Cytoprotective action against oxidative stress in astrocytes and neurons by Bactris guineensis (L.) H.E. Moore (corozo) fruit extracts.

Neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis are characterized by having a significant increase in oxidative stress that can lead to the cellular damage of both neurons and astrocytes. Therefore, the search for molecules that can modulate oxidative stress in these diseases has recently gain interest, especially for those non-traditional antioxidants that can be gained from diet. In the present work, pulp and seed extracts from the fruit of the palm, Bactris guineensis were obtained by hydro-alcoholic solution and by a solid-liquid phase using solvents with different polarities and evaluated for their capacity to protect both neurons and astrocytes against rotenone-induced oxidative stress. Analysis of the chemical antioxidant activity showed that Bactris guineensis pulp crude extract and seed ethyl acetate and ethanol extracts had a high scavenging capacity when compared with extracts obtained in Hexane and dichloromethane. Toxicity assays also showed that the pulp crude extract and seed ethyl acetate and ethanol extracts at low doses did not affect the cell viability of primary astrocyte and SH-SY5Y neuroblastoma cells. In addition, ethyl acetate and ethanol extracts, not only decreased O2- radicals production but also protected both SHSY5Y and astrocytes oxidative stress induced by rotenone. Together our results suggest that Bactris guineensis fruit contain antioxidant molecules that can have therapeutic potential.

Standardized Extract from Caesalpinia spinosa is Cytotoxic Over Cancer Stem Cells and Enhance Anticancer Activity of Doxorubicin.

Cancer stem cells (CSC) are the primary cell type responsible for metastasis and relapse. ABC-transporters are integral membrane proteins involved in the translocation of substrates across membranes protecting CSC from chemotherapeutic agents. A plant extract derived from C. spinosa (P2Et) previously investigated for its antitumor activity has been shown to reduce lung and spleen metastasis in mice that have been transplanted with breast cancer cells, suggesting that P2Et has a significant activity against cancer stem cells (CSC). P2Et extract was thoroughly characterized by HPLC/MS. The cytotoxicity of P2Et extract was evaluated using a MTT assay in human and murine cell lines with different profiles of resistance, by Pgp overexpression or by enrichment in cancer stem cells. The synergistic effect of P2Et with doxorubicin was evaluated in vitro in several cell lines and in vivo in mice transplanted with TS/A cells, a highly resistant cell line and enriched in CD44[Formula: see text]CD24[Formula: see text]CSC. The chromatographic fingerprint of P2Et extract revealed 13 gallotannins. We also found that P2Et extract was cytotoxic to cells regardless of their resistant phenotype. Similarly, complementary activities were observed as drug efflux reversion and antioxidant activity. Short-treatment with P2Et extract, revealed a synergistic effect with doxorubicin in resistant cell lines. In vivo the P2Et increases mice survival in a TS/A breast cancer model associated with augmentation of calreticulin expression. Our results suggest that P2Et treatment could be used as adjuvant along with conventional chemotherapy to treat tumors with a MDR phenotype or with high frequency of CSC.

Obtención de hidroxiapatita sintética por tres métodos diferentes y su caracterización para ser utilizada como sustituto óseo / Synthetic hydroxyapatite obtaining using three different methods and characterization to use it as bone substitute

El método de obtención de la hidroxiapatita (HAp) para ser utilizada como sustituto óseo, debe ofrecer un producto de alta pureza, rendimiento, rapidez y bajo costo, y contar con propiedades como bioactividad, biocompatibilidad, osteoconductividad y unión directa al hueso. En este trabajo se elaboró HAp sintética mediante tres métodos reportados en la literatura de vía sinterización y vía precipitación. El material obtenido se caracterizó por espectrometría de absorción atómica (AAS), espectrometría de absorción molecular (UV-Vis), espectroscopía infrarroja con transformada de Fourier (FTIR), difracción de rayos X (XRD), microscopía electrónica de barrido (SEM) y espectroscopía por dispersión de energía de rayos X (EDX). La ruta de síntesis de HAp por precipitación ofreció mejores resultados, comparados con la muestra estándar comercial y el hueso bovino, obteniéndose un tamaño de grano aproximado de 1 µm, relación molar Ca/P de 1,7, alta pureza y cristalinidad; mientras que los resultados obtenidos por vía sinterización mostraron la presencia de fases amorfas. El método de síntesis por precipitación vía húmeda usando nitratos de calcio y fosfatos, mostró ser práctico y adecuado para realizar la inmovilización de HAp sobre un soporte metálico como silicio, importante para su uso en cirugía reconstructiva en el área odontológica y médica.

The method by which to obtain Hydroxyapatite to be used as bone substitute should offer specific qualities such as, high purity, performance, low cost and has to be the following, bioactive, biocompatible, it has to have osteoconductivity and it has to bond directly to the bone. In this paper, synthetic HAp was prepared using 3 different methods reported in the literature as a route via sintering and precipitation, and subsequently characterized by atomic absorption spectrometry (AAS), molecular absorption spectrometry (UV-Vis), infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy X-ray (EDX). The route of synthesis of HAp precipitation gives better results, compared to the commercial standard sample and bovine bone, such as grain size which is of about 1 µm, molar ratio Ca/P of 1.7, high purity and crystallinity, while the results obtained via sintering show the presence of amorphous phases. The synthesis method using a wet precipitation of calcium nitrates and phosphates is practical and suitable for the immobilization of HAp on a metal substrate such as silicon, important for the use in dental and medical reconstructive surgery.