Ochratoxins are a group of mycotoxins produced by a variety of moulds. Ochratoxin A (OTA), the most prominent member of this toxin family, was first described by van der Merwe et al. in Nature in ...1965. Dietary exposure to OTA represents a serious health issue and has been associated with several human and animal diseases including poultry ochratoxicosis, porcine nephropathy, human endemic nephropathies and urinary tract tumours in humans. More than 30 years ago, OTA was shown to be carcinogenic in rodents and since then extensive research has been performed in order to investigate its mode of action, however, this is still under debate. OTA is regarded as the most toxic family member, however, other ochratoxins or their metabolites and, in particular, ochratoxin mixtures or combinations with other mycotoxins may represent serious threats to human and animal health. This review summarises and evaluates current knowledge about the differential and comparative toxicity of the ochratoxin group.
Aspergillus steynii and Aspergillus tubingensis are possibly the main ochratoxin A (OTA) producing species in Aspergillus section Circumdati and section Nigri, respectively. OTA is a potent ...nephrotoxic, teratogenic, embryotoxic, genotoxic, neurotoxic, carcinogenic and immunosuppressive compound being cereals the first source of OTA in the diet. In this study bioactive ethylene-vinyl alcohol copolymer (EVOH) films containing cinnamaldehyde (CINHO), linalool (LIN), isoeugenol (IEG) or citral (CIT) which are major components of some plant essential oils (EOs) were produced and tested against A. steynii and A. tubingensis growth and OTA production in partly milled maize grains. Due to the favourable safety profile, these bioactive compounds are considered in the category “GRAS”. The study was carried out under different water activity (0.96 and 0.99 aw), and temperature (24 and 32 °C) conditions. ANOVA showed that class of film, fungal species, aw and temperature and their interactions significantly affected growth rates (GR), ED50 and ED90 and the doses for total fungal growth inhibition and OTA production. The most effective EVOH films against both species were those containing CINHO. ED50, ED90 and doses for total growth and OTA inhibition were 165–405, 297–614, 333–666 μg of EVOH-CINHO/plate (25 g of maize grains), respectively, depending on environmental conditions. The least efficient were EVOH-LIN films. ED50, ED90 and doses for total growth and OTA inhibition were 2800–>3330, >3330 and >3330 μg of EVOH-LIN/plate (25 g of maize grains), respectively. The effectiveness of the bioactive films increased with increasing doses. Overall, A. tubingensis was less sensitive to treatments than A. steynii. Depending on the species, aw and temperature affected GR and OTA production in a different way. In A. steynii cultures, optimal growth occurred at 0.96 aw and 32 °C while optimal OTA production happened at 0.99 aw and 32 °C. In A. tubingensis cultures optimal growth happened at 0.99 aw and 32 °C, although the best conditions for OTA production were 0.99 aw and 24 °C. Thus, these species can be very competitive in warm climates and storage conditions. The EVOH-CINHO films followed by EVOH-IEG and EVOH-CIT films, designed in this study and applied in vapour phase, can be potent antifungal agents against A. steynii and A. tubingensis and strong inhibitors of OTA biosynthesis in maize grains at very low doses. This is the first study on the impact that interacting environmental conditions and bioactive films containing individual components of EOs have on the growth of these ochratoxigenic fungi and on OTA production in maize grains.
•Bioactive EVOH films with CINHO are a good tool to control ochratoxigenic fungi.•Bioactive EVOH films with CINHO are a good tool to control ochratoxin A in maize.•Antifungal effect of EVOH films with CINHO, IEG, CIT and LIN depends of aw.•Temperature affects antifungal effect of EVOH films with CINHO, IEG, CIT and LIN.•The ED50 and ED90 permit reliable comparison between bioactive EVOH films.
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•Mycotoxins OTA and DON are widely distributed in agro-products.•The distribution of OTA and DON prevalent in the colder and temperate region.•The interaction of OTA/DON with ...co-existing chemicals pose a serious health issue.•The detection method of OTA/DON with other toxins in food matrix was evaluated.•The mitigation strategy through biocontrol and detoxification were highlighted.
Mycotoxins are secondary metabolites of fungi that cause severe damage to agricultural products and food in the food supply chain. These detrimental pollutants have been directly linked with poor socioeconomic patterns and human health issues. Among the natural micropollutants, ochratoxin A (OTA) and deoxynivalenol (DON) are widely distributed in food materials. The primary occurrence of these mycotoxins is reported in almost all cereal grains and fresh agro-products. Both mycotoxins have shown harmful effects, such as nephrotoxic, hepatotoxic, and genotoxic effects, in humans due to their complex structural formation during the degradation/acetylation reaction. In addition, improper preharvest, harvest, and postharvest handling tend to lead to the formation of OTA and DON in various food commodities, which allows different harmful fungicides in practice. Therefore, this review provides more insight into the distribution and toxicity of OTA/DON in the food matrix and human health. Furthermore, the interactive effects of OTA/DON with co-contaminated organic and inorganic compounds are discussed. Finally, international regulation and mitigation strategies for detoxication are critically evaluated to meet food safety and good agriculture practices.
Ochratoxin A (OTA) is a toxic metabolite produced by Aspergillus and Penicillium fungi commonly found in raw plant sources and other feeds. This review comprises an extensive evaluation of the origin ...and proprieties of OTA, toxicokinetics, biotransformation, and toxicodynamics of ochratoxins. In in vitro and in vivo studies, the compatibility of OTA with oxidative stress is observed through the production of free radicals, resulting in genotoxicity and carcinogenicity. The OTA leads to nephrotoxicity as the chief target organ is the kidney. Other OTA excretion and absorption rates are observed, and the routes of elimination include faeces, urine, and breast milk. The alternations in the Phe moiety of OTA are the precursor for the amino acid alternation, bringing about Phe-hydroxylase and Phe-tRNA synthase, resulting in the complete dysfunction of cellular metabolism. Biodetoxification using specific microorganisms decreased the DNA damage, lipid peroxidation, and cytotoxicity. This review addressed the ability of antioxidants and the dietary components as prophylactic measures to encounter toxicity and demonstrated their capability to counteract the chronic exposure through supplementation as feed additives.
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•Mycotoxin, Ochratoxin A (OTA) broadly circulated in agro-by products.•The OTA has a synergistic consequence with other co-occurring mycotoxins.•The OTA leading to critical illness in the host.•The biochemical proprieties of OTA and existing the toxicokinetics were reviewed.•Implication of antioxidants in feeds and the biodetoxification process were highlighted.
Ochratoxin A (OTA) is a toxic thermostable subordinate metabolite produced by Aspergillus and Penicillium species. OTA contamination occurs in a wide range of foods and poses a threat to human ...health. Therefore, it is crucial to construct a sensitive and reliable method for analyzing OTA to ensure food safety. Herein, a simple yet sensitive ECL aptasensor has been constructed for OTA detection through the synergistic amplification between catalytic DNA assembly (CDA) and exonuclease III (Exo III)-initiated recycling reaction. The anti-OTA aptamer-encoded sensing unit specifically recognizes target OTA and leads to the release of the trigger sequence for stimulating the CDA circuit, yielding numerous dsDNA hybrids that carry the re-assembled S strand. Each of the as-assembled S sequence could hybridize with the Ru(bpy)32+-labeled substrate (S*-Ru) to produce a T-shape structure with a blunt 3′ terminus, which can be hydrolyzed and digested by Exo III, leading to the liberation of mononucleotide functionalized with Ru(bpy)32+ (Ru). Simultaneously, the S sequence was released and hybridized with another S*-Ru sequence for initiating the subsequent cycle of Exo III-stimulated digestion process until all the S*-Ru strands are digested, thus resulting in the generation of numerous Ru and remarkably amplified ECL signals for high-performance detection of OTA. With reliable analyte recognition and high signal gain, the ECL system enabled the high-performance and accurate determination of OTA in buffer, wheat, and wine samples, thus showing considerable potential applications for highly efficient determination of contaminants of low concentration in foodstuff.
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•A robust DNA amplification circuit was devised for OTA detection in food matrices.•The synergistic amplification of CDA and Exo III effectively enhanced ECL signal.•The aptasensor showed high sensitivity toward OTA with a detection limit of 0.2 pM.•The label-free ECL sensor enabled reliable analysis of OTA in wheat and wine samples.
Matrix Binding of Ochratoxin A during Roasting Bittner, Andrea; Cramer, Benedikt; Humpf, Hans-Ulrich
Journal of agricultural and food chemistry,
12/2013, Letnik:
61, Številka:
51
Journal Article
Recenzirano
The mycotoxin ochratoxin A is degraded during coffee roasting by up to 90%. During this process, the two known degradation products, 14R-ochratoxin A and 14-decarboxy-ochratoxin A are formed. ...However, there is still an unexplained loss of more than 50% ochratoxin A. Here, we describe the binding of ochratoxin A to coffee polysaccharides via esterification as a further thermal reaction. This ester formation was studied by heating ochratoxin A with methyl α-d-glucopyranoside, a model compound to mimic polysaccharides. From this experiment, (22 → 6′) ochratoxin A-methyl-α-d-glucopyranoside ester was isolated and characterized as a reaction product, showing the general ability of ochratoxin A for esterification with carbohydrates at roasting temperatures. Subsequently, a sample preparation protocol for the detection of ochratoxin A saccharide esters based on an enzymatic cleavage and purification using immunoaffinity chromatography was developed and applied. The detection was carried out by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Using this method, it was possible to detect ochratoxin A polysaccharide esters formed during roasting of artificially contaminated coffee, confirming the results of the previous model experiments. Thus, the formation of ochratoxin A esters is a further explanation for the loss of ochratoxin A during coffee roasting.
Ochratoxins: A global perspective Bayman, Paul; Baker, James L
Mycopathologia (1975),
09/2006, Letnik:
162, Številka:
3
Journal Article
Recenzirano
Ochratoxins have been overshadowed by better-known mycotoxins, but they are gaining importance. Here we consider ochratoxins in the context of aflatoxins, which are better understood than ochratoxins ...on many levels. We review recent work on taxonomic distribution, contamination of commodities, biosynthesis, toxicity and regulatory aspects of ochratoxins. We focus on ochratoxins in coffee, since coffee is becoming a key commodity in ochratoxin research and regulation.
A polyclonal antibody against ochratoxin A (OTA) was produced from rabbits immunized with the OTA-BSA conjugate. A competitive direct enzyme-linked immunosorbent assay (cdELISA) and a membrane-base ...colloidal gold immunoassay in flow-through format were developed for the rapid detection of OTA in various food matrices. In the cdELISA, the concentration causing 50% inhibition was 0.07 ng mL-¹, and the effects of different chemical conditions (ionic strength, pH value, and organic solvent) were studied. The sensitivity of the assay was higher than those previously reported. A simple, rapid, and efficient extraction method was developed and 74-110% recoveries of spiked samples were obtained. Fifty percent methanol extracts of some food samples such as barley, wheat, oat, corn, rice, and raisins could be analyzed directly by immunoassay after dilution in PBS; grape juice and beer samples could be analyzed directly after dilution with PBS; for coffee samples, a more complex method was used to remove the matrix effect effectively. Membrane-based colloidal gold immunoassays had a visual detection limit of 1.0 ng mL-¹ for OTA with a detection time of less than 10 min. For the validation of the cdELISA and membrane-based colloidal gold immunoassay, samples were analyzed by high-performance liquid chromatography. The correlation between data obtained using the microwell assay and HPLC was good (R ² = 0.984). The developed immunoassay methods are suitable for the rapid quantitative or qualitative determination of OTA in food samples.
In this work, we investigated the effects of red orange and lemon extract (RLE) on ochratoxin A (OTA)‐induced nephrotoxicity. In particular, we analyzed the change in renal function and oxidative ...stress in Sprague–Dawley rats treated with OTA (0.5 mg/kg body weight, b.w.) and with RLE (90 mg/kg b.w.) by oral administration. After OTA treatment, we found alterations of biochemical and oxidative stress parameters in the kidney, related to a severe decrease of glomerular filtration rate. The RLE treatment normalized the activity of antioxidant enzymes and prevented the glomerular hyperfiltration. Histopathological examinations revealed glomerular damages and kidney cortex fibrosis in OTA‐rats, while we observed less severe fibrosis in OTA plus RLE group. Then, we demonstrated that oxidative stress could be the cause of OTA renal injury and that RLE reduces this effect.
Our results confirmed that oxidative stress is involved in the mechanism of nephrotoxicity of ochratoxin A (OTA) and red orange and lemon extract could be taken to avoid simultaneous OTA contamination of feed, to limit animal exposure to these highly toxic mycotoxins and protect animal and human health.
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