Aflatoxina M1 e Aflatoxina B1-lisina como Biomarcadores de Avaliação da Eficiência de Adsorventes para Aflatoxinas: Artigo de Revisão

Author(s):  
Roice Eliana Rosim ◽  
Carlos Augusto Fernandes de Oliveira ◽  
Carlos Humberto Corassin

A contaminação de alimentos por aflatoxinas, principalmente, a aflatoxina B1 (AFB1) representa um problema mundial para a saúde humana e animal. Uma forma de avaliar a exposição a estes contaminantes é analisando a dieta para verificar a ocorrência destes compostos. Esta metodologia, no entanto, tem limitações devido à variabilidade das aflatoxinas encontradas nos alimentos e às diferenças individuais na toxicocinética dos compostos. Por outro lado, o biomonitoramento de aflatoxinas em fluidos biológicos se utilizando de biomarcadores gera informações mais confiáveis sobre a exposição a estas toxinas nos indivíduos. O uso de adsorventes químicos na ração animal possibilita a detoxificação de aflatoxinas sem produzir efeitos tóxicos nem alterar as propriedades nutricionais. Este trabalho teve por objetivo revisar os dados publicados sobre a eficiência in vitro e in vivo de adsorventes para aflatoxinas, bem como estudos referentes ao uso da aflatoxina M1 (AFM1) e da AFB1-lisina como biomarcadores para avaliar a redução da biodisponibilidade da AFB1 por adsorventes em rações. Trabalhos relevantes publicados nos últimos dez anos (2009-presente) foram selecionados nas bases de dados PubMed, Science Direct e Google Scholar. A determinação de AFM1 no leite e/ou na urina, bem como de AFB1-lisina no soro, indica a biodisponibilidade individual da AFB1 em ensaios para avaliar a eficiência de adsorventes em animais. Deste modo, a utilização destes biomarcadores permite reduzir os custos dos ensaios in vivo, além de proporcionar maior padronização dos experimentos e possibilitar a avaliação da eficiência dos adsorventes em condições de campo. Palavras chave: AFB1. - Adsorventes Minerais. Biomarcadores de Exposição - AFB1-lisina - AFM1           AbstractFood contamination by aflatoxins, mainly aflatoxin B1 (AFB1), is a worldwide concern for human and animal health. A possible way to assess the exposure to these contaminants is through the diet analyses to verify the occurrence of mycotoxins. However, this methodology has important limitations due to the variability of mycotoxins found in the food and the individual differences in the toxicokinetics of the compounds. On the other hand, biomonitoring of aflatoxins in biological fluids using biomarkers generates more reliable information on the exposure to these toxins in individuals. The use of chemical adsorbents in animal feed makes it possible to detoxify mycotoxins without producing toxic effects or altering the nutritional properties. The aim of this study was to revise the available published data on the in vitro and in vivo efficacy of adsorbents for aflatoxins, as well as studies on the use of aflatoxin M1 (AFM1) and AFB1-lysine as biomarkers to evaluate the reduction in the bioavailability of AFB1 by adsorbents in feed. Relevant articles published in the last 10 years (2009-present) were selected in PubMed, Science Direct and Google Scholar. Determination of AFM1 in milk and/or urine, and AFB1-lysine in serum, indicate the individual bioavailability of AFB1 in trials conducted for evaluation of adsorbent’s efficiency in animals. Thus, the use of these biomarkers may reduce the costs of in vivo trials, increase the standardization of experiments, and evaluate the adsorbents’ efficiency under field conditions. Keywords: Aflatoxin B1 – Clays - Exposure Biomarkers - Aflatoxin B1-lysine Aflatoxin M1. 

2016 ◽  
Vol 9 (3) ◽  
pp. 419-433 ◽  
Author(s):  
E. Wielogórska ◽  
S. MacDonald ◽  
C.T. Elliott

In the recent years, mycotoxins have undoubtedly gained a keen interest of the scientific community studying food safety. The main reason is their profound impact on both human and animal health. International surveys reveal a low percentage of feed samples being contaminated above permitted/guideline levels, developed to protect consumers of animal derived products. However, the deleterious impact of feed co-contaminated at low levels with numerous both known and regulated as well as novel mycotoxins on producing animals has been described. Associated effects on agro-economics world-wide include substantial pecuniary losses which are borne by the society as a whole. Even though good agronomic practice is thought to be the most effective way of preventing animal feed contamination, the EC have recognised the need to introduce an additional means of management of feed already contaminated with low-levels of mycotoxins to alleviate detrimental effects on agricultural production efficiency. This review discusses types of feed detoxifying agents described in scientific literature, their reported efficacy in both in vitro and in vivo systems, and comparison with available commercial formulations in the light of increasing knowledge regarding mycotoxin prevalence in the changing global environment.


Toxins ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 37 ◽  
Author(s):  
Suvi Vartiainen ◽  
Alexandros Yiannikouris ◽  
Juha Apajalahti ◽  
Colm A. Moran

Ochratoxin A (OTA) is a common mycotoxin contaminant in animal feed. When absorbed from the gastrointestinal tract, OTA has a propensity for pathological effects on animal health and deposition in animal tissues. In this study, the potential of yeast cell wall extracts (YCWE) to adsorb OTA was evaluated using an in vitro method in which consecutive animal digestion events were simulated. Low pH markedly increased OTA binding to YCWE, which was reversed with a pH increased to 6.5. Overall, in vitro analysis revealed that 30% of OTA was adsorbed to YCWE. Additional computational molecular modelling revealed that change in pH alters the OTA charge and modulates the interaction with the YCWE β-d-glucans. The effectiveness of YCWE was tested in a 14-day broiler chicken trial. Birds were subjected to five dietary treatments; with and without OTA, and OTA combined with YCWE at three dosages. At the end of the trial, liver OTA deposition was evaluated. Data showed a decrease of up to 30% in OTA deposits in the liver of broilers fed both OTA and YCWE. In the case of OTA, a tight correlation between the mitigation efficacy of YCWE between in vitro and in vivo model could be observed.


Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 184
Author(s):  
Yanan Gao ◽  
Xiaoyu Bao ◽  
Lu Meng ◽  
Huimin Liu ◽  
Jiaqi Wang ◽  
...  

With the growing diversity and complexity of diet, humans are at risk of simultaneous exposure to aflatoxin B1 (AFB1) and aflatoxin M1 (AFM1), which are well-known contaminants in dairy and other agricultural products worldwide. The intestine represents the first barrier against external contaminants; however, evidence about the combined effect of AFB1 and AFM1 on intestinal integrity is lacking. In vivo, the serum biochemical parameters related to intestinal barrier function, ratio of villus height/crypt depth, and distribution pattern of claudin-1 and zonula occluden-1 were significantly affected in mice exposed to 0.3 mg/kg b.w. AFB1 and 3.0 mg/kg b.w. AFM1. In vitro results on differentiated Caco-2 cells showed that individual and combined AFB1 (0.5 and 4 μg/mL) and AFM1 (0.5 and 4 μg/mL) decreased cell viability and trans-epithelial electrical resistance values as well as increased paracellular permeability of fluorescein isothiocyanate-dextran in a dose-dependent manner. Furthermore, AFM1 aggravated AFB1-induced compromised intestinal barrier, as demonstrated by the down-regulation of tight junction proteins and their redistribution, particularly internalization. Adding the inhibitor chlorpromazine illustrated that clathrin-mediated endocytosis partially contributed to the compromised intestinal integrity. Synergistic and additive effects were the predominant interactions, suggesting that these toxins are likely to have negative effects on human health.


Author(s):  
Gerhard Flachowsky ◽  
◽  
Ulrich Meyer ◽  

Various animal feed products may influence animal health, conversion of animal feed into food of animal origin and the emissions caused by animals. All these matters are regulated in the directives of the European Food Safety Authority (EFSA). This chapter first discusses EFSA guidance on how to compile dossiers for feed additives. The chapter then discusses key issues and steps in demonstrating the efficacy of new animal feed products: reduction of nitrogen (N) excretion, reduction of feed contamination of by mycotoxins and, finally, reduction of methane emissions with feed additives. Key steps, such as the use of in vitro and in vivo studies, to test the effects of feed additives are discussed in detail.


2020 ◽  
Vol 13 (1) ◽  
pp. 41-52
Author(s):  
Ksenija Nesic ◽  
Sandra Jaksic ◽  
Nenad Popov ◽  
Milica Zivkov-Balos ◽  
Marko Pajic ◽  
...  

The contamination of animal feed with mycotoxins is a worldwide problem in the animal husbandry, but it also represents a serious threat for the whole food chain. The health of both animals and humans is potentially endangered. From this point of view aflatoxins are a class of mycotoxins especially well known. Therefore, new strategies to combat these natural contaminants are constantly being developed. The most applied method to protect animals against aflatoxicosis is the utilization of feed additives aimed to adsorb aflatoxins. In order to estimate adsorbing potential of feed additive “MycoStop DUPLO”, designed for the prevention and/or alleviation of adverse effects of aflatoxin B1 in animal nutrition, in vitro trial was conducted. As a result of the experiment, conducted at pH 5 during 120 minutes of incubation at 37°C, the optimal formulation of the adsorbent was revealed. This product, in low concentration and in the presence of high amounts of toxin, met the stringent European regulation requirements for minimum 90% aflatoxin binding efficiency (90.1% achieved with 0.02% adsorbent and 4 mg/L toxin concentration). In higher adsorbent (0.2%), and lower toxin (0.2 mg/L) conditions, adsorption was 99.6%. Such outcome indicated the validity of in vitro experimental approach which can serve as a reliable fast tool for triage of adsorbents and preselect them for in vivo tests.


2021 ◽  
Vol 7 (2) ◽  
pp. 130
Author(s):  
Nathan P. Wiederhold

Invasive infections caused by Candida that are resistant to clinically available antifungals are of increasing concern. Increasing rates of fluconazole resistance in non-albicans Candida species have been documented in multiple countries on several continents. This situation has been further exacerbated over the last several years by Candida auris, as isolates of this emerging pathogen that are often resistant to multiple antifungals. T-2307 is an aromatic diamidine currently in development for the treatment of invasive fungal infections. This agent has been shown to selectively cause the collapse of the mitochondrial membrane potential in yeasts when compared to mammalian cells. In vitro activity has been demonstrated against Candida species, including C. albicans, C. glabrata, and C. auris strains, which are resistant to azole and echinocandin antifungals. Activity has also been reported against Cryptococcus species, and this has translated into in vivo efficacy in experimental models of invasive candidiasis and cryptococcosis. However, little is known regarding the clinical efficacy and safety of this agent, as published data from studies involving humans are not currently available.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4221
Author(s):  
Aage Kristian Olsen Alstrup ◽  
Svend Borup Jensen ◽  
Ole Lerberg Nielsen ◽  
Lars Jødal ◽  
Pia Afzelius

The development of new and better radioactive tracers capable of detecting and characterizing osteomyelitis is an ongoing process, mainly because available tracers lack selectivity towards osteomyelitis. An integrated part of developing new tracers is the performance of in vivo tests using appropriate animal models. The available animal models for osteomyelitis are also far from ideal. Therefore, developing improved animal osteomyelitis models is as important as developing new radioactive tracers. We recently published a review on radioactive tracers. In this review, we only present and discuss osteomyelitis models. Three ethical aspects (3R) are essential when exposing experimental animals to infections. Thus, we should perform experiments in vitro rather than in vivo (Replacement), use as few animals as possible (Reduction), and impose as little pain on the animal as possible (Refinement). The gain for humans should by far exceed the disadvantages for the individual experimental animal. To this end, the translational value of animal experiments is crucial. We therefore need a robust and well-characterized animal model to evaluate new osteomyelitis tracers to be sure that unpredicted variation in the animal model does not lead to a misinterpretation of the tracer behavior. In this review, we focus on how the development of radioactive tracers relies heavily on the selection of a reliable animal model, and we base the discussions on our own experience with a porcine model.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 547
Author(s):  
Marina Ramal-Sanchez ◽  
Antonella Fontana ◽  
Luca Valbonetti ◽  
Alessandra Ordinelli ◽  
Nicola Bernabò ◽  
...  

Since its discovery, graphene and its multiple derivatives have been extensively used in many fields and with different applications, even in biomedicine. Numerous efforts have been made to elucidate the potential toxicity derived from their use, giving rise to an adequate number of publications with varied results. On this basis, the study of the reproductive function constitutes a good tool to evaluate not only the toxic effects derived from the use of these materials directly on the individual, but also the potential toxicity passed on to the offspring. By providing a detailed scientometric analysis, the present review provides an updated overview gathering all the research studies focused on the use of graphene and graphene-based materials in the reproductive field, highlighting the consequences and effects reported to date from experiments performed in vivo and in vitro and in different animal species (from Archea to mammals). Special attention is given to the oxidized form of graphene, graphene oxide, which has been recently investigated for its ability to increase the in vitro fertilization outcomes. Thus, the potential use of graphene oxide against infertility is hypothesized here, probably by engineering the spermatozoa and thus manipulating them in a safer and more efficient way.


Author(s):  
Maria Cristina Budani ◽  
Gian Mario Tiboni

Nitric oxide (NO) is formed during the oxidation of L-arginine to L-citrulline by the action of multiple isoenzymes of NO synthase (NOS): neuronal NOS (nNOS), endotelial NOS (eNOS), and inducible NOS (iNOS). NO plays a relevant role in the vascular endothelium, in central and peripheral neurons, and in immunity and inflammatory systems. In addition, several authors showed a consistent contribution of NO to different aspects of the reproductive physiology. The aim of the present review is to analyse the published data on the role of NO within the ovary. It has been demonstrated that the multiple isoenzymes of NOS are expressed and localized in the ovary of different species. More to the point, a consistent role was ascribed to NO in the processes of steroidogenesis, folliculogenesis, and oocyte meiotic maturation in in vitro and in vivo studies using animal models. Unfortunately, there are few nitric oxide data for humans; there are preliminary data on the implication of nitric oxide for oocyte/embryo quality and in-vitro fertilization/embryo transfer (IVF/ET) parameters. NO plays a remarkable role in the ovary, but more investigation is needed, in particular in the context of human ovarian physiology.


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