Anomalous interaction of tri-acyl ester derivatives of uridine nucleoside with a l-α-dimyristoylphosphatidylcholine biomembrane model: a differential scanning calorimetry study.

OBJECTIVES: Uridine was conjugated with fatty acids to improve the drug lipophilicity and the interaction with phospholipid bilayers. METHODS: The esterification reaction using carbodiimides compounds as coupling agents and a nucleophilic catalyst allowed us to synthesize tri-acyl ester derivatives of uridine with fatty acids. Analysis of molecular interactions between these tri-acyl ester derivatives and l-α-dimyristoylphosphatidylcholine (DMPC) multilamellar vesicles (MLV) - as a mammalian cell membrane model - have been performed by differential scanning calorimetry (DSC). KEY FINDINGS: The DSC thermograms suggest that nucleoside and uridine triacetate softly interact with phospholipidic multilamellar vesicles which are predominantly located between the polar phase, whereas the tri-acyl ester derivatives with fatty acids (myristic and stearic acids) present a strongly interaction with the DMPC bilayer due to the nucleoside and aliphatic chains parts which are oriented towards the polar and lipophilic phases of the phospholipidic bilayer, respectively. However, the effects caused by the tri-myristoyl uridine and tri-stearoyl uridine are different. CONCLUSIONS: We show how the structural changes of uridine modulate the calorimetric behaviour of DMPC shedding light on their affinity with the phospholipidic biomembrane model.

Nanoencapsulation of bioactive ingredients: trends in pharmaceutical industry and functional foods / Nanoencapsulación de ingredientes bioactivos: tendencias en la industria farmacéutica y en alimentos funcionales

Multiple researches have allowed the development of nanoencapsulation techniques that ease the controlled or targeted release of bioactive components and favor their incorporation in different foods and medication formulations to improve their bioavailability. Recent studies have facilitated the development of nanoencapsulation systems of different active ingredients for functional foods, comprising phenolic compounds, antioxidants, essential oils, minerals, flavors, fish oils, essential fatty acids, vitamins, antimicrobials, soluble fiber, peptides, lycopene, lutein, ß-carotene, phytosterols, iron, calcium, among others, as well as bioactive compounds for therapeutic applications as polyphenols, curcumin, quercetin, resveratrol and epigallocatechin-3-gallate.

Functional foods: current issues and trends / Alimentos funcionales: actualidad y tendencias

Functional foods are characterized for containing various components, some of which are classified as nutrients, and they affect diverse important functions in the body producing wellness and health and/or decrease in the risk of some diseases. Accordingly, these foods, besides from satisfying hunger and providing nutrients that are necessary for the organism, also prevent nutrition related diseases and improve the body at physical and mental levels.

Microencapsulation: a technological alternative to preserve active ingredients in functional foods / Microencapsulación: una alternativa tecnológica para preservar ingredientes activos en alimentos funcionales

In the late 80's started the rise of researches related to the obtainment of food capable of supplying the energetic demand, promoting growth and encompassing better properties and benefits for the human being (1-4). Due to their nutritional and pharmacological features, these foods were called nutraceutical or functional foods as they comprise one or more components, not necessarily nutrients, that promote health, prevent diseases and strengthen the immune system or exhibit medical properties (1, 2). Regardless such researches increase and despite the approval for use and commercialization of these foods, in most countries there is neither a statutory definition nor any specific legislation that governs them (3, 4).

Synthesis and cytotoxic activity of tri-acyl ester derivatives of uridine in breast cancer cells / Síntesis y actividad citotóxica de derivados triesterificados de la uridina en células de cáncer de mama

Aims: Synthesize tri-acyl ester derivatives of uridine, and evaluate its cytotoxicity against breast cancer cells line. Methods: The tri-esterified uridine derivatives were obtained through Steglich esterification reaction by fatty and aromatic acids, and with acetic anhydride. An acetonide derivative from uridine was prepared with acid catalysis. Compounds were characterized by NMR spectroscopy (1H NMR and 13C NMR), and mass spectrometry. Derivatives were assessed in chinese hamster ovary (CHO-K1) and human breast cancer (MCF-7) cell lines. Results: Five tri-acyl ester derivatives of uridine were obtained one acetic acid, three fatty acids (myristic acid, stearic acid and oleic acid) with an aromatic acid. The uridine per-acetylated and uridine acetonide were obtained in high yields, however, the tri-acyl ester derivatives of uridine with fatty and aromatic acids were obtained in moderate and low yields, respectively. The acetonide and compounds 2 and 3 exhibited a cell viability inhibition significant on both cell lines to the higher concentration. Conclusions: Esterification method with coupling agents allowed obtained tri-acyl ester uridine derivatives with aliphatic and aromatic acids. However, significant cytotoxic activity (p<0.05) for uridine and its derivatives was not observed

Objetivos: Sintetizar derivados triesterificados de la uridina y evaluar su citotóxicidad sobre una línea celular de cáncer de mama. Métodos: Se prepararon derivados triesterificados de la uridina mediante la esterificación de Steglich para los ácidos grasos y aromáticos, y con anhídrido acético. Además se preparó el derivado acetonido mediante catálisis ácida. Los compuestos se caracterizaron por espectroscopia de RMN (RMN 1H y RMN 13C), y espectrometría de masas. Los derivados se evaluaron sobre líneas celulares de tumor de ovario de hámster chino (CHO) y de cáncer de mamá (MCF-7). Resultados: Se obtuvieron cinco derivados triesterificados de la uridina, uno con ácido acético, tres con ácidos grasos (ácido mirístico, ácido esteárico y ácido oleico) y uno con ácido aromático. Los derivados de uridina per-acetilada y acetonido se obtuvieron con rendimientos altos, sin embargo los derivados con ácidos grasos y aromático, se obtuvieron con rendimientos moderados y bajo, respectivamente. El acetonido y los compuestos 2 y 3, exhibieron inhibición significativa de la viabilidad celular sobre ambas líneas a la concentración más alta evaluada. Conclusiones: El método de esterificación con agentes de acoplamiento utilizado, permitió obtener derivados triesterificados de la uridina con ácidos grasos y aromáticos. No se observó actividad citotóxica significativa (p<0,05) para la uridina y sus derivados

Síntesis y actividad citotóxica de conjugados de la uridina con triterpenos en células de cáncer de mama / Synthesis and cytotoxic activity of conjugates of the uridine with triterpenes on breast cancer cells

Objetivos: Sintetizar conjugados del acetónido de la uridina con triterpenos (colesterol y 3β-5α,8α- endoperoxido-colest-6-en-3-ol) y ácido succínico como puente. Métodos: Se preparó el acetónido de la uridina en acetona mediante catálisis ácida. Se prepararon los succinatos de los esteroles con anhídrido succínico y catalizador nucleofílico 4-N,N-dimetilamino-piridina (DMAP). Los conjugados 1 y 2 se sintetizaron mediante la esterificación de Steglich, con agente de acoplamiento N,N’-diciclohexilcarbodiimida (DCC)y DMAP. Los compuestos se caracterizaron por espectroscopia de RMN (1H RMN y 13C RMN) y espectrometría de masas. Los derivados se evaluaron sobre líneas celulares de ovario de hámster chino (CHO-K1) y de cáncer de mamá (MCF-7). Resultados: Se obtuvieron derivados conjugados del acetónido de la uridina con dos triterpenos con rendimientos superiores al 80%. Los conjugados de uridina con triterpenos no presentaron inhibición significativa de la viabilidad celular sobre las líneas celulares MCF-7 y CHO-K1, tampoco se evidenció una relación dosis-respuesta para los compuestos evaluados. Conclusiones: El método de esterificación con agentes de acoplamiento permitió obtener conjugados de la uridina con triterpenos empleando el ácido succínico como puente. Sin embargo los derivados de uridina obtenidos no presentaron actividad citotóxica significativa (p < 0,05) sobre las líneas celulares evaluadas

Aims: Synthesize of uridine acetonide conjugates with triterpenoids (cholesterol and 3β-5α,8α-endoperoxide- cholest-6-en-3-ol) and succinic acid as linking. Methods: The acetonide derivative of uridine was prepared with acid catalysis in acetone. Sterols succinates were prepared with succinic anhydride and nucleophilic catalyst 4-N,N-dimethylamino-pyridine (DMAP). The conjugates were synthesized by Steglich method with N,N’-dicyclohexylcarbodiimide (DCC) Coupling agent and DMAP. The compounds were characterized by NMR spectroscopy (1H NMR, 13C NMR), and mass spectrometry. The derivatives were assessed in Chinese Hamster Ovary (CHO) and breast cancer (MCF-7) cell lines. Results: The conjugates of uridine acetonide with two triterpenes were obtained with yields higher than 80%. The conjugates prepared don’t showed significant inhibition of cell viability on MCF-7 and CHO cell lines, furthermore these substances did not show a relationship dose-response. Conclusions: The esterification method with coupling agents allowed obtained uridine conjugates with triterpenoids. However the uridine derivatives don’t showed significant cytotoxic activity (p < 0,05) against cell lines evaluated

Efecto de extractos de la esponja calcarea Leucetta aff. floridana sobre el ciclo de líneas celulares leucemoides / Effect of extracts from the calcareous sponge Leucetta aff. floridana on the cell cycle of leukemoid cell lines

La esponja Leucetta aff. floridana produce compuestos con actividad antiproliferativa diferencial en células tumorales de pulmón y mama, la cual no ha sido explorada en otras líneas tumorales y se desconoce si su potencial antiproliferativo está relacionado con la progresión de células a través del ciclo celular. Objetivo: evaluar el potencial antiproliferativo, anticlonogénico y el efecto sobre el ciclo celular de los extractos hexánico y metanólico de la esponja Leucetta aff. floridana del Caribe colombiano en las líneas celulares leucemoides Jurkat y K562. Métodos: la viabilidad y proliferación celular se determinaron mediante el ensayo de azul de tripano a 0, 24, 48, 72 y 96 h. La eficiencia de clonación y el efecto sobre el ciclo celular se evaluaron a 10 y 100 µg/mL. Los datos se analizaron usando ANOVA multifactorial y la prueba Tukey. Resultados: el extracto hexánico presentó actividad antiproliferativa en ambas líneas celulares siendo Jurkat más sensible que K562, lo cual se corroboró con los ensayos de clonogenicidad. Este extracto también mostró un efecto de acumulación de células Sub-G1 dependiente de la dosis, el cual fue diferencial entre las dos líneas celulares. La duración del tratamiento con el extracto hexánico no fue significativa para las células K562 pero sí para la línea celular Jurkat. Además, el porcentaje de acumulación de las células Sub-G1 fue mayor para células K562 comparado con Jurkat. El extracto metanólico presentó un efecto antiproliferativo similar al hexánico, pero fue más potente con la menor concentración (10 µg/mL) en la clonogenicidad de K562. El efecto sobre el ciclo celular, también fue similar al hexánico, pero la duración del tratamiento no fue significativa en la acumulación de células en Sub-G1. Conclusiones: los resultados muestran el potencial diferencial de los extractos sobre el ciclo celular de las líneas leucemoides evaluadas...

Leucetta aff. floridana sponge produces compounds with differential antiproliferative activity on lung and breast cancer. Nevertheless, this activity in other tumour cell lines has not yet been tested and it remains unknown whether its antiproliferative potential is correlated with the cell progression through cell cycle or not. Objective: To evaluate the antiproliferative and anticlonogenic potential and the effect of methanolic and hexanic extracts of sponge L. aff. floridana from the Colombian Caribbean region on the cell cycle of Jurkat and K562 leukemoid cell lines. Methods: The viability and antiproliferative effect were determined using trypan blue assay at 0, 24, 48, 72 and 96 hours. Clongenicity and effect on cell cycle were assayed at 10 and 100 µg/mL Data obtained were analyzed using multifactorial ANOVA and Tukey's test. Results: The hexanic extract presented antiproliferative activity in both Jurkat and K652 cell lines; Jurkat being more sensitive than K652. These results were confirmed by clongenicity assays. The hexanic extract also showed its effect on the dose-dependent accumulation of Sub-G1 cells, although it was different in the two cell lines. The duration of the treatment with the hexanic extract was not significant for K562 cell line, but it was for Jurkat cells. Additionally, the percentage of cell accumulation in Sub-G1 was higher in K562 than in Jurkat cells. The methanolic extract showed antiproliferative effect similar to that of the hexanic extract, but more potent at the lowest concentration (10 µg/mL) in K652 cell line clonegenicity. The effect on cell cycle was also similar to that of the hexanic extract, but in this case the duration of treatment was not significant in the cell accumulation in Sub-G1. Conclusions: Altogether these results show the differential potential of the extracts on the cell cycle of the evaluated leukemoid cell lines...

Validation of a liquid chromatographic method for determination of sulphadoxine and pyrimethamine in whole blood spotted on filter paper / Validación de un método de cromatografía líquida para determinar la presencia de sulfadoxina y pirimetamina en muestra de sangre secada sobre papel de filtro

Objective: to validate an analytical method for simultaneous determination and quantification of sulphadoxine and pyrimethamine in human blood dried onto filter paper, whose cost and analysis time can be reduced. Methods: whole blood spotted on filter paper of a healthy volunteer and solutions of sulphadoxine-pyrimethamine standard mixture were used. HPLC separations were carried out on Agilent equipment using a LiChrospher® column C18 with a mobile phase acetonitrile/0.1 M potassium phosphate buffer at pH 3.0 (1:1) for eight minutes under isocratic conditions. A flow rate of 0.7 mL/min, and a 20 mL volume injection were used. External standard method for quantitation of analytes was used. Results: the HPLC method described for the simultaneous determination of sulphadoxine and pyrimethamine in 100 mL of whole blood spotted on filter paper has been found to be linear, precise, accurate and selective. In this method, the sample preparation is simple using liquid-liquid extraction, and HPLC with ultraviolet detection is used. Conclusions: a simple, fast and sensitive method for determination of sulphadoxine and pyrimethamine in human blood dried onto filter paper was validated. This method can be used for the monitoring of both metabolites in pharmacokinetic and clinical studies.

Objetivo: validar un método de análisis para la determinación y cuantificación simultánea de sulfadoxina y pirimetamina en sangre humana secada sobre papel de filtro que sea rápido y barato. Métodos: se usó sangre de un voluntario sano impregnada sobre papel de filtro y soluciones estándar de la mezcla sulfadoxina y pririmetamina. Las separaciones por cromatografía líquida de alta resolución (CLAR) se hicieron en un equipo Agilent sobre una columna C18 LiChrospher® con acetonitrilo/buffer fosfato de potasio 0,1 M a pH 3,0 como fase móvil, usando condiciones isocráticas durante 8 min. Se usó un flujo de 0,7 mL/min y un volumen de inyección de 20 mL. Para la cuantificación de los analitos se utilizó el método del estándar externo. Resultados: el método CLAR descrito para la determinación simultánea de sulfadoxina y pirimetamina en 100 mL de sangre impregnada sobre el papel de filtro mostró linealidad, precisión, exactitud y selectividad. En este método la preparación de la muestra es simple ya que usa extracción líquido-líquido y detección ultravioleta. Conclusión: se obtuvo un método validado que es simple, rápido y sensible para la determinación de sulfadoxina y pirimetamina en sangre humana impregnada sobre papel de filtro, que puede ser usado para el monitoreo de ambos metabolitos en estudios farmacocinéticos y clínicos.