Quantitative study of the structure-retention index relationship in the imine family.

The Kováts retention index is one of the most popular descriptors of the performance of organic compounds in gas chromatography (GC). The mathematical modeling of this index is an interesting and open problem in analytical chemistry. In this paper, two models for the prediction of the Kováts retention index are presented. Topologic, topographic and quantum-chemical descriptors were used as structural descriptors. Multiple linear regression (MLR) analysis provides the first model using the forward stepwise procedure for the variable selection. For the second one, an ensemble of artificial neural network (ANN) was constructed using the pruning algorithm. Both methods were validated by an external set of compounds, by the Golbraikh and Tropsha method and by the leave-one-out (LOO) and the leave many out (LMO) procedures. The R2, RMScv and Q2, values for the training sets were 0.884, 0.589 and 0.830 for NN and 0.974, 0.417 and 0.970 for MLR models, respectively. The robustness of both models was demonstrated. Both portrait the chromatographic performance of the sample but in this case, the results of MLR equation are better than the NN ones. The MLR model is recommended because of its simplicity.

Biological and Nonbiological Antioxidant Activity of Some Essential Oils.

Fifteen essential oils, four essential oil fractions, and three pure compounds (thymol, carvacrol, and eugenol), characterized by gas chromatography and gas chromatography-mass spectrometry, were investigated for biological and nonbiological antioxidant activity. Clove oil and eugenol showed strong DPPH (2,2-diphenyl-1-picrylhydrazyl) free-radical scavenging activity (IC50 = 13.2 µg/mL and 11.7 µg/mL, respectively) and powerfully inhibited reactive oxygen species (ROS) production in human neutrophils stimulated by PMA (phorbol 12-myristate 13-acetate) (IC50 = 7.5 µg/mL and 1.6 µg/mL) or H2O2 (IC50 = 22.6 µg/mL and 27.1 µg/mL). Nutmeg, ginger, and palmarosa oils were also highly active on this test. Essential oils from clove and ginger, as well as eugenol, carvacrol, and bornyl acetate inhibited NO (nitric oxide) production (IC50 < 50.0 µg/mL). The oils of clove, red thyme, and Spanish oregano, together with eugenol, thymol, and carvacrol showed the highest myeloperoxidase inhibitory activity. Isomers carvacrol and thymol displayed a disparate behavior in some tests. All in all, clove oil and eugenol offered the best antioxidant profile.

Antioxidant and Hepatoprotective Activity of a New Tablets Formulation from Tamarindus indica L.

Hepatotoxic chemicals damage liver cells primarily by producing reactive oxygen species. The decoction of the leaves of Tamarindus indica L. is used for liver disorders. In this work we evaluated the hepatoprotective activity of a tablet formulation of this plant. Thirty-five Sprague Dawley rats were randomly divided into five groups (n = 7). First group (I) is control group, fed with standard diet. Groups II to V (hepatotoxic groups) were subjected to a subcutaneous injection of CCl4 (0.5 mL/kg). Group II was negative control, fed with standard diet; group III was subjected to administration of Silymarin 150 mg/kg and groups IV and V were treated with tablets in dose of 100 mg/kg and 200 mg/kg, respectively. Lipid peroxidation and the activity of superoxide dismutase, catalase, and reduced glutathione were evaluated. Serum levels of alanine aminotransferase, aspartate aminotransferase, gamma-glutamine transferase, alkaline phosphatase, and a lipid profile were evaluated too. The tablets inhibit lipid peroxidation. The redox balance (SOD-CAT-GSH) remains normal in the experimental groups treated with tablets. The liver function using dose of 200 mg/kg of tablets was better than the other experimental groups. These results justify, scientifically, the ethnobotanical use of the leaves of Tamarindus indica L.

Antioxidant activity of Tween-20 and Tween-80 evaluated through different in-vitro tests.

OBJECTIVES: This study aimed to evaluate the possible antioxidant activity of Tween-20 and Tween-80, two amphipathic nonionic surfactants commonly used as solubilizers and stabilizers, whose pharmacological effects have been ignored to a large degree. METHODS: Antioxidant activity was investigated in vitro measuring the scavenging activity on the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH(●) ), the production of reactive oxygen species (ROS) in activated human neutrophils using flow cytometry and the myeloperoxidase (MPO) inhibitory activity. KEY FINDINGS: Tween-20 and Tween-80 did not show scavenging activity on DPPH(●) , while produced a decrease of the ROS production in human neutrophils, being Tween-20 more active than Tween-80. Moreover, Tween-80 and Tween-20 were found to significantly stimulate MPO enzymatic activity. CONCLUSIONS: Our findings raise concerns with regard to the indiscriminate use of Tween-20 and Tween-80 in clinical and laboratory testing, since they could influence the results that are assigned to the tested substance.

Effect of some essential oils on phagocytosis and complement system activity.

The aim of the present study was to investigate the in vitro activity of 15 essential oils, 4 essential oil fractions, and 3 pure compounds (thymol, carvacrol, and eugenol) on phagocytosis by human neutrophils and on complement system. Samples were characterized by GC and GC-MS. Most of the oils (nutmeg, clove, niaouli, tea tree, bay laurel, lemon, red thyme, ginger), nutmeg terpenes, eugenol, and carvacrol showed mild to moderate inhibition of phagocytosis (25-40% inhibition at doses ranging from 40 to 60 µg/mL); highest inhibitory activity was found for thymol (72% at 56 µg/mL), whereas the mixture of bornyl and isobornyl acetates showed a mild stimulating activity (21% at 56 µg/mL). All samples were inactive in the alternative pathway of complement system, whereas on classical pathway, clove oil, eugenol, palmarosa oil, red thyme oil, tarragon oil, and carvacrol showed the highest activity, with IC50 values ranging from 65 to 78 µg/mL.

Composition and biological activity of the essential oil from leaves of Plinia cerrocampanensis, a new source of alpha-bisabolol.

The essential oil from fresh leaves of Plinia cerrocampanensis Barrie (Myrtaceae), obtained by hydrodistillation, was analysed by GC-FID and GC-MS. Forty components, representing more than 91% of the oil, were identified. Oxygenated sesquiterpenes represented the main fraction with alpha-bisabolol (42.8%) as the major constituent, making this plant a new and good source of this substance. Biological activity of the essential oil was evaluated against several bacterial and fungal strains as well as larvae from Aedes aegypti. The highest activity was found against Staphylococcus aureus, Pseudomonas aeruginosa, Microsporum gypseum, Trichophyton mentagrophytes and Trichophyton rubrum with MIC values from 32 to 125 microg/ml. The essential oil also showed potent inhibitory and bactericidal activities against three H. pylori strains, with MIC and MBC values of 62.5 microg/ml, and caused 100% mortality of A. aegypti larvae at a concentration of 500 microg/ml.

Role of polyphenols in the antimicrobial activity of ethanol Tamarindus indica L leaves fluid extract / Papel de los polifenoles en la actividad antimicrobiana del extracto fluido de las hojas de Tamarindus indica L

The aim of this work was to explore in an active, fractioned, and chemically characterized Tamarindus indica L. (TIL) leaves extract, the influence of flavonoids and polyphenol compounds on the antimicrobial activity. A spectrophotometric quantification of the total phenols and flavonoids content was determinate to the TIL leaves extract, as well as, to the four fractions in which was fractioned (n-hexane, chloroform, ethyl acetate and n-butanol). The extracts and their fractions were microbiologically tested against six ATCC bacteria and Candida albicans, being determined their minimum inhibitory and bactericidal concentrations (MIC and MBC). Additionally, the extracts were evaluated in their influence on human complement system (classical and alternative pathways). Fractions with high content of flavonoids and polyphenols (ethyl acetate and n-butanol) are active against Bacillus subtilis and inhibit the human complement system (direct pathway, IC50 31.05 and 33.65 ug/mL respectively), but are not active over Staphylococcus aureus. However, this bacterium was susceptible to fractions with low or null concentration of flavonoid or polyphenol compounds. No fractions neither the fluid extract were active against Salmonella typhimurium and Candida albicans. Experimental data suggest that phenols and flavonoids are not the only components involved in the antimicrobial activity of TIL leaves as has been previously suggested by other authors. Complement activity tests did not support a putative role on the antimicrobial activity.

El objetivo de este trabajo fue explorar en un extracto activo de hojas de Tamarindus indica L. (TIL), fraccionado y caracterizado químicamente, la influencia de los polifenoles y flavonoides en su actividad antimicrobiana. Se cuantificaron por espectroscopia UV-visible los contenidos de fenoles totales y flavonoides en el extracto de TIL así como de las cuatro fracciones obtenidas (n-hexano, cloroformo, acetato de etilo y n-butanol). Se evaluó la actividad microbiológica del extracto y sus fracciones contra seis bacterias ATCC y Candida albicans, determinándose sus concentraciones mínimas inhibitorias y bactericidas (MIC y MBC). Adicionalmente, se evaluó la influencia de los extractos en el sistema de complemento humano (vía clásica y alternativa). Las fracciones con altas concentraciones de polifenoles y flavonoides (acetato de etilo y n-butanol) fueron activas contra el Bacillus subtilis e inhibieron el sistema de complemento humano (vía directa, IC50 31.05 y 33.65 g/mL, respectivamente), pero no fueron activas contra Staphylococcus aureus. Sin embargo, esta bacteria fue susceptible a fracciones con baja o nula concentración de polifenoles y flavonoides. El extracto fluido y todas sus fracciones resultaron inactivos frente a Salmonella typhimurium y Candida albicans. Los datos experimentales sugieren que los fenoles y flavonoides no son los únicos compuestos involucrados en la actividad antimicrobiana de hojas de TIL, como había sugerido por otros autores. La actividad medida sobre el sistema de complemento, no aporta relevancia a la actividad antimicrobiana de las hojas de TIL.

Standardization of the quality control parameters of the Tamarindus indica L. soft extract

Introduction: Tamarindus indica L or Tamarind as commonly known is a medicinal plant witha broad spectrum of application in medicine. Tamarind is the most useful plant for liver disorders treatment in Cuba and The Caribbean. People use it as decoction and have to take up to four liters a day of this preparation, because the use of alcohol in the Tamarind fluid extracts prevent its use in patient with lever desorders. Objective: the aim of this study was the preliminary establisment of quality control parameters of the Tamarindus indica L soft extract as a novel alcohol-free active ingredient for solids pharmaceutical formulation. Methods: organoleptics properties, total solids, relative density, pH, and total ashes were stablished. The polyphenols content was evaluated as a chemical marker using Folin-Ciocalteau spectrophotometric method. The WHO methodology was followed for the establishment of limits for each one of the parameters...

Introducción: el Tamarindus indica L o tamarindo, como se le conoce comúnmente, es una planta medicinal con un amplio espectro de aplicación en la medicina. Es la más utilizada en Cuba y en el Caribe para los trastornos hepáticos. La población la utiliza en forma de decocción y consume alrededor de 4 L/d de esta preparación, porque el contenido de alcohol del extracto fluido de tamarindo impide su utilización en pacientes con estas enfermedades. Objetivo: establecer de forma preliminar los parámetros de control de calidad en el extracto blando de las hojas de Tamarindus indica L como un nuevo ingrediente activo libre de etanol, para la preparación de formas farmacéuticas sólidas. Métodos: se evaluaron las propiedades organolépticas, sólidos totales, densidad relativa, pH y cenizas totales. Se evaluó el contenido de polifenoles como marcador para el control de calidad de este extracto utilizando el método de Folin Ciocalteau. Se empleó la metodología propuesta por la Organización Mundial de la Salud para el establecimiento de los límites de control...

Metabolites extraction optimization in Tamarindus indica L. leaves / Optimización de la extracción de metabolitos de las hojas de Tamarindus indica L

A central composite 2 3 full factorial design was used to study the combined effect of ethanol concentration and moistening time on total phenol (TP), flavonoid (TF) and carbohydrates (TC) content, as well as over total soluble substance (TSS) and ashes content (TA) in the Tamarindus indica L. leaves extraction process. Desirability function (0.8377) suggest the 71.73 percent ethanol concentration and 92.37 minutes of moistening time as the best combination variables, predicting values of 25.972 and 2.678 mg/mL for TP and TF; whereas for TSS and TA was predicted 18.417 and 0.566 percent respectively. The TC variable was discarded, because was impossible to find an statistical strong model to describes this variable. The theoretic values predicted were contrasted with new experimental data (n=5) by a hypothesis contrast test and examining the absolute error in the prediction. Results show a good adjustment to the prediction for TP, TSS and TA variables, meanwhile TF exhibit a slight deviation to the predicted value (absolute error over 10 percent). Nevertheless, this study offers a combination of variables when it is intended to prepare a tamarind extract that afford a high extractive capacity and, as a consequence, a larger probability to exhibit some kind of pharmacologic activity.

Un diseño factorial con compuesto central 2 elevado a 3 fue empleado en la evaluación de la influencia de la concentración de etanol y el tiempo de humectación sobre el contenido de fenoles (TP), flavonoides (TF), carbohidratos (TC) sólidos (TSS) y cenizas totales (TA) en el proceso de extracción de hojas de Tamarindus indica L. Valores de 71.73 por ciento de etanol y de 92.37 minutos de tiempo de humectación fue la combinación de factores sugerida por la función deseabilidad (0,8377), la cual predice concentraciones de 25,972 y 2,678 mg/mL para las variables TP y TF; y 18,417 y 0,566 por ciento para TSS y TA respectivamente. La variable TC fue descartada ante la imposibilidad de encontrar modelos predictivos con significación estadística. Estos valores teóricos fueron comparados por contraste de hipótesis y cálculo del error absoluto de la predicción con los obtenidos por réplicas del experimento (n=5). Los resultados mostraron un buen ajuste a la predicción para las variables TP, TSS y TA, mientras que la variable TF muestra una pequeña desviación con un error absoluto ligeramente superior al 10 por ciento. A pesar de ello, el presente estudio ofrece una combinación de variables a la cual se logra una alta capacidad extractiva en hojas de Tamarindus indica L., ofreciendo una mayor probabilidad de actividad farmacológica.

Concentraciones séricas de calcio y magnesio en alcohólicos durante el tratamiento de desintoxicación / Serum concentration of calcium and magnesium in alcoholics during the detoxification treatment

Se examinaron los cambios de las concentraciones de calcio y magnesio séricos en 24 individuos alcohólicos durante el tratamiento de desintoxicación. El grupo control estuvo compuesto por individuos abstemios supuestamente sanos. Las concentraciones de calcio y magnesio séricos en el grupo de alcohólicos al inicio del tratamiento fueron significativamente más bajas que las del grupo control y por debajo del intervalo de valores normales. Después del tratamiento de desintoxicación se observaron valores similares a los del grupo control pero aún por debajo del intervalo de valores normales para estos minerales. Los resultados indican que los alcohólicos estudiados en este trabajo se enfrentaron a un riesgo nutricional y fisiológico superior al esperado por concepto de la ingestión continuada de alcohol

Concentraciones séricas de calcio y magnesio en alcohólicos durante el tratamiento de desintoxicación / Serum concentrations of calcium and magnesium in alcoholics in the course of detoxification treatment

Se examinaron los cambios de las concentraciones de calcio y magnesio séricos en 24 individuos alcohólicos durante el tratamiento de desintoxicación. El grupo control estuvo compuesto por individuos supuestamente sanos. Las concentraciones de calcio y magnesio séricos en el grupo de alcohólicos al inicio del tratamiento fueron significativamente más bajas que las del grupo control y por debajo del intervalo de valores normales. Después del tratamiento de desintoxicación, se observaron valores similares a los del grupo control pero aún por debajo del intervalo de valores normales para estos minerales. Los resultados indican que los alcohólicos incluidos en este trabajo se enfrentaron a un riesgo nutricional y fisiológico superior al esperado por concepto de la ingestión continuada de alcohol