Browsing by Issue Date, starting with "2019-09-26"
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- Safety assessment of a new matrix metalloproteinase inhibitor extracted from Lupinus albus seeds, through the analysis of its cytotoxic and genotoxic propertiesPublication . Bischoff, Nicolaij; Mota, J.; Louro, Henriqueta; Ventura, Célia; Ferreira, J.R.B.; Lima, A,; Silva, Maria JoãoColorectal cancer (CRC) is the third most common cancer worldwide, being highly metastatic and mostly resistant to anticancer treatment. Especially due to its high incidence in young people and the lack of adequate treatment, CRC is an increasing health risk for future generations. Since death of most colon cancer patients is due to metastatic disease, rather than the primary tumors itself, the mechanisms in the metastatic progression of CRC are intensively being studied. Subgroups of matrix metalloproteinase´s (MMP´s), especially gelatinases (MMP-2, MMP-9) have been identified to be frequently involved in the metastatic process, which makes them a useful drug target. On the other hand, experimental, epidemiological and clinical studies have shown that the consumption of legumes significantly reduces the incidence of several tumor types, including CRC. These effects are generally associated with the inhibitory action of legume seeds on MMP’s. MMP play a key role in cellular homeostasis due to their ability to initiate, enhance or down-regulate signal cascades, involving cell growth, inflammation, cytokine and growth-factor release. Overexpression of MMPs results in matrix degradation and is strongly associated with cancer cell invasion and metastasis. Deflamin is a novel matrix metalloproteinase inhibitor (MMPI) extracted from the seeds of Lupinus albus, which exhibits anti-inflammatory properties, particular at the gastrointestinal level and has been pointed as a promising cancer preventive agent. It shows especially high inhibitory activity against MMP-2 and MMP-9. This makes deflamin a great candidate to become a valuable anti-inflammatory nutraceutical agent, as well as a useful asset in the treatment of inflammatory bowel diseases (IBD). However potential secondary adverse effects must be avoided and for that purpose an early evaluation of its potential toxic effects to human cells is needed. This work is aimed at contributing to the safety evaluation of deflamin through the analysis of cytotoxic and genotoxic properties of the purified deflamin and a Lupinus albus extract in Caco-2 cells. Furthermore, its bioavailability and transport via a Caco-2 monolayer system will be tested to get further insights on possible uptake scenarios in the human intestine. The cytotoxic effects are analyzed by assessing cell viability (MTT assay), following Caco-2 cells exposure to a concentration range (5-640 µg/ml) of the pure deflamin or the extract during 24, 48 and 72 hours. Genotoxicity is assessed by the alkaline comet assay and the cytokinesis-block micronucleus assay. The effects on the intestinal barrier are analyzed by measuring the transepithelial resistance (TER) in a differentiated Caco-2 monolayer upon apical exposure to deflamin or the extract. Preliminary data suggests that neither the pure deflamin nor the extract display cytotoxicity in the tested concentration range. The results of the genotoxicity studies will be presented and discussed, in the light of the future application of deflamin as a chemopreventive agent, ensuring the absence of adverse side effects.
- Availability and information needs in the chemical contaminants domain – PortFIR assessmentPublication . Brazão, Roberto; Fernandes, Paulo; Lopes, Andreia; Oliveira, Luísa; Dias, Maria da GraçaChemical contaminants (Chc) can be naturally present and/or be introduced in food and feed as result of the various stages of its production, processing and transport and/or due to environmental contamination. The analysis of Chc laboratory data allows to generate information for continuous improvement of food safety and protection of public health. In order to define priorities for development of the Contaminants Database of the Portuguese Food Information Resource (PortFIR), it was decided to identify and assess the availability and information needs on food and feed Chc of the main Portuguese stakeholders in the area.
- Use of Human Biomonitoring in food risk assessment: assessing exposure to bisphenols in PortugalPublication . Namorado, Sónia; Kislaya, Irina; Alves-Alves, Clara; Castilho, Emília; Cordeiro, Eugénio; Dinis, Ana; Gouveia, Bruna; Prokopenko, Tamara; Vargas, Patrícia; Nunes, Baltazar; Matias Dias, CarlosBisphenols are among the chemicals with the highest production volume worldwide and are used to make polycarbonate plastic containers for food use, such as beverage containers and plastic dinnerware, and in the internal coatings of food and beverage cans among other products. According to the scientific literature, small amounts of these compounds migrate from packaging into food resulting in human exposure. Although numerous studies have been carried out in order to assess its effects on human health, there are still uncertainties concerning the possible toxic effects of these compounds. Nevertheless, the most commonly used bisphenol, bisphenol A (BPA), is considered an endocrine disrupting compound. As a consequence, current European legislation prohibits the use of BPA in baby bottles, infant sipping cups and in the coating of food containers for children up to 3 years old and significantly tightens the restrictions on the use of BPA in other food contact materials. This has led to the replacement of BPA by other bisphenols, such as BPS and BPF, whose health effects are still largely unknown. Considering the above and that there is no data on the exposure of the Portuguese population to these compounds, a new project named INSEF-ExpoQuim is currently being developed by the National Health Institute Doutor Ricardo Jorge, in cooperation with the five Regional Health Administrations and the Regional Health Secretariats of the Autonomous Regions of the Azores and Madeira, as part of the European Human Biomonitoring Initiative HBM4EU with the aim to assess exposure to bisphenols in the Portuguese population and contribute to the food risk assessment of bisphenols in Portugal. It is expect that project results will contribute to the reduction of the impact on the health of the Portuguese population that could result from the exposure to these chemicals, by producing high quality data on the actual exposure of the population, in order to support the development and implementation of policy measures aimed at minimizing exposure.