Selective antitumoural action of pressurized mango leaf extracts against minimally and highly invasive breast cancer.

Mango leaf tea has been traditionally used by different cultures to reduce inflammation in the body. There is evidence that chronic inflammation increases the risk of cancer. This study investigates the antitumoural effects of pressurized mango leaf extracts on minimally (MCF7) and highly invasive (MDA-MB-231) breast cancer cells as well as on non-tumourigenic cells (MCF10). Extracts showed protective properties against oxidation and cytotoxic effects against breast cancer cell lines, causing minor damage to non-carcinogenic cells. Nonetheless, some selective activity, depending on hormone receptor status, was observed. This was possibly related to the presence of minor compounds. Extracts with high levels of gallotannins showed cytotoxic action against MCF7 cells, while those which had methyl gallate and homomangiferin as common components were more effective against MDA-MB-231 cells. Therefore, the cytotoxic effect of mango leaf extracts might be attributed to the synergistic effect of different polyphenols and not just to mangiferin on its own as the predominant compound in mango leaves.

Generation of quercetin/cellulose acetate phthalate systems for delivery by supercritical antisolvent process.

Supercritical antisolvent process (SAS) has been used to precipitate microparticles of quercetin, a plant pigment found in many foods and used for medical treatments, pharmaceutical and cosmetic industries, together with nanoparticles of cellulose acetate phthalate (CAP), a polymer quite frequently used in drug delivery. Previously, precipitation of nanoparticles of CAP by the same process was studied at different conditions of pressure, temperature, CO2 and solution flow rates, nozzle diameter and initial concentration of the solution. Morphologies of the precipitates were analyzed by scanning electron microscopy (SEM). A range between 84 and 145nm of diameter in spherical particle were achievement in CAP precipitation. A same range of semi-spherical particles of CAP around 145nm and needle-like particle of quercetin was obtained in the coprecipitation experiments. X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) were carried out to find out the possible loss of crystallinity of the coprecipitates and the possible interactions between the polymer and quercetin, respectively. Release profiles of quercetin were carried out in simulated gastric and intestinal fluids. Higher quercetin:polymer ratios in the coprecipitates are recommended to achieve faster release and higher solubilities of quercetin in the assayed time. This fact would allow its use in pharmaceutical, cosmetic or nutraceutical applications.

Polymer encapsulation of amoxicillin microparticles by SAS process.

Encapsulation of amoxicillin (AMC) with ethyl cellulose (EC) by a supercritical antisolvent process (SAS) was investigated. AMC microparticles obtained previously by an SAS process were used as host particles and EC, a biodegradable polymer used for the controlled release of drugs, was chosen as the coating material. In this work, a suspension of AMC microparticles in a solution of ethyl cellulose in dichloromethane (DCM) was sprayed through a nozzle into supercritical CO2. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and HPLC analyses were carried out. The effects of AMC:EC ratio, the initial polymer concentration of the solution, temperature and pressure on the encapsulation process were investigated. Although all the experiments led to powder precipitation, the AMC encapsulation was achieved in only half of the cases, particularly when the lower drug:polymer ratios were assayed. In general, it was observed that the percentages of AMC present in the precipitates were higher on increasing the AMC:EC ratio. In these cases composites rather than encapsulates were obtained. The in vitro release profiles of the resulting materials were evaluated in order to ascertain whether composites can be used as encapsulated systems for drug delivery systems.