Conceição Santos

Centro de Estudios y Servicios Ambientales, Cuba

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Publications (96)219.33 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Cadmium (Cd) is a widespread heavy metal used in numerous industrial processes. Cd exerts toxicological effects mostly in kidney and liver. Bone is also an important target of Cd, however, the cellular mechanisms of Cd toxicological effects in the bone cells are still poorly understood. Therefore, the present work aimed to investigate the putative cytotoxic and genotoxic effects of Cd to human bone cells. For that, the osteoblast-like MG-63 cells were exposed to 20 and 50 μM Cd for 24 and 48 h. Results showed a dose-dependent increase in Cd accumulation in cells and a decrease in cell viability, especially after 48 h. Cell cycle analysis showed a delay at S phase concomitant with a decrease in cells at G0/G1 phase. After 24 h, Cd treatment downregulated the expression of CHEK1, CHEK2 and CDK2 genes and upregulated the expression of CCNE1 gene. After 48 h, the expression of ATM and CCNB1 genes were downregulated. Also, a 3.3 fold increase on the expression of gene CCNE1 was detected. Both Cd doses induced DNA fragmentation at 48 h, while an increase in micronuclei (MN) and nucleoplasmic bridges (NPBs) together with an increase in the percentage of apoptotic/necrotic cells was detected for both time periods. Overall, our results demonstrate the cytotoxicity and genotoxicity of Cd in human bone cells. Also, the cytokinesis-block micronucleus (CBMN) assay parameters (MN, NPBs and the percentage of cells under apoptosis or necrosis) together with the cell cycle appear as the most sensitive to Cd cyto- and genotoxicity, being early affected even with the lowest Cd dose. Therefore, these cyto-/genotoxic techniques may be selected for early detection of Cd-induced toxicity.
    Mutation Research/Genetic Toxicology and Environmental Mutagenesis 10/2014; 775-776:38-47. DOI:10.1016/j.mrgentox.2014.10.002 · 2.48 Impact Factor
  • 50th Congress of the European-Societies-of-Toxicology; 09/2014
  • 50th Congress of the European-Societies-of-Toxicology; 09/2014
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    ABSTRACT: Background & Scope of the review: This review focuses on the UV radiation effects on skin, emphasizing the photoaging process, and the photoprotection conferred by tretinoin (all-trans retinoic acid or ATRA). Tretinoin is still the best tested retinoid to reverse photoaged skin. Major Conclusions: Tretinoin can be used for photoaging treatment or combined treatment by different mechanisms. It binds to and activates retinoic acid receptors, inducing changes in gene expression that leads to cell differentiation, decreased cell proliferation, and inhibition of tumourigenesis. It has been demonstrated that photoaging resulting from UV-B radiation can be treated by retinoid formulations. Pretreatment of human skin with tretinoin blocks dermal matrix degradation followed by sun exposure, inhibiting the induction of the activated protein-1 (AP-1) transcription factor and AP-1 regulated matrix-degrading metalloproteinases. General Significance and Interest: Tretinoin should be considered as a key factor as it is the most potent and best-studied retinoid. In addition, the development of advanced drug delivery systems, especially novel nanoformulations, has contributed to overpass some technical drawbacks besides the skin irritation potential. The triple combination of tretinoin, hydroquinone and corticosteroids is still considered the gold standard for melasma. Although there are other novel therapeutic approaches, more high-quality clinical trials are still needed.
    Mini Reviews in Medicinal Chemistry 08/2014; DOI:10.2174/1389557514666140820102735 · 3.19 Impact Factor
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    ABSTRACT: Background & Scope of the reviewThis review focuses on the photoprotection conferred by lycopene, one of the most potent antioxidants. Lycopene has been recently proposed to play a critical role on anticarcinogenic action at different levels.Major Conclusions The photoprotective properties of lycopene remain contradictory. Some studies point out a positive and others a negative effect in both in vitro and in vivo models. Currently, researchers recognize that crucial gaps exist in understanding the role of carotenoids as effective modulators of apoptosis, cell cycle dynamics and/or of their in vivo behavior as cellular antioxidants.General SignificanceThe development of novel therapeutic strategies for skin disorders depends on our understanding of the molecular mechanism of UV damage on skin cells. The use of several effective phytocompounds, including lycopene, working through preventive and/ or corrective pathways in the cell, may be an approach for reducing UV-B generated damage.This article is protected by copyright. All rights reserved.
    Experimental Dermatology 07/2014; 23(12). DOI:10.1111/exd.12491 · 4.12 Impact Factor
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    ABSTRACT: Ultradeformable vesicles are highly promising tools to enhance the percutaneous transport of different drugs such as tretinoin across the skin barrier, and also to increase the formulationstability at absorption site and reduce the drug induced irritation.
    European Journal of Pharmaceutics and Biopharmaceutics 05/2014; DOI:10.1016/j.ejpb.2014.05.002 · 4.25 Impact Factor
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    Ana Capelo, Conceição Santos, Maria Arminda Pedrosa
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    ABSTRACT: Purpose ‐ The purpose of this paper is to explore the relevance of Education for Sustainable Development (ESD) in East Timor and proposes a set of ESD indicators to be implemented in the formal education sector. Design/methodology/approach ‐ A detailed analysis of relevant literature concerning national development plans (Republica Democrática de Timor-Leste, 2011), literature centred in East Timor and international perspectives about ESD principles, policies and values (UN reports) was carried, in order to examine the relevance of ESD in East Timor and to assist the selection of a set of ESD indicators. These indicators are proposed in order to assess and monitor if the current national policies, educational programmes, secondary school content, learning goals and activities in formal education express concerns related with ESD promotion in terms of specific curricular themes, learning characteristics, learning resources, skills, values and attitudes. Findings ‐ This paper argues that the East Timor government has intentions in ESD promotion and implementation. Thus, ESD indicators could be helpful in assessment of new curricular practices. However, even though ESDI may indicate that secondary school programmes, content, learning goals or activities are aligned with ESD principles, it is also important to assess if they then contribute effectively to sustainable development. Originality/value ‐ The case study of East Timor adds to the literature about the current interests of young countries such as this in progressing towards a sustainable future, starting from the selection and implementation of ESD indicators in the current curriculum reform. If it is successful, ESD will contribute to transforming not only education but also the quality of life of the East Timorese.
    04/2014; 3(2). DOI:10.1108/AEDS-03-2013-0021
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    ABSTRACT: Hormonal conditioning of plants in order to increase photosynthetic performance and reduce oxidative stress may improve plants’ tolerance to stress. This study aims to elucidate the effects of ABA pretreatment on the photosynthetic apparatus and antioxidant battery of Ulmus minor plants under well watered (WW) and drought stress (DS) conditions. Leaves were sprayed with ABA (50 and 100 μM). After 25 days of treatment DS was initiated by withholding water for 6 days. Water deficit decreased the RWC, induced stomatal closure and impaired net CO2 assimilation rate (A). However, independently of the water regime, ABA pretreatment increased plant DW accumulation, A, carotenoids and Chl a contents and reduced water loss. DS induced oxidative stress, but ABA application increased DS tolerance by the enhancement of the antioxidant system. Under WW conditions, the benefits of ABA application in reducing the cell membrane damages were noticeable. ABA pretreatment and DS induced changes in U. minor cell cycle of leaf cells, with a delay in S phase and an increase of FPCV coefficient. We propose that ABA pretreatment improves plant performance by increasing plant DW accumulation and augmenting the antioxidant system of U. minor plants, not only under DS conditions, but also under WW conditions. The use of ABA as pretreatment to alleviate the negative effects of DS seems to be a promising strategy to reduce plant's loss and improve plant productivity in drought prone habitats.
    Environmental and Experimental Botany 04/2014; 100. DOI:10.1016/j.envexpbot.2013.12.013 · 3.00 Impact Factor
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    ABSTRACT: Sulforaphane (SFN) is a naturally-occurring isothiocyanate best known for its role as an indirect antioxidant. Notwithstanding, in different cancer cell lines, SFN may promote the accumulation of reactive oxygen species (ROS) and cause cell death e.g. by apoptosis. Osteosarcoma often becomes chemoresistant, and new molecular targets to prevent drug resistance are needed. Here, we aimed to determine the effect of SFN on ROS levels and to identify key biomarkers leading to ROS unbalance and apoptosis in the p53-null MG-63 osteosarcoma cell line. MG-63 cells were exposed to SFN for up to 48 h. At 10 μM concentration or higher, SFN decreased cell viability, increased the%early apoptotic cells and increased caspase 3 activity. At these higher doses, SFN increased ROS levels, which correlated with apoptotic endpoints and cell viability decline. In exposed cells, gene expression analysis revealed only partial induction of phase-2 detoxification genes. More importantly, SFN inhibited ROS-scavenging enzymes and impaired glutathione recycling, as evidenced by inhibition of glutathione reductase (GR) activity and combined inhibition of glutathione peroxidase (GPx) gene expression and enzyme activity. In conclusion, SFN induced oxidative stress and apoptosis via a p53-independent mechanism. GPx expression and activity were found associated with ROS accumulation in MG-63 cells and are potential biomarkers for the efficacy of ROS-inducing agents e.g. as co-adjuvant drugs in osteosarcoma.
    PLoS ONE 03/2014; 9(3):e92980. DOI:10.1371/journal.pone.0092980 · 3.53 Impact Factor
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    ABSTRACT: Cork oak (Quercus suber L.) is a research priority in the Mediterranean area and because of cork oaks’ distribution these stands are experiencing daily stress. Based on projections of intensifying climate change and considering the key role of exploring the recovery abilities, cork oak seedlings were subjected to a cumulative temperature increase from 25 °C to 55 °C and subsequent recovery. CO2 assimilation rate, chlorophyll fluorescence, anthocyanins, proline and lipid peroxidation were used to evaluate plant performance, while the relative abundance of seven genes encoding for proteins of cork oak with a putative role in thermal/stress regulation (POX1, POX2, HSP10.4, HSP17a.22, CHS, MTL and RBC) was analyzed by qPCR (quantitative Polymerase Chain Reaction). A temperature change to 35 °C showed abundance alterations in the tested genes; at 45 °C, the molecular changes were associated with an antioxidant response, possibly modulated by anthocyanins. At 55 °C, HSP17a.22, MTL and proline accumulation were evident. After recovery, physiological balance was restored, whereas POX1, HSP10.4 and MTL abundances were suggested to be involved in increased thermotolerance. The data presented here are expected to pinpoint some pathways changes occurring during such stress and further recovery in this particular Mediterranean species.
    Journal of plant physiology 03/2014; 171(6):399–406. DOI:10.1016/j.jplph.2013.12.004 · 2.77 Impact Factor
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    ABSTRACT: Osteosarcoma is a recalcitrant bone malignancy with poor responsiveness to treatments; therefore, new chemotherapeutic compounds are needed. Sulforaphane (SFN) has been considered a promising chemotherapeutic compound for several types of tumors by inducing apoptosis and cytostasis, but its effects (e.g., genotoxicity) in osteosarcoma cells remains exploratory. In this work, the MG-63 osteosarcoma cell line was exposed to SFN up to 20 μM for 24 and 48 h. SFN induced G2/M phase arrest and decreased nuclear division index, associated with disruption of cytoskeletal organization. Noteworthy, SFN induced a transcriptome response supportive of G2/M phase arrest, namely a decrease in Chk1- and Cdc25C-encoding transcripts, and an increase in Cdk1-encoding transcripts. After 48-h exposure, SFN at a dietary concentration (5 μM) contributed to genomic instability in the MG-63 cells as confirmed by increased number of DNA breaks, clastogenicity, and nuclear and mitotic abnormalities. The increased formation of nucleoplasmic bridges, micronuclei, and apoptotic cells positively correlated with loss of viability. These results suggest that genotoxic damage is an important step for SFN-induced cytotoxicity in MG-63 cells. In conclusion, SFN shows potential to induce genotoxic damage at low concentrations and such potential deserves further investigation in other tumor cell types.
    Nutrition and Cancer 01/2014; DOI:10.1080/01635581.2014.864777 · 2.47 Impact Factor
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    ABSTRACT: This paper describes a proton high resolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR) metabolomic study of lettuce (Lactuca sativa L) leaves to characterise metabolic adaptations during leaf growth and exposure to mancozeb. Metabolite variations were identified through multivariate analysis and checked through spectral integration. Lettuce growth was accompanied by activation of energetic metabolism, preferential glucose use and changes in amino acids, phospholipids, ascorbate, nucleotides and nicotinate/nicotinamide. Phenylalanine and polyphenolic variations suggested higher oxidative stress at later growth stages. Exposure to mancozeb induced changes in amino acids, fumarate and malate, suggesting Krebs cycle up-regulation. In tandem disturbances in sugar, phospholipid, nucleotide and nicotinate/nicotinamide metabolism were noted. Additional changes in phenylalanine, dehydroascorbate, tartrate and formate were consistent with a higher demand for anti-oxidant defence mechanisms. Overall, lettuce exposure to mancozeb was shown to have a significant impact on plant metabolism, with mature leaves tending to be more extensively affected than younger leaves.
    Food Chemistry 01/2014; 154:291-298. DOI:10.1016/j.foodchem.2014.01.019 · 3.26 Impact Factor
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    ABSTRACT: This paper presents a new combination, Calendula suffruticosa subsp. cinerea, and two lectotypifications, for Calendula suffruticosa subsp. tomentosa and Calendula suffruticosa subsp. cinerea, in the course of a taxonomic revision for Flora Iberica. Explanations about the taxonomic concept here adopted are also provided.
    Phytotaxa 10/2013; 145(1):47-53. DOI:10.11646/phytotaxa.145.1.5 · 1.38 Impact Factor
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    ABSTRACT: Cork oak is an economically important forest species showing a great tolerance to high temperatures and shortage of water. However, the mechanisms underlying this plasticity are still poorly understood. Among the stress regulators, transcription factors (TFs) are especially important since they can control a wide range of stress-inducible genes, which make them powerful targets for genetic engineering of stress tolerance. Here we evaluated the influence of increasing temperatures (up to 55 °C) or drought (18% field capacity, FC) on the expression profile of an R2R3-MYB transcription factor of cork oak, the QsMYB1. QsMYB1 was previously identified as being preferentially expressed in cork tissues and as having an associated alternative splicing mechanism, which results in two different transcripts (QsMYB1.1 and QsMYB1.2). Expression analysis by reverse transcription quantitative PCR (RT-qPCR) revealed that increasing temperatures led to a gradual down-regulation of QsMYB1 transcripts with more effect on QsMYB1.1 abundance. On the other hand, under drought condition, expression of QsMYB1 variants, mainly the QsMYB1.2, was transiently up-regulated shortly after the stress imposition. Recovery from each stress has also resulted in a differential response by both QsMYB1 transcripts. Several physiological and biochemical parameters (plant water status, chlorophyll fluorescence, lipid peroxidation and proline content) were determined in order to monitor the plant performance under stress and recovery. In conclusion, this report provides the first evidence that QsMYB1 TF may have a putative function in the regulatory network of cork oak response to heat and drought stresses and during plant recovery.
    Plant Physiology and Biochemistry 10/2013; 73C:274-281. DOI:10.1016/j.plaphy.2013.10.007 · 2.35 Impact Factor
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    ABSTRACT: Eucalyptus plantations are among the most productive forest stands in Portugal and Spain, being mostly used for pulp production and, more recently, as an energy crop. However, the region's Mediterranean climate, with characteristic severe summer drought, negatively affects eucalypt growth and increases mortality. Although the physiological response to water shortage is well characterized for this species, evidence about the plants' recovery ability remains scarce. In order to assess the physiological and biochemical response of E. globulus during the recovery phase, two genotypes (AL-18 and AL-10) were submitted to a three-week water stress period at two different intensities (18% and 25% of field capacity), followed by one week of rewatering. Recovery was assessed one day and one week after rehydration. Drought reduced height, biomass, water potential, NPQ and gas exchange in both genotypes. Contrarily, the levels of pigments, chlorophyll fluorescence parameters (Fv /Fm and ɸPSII ), MDA and ABA increased. During recovery, the physiological and biochemical profile of stressed plants showed a similar trend: they experienced reversion of altered traits (MDA, ABA, E, gs , pigments), while other parameters did not recover (ɸPSII , NPQ). Furthermore, an overcompensation of CO2 assimilation was achieved one week after rehydration, which was accompanied by greater growth and re-establishment of oxidative balance. Both genotypes were tolerant to the tested conditions, although clonal differences were found. AL-10 was more productive and showed a more rapid and dynamic response to rehydration (namely in carotenoid content, ɸPSII and NPQ) compared to clone AL-18.
    Physiologia Plantarum 10/2013; 150(4). DOI:10.1111/ppl.12110 · 3.26 Impact Factor
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  • Toxicology Letters 08/2013; 221:S242-S243. DOI:10.1016/j.toxlet.2013.05.598 · 3.36 Impact Factor
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    ABSTRACT: This experimental work aimed to develop a simple, fast, economic and environmental friendly process for the extraction of lycopene from tomato and incorporate this lycopene-rich-extract in ultradeformable vesicular nanocarriers suitable for topical application. The lycopene extraction was carried out without a co-solvent for 30 min. The extracts were analyzed and incorporated in transfersomes and ethosomes. These formulations were characterized and the cellular uptake was observed by confocal microscopy. Dermal delivery of lycopene formulations was tested in vitro and in vivo conditions. Lycopene extraction proved to be quite safe and selective. The vesicular formulation was uptaken by the cells being more concentrated around the nucleus. Lycopene formulations epicutaneous application decreased anthralin-induced ear swelling by 97% and 87%, in a non-statistically different manner from the positive control. These results support that the lycopene-rich extract may be a good alternative to the expensive commercial lycopene to be incorporated in advanced topical delivery systems.
    Journal of Agricultural and Food Chemistry 07/2013; DOI:10.1021/jf401368w · 3.11 Impact Factor
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    ABSTRACT: he indoor environment is an important source of contaminants not only for humans but also for their pets. Animals and humans respond similarly to toxic agents. However, animals, due to their shorter lifespan, develop more rapidly, pathological conditions caused by environmental stressors. Consequently, household cats and dogs are good sentinels to assess adverse human health outcomes related to low levels of many indoor contaminants, some of which are known genotoxic agents. In this pilot survey, DNA damage in pet cats and dogs is evaluated and compared for the first time. Furthermore the importance of specific life traits in pets DNA damage is investigated. Single cell gel electrophoresis (“comet assay”) was used to evaluate DNA damage in pets leukocytes. A total of 25 dogs and 16 cats were selected for the present study that was approved by the Animal Welfare Commission from Aveiro University. After owners consent, 2 mL of blood was collected and data relative to each animal including gender, age, breed, health status, food type regularly consumed, residence and geographic location recorded. The obtained results demonstrate that the levels of DNA damage in pets cats and dogs from central Portugal are relatively low (<35% of DNA in tail) and that there are no significant differences between the two species. Furthermore, no determinant factors for DNA damage could be established without any significant differences detected for both cats and dogs and the following factors: gender, age, health status, residence, location and diet.
    Current Opinion in Biotechnology 07/2013; 24(S1):S76. DOI:10.1016/j.copbio.2013.05.216 · 8.04 Impact Factor

Publication Stats

1k Citations
219.33 Total Impact Points

Institutions

  • 2014
    • Centro de Estudios y Servicios Ambientales
      Cuba
  • 2004–2014
    • University of Aveiro
      • • Division of Biology
      • • Centre for Environmental and Marine Studies (CESAM)
      Aveiro, Aveiro, Portugal
  • 2012
    • Franciszek Górski Institute of Plant Physiology of the Polish Academy of Sciences
      Cracovia, Lesser Poland Voivodeship, Poland
  • 2007–2009
    • Instituto Universitario Valle de Santiago
      Santiago, Nayarit, Mexico