Alexandre Soares Leal

Occurrence of aflatoxin B1 in natural products

The media claims for the consumption of natural resource-based food have gradually increased in both developing and developed countries. The interest in the safety of these products is partially due to the possible presence of toxigenic fungi acting as mycotoxin producers, such as aflatoxins produced during the secondary metabolism of Aspergillus flavus, A. parasiticus and A. nomius. Aflatoxins, mainly aflatoxin B1, are directly associated with liver cancer in human beings. This paper is aimed at evaluating the presence of aflatoxin B1 in a few vegetable drugs, dried plant extracts and industrialized products traded in 2010 in the city of Belo Horizonte, State of Minas Gerais, Brazil. The method used for the quantification of aflatoxin B1 was based on extraction through acetone:water (85:15), immunoaffinity column purification followed by separation and detection in high efficiency liquid chromatography. Under the conditions of analysis, the Limits of Detection and Quantification were 0.6 µg kg-1 and 1.0 µg kg-1respectively. The complete sets of analyses were carried out in duplicate. Aflatoxin B1 was noticed in a single sample (< 1.0 µg kg-1). The results revealed low aflatoxin B1contamination in the products under analysis. However, it is required to establish a broad monitoring program in order to obtain additional data and check up on the actual extension of contamination.

Determination of metals in medicinal plants highly consumed in Brazil

In this work, samples of the medicinal plants: Boldo (Peumus boldus), Castanha da India (Aesculus hippocastanum), Cha Verde (Camelia sinensis), Erva Cidreira (Melissa officinalis), Espinheira Santa (Maytenus ilicifolia), Guarana (Paullinia cupana), Maracuja (Passiflora sp.), Mulungu (Erythrina velutina), Sene (Cassia angustifolia) and Valeriana (Valeriana officinalis) were evaluated BY using the Neutron Activation Analysis technique (NAA- k0) in order to determine the levels of metals and other chemical contaminants. The results showed the presence of non essential elements to the human body. The diversity of chemical impurities found even at low concentration levels, considering the potential for chronic toxicity of these elements, reinforces the need to improve the implementation of good practices by growers and traders, and the hypothesis of lack of quality control in plant products.

Efeito da irradiação na microbiota fúngica de plantas medicinais

The increasing consumption of natural products has brought about problems related to public health due to the risk of fungi contamination and the considerable possibility of mycotoxin presence. The aim of this work was to identify the fungi species with mycotoxigenic potential and to evaluate the effect of gamma irradiation (60Co) on killing the natural fungi microbiota of five medicinal plants: artichoke (Cynara scolymus L.), boldo (Peumusboldus Molina), chamomile (Matricaria recutita L.), burhead (Echinodorusgrandiflorus Micheli), and senna (Cassia acutifolia Delile). The qualification of filamentous fungi and yeast was carried out utilizing the Technique of Serial Dilutions on DRBC medium. Eight isolates of Aspergillus flavus were identified onchamomile, two (25%) beingproducers of aflatoxins B1 and B2 as well as five isolates of Aspergillus ochraceus, two (40%) being producers of ocratoxin. On artichoke, one isolate of Aspergillus ostianus was identified as ocratoxin A producer. A reduction on the total counting of fungi was observed in boldo with irradiation higher than 3 kGy, and in both burhead and senna with irradiation higher than 5 kGy. The initial counting on artichoke of 5.0 x 106 CFU/g experienced a reduction to 3.5 x 102 with doses of 10 kGy. With this same dose the fungi counting on chamomile was reduced from 3.0 x 105 CFU/g to 2.2 x 103 CFU/g.

An Assessment of the Potential Use of BNNTs for Boron Neutron Capture Therapy

Currently, nanostructured compounds have been standing out for their optical, mechanical, and chemical features and for the possibilities of manipulation and regulation of complex biological processes. One of these compounds is boron nitride nanotubes (BNNTs), which are a nanostructured material analog to carbon nanotubes, but formed of nitrogen and boron atoms. BNNTs present high thermal stability along with high chemical inertia. Among biological applications, its biocompatibility, cellular uptake, and functionalization potential can be highlighted, in addition to its eased utilization due to its nanometric size and tumor cell internalization. When it comes to new forms of therapy, we can draw attention to boron neutron capture therapy (BNCT), an experimental radiotherapy characterized by a boron-10 isotope carrier inside the target and a thermal neutron beam focused on it. The activation of the boron-10 atom by a neutron generates a lithium atom, a gamma ray, and an alpha particle, which can be used to destroy tumor tissues. The aim of this work was to use BNNTs as a boron-10 carrier for BNCT and to demonstrate its potential. The nanomaterial was characterized through XRD, FTIR, and SEM. The WST-8 assay was performed to confirm the cell viability of BNNTs. The cells treated with BNNTs were irradiated with the neutron beam of a Triga reactor, and the apoptosis caused by the activation of the BNNTs was measured with a calcein AM/propidium iodide test. The results demonstrate that this nanomaterial is a promising candidate for cancer therapy through BNCT.

Quality Control of Formulated Medicines

A pharmaceutical drug is technically obtained or prepared for prophylactic, curative, pallia‐ tive or diagnostic purposes. The final product must meet quality standard, be safe and effec‐ tive. In Brazil, there is a high demand for formulated drugs. This is mainly due to their lower price compared to manufactured drugs, evidenced by the rapid growth – an increase of 350% from 1998 to 2010. Even after the ANVISA’s (Agency National Health Surveillance) establishment of the new handling standards to be followed by the magistral pharmacies, several serious cases, in‐ cluding death reports, caused by the consumption of formulated drugs have recently be‐ come public [1-5]. Other problems related to this subject occurred in 2004, when deaths caused by manipulated medicines of low therapeutic index (clonidine and levotiroxine) led ANVISA to modify the regulation for manipulated medicines. The concentration of each compound was not totally assured and the contamination by impurities, not included in the original formula, were present in the final product. In a previous work, we have also observed the presence of impurities – such as metals in different kinds of medicines. The ingestion of metals, even at low levels, can be very harm‐ ful to humans. Besides this, the long-term uptake of some drugs is also risky. This should require attention and surveillance from the public health-related agencies [6-10]. The quality and safety of drugs must follow the specifications described in the official compendia among them, the pharmacopoeias. Medicines cannot contain impurities or

A theoretical model for the scattering of I2 molecule from a perfluoropolyeter liquid surface

In order to simulate experimental results of scattering of an I2 beam from liquid perfluorpolyeter ( PFPE ) surface we developed a model potential for the gas-polymer interaction at the liquid surface and solved the dynamics of the collision process by the classical trajectory method. The energy transferred in the process to the vibrational mode of the I2 molecule and to the liquid surface was investigated as a function of potential parameters.

Samarium doped boron nitride nanotubes

Boron nitride nanotubes doped in situ with samarium (Sm-doped BNNTs) were synthesized at 1150°C under atmosphere of NH3/N2 gas mixture by thermal chemical vapor deposition (TCVD) using samarium oxide that is a product of the process separation of thorium and uranium tailings. The samarium in the BNNTs sample was activated by neutron capture, in a nuclear reactor, producing 152Sm radioisotopes. The STEM-EELS spectrum and neutron activation show energies attributed to the samarium confirming the in situ doping process during BNNTs growth. The results demonstrate that this material has great potential as a nanosized β- emission source for medical therapy.

Avaliação preliminar da qualidade da fluoxetina comercializada por farmácias de manipulação em Belo Horizonte/MG

In this study, fourteen samples of fluoxetine being commercialized by thirteen different establishments of the network of magistral pharmacies in the City of Belo Horizonte/MG were assessed. The sampling corresponds to 47,0% of the total 30 different units of preparation of the city, which corresponds to about 180 points of sale. Analyses for determining weight, identification, active ingredient content and uniformity of dosage units were performed by the State Foundation Ezequiel Dias (FUNED /MG) based on methodologies described by reference pharmacopoeias. Irregularities, on the labeling and the content testing, were observed in some samples. It was also investigated, through the technique of neutron activation analysis (NAA), the presence and concentrations of metals and other inorganic impurities. The results showed the presence of elements such as As, Br, Cr Co, Cr, Hf and others, that even at low concentrations, may be harmful to human health if consumed steadily for a long term.

Avaliação da Qualidade da Sinvastatina Comercializada por Farmácias de Manipulação em Belo Horizonte/MG

The growing expansion of the magistral sector associated with reports of deviations from quality of compounded drugs, with serious cases, has generated a series of efforts by the Health Surveillance in the search for an efficient monitoring of pharmacies and products offered to the population. Thus, the aim of this study was to evaluate the quality of preparations containing simvastatin, manipulated in some pharmacies of Belo Horizonte/MG, after reviewing the health legislation occurred in 2007, through the realization of pharmacopoeic physicochemical analyzes of determination weight, identity and content of active ingredient and uniformity of dosage units. Further, research by neutron activation analysis, the presence and concentration of inorganic impurities in the samples of simvastatin manipulated. The results expressed an index of satisfactoriness of only 30%. This fact confirms the need for fast and efficient acts by public health authorities, and improving processes used in the manipulation within the establishments, to ensure the quality of compounded drugs.

A 2d model of the dynamic of the collision: i2-polymeric liquid surfaces of perfluorinatedpolyether (PFPE), polydimetilsiloxane (PDMS) and squalane

This paper presents two dimension classical trajectory calculations for the scattering of an I 2 molecule in the liquid polymeric surfaces of perfluorinatedpolyether (PFPE), polydimethyl-siloxane (PDMS) and squalane. The potential function describing the interaction of the gas molecule with the liquid surface is formulated as a modified LEPS potential. Each diatomic I 2 molecule and the I-surface potential are represented as a Morse function, with parameters adjusted from experimental data of scattering experiments. The surface was modeled as a typical effective mass with two harmonic vibrational degrees of freedom. This dynamics of the scattering process is in good agreement with experimental dynamical data. The experimentally observed inelastic scattering (IS) and the trapping and desorption (TD) processes were characterized and the determined I 2 vibrational temperatures showed good agreement with experimental values.