Nuestros investigadores

Adela López de Cerain Salsamendi

Farmacología y Toxicología
Facultad de Farmacia y Nutrición. Universidad de Navarra
Líneas de investigación
Nanocarriers para el encapsulado de fármacos., Nanopartículas, Aflatoxina B1, Ocratoxina A, Micotoxinas, Toxicogenómica, Toxicidad sistémcia y Toxicocinética, Genotoxicidad in vitro e in vivo, Sexenios CNEAI: 3 (1992-1997, 1998-2004, 2005-2010)

Publicaciones científicas más recientes (desde 2010)

Autores: Vettorazzi, Ariane Renata, (Autor de correspondencia); Guruceaga, Elisabet; et al.
ISSN 0278-6915  Vol. 123  2019  págs. 337 - 348
Ochratoxin A (OTA) is a potent rodent nephrocarcinogen; being males more sensitive than females. The objective was to study the response between sexes at gene expression level (whole genome transcriptomics) in kidneys of F344 rats treated with 0.21 or 0.50 mg/kg bw OTA for 21 days. DNA methylation analysis of selected genes was also studied (MALDI-TOF mass spectrometry). OTA-induced response was dose-dependent in males and females, although clearer in males. Females showed a higher number of altered genes than males but functional analysis revealed a higher number of significantly enriched toxicity lists in 0.21 mg/kg treated males. OTA modulated damage, signaling and metabolism related lists, as well as inflammation, proliferation and oxidative stress in both sexes. Eleven toxicity lists (damage, fibrosis, cell signaling and metabolism) were exclusively altered in males while renal safety biomarker and biogenesis of mitochondria lists were exclusively enriched in females. A high number of lists (39) were significantly enriched in both sexes. However, they contained many sex-biased OTA-modulated genes, mainly phase I and II, transporters and nuclear receptors, but also others related to cell proliferation/apoptosis. No biologically relevant changes were observed in the methylation of selected genes.
Autores: Azqueta, A; Enciso, J. M.; et al.
ISSN 0278-6915  Vol. 132  2019 
The in vivo comet assay is usually performed in fresh tissues by processing cells immediately after collection, an approach that is not always possible from a logistical point of view. Although the comet assay has been applied to frozen rodent tissue samples on several occasions, there is currently no agreement on the best way to freeze and thaw them. We have tested two different thawing procedures and compared the levels of DNA strand breaks (SBs) and Fpg-sensitive sites in fresh and frozen (for up to year) liver, kidney and lung tissue samples, from untreated and methyl methanosulfonate treated rats. Tissues were snap frozen, stored at - 80 degrees C and processed in such a way that the tissue remained frozen until the cells were in suspension. Our results showed that comparable levels of DNA SBs were detected in fresh and frozen liver and lung samples stored at - 80 degrees C for up to 1 year and 3 months, respectively. In kidney, similar levels of SBs were detected either in fresh or in frozen tissues stored for up to 1 year. However, more studies are needed to control the variability observed in the Fpg-sensitive site levels in this tissue at the different freezing periods.
Autores: González-Peñas, E., (Autor de correspondencia); Vettorazzi, Ariane Renata; Lizarraga, Elena; et al.
Revista: TOXINS
ISSN 2072-6651  Vol. 11  Nº 7  2019 
Autores: de Cerain, A.L.; et al.
ISSN 0378-4274  Vol. 314  Nº S  2019  págs. S124 - S124
Autores: Vettorazzi, Ariane Renata; Izco, M.; de Cerain, A.L.; et al.
ISSN 0378-4274  Vol. 314  Nº S  2019  págs. S220 - S220
Autores: Vettorazzi, Ariane Renata, (Autor de correspondencia); Enciso, J. M.; et al.
ISSN 0278-6915  Vol. 111  2018  págs. 363 - 373
Ochratoxin A (OTA) is a potent renal carcinogen in male rats but not in females. The mechanisms underlying these differences are unknown. The sex-dependent response of F344 rats after a repeated OTA oral administration for 7 (0.50 mg/kg bw) or 21 days (0.21 and 0.50 mg/kg bw) was evaluated. General toxicity, sex and thyroid hormones and histopathology were studied. OTA was quantified (HPLC-FLD) in plasma, kidney and liver and the expression of kidney transporters (RT-qPCR) was studied. After 7 days, kidney histopathology showed more pronounced signs of toxicity in males than in females. After 21 days, a higher toxicity was observed but sex differences disappeared. OTA concentration in plasma and tissues was similar in both sexes. Downregulation was the general OTA-induced effect. Oats' downregulation was slow in males and Oat3 did not change in females. Oatp1 was strongly downregulated in males after 21 days. An opposite effect was observed in Bcrp after 21 days: downregulation in males and upregulation in females. Females showed a dose- and time-dependent decrease of progesterone. Despite the sex differences, the final balance in OTA toxicokinetics at renal cell level does not seem to support a higher accumulation of OTA in male kidneys.
Autores: Quiliano, M.; Pabon, A.; Moles, E. ; et al.
ISSN 0223-5234  Vol. 152  2018  págs. 489 - 514
Design, synthesis, structure-activity relationship, cytotoxicity studies, in silico drug-likeness, genotoxicity screening, and in vivo studies of new 1-aryl-3-substituted propanol derivatives led to the identification of nine compounds with promising in vitro (55, 56, 61, 64, 66, and 70-73) and in vivo (66 and 72) antimalarial profiles against Plasmodium falciparum and Plasmodium berghei. Compounds 55, 56, 61, 64, 66 and 70-73 exhibited potent antiplasmodial activity against chloroquine-resistant strain FCR-3 (IC(50)s <0.28 mu M), and compounds 55, 56, 64, 70, 71, and 72 showed potent biological activity in chloroquine-sensitive and multidrug-resistant strains (IC(50)s < 0.7 mu M for 3D7, D6, FCR-3 and C235). All of these compounds share appropriate drug-likeness profiles and adequate selectivity indexes (77 < SI < 184) as well as lack genotoxicity. In vivo efficacy tests in a mouse model showed compounds 66 and 72 to be promising candidates as they exhibited significant parasitemia reductions of 96.4% and 80.4%, respectively. Additional studies such as liver stage and sporogony inhibition, target exploration of heat shock protein 90 of P. falciparum, targeted delivery by immunoliposomes, and enantiomer characterization were performed and strongly reinforce the hypothesis of 1-aryl-3-substituted propanol derivatives as promising antimalarial compounds. (C) 2018 Elsevier Masson SAS. All rights reserved.
Autores: Bonilla-Ramirez, L.; Rios, A.; Quiliano, M.; et al.
ISSN 0223-5234  Vol. 158  2018  págs. 68 - 81
Emergence of drug resistance and targeting all stages of the parasite life cycle are currently the major challenges in antimalarial chemotherapy. Molecular hybridization combining two scaffolds in a single molecule is an innovative strategy for achieving these goals. In this work, a series of novel quinoxaline 1,4-di-N-oxide hybrids containing either chloroquine or primaquine pharmacophores was designed, synthesized and tested against both chloroquine sensitive and multidrug resistant strains of Plasmodium falciparum. Only chloroquine-based compounds exhibited potent blood stage activity with compounds 4b and 4e being the most active and selective hybrids at this parasite stage. Based on their intraerythrocytic activity and selectivity or their chemical nature, seven hybrids were then evaluated against the liver stage of Plasmodium yoelii, Plasmodium berghei and Plasmodium falciparum infections. Compound 4b was the only chloroquine-quinoxaline 1,4-di-N-oxide hybrid with a moderate liver activity, whereas compound 6a and 6b were identified as the most active primaquine-based hybrids against exoerythrocytic stages, displaying enhanced liver activity against P. yoelii and P. berghei, respectively, and better SI values than primaquine. Although both primaquine-quinoxaline 1,4-di-N-oxide hybrids slightly reduced the infection of mosquitoes, they inhibited sporogony of P. berghei and compound 6a showed 92% blocking of transmission. In vivo liver efficacy assays revealed that compound 6a showed causal prophylactic activity affording parasitaemia reduction of up to 95% on day 4. Absence of genotoxicity and in vivo acute toxicity were also determined. These results suggest the approach of primaquine-quinoxaline 1,4-di-N-oxide hybrids as new potential dual-acting antimalarials for further investigation.
Autores: Enciso, J. M.; Gutzkow, K. B.; Brunborg, G.; et al.
ISSN 0267-8357  Vol. 33  Nº 1  2018  págs. 25-30
The alkaline comet assay, in vivo and in vitro, is currently used in several areas of research and in regulatory genotoxicity testing. Several efforts have been made in order to decrease the inter-experimental and inter-laboratory variability and increase the reliability of the assay. In this regard, lysis conditions are considered as one of the critical variables and need to be further studied. Here, we tested different times of lysis (from no lysis to 1 week) and two different lysis solutions in human lymphoblast (TK6) cells unexposed or exposed to X-rays. Similar % tail DNA values were obtained independently of the time of lysis employed for every X-ray dose tested and both lysis solutions. These results, taken together with our previous ones with methyl methanesulfonate and H2O2, which showed clear lysis-time dependence, support that the influence of the lysis time in the comet assay results depends on the type of lesion being detected; some DNA lesions may spontaneously give rise to apurinic or apyrimidinic (AP) sites during the lysis period, which can be converted into strand breaks detectable with the comet assay. Testing different times of lysis would be useful to increase the sensitivity of the comet assay and to ensure the detection of DNA lesions of an unknown compound, thereby providing some insight into the chemical nature of the lesions induced. However, the same lysis conditions (i.e. lysis time and lysis solution) should be used when comparing results between different experiments or laboratories.
Autores: Enciso, J. M.; de Cerain, A.L.; et al.
ISSN 0278-6915  Vol. 116  2018  págs. 379 - 387
Ochratoxin A (OTA) is a mycotoxin considered the most powerful renal carcinogen in rodents and classified as a possible human carcinogen. Though its mechanism of action is still unknown, indirect DNA reactivity mediated by oxidative stress has been hypothesized to play an important role. Moreover, large sex-differences have been observed in carcinogenicity studies, male rats being more sensitive than females. Male and female F344 rats were administered (p.o.) with bicarbonate or 0.5 mg OTA/kg b.w. for 7 days; or with bicarbonate, 0.21 or 0.5 mg OTA/kg b.w. for 21 days. Total glutathione (tGSH) and oxidized glutathione (GSSG) levels, glutathione S.transferase (GST) and superoxide dismutase (SOD) activities were analysed in kidneys. The standard alkaline comet assay was used in combination with Formamidopyrimidine-DNA glycosylase (Fpg) to detect oxidized DNA bases in kidney. No biologically relevant sex-differences were observed in all the oxidative-stress related parameters analysed. Indeed, no relevant oxidative-stress related response was observed between treated animals and controls. In accordance with the similar OTA levels and histopathological changes between both sexes observed previously in the same animals, and with other oxidative-stress related parameters measured by others, results support that there are no differences between sexes in the oxidative stress response to OTA.
Autores: Gil, Ana Gloria; Irache, Juan M.; Peñuelas, Iván; et al.
ISSN 0278-6915  Vol. 106  2017  págs. 477 - 486
In the last years, casein nanoparticles have been proposed as carriers for the oral delivery of biologically active compounds. However, till now, no information about their possible specific hazards in vivo was available. The aim of this work was to assess the safety of casein nanoparticles when administered orally to animals through a 90 days dose-repeated toxicity study (OECD guideline 408), that was performed in Wistar rats under GLP conditions. After 90 days, no evidences of significant alterations in animals treated daily with 50,150 or 500 mg/kg bw of nanoparticles were found. This safety agrees well with the fact that nanoparticles were not absorbed and remained within the gut as observed by radiolabelling in the biodistribution study. After 28 days, there was a generalized hyperchloremia in males and females treated with the highest dose of 500 mg/kg bw, that was coupled with hypernatremia in the females. These effects were related to the presence of mannitol which was used as excipient in the formulation of casein nanoparticles. According to these results, the No Observed Adverse Effect Level (NOAEL) could be established in 150 mg/kg bw/day and the Lowest Observed Effect Level (LOEL) could be established in 500 mg/kg bw/day. (C) 2017 Published by Elsevier Ltd.
Autores: Pastor, Y.; Camacho, Ana Isabel; Gil, Ana Gloria; et al.
ISSN 0022-2615  Vol. 66  Nº 7  2017  págs. 946 - 958
Purpose. The aim of this study was to develop an immunogenic protective product against Shigella flexneri by employing a simple and safe heat treatment-based strategy. Methodology. The physicochemical characteristics of naturally produced (OMV) and heat-induced (HT) outer-membrane vesicles from S. flexneri were examined, including a comparison of the protein content of the products. Toxicological and biodistribution studies, and a preliminary experiment to examine the protective effectiveness of HT in a murine model of S. flexneri infection, were also included. Results. This method simultaneously achieves complete bacterial inactivation and the production of the HT vaccine product, leading to a safe working process. The obtained HT complex presented a similar morphology (electron microscopy) and chemical composition to the classical OMV, although it was enriched in some immunogens, such as lipoproteins, OmpA or OmpC, among others. The HT formulation was not toxic and biodistribution studies performed in mice demonstrated that the vaccine product remained in the small intestine after nasal administration. Finally, a single dose of HT administered nasally was able to protect mice against S. flexneri 2a. Conclusion. The convenient and safe manufacturing process, and the preliminary biological evaluation, support the use of the self-adjuvanted HT complex as a new vaccine candidate to face shigellosis. Further development is required, such as additional immune analyses, to evaluate whether this new subunit vaccine can be useful in achieving full protection against Shigella.
Autores: Iglesias, Tamara; Dusinska, M.; El Yamani, N.; et al.
ISSN 0378-5173  Vol. 523  Nº 1  2017  págs. 418 - 426
In the last years, the development of nanomaterials has significantly increased due to the immense variety of potential applications in technological sectors, such as medicine, pharmacy and food safety. Focusing on the nanodevices for oral drug delivery, poly(anhydride) nanoparticles have received extensive attention due to their unique properties, such as their capability to develop intense adhesive interactions within the gut mucosa, their modifiable surface and their biodegradable and easy-to produce profile. However, current knowledge of the possible adverse health effects as well as, toxicological information, is still exceedingly limited. Thus, we investigated the capacity of two poly(anhydride) nanoparticles, Gantrez (R) AN 119 -NP (GN-NP) and Gantrez (R) AN 119 covered with mannosamine (GN-MA-NP), and their main bulk material (Gantrez (R) AN 119-Polymer), to induce DNA damage and thymidine kinase (TK+/-) mutations in L5178Y TK+/- mouse lymphoma cells after 24 h of exposure. The results showed that GN-NP, GN-MA-NP and their polymer did not induce DNA strand breaks or oxidative damage at concentrations ranging from 7.4 to 600 mu g/mL. Besides, the mutagenic potential of these nanoparticles and their polymer revealed no significant or biologically relevant gene mutation induction at concentrations up to 600 mu g/mL under our experimental settings. Considering the non-genotoxic effects of GN-NP and GN-MA-NP, as well as their exceptional properties, these nanoparticles are promising nanocarriers for oral medical administrations. (C) 2017 Elsevier B.V. All rights reserved.
Autores: Iglesias, Tamara; de Cerain, A.L.; Irache, Juan M.; et al.
ISSN 0378-5173  Vol. 517  Nº 1 - 2  2017  págs. 67 - 79
he main concerns with drugs designed for oral administration are their inactivation or degradation in the harsh conditions of the gastrointestinal tract, their poor solubility through the gastrointestinal mucus gel layer, the poor intestinal epithelium permeability that limits their absorption, and their toxicity. In this context, poly(anhydride) nanoparticles are capable of protecting the drug from the harsh environment, reduce the drug's toxicity and, by virtue of surface modification, to enhance or reduce their mucus permeability and the bioadhesion to specific target cells. The copolymer between methyl vinyl ether and maleic anhydride (commercialized as Gantrez® AN 119) are part of the poly(anhydride) nanoparticles. These biocompatible and biodegradable nanoparticles (NPs) can be modified by using different ligands. Their usefulness as drug carriers and their bioadhesion with components of the intestinal mucosa have been described. However, their toxicity, genotoxicity and mucus permeation capacity has not been thoroughly studied. The aim of this work was to evaluate and compare the in vitro toxicity, cell viability and in vitro genotoxicity of the bioadhesive empty Gantrez® AN 119 NPs modified with dextran, aminodextran, 2-hydroxypropyl-ß-cyclodextrin, mannosamine and poly-ethylene glycol of different molecular weights. Results showed that, in general, coated NPs exhibit better mucus permeability than the bare ones, those coated with mannosamine being the most permeable ones. The NPs studied did not affect cell metabolism, membrane integrity or viability of Caco-2 cells at the different conditions tested. Moreover, they did not induce a relevant level of DNA strand breaks and FPG-sensitive sites (as detected with the comet assay).
Autores: Vettorazzi, Ariane Renata; de Cerain, A.L.;
ISSN 0378-4274  Vol. 280  Nº Supl. 1  2017  págs. S88 - S88
Autores: Moreno-Viguri, Elsa; Jiménez-Montes, C.; Martín-Escolano, R.; et al.
ISSN 0022-2623  Vol. 59  Nº 24  2016  págs. 10929 - 10945
Chagas disease is a neglected tropical disease with 6-7 million people infected worldwide, and there is no effective treatment. Therefore, there is an urgent need to continue researching in order to discover novel therapeutic alternatives. We present a series of arylaminoketone derivatives as means of identifying new drugs to treat Chagas disease in the acute phase with greater activity, less toxicity, and a larger spectrum of action than that corresponding to the reference drug benznidazole. Indexes of high selectivity found in vitro formed the basis for later in vivo assays in BALB/c mice. Murine model results show that compounds 3, 4, 7, and 10 induced a remarkable decrease in parasitemia levels in acute phase and the parasitemia reactivation following immunosuppression, and curative rates were higher than with benznidazole. These high antiparasitic activities encourage us to propose these compounds as promising molecules for developing an easy to synthesize anti-Chagas agent.
Autores: Quiliano, M.; Fong, K. Y.; et al.
ISSN 2211-3207  Vol. 6  Nº 3  2016  págs. 184 - 198
Synthesis of new 1-aryl-3-substituted propanol derivatives followed by structure-activity relationship, in silico drug-likeness, cytotoxicity, genotoxicity, in silico metabolism, in silico pharmacophore modeling, and in vivo studies led to the identification of compounds 22 and 23 with significant in vitro anti-plasmodial activity against drug sensitive (D6 IC50 <= 0.19 mu M) and multidrug resistant (FCR-3 IC50 <= 0.40 mu M and C235 IC50 <= 0.28 mu M) strains of Plasmodium falciparum. Adequate selectivity index and absence of genotoxicity was also observed. Notably, compound 22 displays excellent parasitemia reduction (98 +/- 1%), and complete cure with all treated mice surviving through the entire period with no signs of toxicity. One important factor is the agreement between in vitro potency and in vivo studies. Target exploration was performed; this chemotype series exhibits an alternative antimalarial mechanism. (C) 2016 The Authors. Published by Elsevier Ltd on behalf of Australian Society for Parasitology.
Autores: Vettorazzi, Ariane Renata; Campión, Francisco Javier; et al.
ISSN 0278-6915  Vol. 98  2016  págs. 169 - 178
Ochratoxin A (OTA) is a mycotoxin that contaminates foodstuffs. The most relevant concern is its high kidney carcinogenicity in male rats and its unclear mechanism of action. It has been hypothesized that variations in transport mechanisms in kidney cells may be the reason of different sex-dependent sensitivities towards OTA. The aim of this study was to analyze, by RT-qPCR, renal transporters expression in 15-week-old male (M) and female (F) F344 rats at basal level and after single oral OTA administration (0.50 mg/kg bw). Temporal profiles (24h, 48h, 72h, 96h, 1 and 2 months) were studied per sex and transporter. The reference gene for all comparisons was Ppia. At basal level, sex differences were confirmed for Oatp1, Bcrp (M>F) and Oat2 (F>M). OTA tended to inhibit the expression of almost all transporters in both sexes, but clearly induced the expression of Oat2 in males. Regarding time profiles, the highest sex differences involved Oat (Slc22) transporters: Oat2, Oat3 and Oat5 expression showed a significant increase in males (24h) while Oat1, Oat2 and Oat5 level decreased in females (48h). Overall, basal sex differences in F344 rats and the specific sex-dependent response to OTA of Oat2 might contribute to high kidney damage in male rats. (C) 2016 Elsevier Ltd. All rights reserved.
Autores: Bengoetxea, Xabier; de Cerain, A.L.; Azqueta, A; et al.
ISSN 1387-2877  Vol. 54  Nº 3  2016  págs. 1085 - 1094
Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by the presence of aggregates of the amyloid-ß peptide (Aß) that are believed to be neurotoxic. One of the purposed damaging mechanisms of Aß is oxidative insult, which eventually could damage the cellular genome. Stress and associated increases in glucocorticoids (GCs) have been described as a risk factor for the development of AD, although the purported genotoxic effects of GCs have not been fully characterized. Therefore, it is possible to speculate about purported synergistic effects of GCs on the Aß-driven genotoxic damage. This in vitro study addresses the single and combined cyto/genotoxic effects of Aß and GCs in SH-SY5Y cells. Cytotoxicity was determined by the MTT assay, and the genotoxic effects were studied using the comet assay. A comet assay derivation allows for measuring the presence of the FPG-sensitive sites (mainly 8-oxoguanines) in the DNA, apart from the DNA strand breaks. Treatment with Aß (10 ¿M, 72¿h) induced cytotoxicity (35% decrease in cell viability) and DNA strand breaks, but had no significant effect on oxidative DNA damage (FPG sites). Corticosterone showed no effect on cell viability, genotoxicity, or reparation processes. Corticosterone was unable to neither reverse nor potentiate Aß driven effects. The present results suggest the existence of alternative mechanisms for the Aß driven damage, not involving oxidative damage of DNA. In addition, could be suggested that the interaction between Aß and GCs in AD does not seem to involve DNA damage.
Autores: Gadea, J. E., (Autor de correspondencia); Azqueta, A; et al.
ISSN 0378-4274  Vol. 258  Nº Supl.  2016  págs. S247 - S247
Autores: Iglesias, Tamara; El Yamani, N.; Dusinska, M. ; et al.
ISSN 0378-4274  Vol. 258  Nº Supl.  2016  págs. S270 - S270
Autores: Lizarraga, Elena; de Cerain, A.L.; et al.
ISSN 0956-7135  Vol. 53  2015  págs. 163 - 176
Mycotoxins can cause toxicity when ingested by humans and animals. Although the rumen is supposed to be a barrier against mycotoxins, some studies demonstrate that carry-over of mycotoxins to milk is possible. Different studies have found mycotoxin levels in animal milk, mainly related to contaminated feed for ruminants. Aflatoxin M1 is the most studied mycotoxin in milk and levels exceeding the EU maximum level for this mycotoxin in this matrix (0.050 mu g/kg) have been found. Maximum levels in milk for other mycotoxins have not been established; however ochratoxin A, aflatoxins G1, G2, B1, B2 and M2, fumonisin B1, cyclopiazonic acid, zearalenone and its metabolites and deepoxy-deoxynivalenol have also been found in milk samples. Taking into account that multi-exposure to mycotoxins is the most likely scenario and co-occurrence of mycotoxins could affect their toxicological effects in humans and animals, there is a need to determine the co-occurrence of mycotoxins in milk.
Autores: Iglesias, Tamara; Azqueta, A; et al.
ISSN 0939-6411  Vol. 97  Nº A  2015  págs. 206 - 217
Oral administration is the most commonly used and accepted route for drug administration. However, two of the main concerns are the poor intestinal epithelium permeability and rapid degradation, which limit absorption of drugs. In this context, nanocarriers have shown great potential for oral drug delivery. Nevertheless, special importance should be given to the possible toxic effect of these nanocarriers, such as their bioaccumulation in different tissues of the body, as well as, the different physicochemical parameters influencing their properties and so their potential toxic effect. This review describes first some aspects related to the behavior of nanosystems within the gastrointestinal tract and then some aspects of nanotoxicology and its evaluation, including the most popular techniques and approaches used for in vitro and in vivo toxicity studies. It also reviews the physicochemical characteristics of polymeric nanoparticles that may influence the development of toxicological effects, and finally it summarizes the toxicity results that have been published regarding polymeric nanocarriers.
Autores: Enciso, J. M.; Sánchez, O.; de Cerain, A.L.; et al.
ISSN 0267-8357  Vol. 30  Nº 1  2015  págs. 21 - 28
The alkaline comet assay is now the method of choice for measuring different kinds of DNA damage in cells. Several attempts have been made to identify and evaluate the critical points affecting the comet assay outcome, highlighting the requirement of arriving at a standardised protocol in order to be able to compare the results obtained in different laboratories. However, reports on the effect of modifying the time of lysis are lacking. Here we tested different times of lysis (from no lysis to 1 week) in control HeLa cells and HeLa cells treated with different concentrations of methyl methanesulfonate (MMS) or H2O2. We also tested different times of lysis in the comet assay combined with formamidopyrimidine DNA glycosylase (FPG) in untreated and Ro 19-8022 plus light-treated HeLa cells. The same DNA damage levels were detected in the absence of lysis or after 1h of lysis when the standard comet assay was used to detect the MMS- and H2O2-induced lesions; the response increased when longer lysis was used, up to at least 1 week. When FPG was used, a minimum lysis period of 5 min was necessary to allow the enzyme to reach the DNA; the same DNA damage levels were detected after 5 min or 1h of lysis and the response increased up to 24h. In conclusion, the time of lysis can be varied depending on the sensitivity needed in both versions of the assay, and a constant time of lysis should be used if results from different experiments or laboratories are to be compared.
Autores: Ibero, Idoya; Azqueta, A; de Cerain, A.L.; et al.
ISSN 0267-8357  Vol. 30  Nº 1  2015  págs. 139 - 146
Nutrient excess and unbalanced diets can result in overproduction of reactive oxygen species (ROS), which are associated with oxidative stress. Cocoa extract contains antioxidants that inhibit the harmful effects of ROS. This trial analysed the effect of cocoa extract consumption integrated as a bioactive compound into ready-to-eat meals, on oxidative stress at the level of DNA in overweight/obese subjects. Fifty volunteers [57.26(5.24) years, 30.59(2.33)kg/m(2)] participated in a 4-week double-blind, randomised, placebo-controlled parallel nutritional intervention. Half of the volunteers received meals supplemented with 1.4 g/day cocoa extract, while the other half received control meals, both within a 15% energy restriction diet. Lymphocytes were isolated and endogenous strand breaks, oxidised bases and resistance to H2O2-induced damage were measured by the comet assay. The intake of ready-to-eat meals supplemented with cocoa extract did not show relevant changes in the oxidative status of DNA. However, in the cocoa group, oxidised bases negatively correlated with methyl epicatechin-O-sulphate (r = -0.76; P = -0.007) and epicatechin sulphate (r = -0.61; P = -0.046). When volunteers of both groups were analysed together, a marginal decrease (P = 0.072) in oxidised bases was observed, which attributed to weight loss. Subjects who started the intervention with higher levels of damage showed a greater reduction in oxidised bases after 4 weeks (P = 0.040) compared to those who had lower baseline levels. In conclusion, even if 1.4 g of cocoa supplementation for 4 weeks did not show notable changes in terms of antioxidant status of DNA, the energy restriction showed a slightly decrease in oxidised bases and this was seen to a greater extent in subjects who started the intervention with higher levels of damage. On the other hand, the inverse associations found between oxidised bases and some cocoa-derived metabolites suggest that a protective effect might be seen in a longer period of time or in subjects with higher baseline DNA damage.
Autores: Vettorazzi, Ariane Renata; Arbillaga, L; et al.
ISSN 0278-6915  Vol. 76  2015  págs. 116 - 124
Aflatoxin B1 (AFB1) and Ochratoxin A (OTA) are genotoxic mycotoxins that can contaminate a variety of foodstuffs, the liver and the kidney being their target organs, respectively. The micronucleus (MN) assay (bone marrow) and the comet assay (liver and kidney) were performed simultaneously in F344 rats, treated with AFB1 (0.25 mg/kg b.w.), OTA (0.5 mg/kg b.w.) or both mycotoxins. After AFB1 treatment, histopathology and biochemistry analysis showed liver necrosis, focal inflammation and an increase in Alanine Aminotransferase and Aspartate Aminotransferase. OTA alone did not cause any alteration. The acute hepatotmdc effects caused by AFB1 were less pronounced in animals treated with both mycotoxins. With regard to the MN assay, after 24 h, positive results were obtained for AFB1 and negative results were obtained for OTA, although both toxins caused bone marrow toxicity. In the combined treatment, OTA reduced the toxicity and the number of MN produced by AFB1. In the comet assay, after 3 h, positive results were obtained for AFB1 in the liver and for OTA in the kidney. The combined treatment reduced DNA damage in the liver and had no influence in the kidney. Altogether, these results may be indicative of an antagonistic relationship regarding the genotoxicity of both mycotoxins
Autores: Gil, Ana Gloria; Arbillaga, L; de Cerain, A.L.;
ISSN 0963-7486  Vol. 66  Nº Supl. 1  2015  págs. S13 - S21
The growing presence of products on the market with added value in terms of health makes essential their regulation and harmonization in critical aspects such as safety. The toxicology applied to the bioactive compounds should demonstrate the absence of toxic effects at doses advised for consumption, as well as evaluate the potential toxic effects in the assumption that the products are used in quantities superior to those recommended. The specific strategy should be defined case by case; therefore, prior to any toxicological development, it is essential to study all the information regarding the bioactive compounds (BACs) characterization, nutridynamics and nutrikinetics, that is available. In this guideline, a general strategy to be applied in the development of BACs is proposed. It includes a first in vitro phase to discard genotoxicity and endocrine effects and a second in vivo phase with different possibilities regarding the duration and the extension of the studies.
Autores: Vettorazzi, Ariane Renata; González-Peñas, E.; de Cerain, A.L.;
ISSN 0278-6915  Vol. 72  2014  págs. 273 - 288
Ochratoxin A (OTA) is a thermostable mycotoxin that contaminates a great variety of foodstuffs. It is nephrotoxic in all of the mammalian species tested, being the pig the most sensitive one; among rodents, rats are the most susceptible to OTA carcinogenicity. Kinetics, by studying the absorption, distribution, metabolism and excretion of xenobiotics, is an important tool for the extrapolation of animal toxicity data. The most important kinetic studies performed with OTA in rats have been reviewed, together with the different methods used for OTA quantification in biological matrices. Thirteen studies in Wistar, Sprague-Dawley or F344 rats, using radiolabeled OTA or TLC, HPLC-FLD or HPLC-MS have been summarized. Very often methods validated for food have been directly applied to tissues. Strain, sex and age differences have been detected but the interpretation is difficult due to the different experimental conditions, and the connection of the several factors that may account for these differences.
Autores: Godschalk, R.W.L.; Ersson, C.; Stepnik, M.; et al.
ISSN 0267-8357  Vol. 29  Nº 4  2014  págs. 241 - 249
This study investigated the levels of DNA strand breaks and formamidopyrimidine DNA glycosylase (FPG) sensitive sites, as assessed by the comet assay, in peripheral blood mononuclear cells (PBMC) from healthy women from five different countries in Europe. The laboratory in each country (referred to as 'centre') collected and cryopreserved PBMC samples from three donors, using a standardised cell isolation protocol. The samples were analysed in 13 different laboratories for DNA damage, which is measured by the comet assay. The study aim was to assess variation in DNA damage in PBMC samples that were collected in the same way and processed using the same blood isolation procedure. The inter-laboratory variation was the prominent contributor to the overall variation. The inter-laboratory coefficient of variation decreased for both DNA strand breaks (from 68 to 26%) and FPG sensitive sites (from 57 to 12%) by standardisation of the primary comet assay endpoint with calibration curve samples. The level of DNA strand breaks in the samples from two of the centres (0.56-0.61 lesions/10(6) bp) was significantly higher compared with the other three centres (0.41-0.45 lesions/10(6) bp). In contrast, there was no difference between the levels of FPG sensitive sites in PBMC samples from healthy donors in the different centres (0.41-0.52 lesion/10(6) bp).
Autores: Godschalk, R. W.; Ersson, C.; Stepnik, M.; et al.
ISSN 0267-8357  Vol. 29  Nº 4  2014  págs. 241 - 249
This study investigated the levels of DNA strand breaks and formamidopyrimidine DNA glycosylase (FPG) sensitive sites, as assessed by the comet assay, in peripheral blood mononuclear cells (PBMC) from healthy women from five different countries in Europe. The laboratory in each country (referred to as 'centre') collected and cryopreserved PBMC samples from three donors, using a standardised cell isolation protocol. The samples were analysed in 13 different laboratories for DNA damage, which is measured by the comet assay. The study aim was to assess variation in DNA damage in PBMC samples that were collected in the same way and processed using the same blood isolation procedure. The inter-laboratory variation was the prominent contributor to the overall variation. The inter-laboratory coefficient of variation decreased for both DNA strand breaks (from 68 to 26%) and FPG sensitive sites (from 57 to 12%) by standardisation of the primary comet assay endpoint with calibration curve samples. The level of DNA strand breaks in the samples from two of the centres (0.56-0.61 lesions/10(6) bp) was significantly higher compared with the other three centres (0.41-0.45 lesions/10(6) bp). In contrast, there was no difference between the levels of FPG sensitive sites in PBMC samples from healthy donors in the different centres (0.41-0.52 lesion/10(6) bp).
Autores: Forchhammer, L.; Ersson, E.; Loft, S.; et al.
ISSN 0267-8357  Vol. 28  Nº 2  2013  págs. 241
Correction to Forchhammer et al. 27 (6): 665
Autores: Vettorazzi, Ariane Renata; van-Delft, J.; de Cerain, A.L.;
ISSN 0278-6915  Vol. 59  2013  págs. 766 - 783
The mycotoxin Ochratoxin A (OTA) is a potent renal carcinogen in male rats. Transcriptomic studies on OTA (4 in vitro, 6 in vivo, 2 in vitro/in vivo) have been reviewed. The aim of 6 of them was mainly mechanistic whereas the rest had mostly predictive (1) or evaluation (5) purposes. An overall tendency towards gene expression downregulation was observed, probably as a result of protein synthesis inhibition. DNA damage response genes were not deregulated in most of the studies. Genes involved in acute renal injury, cell survival and cell proliferation were upregulated in several in vivo studies. Apoptosis genes were deregulated in vitro but less affected in vivo; activation of several MAPKs has been observed. Many genes related to oxidative stress or involved in cell-to-cell interaction pathways (Wnt) or cytoskeleton structure appeared to be deregulated either in vitro or in vivo. Regucalcin was highly downregulated in vivo and other calcium homeostasis genes were significantly deregulated in vitro. Genes related to OTA transport (OATs) and metabolism (CYPs) appeared downregulated in vivo. Overall, the mechanism of action of OTA remains unclear, however transcriptomic data have contributed to new mechanistic hypothesis generation and to in vitro-in vivo comparison.
Autores: Arbillaga, L; et al.
ISSN 1757-6180  Vol. 5  Nº 3  2013  págs. 289 - 305
Background: IFN-alpha 5 has been demonstrated to induce stronger signaling and higher expression of antiviral genes than IFN-alpha 2, which is the current treatment in chronic viral hepatitis. However, there is no specific and validated quantification method in order to conduct kinetic studies as part of the preclinical and clinical evaluation for regulatory purposes. Results: A novel integration of an antiviral assay against the cytopathic effect of the encephalomyocarditis virus in HeLa cells with a very sensitive method for assay processing - the Vialight (R) Plus assay - is presented for IFN-alpha 5 activity quantification. The bioassay has been validated in macaque and human serum and it has been demonstrated to be selective, precise and accurate. Conclusion: The validated bioassay meets suitable acceptance criteria for these types of biological assays.
Autores: Azqueta, A; Arbillaga, L; de Cerain, A.L.; et al.
ISSN 0267-8357  Vol. 28  Nº 3  2013  págs. 271 - 277
The alkaline comet assay, when employed as a genotoxicity test, has relatively low sensitivity because it fails to detectuat non-cytotoxic concentrationsuknown genotoxins that do not induce breaks or alkali-labile sites. We demonstrate that this limitation is overcome by incorporating in the assay the DNA repair enzyme formamidopyrimidine DNA glycosylase (FPG) to convert damaged bases to breaks. We tested 11 chemicals in human TK-6 cells: three non-cytotoxicud-mannitol, Tris and EDTA; two cytotoxicuTriton X-100 and fluometuron; and six genotoxicumethylmethanesulphonate (MMS), methylnitrosourea (MNU), cyclophosphamide, benzo(a)pyrene, 4-nitroquinoline-1-oxide (4NQO) and etoposide. At concentrations of MMS, MNU, benzo(a)pyrene or 4NQO causing little or no cytotoxicity and few if any DNA breaks, FPG substantially enhanced the cellular response. Etoposide increased breaks but not FPG-sensitive sites. Cyclophosphamide, a DNA cross linker, gave a response without FPG at 1 M, but there was no increase with FPG. Triton X-100-induced breaks were secondary to cytotoxicity. The remaining compounds induced no damage. Thus, FPG enhances sensitivity of the comet assay without compromising selectivity.
Autores: Irigoyen, Ángel María; González-Peñas, E.; et al.
ISSN 0956-7135  Vol. 32  Nº 1  2013  págs. 63 - 68
The co-occurrence of ochratoxin A (OTA) and its five analogs (OTB, OTC, MeOTA, MeOTB and EtOTB) in 96 red wine samples from Mediterranean countries has been demonstrated, for the first time, in this study. OTA was detected in 99% of the samples (<LOD - 455 ng L-1). This mycotoxin appeared simultaneously with OTB (2.05-119 ng L-1) in all the samples and in 89.6% of them OTC (<LOD - 31.5 ng L-1) also accompanied both. OTB appears at comparable levels and incidence just like OTA does, and OTC median concentration is approximately 10% of that of OTA. A high statistical association was found between the concentrations of OTA OTB and OTA OTC. MeOTA, MeOTB and EtOTB were detected in 62.5, 83.3 and 83.3% of the samples, respectively. In 44.8% of the wines, the 6 ochratoxins appeared simultaneously. There was no evidence for ochratoxin A levels being greater in wines from Southern Europe than those described from North Europe. Samples from North Africa presented statistically the highest values for OTA, OTB, OTC and EtOTB.
Autores: Neutsch, L.; Gabor, F.; et al.
ISSN 1550-7033  Vol. 9  Nº 11  2013  págs. 1891 - 1903
The use of bioadhesive polymers as nanodevices has emerged as a promising strategy for oral delivery of therapeutics. In this regard, poly(anhydride) nanoparticles have shown great potential for oral drug delivery and vaccine purposes. However, despite extensive research into the biomedical and pharmaceutical applications of poly(anhydride) nanoparticles, there are no studies to evaluate the interaction of these nanoparticles at a cellular level. Therefore, the main objectives of this study were to evaluate the cytotoxicity as well as the cell interaction of different poly(anhydride) nanoparticles: conventional (NP), nanoparticles containing 2-hydroxypropyl-beta-cyclodextrin (NP-HPCD) and nanoparticles coated with poly(ethylene glycol) 6000 (PEG-NP). For this purpose, nanoparticles were prepared by solvent displacement method and labelled with BSA-FITC. Nanoparticles displayed a size about 175 nm with negative surface charge. Cytotoxicity studies were developed by MTS and LDH assays in HepG2 and Caco-2 cells. Results showed that only in HepG2 cells, NP and NP-HPCD induced significant cytotoxicity at the highest concentrations (1 and 2 mg/mL) and incubation times (48 and 72 h) tested. Studies to discriminate between cytoadhesion and cytoinvasion were performed at 4 degrees C and 37 degrees C in Caco-2 cell line as intestinal cell model. Nanoparticles showed cytoadhesion to the cell surface but not internalization; PEG-NP was the most bioadhesive followed by NP-HPCD and NP as demonstrated by flow cytometry. Finally, cellular localization of particles by fluorescence confocal microscopy confirmed the association of these nanoparticles with cells. Thus, this study demonstrated the safety of NP, NP-HPCD and PEG-NP at cellular level and its bioadhesive properties within cells.
Autores: Ersson, C.; Moller, P.; Forchhammer, L.; et al.
ISSN 0267-8357  Vol. 28  Nº 3  2013  págs. 279 - 286
The alkaline comet assay is an established, sensitive method extensively used in biomonitoring studies. This method can be modified to measure a range of different types of DNA damage. However, considerable differences in the protocols used by different research groups affect the inter-laboratory comparisons of results. The aim of this study was to assess the inter-laboratory, intra-laboratory, sample and residual (unexplained) variations in DNA strand breaks and formamidopyrimidine DNA glycosylase (FPG)-sensitive sites measured by the comet assay by using a balanced Latin square design. Fourteen participating laboratories used their own comet assay protocols to measure the level of DNA strand breaks and FPG-sensitive sites in coded samples containing peripheral blood mononuclear cells (PBMC) and the level of DNA strand breaks in coded calibration curve samples (cells exposed to different doses of ionising radiation) on three different days of analysis. Eleven laboratories found doseresponse relationships in the coded calibration curve samples on two or three days of analysis, whereas three laboratories had technical problems in their assay. In the coded calibration curve samples, the dose of ionising radiation, inter-laboratory variation, intra-laboratory variation and residual variation contributed to 60.9, 19.4, 0.1 and 19.5%, respectively, of the total variation. In the coded PBMC samples, the inter-laboratory variation explained the largest fraction of the overall variation of DNA strand breaks (79.2%) and the residual variation (19.9%) was much larger than the intra-laboratory (0.3%) and inter-subject (0.5%) variation. The same partitioning of the overall variation of FPG-sensitive sites in the PBMC samples indicated that the inter-laboratory variation was the strongest contributor (56.7%), whereas the residual (42.9%), intra-laboratory (0.2%) and inter-subject (0.3%) variations again contributed less to the overall variation. The results suggest that the variation in DNA damage, measured by comet assay, in PBMC from healthy subjects is assay variation rather than variation between subjects.
Autores: Gonda, M.; Marcos, N.; Nunes, E.; et al.
ISSN 2040-2503  Vol. 4  Nº 3  2013  págs. 595 - 607
Phenazine-5,10-dioxides have been identified as prodrugs for antitumour therapy that undergo hypoxic-selective bioreduction, in the solid tumour cells, to form cytotoxic species. We investigated structural modifications of the phenazine-5,10-dioxide scaffold attempting to find new selective hypoxic cytotoxins with additional ability to inhibit DNA topoisomerase II. Four series of new phenazine-5,10-dioxides aryl-substituted connected by different linkers were prepared. The clonogenic survivals of V79 cells on aerobic and anaerobic conditions were determined, and studies of oxic DNA-interaction and hypoxic DNA topoisomerase II-inhibition, for the most relevant derivatives, were performed. Four new hypoxic-selective cytotoxins were identified at the assayed doses. In some of them were operative the DNA-interaction and/or the inhibition of DNA topoisomerase II. For one of the unselective cytotoxin biotransformation studies were performed on aerobic and anaerobic conditions, explaining the lack of selectivity.
Autores: Schorr-Galindo, S.; et al.
ISSN 0956-7135  Vol. 26  Nº 2  2012  págs. 259 - 268
Ochratoxin A (OTA) is a secondary metabolite produced by filamentous fungi of the genera Aspergillus and Penicillium present in a wide variety of foodstuffs. The most relevant OTA-producing species are Penicillium verrucosum (P. verrucosum), Aspergillus ochraceus (A. ochraceus), Aspergillus niger and Aspergillus carbonarius due to their prevalence in foodstuffs (cereals, grapes, coffee, etc.) and the number of strains able to produce OTA. To target pre- and post-harvest control programs, studies concerning the toxigenic fungi in each foodstuff are essential. This paper summarizes the state-of-the-art and the requirements in OTA control.
Autores: Ibáñez, María; González-Peñas, E.; Lizarraga, Elena; et al.
ISSN 0308-8146  Vol. 132  Nº 1  2012  págs. 35-42
One-hundred and twenty-three barley samples from a region of Spain (Navarra) were analysed in order to evaluate the possible co-occurrence of aflatoxins (AFB1, AFG1, AFB2 and AFG2), ochratoxin A (OTA) and zearalenone (ZEA). The results indicated that 80% of the samples presented detectable, although very low levels, of two or more mycotoxins. The most frequent combinations were AFB1 and OTA; AFB1, ZEA and OTA; and AFB1 and ZEA. In general, the statistical study did not show significant differences between levels or incidence for the mycotoxins in different years of harvest, variety of barley, farming or origin. The calculated values for daily intake were low and the risk to consumers could be assumed to be very low. However, the co-occurrence of several mycotoxins, and therefore synergic or additive effects, should be taken into account when determining permitted levels or risk assessment. (C) 2011 Elsevier Ltd. All rights reserved.
Autores: Ibáñez, María; González-Peñas, E.; Lizarraga, Elena; et al.
ISSN 0956-7135  Vol. 28  Nº 2  2012  págs. 295-298
In this paper, a statistical overview of the simultaneous presence of 14 mycotoxins in Spanish barley is presented. The co-occurrence of more than two mycotoxins has been observed in 95% of the samples. From a descriptive standpoint, the results show that the most common combinations were AFB1, OTA and DON (29%), and AFB1, OTA, DON and ZEA (26%), although other combinations could also occur. However, the statistical study determined that other associations had a higher impact or importance. Four factors or combinations of variables could explain the 63% of variability found for the samples. These factors were the associations of: type-B trichothecenes and DAS; type-A trichothecenes and NIV; AFB1, AFG1 and ZEA; and AFB2 and AFG2. The toxin-producing fungi and environmental conditions have been essential in explaining the associations between the toxins. (C) 2012 Elsevier Ltd. All rights reserved.
Autores: Vettorazzi, Ariane Renata; Arbillaga, L; et al.
ISSN 0278-6915  Vol. 50  Nº 10  2012  págs. 3440-3446
Humans are exposed to the hepatotoxic aflatoxin B1 (AFB1) and nephrotoxic ochratoxin A (OTA) through diet. However, kinetic and toxicological data after their co-administration are scarce. In this study, a single oral dose of AFB1 (0.25 mg/kg bw) + OTA (0.5 mg/kg bw) was administered to fasted F344 rats. Blood, liver and kidney were harvested at different timepoints for mycotoxins quantification, relative weight calculation, clinical biochemistry and histopathology analysis. Toxicity parameters pointed to acute toxicity in liver due to AFB1. No remarkable toxicity was observed in kidneys or immunological organs. Maximum observed concentrations in plasma (C-max) were at 10 min and 2 h for AFB1 and OTA, respectively. AFB1 plasma concentration could indicate a rapid absorption/metabolism of the mycotoxin; and AFB1 liver and kidney concentrations were lower than LOQ and LOD, respectively. For OTA, C-max was 4326.2 mu g/L in plasma. In kidney and liver C-max was reached at 8 h and concentrations were very similar between both organs at all timepoints. Due to the low levels of AFB1, the effect of OTA on AFB1 kinetics could not be assessed. However, AFB1 seems not to affect OTA kinetics, as its profile seems very similar to kinetic studies performed only with OTA in similar conditions. (C) 2012 Elsevier Ltd. All rights reserved.
Autores: González-Peñas, E.; Lizarraga, Elena; et al.
ISSN 0956-7135  Vol. 27  Nº 1  2012  págs. 139 - 145
Ochratoxin A (OTA), B (OTB) and their methyl (MeOTA, MeOTB) and ethyl (OTC, EtOTB) esters were evaluated in 51 red wine samples from Navarra (Spain). Detectable levels of OTA and OTB were found in 100% of the samples, and 71% showed the presence of OTC. The six ochratoxins appeared simultaneously in 18% of the samples. Results indicated that OTC is hydrolyzed to OTA in red wine. Therefore, ochratoxin intake from wine can be underestimated when only assessed by OTA analysis. Analyzed Navarra wines are scarcely contaminated with ochratoxins and their contribution to human intake is low, with the worst case being 4.7% and 6.6% of the provisional tolerable weekly intake (PTWI) for OTA and for the sum of ochratoxins, respectively. No significant differences were generally found between vintages. With the exception of OTA, no significant differences were observed between organic and traditional farming. Levels of ochratoxins were positively correlated with temperature and inversely correlated with humidity and rainfall.
Autores: Ibáñez, María; Lizarraga, Elena; González-Peñas, E.; et al.
ISSN 0956-7135  Vol. 25  Nº 1  2012  págs. 81-88
In this survey, 123 barley samples from a northern region of Spain (Navarra) have been analyzed for co-occurrence of eight type-A and type-B trichothecenes (DON, NIV, 3-ADON, 15-ADON, FUS-X, T-2, HT-2 and DAS). Samples were classified according to place and year of harvest (2007 and 2008), type of farming (organic or traditional) and variety of barley. The rains during anthesis had a great influence on the trichothecene levels, observing higher contaminations in samples collected during 2008. In addition, type-A trichothecenes tend to be more present in cooler areas, while type-B appears more often in warmer regions. The type of farming has not led to significant differences in mycotoxins levels, although a trend toward higher incidence and contamination in traditional samples has been observed. On the other hand, it was observed that Pewter, the favorite barley variety for the malting industry in Spain, has been the most susceptible to contamination with trichothecenes. (c) 2011 Elsevier Ltd. All rights reserved.
Autores: Ojer, P.; de Cerain, A.L.; Areses, P.; et al.
ISSN 0724-8741  Vol. 29  Nº 9  2012  págs. 2615 - 2627
To evaluate the acute and subacute toxicity of poly(anhydride) nanoparticles as carriers for oral drug/antigen delivery. Three types of poly(anhydride) nanoparticles were assayed: conventional (NP), nanoparticles containing 2-hydroxypropyl-beta-cyclodextrin (NP-HPCD) and nanoparticles coated with poly(ethylene glycol) 6000 (PEG-NP). Nanoparticles were prepared by a desolvation method and characterized in terms of size, zeta potential and morphology. For in vivo oral studies, acute and sub-acute toxicity studies were performed in rats in accordance to the OECD 425 and 407 guidelines respectively. Finally, biodistribution studies were carried out after radiolabelling nanoparticles with (99m)technetium. Nanoparticle formulations displayed a homogeneous size of about 180 nm and a negative zeta potential. The LD50 for all the nanoparticles tested was established to be higher than 2000 mg/kg bw. In the sub-chronic oral toxicity studies at two different doses (30 and 300 mg/kg bw), no evident signs of toxicity were found. Lastly, biodistribution studies demonstrated that these carriers remained in the gut with no evidences of particle translocation or distribution to other organs. Poly(anhydride) nanoparticles (either conventional or modified with HPCD or PEG6000) showed no toxic effects, indicating that these carriers might be a safe strategy for oral delivery of therapeutics.
Autores: Forchhammer, L.; Ersson, C.; Loft, S.; et al.
ISSN 0267-8357  Vol. 27  Nº 6  2012  págs. 665 - 672
There are substantial inter-laboratory variations in the levels of DNA damage measured by the comet assay. The aim of this study was to investigate whether adherence to a standard comet assay protocol would reduce inter-laboratory variation in reported values of DNA damage. Fourteen laboratories determined the baseline level of DNA strand breaks (SBs)/alkaline labile sites and formamidopyrimidine DNA glycosylase (FPG)-sensitive sites in coded samples of mononuclear blood cells (MNBCs) from healthy volunteers. There were technical problems in seven laboratories in adopting the standard protocol, which were not related to the level of experience. Therefore, the inter-laboratory variation in DNA damage was only analysed using the results from laboratories that had obtained complete data with the standard comet assay protocol. This analysis showed that the differences between reported levels of DNA SBs/alkaline labile sites in MNBCs were not reduced by applying the standard assay protocol as compared with the laboratory's own protocol. There was large inter-laboratory variation in FPG-sensitive sites by the laboratory-specific protocol and the variation was reduced when the samples were analysed by the standard protocol. The SBs and FPG-sensitive sites were measured in the same experiment, indicating that the large spread in the latter lesions was the main reason for the reduced inter-laboratory variation. However, it remains worrying that half of the participating laboratories obtained poor results using the standard procedure. This study indicates that future comet assay validation trials should take steps to evaluate the implementation of standard procedures in participating laboratories.
Autores: Arbillaga, L; et al.
ISSN 0278-6915  Vol. 50  Nº 3-4  2012  págs. 989-995
Polyphenols are characterized by the presence of phenol units in the molecules. These compounds may show antioxidant ability by scavenging reactive oxygen species (ROS) of the free radical type. A polyphenol enriched cocoa extract (PECE) was obtained from cocoa seeds with 28% of procyanidins which were mainly epicatechin oligomers. PECE was very active as free radical scavenger against 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and tris(2,4,6-trichloro-3,5-dinitrophenyl)methyl (HNTTM) radicals; and the tris(2,3,5,6-tetrachloro-4-nitrophenyl)methyl (TNPTM) assay showed that the PECE might not be pro-oxidant. Thus it was considered a good candidate to be tested in in vitro models. It showed mild cytotoxic power on Hep G2 cells and induced ROS in a dose-dependent manner being weak oxidant only at high concentrations near the limit of solubility. The antioxidant properties were assayed in Hep G2 treated with the mycotoxins ochratoxin A (OTA) and/or aflatoxin B1 (AFB1). The PECE was not effective against AFB1 but it increased the cell viability and reduced significantly the amounts of ROS in cells treated with OTA or mixtures of AFB1 + OTA. These results are coherent with the role of oxidative pathways in the mechanism of OTA and indicate that polyphenols extracted from cocoa may be good candidates as antioxidant agents. (C) 2011 Elsevier Ltd. All rights reserved.
Autores: Lavaggi, María L.; Ola-Azar, Claudio; de Cerain, A.L.; et al.
ISSN 2090-5165  Vol. 2011  2011  págs. 314209 -
Autores: Cabrera, Mauricio; López, Gloria V.; Gómez, Luis E.; et al.
ISSN 0148-0545  Vol. 34  Nº 3  2011  págs. 285 - 293
Autores: Vettorazzi, Ariane Renata; Fernández de Trocóniz, José Ignacio; González-Peñas, E.; et al.
ISSN 0278-6915  Vol. 49  Nº 9  2011  págs. 1935 - 1942
The impact of age and gender on Ochratoxin A (OTA) distribution in kidney and liver were studied. OTA was quantified in kidney and liver of young and mature rats of both sexes. Data was fit simultaneously using the population approach with NONMEM program. Fed and fasted mature males showed a 30% decrease and an 11% increase in relative bioavailability, respectively, in comparison with the rest of the groups. The OTA concentrations reached in kidney and liver were very similar between both organs. The models that best fit to data were the ones that considered that distribution of OTA to kidney and liver occurs from the central compartment and that elimination occurs mainly from the liver compartment. The kinetic analysis revealed that both, the apparent volume of distribution of the central compartment (V/F) and the apparent volume of distribution of the liver and kidney compartments (V(L,K)/F) increased significantly with body weight. Thus, the sex differences observed in organs distribution are a reflection of the differences in relative bioavailability observed in adult males, as a consequence of the fed and fasted conditions and to the significant higher body weight of mature males which directly affected the V/F and V(L,K)/F.
Autores: Benítez, Diego; Cabrera, Mauricio; Hernández, Paola; et al.
ISSN 0022-2623  Vol. 54  Nº 10  2011  págs. 3624 - 3636
Autores: Ibáñez, María; Vettorazzi, Ariane Renata; et al.
ISSN 1570-0232  Vol. 879  Nº 26  2011  págs. 2733 - 2740
A rapid and simple method for the simultaneous quantification of AFB1 and OTA in rat plasma, liver and kidney by UHPLC-FLD has been successfully validated according to the following criteria: selectivity, stability, linearity, precision, accuracy, recovery, robustness and limits of quantification and detection. The extraction method, calibration curves and chromatographic conditions are common for the three matrices. Plasma and homogenized tissue samples (100 mu L) were extracted with acetonitrile:formic acid mixture (99:1) (300 mu L). Chromatographic separation was performed with a mixture of water and acetonitrile:methanol (50:50), both acidified with 0.5% of formic acid using a gradient profile. The method avoids the use of immunoaffinity columns and allows reduction of sample and solvent volumes as well as toxic wastes. The detection is based on a photochemical reaction which enhances the AFB1 response without affecting the OTA signal before reaching the fluorescent detector. The mycotoxin recovery for each matrix was very efficient, between 93% and 96% for AFB1 and between 94% and 96% for OTA. For both mycotoxins the LOQs were 2 mu g/L in plasma and 8 mu g/kg in liver and kidney. The method has successfully been applied to rat samples after a single oral administration of a mixture of AFB1 and OTA and it could be a useful tool in toxicokinetic and toxicological studies.
Autores: Ibáñez, María; Martínez, R.; González-Peñas, E.; et al.
ISSN 0956-7135  Vol. 22  Nº 12  2011  págs. 1949 - 1955
Forty-six breakfast cereal samples from the Spanish market have been analyzed for the occurrence of aflatoxins (AFB1, AFG1, AFB2 and AFG2), ochratoxin A (OTA) and zearalenone (ZEA). According to the results, 9% of the samples were contaminated with AFB1 although no sample exceeded the LOQ (0.2 mu g kg(-1)), and no sample presented detectable levels of the other aflatoxins (AFB2, AFG1 and AFG2). Zearalenone and OTA contaminated 48 and 39% of the samples, respectively, with mean values of the samples having quantification levels of 25.40 and 0.37 mu g kg(-1), respectively. The co-occurrence of OTA and ZEA was observed in 28% of the samples. Aflatoxin B1 appeared only in the corn-based breakfast cereals, whereas ZEA and OTA showed the highest contamination rates in the samples containing wheat and wheat and rice, respectively. No sample of high-fiber content was contaminated with AFB1, whereas OTA and ZEA occurred with higher incidence in high-fiber content samples. Moreover, the daily exposure to AFB1, OTA and ZEA is discussed.
Autores: Arbillaga, L; Vettorazzi, Ariane Renata; et al.
ISSN 0278-6915  Vol. 49  Nº 11  2011  págs. 2883 - 2889
Mycotoxins aflatoxin B1 (AFB1) and ochratoxin A (OTA) can be present together in food commodities. These food contaminants are considered to be genotoxins, acting by different mechanisms. The aim of this work was to characterize combined genotoxic in vitro effects of both mycotoxins in Hep G2 cells. For this purpose, cytotoxicity was first determined in isolated and combined treatments in order to determine the dose range of genotoxicity studies. Co-exposure of cells to OTA + AFB1 for 24 h resulted in additive effects. Genotoxicity was determined in Hep G2 cells by the modified comet assay with restriction enzymes (endo ill and FPG). Significant reactive oxygen species formation was detected in both single and combined treatments. AFB1 was genotoxic after 3 h with external metabolic activation (S9 mix) and after 24 h without metabolic activation. Co-exposure to OTA significantly decreased DNA damage induced by AFB1, not only in breaks and apurinic sites but also in FPG-sensitive sites. The apparent contradiction between additive cytotoxic effects and antagonic genotoxic effects may be explained if AFB1 and OTA compete for the same CYPs, yielding more ROS but less AFB1 adducts.
Autores: Lavaggi, M. L.; Nieves, M.; Cabrera, M.; et al.
Revista: European Journal of Medicinal Chemistry
ISSN 0223-5234  Vol. 45  Nº 11  2010  págs. 5362 - 5369
Autores: Cabrera, M.; Lavaggi, M. L.; Croce, F.; et al.
Revista: Bioorganic & Medicinal Chemistry
ISSN 0968-0896  Vol. 18  Nº 14  2010  págs. 5391 - 5399
Autores: Vettorazzi, Ariane Renata; Fernández de Trocóniz, José Ignacio; González-Peñas, E.; et al.
Revista: Food and Chemical Toxicology
ISSN 0278-6915  Vol. 48  Nº 11  2010  págs. 3159 - 3166
Autores: González-Peñas, E.; et al.
Revista: TOXINS
ISSN 2072-6651  Vol. 2  Nº 5  2010  págs. 1054 - 1064
Autores: Lavaggi, M. L.; Cabrera, M.; Aravena, M. A.; et al.
Revista: Bioorganic & Medicinal Chemistry
ISSN 0968-0896  Vol. 18  Nº 12  2010  págs. 4433 - 4440
Autores: Salman, Hesham; Da Costa Martins, Raquel Maria ; et al.
ISSN 1773-2247  Vol. 20  Nº 5  2010  págs. 353 - 359
Autores: Junnotula, V.; Rajapakse, A.; Arbillaga, L; et al.
Revista: Bioorganic & Medicinal Chemistry
ISSN 0968-0896  Vol. 18  Nº 9  2010  págs. 3125 - 3132
Autores: Irache, Juan M.; Martín-Arbella, N; et al.
Libro:  Polymer nanoparticles for nanomedicines: a guide for their design, preparation and development
2016  págs. 521 - 550
Autores: Azqueta, A; Arbillaga, L; de Cerain, A.L.;
Libro:  Biointeractions of nanomaterials
2015  págs. 353 - 363
Autores: Gil, Ana Gloria; de Cerain, A.L.;
Libro:  Enfermedad de Chagas: Estrategia en la búsqueda de nuevos medicamentos. Una visión Iberoamericana
2011  págs. 341 - 364
Autores: de Cerain, A.L.; Azqueta, A; Vettorazzi, Ariane Renata;
Libro:  Olives and olive oil in health and disease prevention
2010  págs. 989 - 996
Autores: de Cerain, A.L.; Azqueta, A; Vettorazzi, Ariane Renata;
Libro:  Olives and olive oil in health and disease prevention
2010  págs. 989 - 996
Meat composition and temperature are the most important factors that determine the generation of mutagens in fried meat. At moderate temperatures (below 200°C), a high content of proteins and creatine is necessary for generating, by Maillard reaction, the heterocyclic amines (HCAs) that are responsible for mutagenic activity. For this reason, the browner the external crust of fried meat, the more potent the mutagenic activity. The presence of fat or oil has two opposite effects: it can facilitate heat transfer and thus increase the generation of mutagens or it may act as a dilutant for the mutagenic compounds. Deep-frying of meat in vegetable oils for long times (approximately 10 min) gives rise to a significant quantity of mutagens; olive oil yields slightly more mutagens than sunflower oil does, probably because the smoking temperature for olive oil is higher (180°C versus 170°C). Very long frying times (20¿30 min) significantly increase the mutagenic activity in meat fried in sunflower oil, probably due to the degradation of polyunsaturated fatty acids (PUFA). Thus, a general recommendation for reducing the presence of mutagens in fried meat would be to cook during short times and at moderate temperatures (below 170 °C).