partial Least Squares (PLS) and Orthogonal Projections to Latent Structures (O-PLS). Results reveal that exploratory analysis using PCA shows somewhat diverging clustering tendencies between Mallotus and Phyllanthus samples than HCA. However, both approaches mainly confirm each other. Concerning the multivariate calibration techniques, both PLS and O-PLS models demonstrate good predictive abilities. By comparing the regression coefficients of the models with the chromatographic fingerprints, the peaks that are potentially responsible for the antioxidant activity of the extracts could be confirmed.


Asunto(s)
Antioxidantes/análisis , Mallotus (Planta)/química , Phyllanthus/química , Extractos Vegetales/análisis , Calibración , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Líquida de Alta Presión/normas , Análisis de los Mínimos Cuadrados , Análisis de Componente Principal
11.
Anal Chim Acta ; 721: 35-43, 2012 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-22405298

RESUMEN

Some Mallotus species are commonly used as traditional medicine (TM) ingredients in Vietnam and China, but only a few are studied for their activities. In Part I, high-performance liquid chromatography (HPLC) fingerprints of 39 Mallotus samples (17 species) were developed and, because of the complexity of and the large differences between the samples, it was chosen to analyse the unaligned fingerprints. The peaks, potentially responsible for the antioxidant activity in given Mallotus species, were indicated by the regression coefficients from an orthogonal projections to latent structures (O-PLS) model. In the present study, an in depth discussion on the need for alignment of the Mallotus fingerprints for the indication of the potentially active compounds is made, as well as an experimental analysis and identification of the previously indicated peaks by HPLC-mass spectrometry (HPLC-MS). Additionally, to thoroughly study and discuss the alignment problem, the modelling and prediction of the antioxidant activity of green tea samples based on HPLC fingerprints were also considered.


Asunto(s)
Antioxidantes/química , Cromatografía Líquida de Alta Presión , Mallotus (Planta)/química , Espectrometría de Masas , Medicina Tradicional , Análisis de Componente Principal , Té/química
12.
Talanta ; 83(4): 1198-208, 2011 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-21215855

RESUMEN

The genus of Mallotus contains several species commonly used as traditional medicines in oriental countries. A data set containing 39 Mallotus samples, differing in species, cultivation conditions, harvest season and/or part of the plant was used to develop fingerprints on two dissimilar chromatographic systems. An exploratory analysis with principal component analysis (PCA) was performed on both data sets individually. The results were also combined to obtain additional information on the unknown samples included in the data set. Furthermore, the antioxidant activity of the samples was measured and modelled as a function of the fingerprints using the orthogonal projections to latent structures (O-PLS) technique. The regression coefficients of the models were studied to indicate the peaks potentially responsible for the antioxidant activity. The indicated peaks were analyzed and identified by HPLC coupled to mass spectrometry (HPLC-MS). Because of the complexity of biological samples, it was aspired to separate co-eluting components based on the significant difference in chromatographic selectivity on the dissimilar systems and consequently obtain additional, complementary information on the contribution of the individual components to the antioxidant activity. The results illustrate the potential use of dissimilar chromatographic systems. Several initially co-eluting compounds could be separated on the dissimilar system. The corresponding regression coefficients provided complementary information on the potential antioxidant activity of the separated compounds.


Asunto(s)
Antioxidantes/análisis , Cromatografía/métodos , Mallotus (Planta)/química , Métodos Analíticos de la Preparación de la Muestra , Antioxidantes/química , Antioxidantes/aislamiento & purificación , Compuestos de Bifenilo/química , Cromatografía Líquida de Alta Presión , Análisis de los Mínimos Cuadrados , Picratos/química , Extractos Vegetales/química , Análisis de Componente Principal
13.
Anal Chim Acta ; 652(1-2): 189-97, 2009 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-19786180

RESUMEN

Some Mallotus species are used in traditional medicine in Vietnam and China. Some also show interesting activities, such as antioxidant and cytotoxic ones. Combining fingerprint technology with data-handling techniques allows indicating the peaks potentially responsible for given activities. In this study it is aspired to indicate from chromatographic fingerprints the peaks potentially responsible for the antioxidant activity of several Mallotus species. Relevant information was extracted using linear multivariate calibration techniques, both before and after alignment of the fingerprints with correlation optimized warping (COW). From the studied techniques, stepwise multiple linear regression is least recommended as it made an inadequate variable selection. Principal component regression theoretically can take largely varying variables uncorrelated to the antioxidant activity into account. However, in practice in the actual case study this problem was limited. These problems in principle do not occur using partial least squares (PLS) models. Of the tested PLS methods, orthogonal projections to latent structures was preferred because of its simplicity, reproducibility, reduced model complexity and improved interpretability of the regression coefficients, yielding a clearer view on the individual contribution of the compounds. Furthermore, reducing analysis times from 60min to 35 and 22.5min resulted in the same main compounds, indicated responsible for the antioxidant activity. Models built after alignment by COW did not result in additional information.

14.
Anal Chim Acta ; 649(1): 24-32, 2009 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-19664459

RESUMEN

Some Mallotus species are used in traditional medicine in Vietnam and China. Some also show interesting activities, such as antioxidant and cytotoxic ones. Combining fingerprint technology with data-handling techniques allows indicating the peaks potentially responsible for given activities. In this study it is aspired to indicate from chromatographic fingerprints the peaks potentially responsible for the antioxidant activity of several Mallotus species. Relevant information was extracted using linear multivariate calibration techniques, both before and after alignment of the fingerprints with correlation optimized warping (COW). From the studied techniques, Stepwise Multiple Linear Regression is least recommended as it made an inadequate variable selection. Principal Component Regression theoretically can take largely varying variables uncorrelated to the antioxidant activity into account. However, in practice in the actual case study this problem was limited. These problems in principle do not occur using Partial Least Squares (PLS) models. Of the tested PLS methods, Orthogonal Projections to Latent Structures was preferred because of its simplicity, reproducibility, reduced model complexity and improved interpretability of the regression coefficients, yielding a clearer view on the individual contribution of the compounds. Furthermore, reducing analysis times from 60 min to 35 and 22.5 min resulted in the same main compounds, indicated responsible for the antioxidant activity. Models built after alignment by COW did not result in additional information.


Asunto(s)
Antioxidantes/análisis , Cromatografía Líquida de Alta Presión/normas , Mallotus (Planta)/química , Calibración , Cromatografía Líquida de Alta Presión/métodos , Análisis de los Mínimos Cuadrados , Análisis Multivariante , Plantas Medicinales/química , Análisis de Componente Principal
15.
J Pharm Biomed Anal ; 50(5): 753-63, 2009 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-19586736

RESUMEN

Some Mallotus species are used in traditional medicine in Vietnam. To use certain species in Western medicines or as food supplements, they should be identified and quality control should be more strict, for instance, to avoid the erroneous switching of species. In species with interesting activities, the compounds responsible for them should be identified. For these identifications, HPLC fingerprint methodology can be used. In this paper, HPLC fingerprints of different lengths were developed for a number of Mallotus species. Secondly, a multivariate regression model was constructed to model the antioxidant activity of the Mallotus samples from the HPLC fingerprints with the aim to indicate peaks possibly responsible for this activity. For this purpose, after data pretreatment, the calibration technique partial least squares (PLS) was applied.


Asunto(s)
Antioxidantes/análisis , Química Farmacéutica/métodos , Cromatografía Líquida de Alta Presión/instrumentación , Cromatografía Líquida de Alta Presión/métodos , Mallotus (Planta)/metabolismo , Extractos Vegetales/análisis , Antioxidantes/química , Antioxidantes/aislamiento & purificación , Compuestos de Bifenilo/química , Calibración , Cromatografía/métodos , Suplementos Dietéticos , Radicales Libres , Indicadores y Reactivos/análisis , Indicadores y Reactivos/aislamiento & purificación , Análisis de los Mínimos Cuadrados , Análisis Multivariante , Picratos/química , Extractos Vegetales/aislamiento & purificación , Análisis de Componente Principal , Tecnología Farmacéutica/métodos
16.
J Chromatogr B Analyt Technol Biomed Life Sci ; 877(23): 2396-402, 2009 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-19349219

RESUMEN

The simultaneous quantification of madecassoside, asiaticoside, madecassic acid and asiatic acid in Centella asiatica by HPLC-UV is proposed. Asiaticoside was used as reference for the quantification of heterosides and asiatic acid for aglycones. The evaluation of the extraction efficiency of the four molecules led to use Soxhlet extraction for 8 h. The method was validated and was found to be accurate in the concentration range of 1.0-3.0 mg/ml for asiaticoside and 0.5-2.0 mg/ml for asiatic acid with CV <3% for all investigated compounds. LOD and LOQ were, respectively, 0.0113 and 1.0 mg/ml for asiaticoside and 0.0023 and 0.5 mg/ml for asiatic acid. This method was shown to be convenient for routine analysis of samples of C. asiatica.


Asunto(s)
Centella/química , Cromatografía Líquida de Alta Presión/métodos , Glicósidos/análisis , Triterpenos/análisis , Cromatografía Líquida de Alta Presión/instrumentación , Hojas de la Planta/química
17.
Antonie Van Leeuwenhoek ; 93(1-2): 27-36, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-17610142

RESUMEN

Fungal endophytes were isolated from leaves of Centella asiatica (Apiaceae) collected at Mangoro (middle eastern region of Madagascar, 200 km from Antananarivo). Forty- five different taxa were recovered. The overall foliar colonization rate was 78%. The most common endophytes were the non-sporulating species 1 (isolation frequency IF 19.2%) followed by Colletotrichum sp.1 (IF 13.2%), Guignardia sp. (IF 8.5%), Glomerella sp. (IF 7.7%), an unidentified ascomycete (IF 7.2%), the non-sporulating species 2 (IF 3.7%) and Phialophora sp. (IF 3.5%). Using sequences of the ribosomal DNA internal transcribed spacer (ITS) regions, major endophytes (IF > 7%) were identified as xylariaceous taxa or as Colletotrichum higginsianum, Guignardia mangiferae and Glomerella cingulata. Results from in vitro fungal disk experiments showed a strong inhibitory activity of the xylariaceous non-sporulating species 1 against G. mangiferae and C. higginsianum and of C. higginsianum against G. mangiferae. This can be explained by antagonism between dominant taxa.


Asunto(s)
Ascomicetos/genética , Centella/microbiología , Hojas de la Planta/microbiología , Ascomicetos/clasificación , Colletotrichum/clasificación , Colletotrichum/genética , ADN Espaciador Ribosómico/genética , Datos de Secuencia Molecular , Análisis de Secuencia de ADN
18.
J Ethnopharmacol ; 115(1): 25-9, 2008 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-17942256

RESUMEN

Alchornea cordifolia is one of the most widely-used plants in traditional medicine throughout Africa, principally for inflammatory, antimicrobial and parasitic diseases. In continuation of our investigations on its anti-inflammatory activity, we fractionated the leaf and root bark extracts and isolated six compounds which exhibited significant topical anti-inflammatory activity in the mouse ear oedema model using croton oil at a dose of 90 microg/cm2. Daucosterol (2), acetyl aleuritolic acid (4), N1,N2-diisopentenyl guanidine (5) and N1,N2,N3-triisopentenyl guanidine (6) were shown to be more active than indomethacin, while beta-sitosterol (1) and di(2-ethylhexyl) phthalate (3) were less effective. This is the first report on the presence of compounds 1, 2, 3 and 4 in this plant and of the anti-inflammatory activity of 3, 5 and 6. These compounds may account, at least in part, for the use of A. cordifolia in folk medicine to treat inflammation.


Asunto(s)
Antiinflamatorios/farmacología , Euphorbiaceae/química , Extractos Vegetales/farmacología , Animales , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Modelos Animales de Enfermedad , Oído , Edema/inducido químicamente , Edema/tratamiento farmacológico , Inflamación/tratamiento farmacológico , Masculino , Medicinas Tradicionales Africanas , Ratones , Extractos Vegetales/química , Hojas de la Planta , Raíces de Plantas
19.
Anticancer Res ; 25(1A): 363-8, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15816559

RESUMEN

BACKGROUND: Trachylobane diterpenes are secondary metabolites, quite rare in nature, and their bioactivities are poorly understood. Recently, we have described the cytotoxic activity of ent-trachyloban-3beta-ol isolated from the leaves of Croton zambesicus, a plant used in African folk medicine. MATERIALS AND METHODS: Cell viability on several cell lines, cell morphology, DNA laddering, annexin Vand caspase-3 activation experiments were undertaken in order to analyse the cytotoxicty of trachylobane diterpene and to determine if this compound is able to induce apoptosis. RESULTS: ent-Trachyloban-3beta-ol exerts a dose-dependent cytotoxic effect, which varies between cell lines. Induction of apoptosis in HL-60 cells could be detected at a concentration of 50 microM after 24-h treatment. CONCLUSION: We show here, for the first time, that a trachylobane diterpene is able to induce apoptosis in human promyelocytic leukemia cells via caspase-3 activation in a concentration-dependent manner.


Asunto(s)
Apoptosis/efectos de los fármacos , Diterpenos/farmacología , Leucemia Promielocítica Aguda/tratamiento farmacológico , Caspasa 3 , Caspasas/metabolismo , Croton/química , Activación Enzimática/efectos de los fármacos , Células HL-60 , Humanos , Leucemia Promielocítica Aguda/metabolismo , Leucemia Promielocítica Aguda/patología , Fosfatidilserinas/metabolismo
20.
Curr Med Chem Anticancer Agents ; 5(2): 173-82, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15777224

RESUMEN

Aporphinoids form an important group of plant secondary metabolites. Some of these compounds are used for a long time in traditional medicine for the treatment of various diseases, from benign syndromes to more severe illnesses. More than 500 aporphine alkaloids have been isolated from various plant families and many of these compounds display potent cytotoxic activities which may be exploited for the design of anticancer agents. Here we review the origin, biosynthesis, structure and cytotoxic properties of the prominent members of this class of compounds. Simple aporphinoids (boldine, dicentrine) as well as oxo-, pro- and dehydro-aporphines, and dimeric forms such as thalicarpine, are discussed here. Their mechanisms of action are not well known but DNA-manipulating enzymes such as polymerases and topoisomerases are among the most frequently cited targets for these benzylisoquinoline compounds. This review presents an updated view of the cytotoxic properties of the aporphinoids and their potential contribution to the development of anticancer agents.


Asunto(s)
Alcaloides/farmacología , Antineoplásicos/farmacología , Aporfinas/farmacología , Alcaloides/química , Alcaloides/aislamiento & purificación , Animales , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Aporfinas/química , Aporfinas/aislamiento & purificación , División Celular/efectos de los fármacos , Línea Celular Tumoral , Diseño de Fármacos , Humanos , Estructura Molecular
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