Polymeric nanoparticles of Brazilian red propolis extract : preparation, characterization, antioxidant and leishmanicidal activity

The ever-increasing demand for natural products and biotechnology derived from bees and ultra-modernization of various analytical devices has facilitated the rational and planned development of biotechnology products with a focus on human health to treat chronic and neglected diseases. The aim of the present study was to prepare and characterize polymeric nanoparticles loaded with Brazilian red propolis extract and evaluate the cytotoxic activity of "multiple-constituent extract in co-delivery system" for antileishmanial therapies. The polymeric nanoparticles loaded with red propolis extract were prepared with a combination of poly-ε-caprolactone and pluronic using nanoprecipitation method and characterized by different analytical techniques, antioxidant and leishmanicidal assay. The red propolis nanoparticles in aqueous medium presented particle size (200–280 nm) in nanometric scale and zeta analysis (−20 to −26 mV) revealed stability of the nanoparticles without aggregation phenomenon during 1 month. After freeze-drying method using cryoprotectant (sodium starch glycolate), it was possible to observe particles with smooth and spherical shape and apparent size of 200 to 400 nm. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and thermal analysis revealed the encapsulation of the flavonoids from the red propolis extract into the polymeric matrix. Ultra performance liquid chromatography coupled with diode array detector (UPLC-DAD) identified the flavonoids liquiritigenin, pinobanksin, isoliquiritigenin, formononetin and biochanin A in ethanolic extract of propolis (EEP) and nanoparticles of red propolis extract (NRPE). The efficiency of encapsulation was determinate, and median values (75.0 %) were calculated using UPLC-DAD. 2,2-Diphenyl-1-picryhydrazyl method showed antioxidant activity to EEP and red propolis nanoparticles. Compared to negative control, EEP and NRPE exhibited leishmanicidal activity with an IC50 value of ≅38.0 μg/mL and 31.3 μg/mL, 47.2 μg/mL, 154.2μg/mL and 193.2 μg/mL for NRPE A1, NRPE A2, NRPE A3 and NRPE A4, respectively. Nanoparticles loaded with red propolis extract in co-delivery system and EEP presented cytotoxic activity on Leishmania (V.) braziliensis. Red propolis extract loaded in nanoparticles has shown to be potential candidates as intermediate products for preparation of various pharmaceutical dosage forms containing red propolis extract in the therapy against negligible diseases such as leishmaniasis

Evaluation of the leishmanicide action of ethanol extracts of Crotalaria retusa L. (Fabaceae)

The purpose of the present work is to conduct an evaluation of the cytotoxicity of ethanol extracts and the total alkaloid fraction (TAF) from Crotalaria retusa for procyclic promastigotes cells of Leishmania chagasi. The kinetic study of extraction assisted by ultrasound of the total alkaloids present in Crotalaria retusa made it possible the optimization of the extraction parameters. It was evaluated the leishmanicide action of the TAF which did not show toxic activity for cells of the parasite in high concentrations. It was observed a powerful leishmanicide action of the ethanol extracts (10 and 30%) after the concentration of 5.6 mg/mL of Crotalaria retusa, and the ethanol present in the extractive solution (10 and 30%) in the concentration from 70 and 210 x 10-4 %, respectively. These results suggest that the cytotoxicity of the ethanol extract of Crotalaria retusa at 10 and 30% for cells of Leishmania chagasi, can be associated only to the concentration of the alcohol present in the extract

Effect of paclitaxel (Taxol®) on the biodistribution of sodium pertechnetate (Na99mTcO4) in female Wistar rats

The evidence that natural or synthetic drugs can affect the biodistribution of radiopharmaceuticals (radiobiocomplexes) in setting of nuclear medicine clinic is already known. We studied the effect of Paclitaxel, an anti-neoplastic agent for the treatment of solid tumors, on the biodistribution of Na99mTcO4 in female rats. Paclitaxel (1mg/mL/week) was administered into animals in single dose during 3 weeks, with interval of 1 week among them. The control group received NaCl 0.9% solutions by the same via. One hour after the last dose, it was injected Na99mTcO4 in the animals. The percentage of activity per gram (%ATI/g) and biochemical and hematological determinations were performed. A significant increase were found in alanine aminotransferase, aspartate aminotransferase, glucose and in the %ATI/g of some organs (ovaries, uterus, vagina, breasts, large intestine and liver).These results can be associated, probably, to the capacity of paclitaxel to alter the biodistribution of Na99mTcO4 and the metabolism of glucose and hepatic enzymes.<br>Já está bem estabelecido na literatura científica que produtos naturais ou sintéticos podem alterar a biodistribuição de radiofármacos. O objetivo desse estudo foi avaliar a influência do paclitaxel, um agente antineoplásico para tratamento de tumores sólidos na biodistribuição do pertecnetato de sódio em ratas Wistar e na determinação de componentes bioquímicos e hematológicos. Paclitaxel, comercialmente conhecido por Taxol® (1mg/mL/semana), foi administrado, intraperitoneamente, nos animais do grupo tratado, em dose única, por 3 semanas, mas com intervalo de uma semana entre elas. O grupo controle recebeu solução de NaCl 0,9%. Uma hora após a última dose de paclitaxel, os animais receberam 0,1 mL de Na99mTcO4 (3,7MBq) via plexo orbital. O percentual de radioatividade por grama (%ATI/g) e parâmetros laboratoriais foram determinados. Ocorreu um aumento significativo (p<0,05) do %ATI/g nos ovários, útero, vagina, mamas, intestino grosso e fígado. Os níveis de glicose sangüínea e das enzimas hepáticas (ALT e AST) também aumentaram significantemente (p<0,01). Esses resultados podem estar associados, provavelmente, à capacidade do paclitaxel em alterar a biodistribuição do Na99mTcO4 e o metabolismo da glicose e de enzimas hepáticas