Ochratoxin A: 50 Years of Research

Effect of a Debaryomyces hansenii and Lactobacillus buchneri Starter Culture on Aspergillus westerdijkiae Ochratoxin A Production and Growth during the Manufacture of Short Seasoned Dry-Cured Ham

Recently, specific dry-cured hams have started to be produced in San Daniele and Parma areas. The ingredients are similar to protected denomination of origin (PDO) produced in San Daniele or Parma areas, and include pork leg, coming from pigs bred in the Italian peninsula, salt and spices. However, these specific new products cannot be marked as a PDO, either San Daniele or Parma dry cured ham, because they are seasoned for 6 months, and the mark PDO is given only to products seasoned over 13 months. Consequently, these products are called short-seasoned dry-cured ham (SSDCH) and are not branded PDO. During their seasoning period, particularly from the first drying until the end of the seasoning period, many molds, including Eurotium spp. and Penicillium spp., can grow on the surface and work together with other molds and tissue enzymes to produce a unique aroma. Both of these strains typically predominate over other molds. However, molds producing ochratoxins, such as Aspergillus ochraceus and Penicillium nordicum, can simultaneously grow and produce ochratoxin A (OTA). Consequently, these dry-cured hams may represent a potential health risk for consumers. Recently, Aspergillus westerdijkiae has been isolated from SSDCHs, which could represent a potential problem for consumers. Therefore, the aim of this study was to inhibit A. westerdijkiae using Debaryomyces hansenii or Lactobacillus buchneri or a mix of both microorganisms. Six D. hansenii and six L. buchneri strains were tested in vitro for their ability to inhibit A. westerdijkiae. The strains D. hansenii (DIAL)1 and L. buchneri (Lb)4 demonstrated the highest inhibitory activity and were selected for in situ tests. The strains were inoculated or co-inoculated on fresh pork legs for SSDCH production with OTA-producing A. westerdijkiae prior to the first drying and seasoning. At the end of seasoning (six months), OTA was not detected in the SSDCH treated with both microorganisms and their combination. Because both strains did not adversely affect the SSDCH odor or flavor, the combination of these strains are proposed for use as starters to inhibit OTA-producing A. westerdijkiae.

Toxin Degradation by Rumen Microorganisms: A Review

Animal feeds may contain exogenous compounds that can induce toxicity when ruminants ingest them. These toxins are secondary metabolites originating from various sources including plants, bacteria, algae and fungi. Animal feed toxins are responsible for various animal poisonings which negatively impact the livestock industry. Poisoning is more frequently reported in newly exposed, naïve ruminants while ‘experienced’ ruminants are observed to better tolerate toxin-contaminated feed. Ruminants can possess detoxification ability through rumen microorganisms with the rumen microbiome able to adapt to utilise toxic secondary metabolites. The ability of rumen microorganisms to metabolise these toxins has been used as a basis for the development of preventative probiotics to confer resistance against the poisoning to naïve ruminants. In this review, detoxification of various toxins, which include plant toxins, cyanobacteria toxins and plant-associated fungal mycotoxins, by rumen microorganisms is discussed. The review will include clinical studies of the animal poisoning caused by these toxins, the toxin mechanism of action, toxin degradation by rumen microorganisms, reported and hypothesised detoxification mechanisms and identified toxin metabolites with their toxicity compared to their parent toxin. This review highlights the commercial potential of rumen inoculum derived probiotics as viable means of improving ruminant health and production.

Mycotoxins in Ethiopia: A Review on Prevalence, Economic and Health Impacts

Mycotoxigenic fungi and their toxins are a global concern, causing huge economic and health impacts in developing countries such as Ethiopia, where the mycotoxin control system is inadequate. This work aimed to review the occurrences of agriculturally essential fungi such as Aspergillus, Fusarium, and Penicillium and their major mycotoxins in Ethiopian food/feedstuffs. The incidents of crucial toxins, including aflatoxins (B1, B2, G1, G2, M1), fumonisins (B1, B2), zearalenone, deoxynivalenol, and ochratoxin A, were studied. The impacts of chronic aflatoxin exposure on liver cancer risks, synergy with chronic hepatitis B infection, and possible links with Ethiopian childhood malnutrition were thoroughly examined. In addition, health risks of other potential mycotoxin exposure are also discussed, and the impacts of unsafe level of mycotoxin contaminations on economically essential export products and livestock productions were assessed. Feasible mycotoxin mitigation strategies such as biocontrol methods and binding agents (bentonite) were recommended because they are relatively cheap for low-income farmers and widely available in Ethiopia, respectively. Moreover, Ethiopian mycotoxin regulations, storage practice, adulteration practice, mycotoxin tests, and knowledge gaps among value chain actors were highlighted. Finally, sustained public awareness was suggested, along with technical and human capacity developments in the food control sector.

Melatonin as a potential inhibitor of kidney cancer: A survey of the molecular processes

Studies have shown that despite the decreasing mortality rates of kidney cancer patients, its incidence is increasing. Therefore, a comprehensive re-evaluation of treatment options is necessary to provide appropriate treatments for the increasing number of patients. Moreover, the side effects caused by surgery, which is the main treatment of this disease, may lead to higher morbidity rates. Consequently, new safer approaches must be examined and considered. Major advancements have been made in the field of targeted agents as well as treatments based on immunotherapy since renal cell carcinoma (RCC) does not respond well to chemotherapy. While the therapeutic options for this cancer are increasing, the resulting complexity of selecting the best strategy for treating the patients is daunting. Moreover, each therapeutic option must be evaluated concerning toxicity, cost, and clinical advantages. Several characteristics, which are beneficial for cancer therapies have been attributed to melatonin. For decades, investigations have explored the application of melatonin in the treatment of cancer; insufficient attention has been paid to this molecule at the clinical level. Melatonin plays a role in cancer therapy due to its anti-tumor effects as well as by enhancing the efficacy of other drugs as an adjuvant. In this review, we discuss different roles of melatonin in the treatment of kidney cancer. The studies concerned with the applications of melatonin as an adjuvant in the immunotherapy of patients with kidney cancer are summarized. Also, we highlight the apoptotic and anti-angiogenic effects of melatonin on renal cancer cells which are mediated by different molecules (e.g., HIF-1 and VEGF, ADAMTS1, and MMP-9) and signaling pathways (e.g., P56, P52, and JNK). Furthermore, we take a look into available data on melatonin's ability to reduce the toxicities caused by kidney carcinogens, including ochratoxin A, potassium bromate, and Fe-NTA.

Development of a horseradish peroxidase-nanobody fusion protein for visual detection of ochratoxin A by dot immunoassay

Ochratoxin A (OTA) is a common cereal mycotoxin that seriously threatens food safety and public health. Herein a horseradish peroxidase-nanobody fusion protein (HRP-Nb) retaining antibody and enzyme activity was obtained after inclusion body denaturation and renaturation and enzyme reconstitution, which served both as the primary antibody and reporter enzyme and was applied to develop a membrane-based dot immunoassay (HN-DIA) for OTA visual detection. Based on the optimal experimental conditions, the HN-DIA could be finished in 10 min with a cut-off limit of 50 μg kg-1 in rice and oat samples by eye. The HN-DIA showed high selectivity for OTA and had good accuracy and reproducibility in the recovery experiments. Spiked sample analysis results of the HN-DIA and high performance liquid chromatography (HPLC) correlated well with each other. Therefore, the proposed HN-DIA has the potential for rapid screening of OTA and other small molecule pollutants in food and the environment by naked eye.

Removal of ochratoxin A from liquid media using novel low-cost biosorbents

Ground shells of almonds (ALM), hazelnuts (HAZ), walnuts (WAL), and chestnuts (CHE), coconut fiber (COC), spent coffee grounds (COF), and clementine peel (CLE) were used to remove ochratoxin A (OTA) from both water and an ethanol/water mixture (14:86, v/v). Other very efficient adsorbents like wood biochar (BC) and hydrochar (HC) and a humic acid (HA) were also adopted as a comparison. In batch experiments, sorption of OTA from water followed the trend BC (100% removed) > HA > CLE > COC > HC > COF > ALM > HAZ > CHE > WAL (8% removed), whereas sorption of OTA from ethanol/water mixture (14:86, v/v) onto only the raw materials was COC (54% removed) > CLE > HAZ > ALM > COF > CHE > WAL (0.4% removed). The desorption of the toxin from all materials in water was rather low. Afterwards, sorption kinetics and isotherms of OTA onto CLE, COC, and COF were performed. The three materials adsorbed OTA in about 2 h according to a pseudo-second-order kinetic model, thus indicating the occurrence of a chemisorption mechanism. Equilibrium sorption data of OTA onto CLE followed preferentially the Freundlich model, whereas those on COC and COF fitted well both Freundlich and Langmuir isotherms (r > 0.996). The values of Freundlich sorption constants, KFads, for CLE, COC, and COF were 313, 202, and 98 L kg-1, respectively. OTA desorption from each of the three materials showed hysteretic effects. Overall findings of this work suggest that raw plant wastes could be effectively used as biosorbents to abate the level of OTA in liquid media.

An ultrasensitive non-noble metal colorimetric assay using starch-iodide complexation for Ochratoxin A detection

Colorimetric sandwich-type biosensors that can both provide sensitivity competitive with fluorescence-based approaches, and leverage reagents that are cost-effective, widely available and as safe as possible, are highly sought after. Herein, we demonstrate an alternative highly-sensitive colorimetric method for paper-based sandwich-type biosensing that uses starch-iodide complexation to simplify practical biosensing using ubiquitous reagents. Targeting the mycotoxin ochratoxin A (OTA), a covalently-immobilised OTA antibody on a cellulose surface captures OTA and forms a sandwich with OTA aptamer-conjugated glucose oxidase. Adding the chromogenic reagents at an optimized concentration, a distinct blue color develops within 30 min, offering excellent contrast with the clear/white of the negative sample. With a sampling volume down to just 5 μL, the assay exhibits concentration limits of detection and quantitation of 20 and 320 pg mL^-1, respectively, and a linear range from 10^-1 to 10⁵ ng mL^-1 (R² = 0.997). The method displays excellent selectivity against related mycotoxins, excellent %recovery (95-117%) and robust operation in complex matrices (beer, urine and human serum), with no significant difference versus gold-standard liquid chromatography. Along with its excellent analytical performance, this assay benefits from non-toxic and extremely cheap reagents that can be safely disposed of in the field, and presents an attractive alternative to toxic dyes and nanoparticles.

Impedimetric Aptamer-Based Biosensors: Applications

Impedimetric aptamer-based biosensors show high potential for handheld devices and point-of-care tests. In this review, we report on recent advances in aptamer-based impedimetric biosensors for applications in biotechnology. We detail on analytes relevant in medical and environmental biotechnology as well as food control, for which aptamer-based impedimetric biosensors were developed. The reviewed biosensors are examined for their performance, including sensitivity, selectivity, response time, and real sample validation. Additionally, the benefits and challenges of impedimetric aptasensors are summarized.

Modification performance and electrochemical characteristics of different groups of modified aptamers applied for label-free electrochemical impedimetric sensors

Amino and thiolated aptamers are the main aptamers used to construct label-free electrochemical impedimetric aptasensors. In this study, the modification performance and electrochemical properties of amino aptamers and thiolated aptamers were studied in the construction of label-free impedimetric sensors. The results showed that the initial modification density of amino aptamers was higher than that of thiol aptamers. Aptamers can recognize and bind OTA to generate electrical signals. The higher the density of aptamer modification was, the better the electric signals were. If only considering the initial modification density, amino aptamers were more suitable for the preparation of aptasensors than thiolated aptamers. However, the modification density of the amino aptamer decreased with the prolonged immersion time in 1 mM HCl solution, which suggests that the stability of this sensor was poor. However, the thiolated aptamer maintained relatively constant density and could be reused. Thus, the thiolated aptasensor had a wide range and good reproducibility and stability for the determination of ochratoxin A (OTA). In addition, this study proved that gold nanoparticles play an important role in signal amplification by increasing the effective gold surface to fix more aptamers in the process of sensor preparation.

Mycotoxins Detection and Fungal Contamination in Black and Green Tea by HPLC-Based Method

The fungal contamination and total aflatoxins (AF) and ochratoxin A (OTA) of tea samples were examined. A total of 60 tea samples were extracted and treated with immunoaffinity columns. The amount of AF and OTA were determined by using high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). Tea samples were cultured and the fungi were identified. The results showed that 24 (40%) samples were contaminated with AFs and none of the tea samples were above the acceptable limit of AFs (≥10 μg/kg). All of the samples were contaminated with OTA where only 3 black tea samples (6.6%) and 1 green tea sample (6.7%) were detected to have more than the standard limits of toxin (10 μg·kg⁻¹). The mean concentration of OTA in the black tea was higher than green tea. Aspergillus niger was the predominant fungi isolated from black and green tea samples. Considering the high contamination of mycotoxins in tea samples, regular monitoring in the tea process for improving quality is recommended.

Case Study: Rapid Complete Recovery From An Autism Spectrum Disorder After Treatment of Aspergillus With The Antifungal Drugs Itraconazole And Sporanox

CONTEXT

A child with symptoms placing him within the autism spectrum and with urine biochemical markers consistent with fungal (Aspergillus) colonization of the gastrointestinal tract was first treated with the antifungal probiotic Saccharomyces boulardii. A dramatic Herxheimer reaction provided strong clinical indications that mold colonization might be a factor in causing autism in this child.

OBJECTIVE

The child's physician (Baker) wished to try a more potent antifungal therapy, itraconazole, in an attempt to reverse the child's autism since itraconazole is an especially effective agent against Aspergillus species.

SETTING

The child was treated as an outpatient by the physician who had first diagnosed the child with an autism spectrum disorder.

PARTICIPANT

A child with an autism spectrum disorder.

INTERVENTION

The major intervention was increasing doses of the antifungal drug itraconazole. However, the Sporanox^® brand of itraconazole gave the best results. The child was monitored twice weekly with liver function tests which remained normal throughout the therapy.

RESULTS

The child had a complete recovery from all the symptoms of autism and in addition developed excellent academic, athletic, and musical skills. The recovery coincided with a marked reduction of urine markers of Aspergillus colonization.

CONCLUSIONS

Escalation of the dose of itraconazole resulted in a complete loss of all symptoms of autism over the course of three months. This rapid complete reversal of autism is consistent with several articles proposing mold in general and Aspergillus specifically as a potential major cause of autism.

Ochratoxin A induces glomerular injury through activating the ERK/NF-κB signaling pathway

Ochratoxin A (OTA) was reported to induce proximal tubules nephrotoxicity in humans and animals. However, the toxicity of OTA on glomeruli has rarely been studied. We investigated OTA-induced glomerular injury and the underlying mechanisms. Mice were intraperitoneally treated with OTA (0, 0.5, 1.5 and 2.5 mg/kg b.w.) on alternate day for 3 weeks. OTA exposure decreased the weight gain ratio, the kidney index and increased the levels of serum creatinine and blood urea nitrogen. It induced also fragmentation and atrophy in glomeruli, and increased the expression of TNF-α, IL-6, COX-2, TGF-β, α-SMA and vimentin in a dose-dependent manner. Human mesangial cells (HMC) were treated with OTA (0-8 μM) for 48 h. Treatment of HMC cells with OTA increased cell inhibition rate, up-regulated the expression of IL-6, TGF-β, α-SMA and vimentin in a dose-dependent manner. Additionally, it enhanced the phosphorylation of ERK1/2 and p65, degradation of IκB-α and translocation of p65 into the nucleus. OTA-induced toxicity was attenuated by NF-κB and ERK1/2 inhibitors. In conclusion, these results suggest that OTA exposure induces glomerular injury via activation of the ERK/NF-κB signaling pathway, and provide novel insights into the research of OTA induced nephrotoxicity.

Reducing Ochratoxin A Content in Grape Pomace by Different Methods

Grape pomace (GP) is the residue of grapes after wine making and is a valuable source of dietary polyphenol and fiber for health promotion. However, studies found the presence of ochratoxin A (OTA) in GP at very high concentrations, which raises a safety issue in the value-added utilization of GP. This study evaluated the effects of thermal pressure, baking, acid and enzymatic treatments on OTA content in GP. Thermal pressure treatment was conducted with wet GP at 121 °C for 10-30 min in an autoclave; acid treatments were conducted with hydrochloric acid, acetic acid, citric acid, and lactic acid, respectively, at 50 °C for 24 h. Baking was conducted using a cookie model. For enzymatic treatment, purified OTA solution was treated with carboxypeptidase A, alcalase, flavourzyme, pepsin, and lipase, respectively, and the effective enzymes were selected to treat GP. Results show that autoclaving for 10-30 min reduced 19-80% of OTA, varying with treatment time and GP variety. The effectiveness of acid treatment was similar to that of autoclaving and varied with acid type and GP variety. Baking increased the detectable OTA. Among all tested enzymes, carboxypeptidase A was the most effective in reducing OTA, followed by lipase and flavourzyme, but their effects were significantly lower in GP samples.

Exposure assessment to ochratoxin A through the intake of three cereal derivatives from the Moroccan market

Previous studies reported the contamination of cereals products with OTA in Morocco. Given bread, pasta and semolina are staple consumed food in the country, this study aims to assess the OTA exposure levels for the adult consumers in the country through cereal derivatives intake, by using a deterministic model based on the crossover of consumption and contamination data of 457 cereals products samples. The study also set out to determine under what conditions the OTA contributions from these 3 cereal derivatives alone were enough to cause a real public health problem in the country. The Estimated Weekly Intake EWI (ng/kg b.w./week) was used as an indicator of exposure for each cereal derivative. The global exposure (Total EWI) was determined by the summation of the EWI obtained for each cereal derivative for different consumers groups and at different OTA levels and nine scenarios were elaborated. Results showed that the total average OTA intake from the three cereal derivatives was estimated at 13.5 ng/kg b.w./week. Despite its low contamination levels, bread has been shown to be the main vector of exposure to OTA because of the high consumption levels by Moroccan adults. Its contribution to the total OTA intake was between 81 and 84% depending on the scenario. The contribution of the other investigated cereal products to total OTA intake seems to be modest and does not exceed 10% and 7% for semolina and pasta, respectively. The predominance of cereal derivatives in Moroccan food thus constitutes a potential risk factor for OTA exposure. Indeed, the risk of occurrence of potential adverse effects of OTA is real in three scenarios discussed in the study since the PTWI established by JECFA (100 ng/kg b.w./week) was exceeded. Moreover, the Maximum limit (3 ng/g) set by Moroccan regulations in 2016, seems to be less protective for the Moroccan consumers compared to other countries due to the high consumption level of cereal products. This situation is likely to cause a public health problem by the occurrence of specific pathologies at highly OTA exposed adults, especially high bread consumers.

Safety evaluation of Ochratoxin A and Citrinin after 28 days repeated dose oral exposure to Wistar rats

Mycotoxins, ochratoxin A (OTA), and citrinin (CTN) are toxic metabolites of filamentous fungi. The most common fungal species that produce OTA and CTN belong to genera Aspergillus, Penicillium, Fusarium, and Monascus, and these fungal species are found to be contaminant a wide range of grains, food, and food product. The aim of our study was to evaluate the sub-acute repeated dose oral toxicity of OTA and CTN in experimental rodents by following OECD test guidelines for testing chemicals no. 407 with minor modifications. Twenty-five rats of each sex were divided equally into five groups; vehicle control, OTA 25 μg/kg b. wt., OTA 100 μg/kg b. wt., CTN 25 μg/kg b.wt. and CTN 100 μg/kg b. wt. The results of this study showed no abnormal clinical signs during 28 days of the experimental period. We did not found any significant changes in body weight gain, food consumption pattern, organ weight, hematology except few parameters, and biochemical values in any of the treatment and control groups. However, histopathological observations revealed severe nephrotoxicity and mild follicular depletion in the spleen of 100 μg/kg b. wt. treated groups of both OTA and CTN mycotoxins. The findings of our study are of its first kind that reports the systemic toxicity of OTA and CTN oral exposure to laboratory rodents.

HPLC-MS/MS Method for the Detection of Selected Toxic Metabolites Produced by Penicillium spp. in Nuts

Penicillium spp. are emerging as producers of mycotoxins and other toxic metabolites in nuts. A HPLC-MS/MS method was developed to detect 19 metabolites produced by Penicillium spp. on chestnuts, hazelnuts, walnuts and almonds. Two extraction methods were developed, one for chestnuts and one for the other three nuts. The recovery, LOD, LOQ and matrix effect were determined for each analyte and matrix. Correlation coefficients were always >99.99%. In walnuts, a strong signal suppression was observed for most analytes and patulin could not be detected. Six strains: Penicillium bialowiezense, P. brevicompactum, P. crustosum, P. expansum, P. glabrum and P. solitum, isolated from chestnuts, were inoculated on four nuts. Chestnuts favored the production of the largest number of Penicillium toxic metabolites. The method was used for the analysis of 41 commercial samples: 71% showed to be contaminated by Penicillium-toxins. Cyclopenin and cyclopenol were the most frequently detected metabolites, with an incidence of 32% and 68%, respectively. Due to the risk of contamination of nuts with Penicillium-toxins, future studies and legislation should consider a larger number of mycotoxins.

Effects of mycotoxin-contaminated feed on farm animals

Mycotoxins are secondary products produced by fungi in cereals and are frequently found in the livestock industry as contaminants of farm animal feed. Studies analyzing feed mycotoxins have been conducted worldwide and have confirmed the presence of mycotoxins with biological activity, including aflatoxin, ochratoxin A, fumonisin, zearalenone, and deoxynivalenol, in a large proportion of feed samples. Exposure to mycotoxins can cause immunotoxicity and impair reproductive function in farm animals. In addition, exposure of tissues, such as the kidneys, liver, and intestines, to mycotoxins can exert histopathological changes that can interfere with animal growth and survival. This review describes previous studies regarding the presence of major mycotoxins in the feed of farm animals, especially pigs and poultry. Moreover, it describes the adverse effects of mycotoxins in farm animals following exposure, as well as the biological activity of mycotoxins in animal-derived cells. Mycotoxins have been shown to regulate signaling pathways, oxidative stress, endoplasmic reticulum stress, apoptosis, and proliferation in porcine and bovine cells. A clear understanding of the effects of mycotoxins on farm animals will help reduce farm household economic loss and address the health concerns of people who consume these meat and dairy products.

Risk assessment of ochratoxin A in food

The European Commission asked EFSA to update their 2006 opinion on ochratoxin A (OTA) in food. OTA is produced by fungi of the genus Aspergillus and Penicillium and found as a contaminant in various foods. OTA causes kidney toxicity in different animal species and kidney tumours in rodents. OTA is genotoxic both in vitro and in vivo; however, the mechanisms of genotoxicity are unclear. Direct and indirect genotoxic and non-genotoxic modes of action might each contribute to tumour formation. Since recent studies have raised uncertainty regarding the mode of action for kidney carcinogenicity, it is inappropriate to establish a health-based guidance value (HBGV) and a margin of exposure (MOE) approach was applied. For the characterisation of non-neoplastic effects, a BMDL 10 of 4.73 μg/kg body weight (bw) per day was calculated from kidney lesions observed in pigs. For characterisation of neoplastic effects, a BMDL 10 of 14.5 μg/kg bw per day was calculated from kidney tumours seen in rats. The estimation of chronic dietary exposure resulted in mean and 95th percentile levels ranging from 0.6 to 17.8 and from 2.4 to 51.7 ng/kg bw per day, respectively. Median OTA exposures in breastfed infants ranged from 1.7 to 2.6 ng/kg bw per day, 95th percentile exposures from 5.6 to 8.5 ng/kg bw per day in average/high breast milk consuming infants, respectively. Comparison of exposures with the BMDL 10 based on the non-neoplastic endpoint resulted in MOEs of more than 200 in most consumer groups, indicating a low health concern with the exception of MOEs for high consumers in the younger age groups, indicating a possible health concern. When compared with the BMDL 10 based on the neoplastic endpoint, MOEs were lower than 10,000 for almost all exposure scenarios, including breastfed infants. This would indicate a possible health concern if genotoxicity is direct. Uncertainty in this assessment is high and risk may be overestimated.

Change of Amino Acid Residues in Idiotypic Nanobodies Enhanced the Sensitivity of Competitive Enzyme Immunoassay for Mycotoxin Ochratoxin A in Cereals

Anti-idiotypic nanobodies, usually expressed by gene engineering protocol, has been shown as a nontoxic coating antigen for toxic compound immunoassays. We here focused on how to increase immunoassay sensitivity by changing the nanobody’s primary sequence. In the experiments, two anti-idiotype nanobodies against monoclonal antibody 1H2, which is specific to ochratoxin A, were obtained and named as nontoxic coating antigen 1 (NCA1) and nontoxic coating antigen 2 (NCA2). Three differences between the nanobodies were discovered. First, there are six amino acid residues (AAR) of changes in the complementarity determining region (CDR), which compose the antigen-binding site. One of them locates in CDR1 (I–L), two of them in CDR2 (G–D, E–K), and three of them in CDR3 (Y–H, Y–W). Second, the affinity constant of NCA1 was tested as 1.20 × 10⁸ L mol⁻¹, which is about 4 times lower than that of NCA2 (5.36 × 10⁸ L mol⁻¹). Third, the sensitivity (50% inhibition concentration) of NCA1 for OTA was shown as 0.052 ng mL⁻¹, which was 3.5 times lower than that of nontoxic coating antigen 2 (0.015 ng mL⁻¹). The results indicate that the AAR changes in CDR of the anti-idiotypic nanobodies, from nonpolar to polar, increasing the affinity constant may enhance the immunoassay sensitivity. In addition, by using the nontoxic coating antigen 2 to substitute the routine synthetic toxic antigen, we established an eco-friendly and green enzyme-linked immunosorbent assay (ELISA) method for rapid detection of ochratoxin A in cereals. The half-maximal inhibitory concentration (IC₅₀) of optimized ELISA was 0.017 ng mL⁻¹ with a limit of detection (LOD) of 0.003 ng mL⁻¹. The optimized immunoassay showed that the average recoveries of spiked corn, rice, and wheat were between 80% and 114.8%, with the relative standard deviation (RSD) ranging from 3.1–12.3%. Therefore, we provided not only basic knowledge on how to improve the structure of anti-idiotype nanobody for increasing assay sensitivity, but also an available eco-friendly ELISA for ochratoxin A in cereals.

A rapid HPLC-FLD method for Ochratoxin A detection in pig muscle, kidney, liver by using enzymatic digestion with MISPE extraction

Ochratoxin A (OTA) is a mycotoxin produced as a secondary metabolite by various Aspergillus and Penicillium species with nephrotoxic, carcinogenic, immunotoxic and teratogenic effects. OTA has been found in several food commodities, including cereals, beer, wine and spices. OTA can also be present in animal products (especially in pig derived products) as a result of carryover from contaminated feed. Permitted level of 1 µg/kg OTA in pig meat or pig-derived products was set in Italy, as in other countries. Key parameters which affected MISPE, should be described such as extraction efficiency and were optimized, analyzed by an isocratic HPLC-FLD method. Under the optimized conditions, for all analyzed matrices mean recovery was > 89%. Method can be applied as alternative routine procedure to detect OTA presence in pig products. Points:  *Aim of the study was to develop and validate a quantitative HPLC-FLD method based on MISPE with complex solid matrices (edible tissues) followed by chromatographic analysis.  *The new method was developed and validated in pig complex matrix and is very sensitive LOD and LOQ respectively 0.001 and 0.003 µg/kg.  *This method is relatively simple to use and with good performances. Was possible to reuse MISPE column with a "regeneration" solution, until to 7 times.

Ochratoxin A in Beers Marketed in Portugal: Occurrence and Human Risk Assessment

Ochratoxin A (OTA) is produced by fungi present in several agricultural products with much relevance to food safety. Since this mycotoxin is widely found in cereals, beer has a potential contamination risk. Therefore, it was deemed essential to quantify, for the first time, the levels of OTA in beer, a cereal-based product that is marketed in Portugal, as well as to calculate the human estimated weekly intake (EWI) and risk assessment. A total of 85 samples were analyzed through immunoaffinity clean-up, followed by liquid chromatography-fluorescence detection (LC-FD). This analytical methodology allowed a limit of quantification (LOQ) of 0.43 µg/L. The results showed that 10.6% were contaminated at levels ranging between <LOQ and 11.25 µg/L, with an average of 3.14 ± 4.09 µg/L. Samples of industrial production presented lower incidence and contamination levels than homemade and craft beers. On what concerns human risk, the calculated EWI was significantly lower than the tolerable weekly intake (TWI). However, in the worst case scenario, based on a high concentration, the rate EWI/TWI was 138.01%.

Design of Ru(II)-NHC-Diamine Precatalysts Directed by Ligand Cooperation: Applications and Mechanistic Investigations for Asymmetric Hydrogenation

A modular synthesis of Ru(II)-NHC-diamine complexes from readily available chiral N-heterocyclic carbenes (NHCs) and chiral diamines is disclosed for the first time. The well-defined Ru(II)-NHC-diamine complexes show unique structure and coordination chemistry including an unusual tridentate coordination effect of 1,2-diphenylethylenediamine. The isolated air- and moisture-stable Ru(II)-NHC-diamine complexes act as versatile precatalysts for the asymmetric hydrogenation of isocoumarines, benzothiophene 1,1-dioxides, and ketones. Moreover, on the basis of the identification of reaction intermediates by stoichiometric reactions and NMR experiments, together with the DFT calculations, a possible catalytic cycle was proposed.

Protective Effect of Astaxanthin on Ochratoxin A-Induced Kidney Injury to Mice by Regulating Oxidative Stress-Related NRF2/KEAP1 Pathway

The present study aimed to investigate the effects of astaxanthin (ASX) on ochratoxin A (OTA)-induced renal oxidative stress and its mechanism of action. Serum kidney markers, histomorphology, ultrastructural observation, and oxidative stress indicators were assessed. Meanwhile, quantitative real-time reverse transcription PCR and western blotting detection of NRF2 (encoding nuclear factor, erythroid 2 like) and members of the NRF2/KEAP1 signaling pathway (KEAP1 (encoding Kelch-like ECH-associated protein), NQO1 (encoding NAD(P)H quinone dehydrogenase), HO-1 (encoding heme oxygenase 1), γ-GCS (gamma-glutamylcysteine synthetase), and GSH-Px (glutathione peroxidase 1)) were performed. Compared with the control group, the OTA-treated group showed significantly increased levels of serum UA (uric acid) and BUN (blood urea nitrogen), tubular epithelial cells were swollen and degenerated, and the levels of antioxidant enzymes decreased significantly, and the expression of NRF2 (cytoplasm), NQO1, HO-1, γ-GCS, and GSH-Px decreased significantly. More importantly, after ASX pretreatment, compared with the OTA group, serum markers were decreased, epithelial cells appeared normal; the expression of antioxidant enzymes increased significantly, NQO1, HO-1, γ-GCS and GSH-Px levels increased significantly, and ASX promoted the transfer of NRF2 from the cytoplasm to the nucleus. These results highlight the protective ability of ASX in renal injury caused by OTA exposure, and provide theoretical support for ASX’s role in other mycotoxin-induced damage.

Environmental-friendly gold nanoparticle immunochromatographic assay for ochratoxin A based on biosynthetic mimetic mycotoxin-conjugates

Ochratoxin A (OTA) is a possibly carcinogenic mycotoxin which is one of the most abundant food contaminants. It can be normally monitored and detected by immunochromatographic assays (ICG) which have a good sensitivity and specificity and easy to operate. However, the development of normal ICG is based on traditional OTA-conjugates or chemosynthetic mimotope peptides, which are very high-cost reagents with a detrimental effect on the environment and operators. This study takes advantage of both biosynthetic mimetic OTA-conjugates and a convenient IGG to develop a novel environmental-friendly and low-cost ICG for the rapid detection of OTA. Qualitatively, the visual cut-off level of the developed ICG for OTA was 0.8 ng/ml, which is 10-fold more sensitive than the chemosynthetic mimotope peptide based ICG, while there is no cross-reaction with other mycotoxins. The assay takes only 15 min to acquire results visible to the naked eye. Quantitatively, the half inhibition concentration of the ICG setup with mimetic OTA-conjugates was 0.187 ng/ml, with a linear range of 0.015 to 0.5 ng/ml. These results demonstrate the potential to adapt the method for detecting other toxic mycotoxins.

Occurrence of Mycotoxins in Fish Feed and Its Effects: A Review

Plant-based ingredients have been successfully replacing fishmeal in finished fish feeds. However, using crops in feeds results in an increased risk of contamination by fungi and mycotoxins and a higher incidence of mycotoxicosis in fish. This might decrease aquaculture's productivity as mycotoxicosis generally result in decreased body weight, growth impairment and higher rates of disease and mortality in fish. Additionally, some mycotoxins might accumulate in the fish musculature. As such, fish consumption might become another way for mycotoxins to enter the human food chain, threatening food security and public health as mycotoxins are important genotoxins, carcinogens and immunosuppressors to humans. In this work we aim to provide a review on the most important mycotoxins found in crops and in finished fish feed, i.e., aflatoxins, fumonisins, ochratoxins, trichothecenes and zearalenone. We present their effects on the health of fish and humans and their regulations in the European Union. Although work has been performed in mycotoxin research ever since the 1960s, a lot of information is still lacking regarding its effects. However, it is noticed that in order to use crops in aquafeed production, efforts should be made in order to monitor its contamination by mycotoxinogenic fungi and mycotoxins.

Astaxanthin Protects Ochratoxin A-Induced Oxidative Stress and Apoptosis in the Heart via the Nrf2 Pathway

This study assessed the protective mechanism of astaxanthin (ASX) against ochratoxin A- (OTA-) induced cardiac injury in mice. Four groups of mice were established: control group (0.1 mL olive oil + 0.1 mL NaHCO₂), OTA group (0.1 mL OTA 5 mg/kg body weight), ASX group (0.1 mL ASX 100 mg/kg body weight), and ASX + OTA group (0.1 mL ASX 100 mg/kg body weight, 2 h later, 0.1 mL OTA 5 mg/kg body weight). The test period lasted for 27 days (7 days of dosing, 2 days of rest). Electrocardiogram, body weight, heart weight, tissue pathology, oxidative markers (malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH)), biochemical markers (creatine kinase (CK), creatine kinase isoenzyme (CK-MB), and lactate dehydrogenase (LDH)), electron microscopy, TUNEL, and Western blot tests were used to examine the effects of OTA on myocardial injury and ASX detoxification. The results showed that OTA exposure significantly decreased both body weight and heart weight. OTA induced a decrease in heart rate in mice and decreased tissue concentrations of SOD, CAT, and GSH, while increasing serum concentrations of cardiac enzymes (CK, CK-MB, and LDH) and tissue MDA. ASX improved heart rate, cardiac enzymes, and antioxidant levels in mice. The results of tissue pathology and TUNEL assay showed that ASX protects against OTA-induced myocardial injury. In addition, Western blot results showed that the OTA group upregulated Keap1, Bax, Caspase3, and Caspase9, while it downregulated Nrf2, HO-1, and Bcl-2 protein expression. ASX played a protective role by changing the expression of Keap1, Nrf2, HO-1, Bax, Bcl-2, Caspase3, and Caspase9 proteins. These results indicate that the protective mechanism of ASX on the myocardium works through the Keap1-Nrf2 signaling pathway and mitochondria-mediated apoptosis pathway. This study provides a molecular rationale for the mechanism underlying OTA-induced myocardial injury and the protective effect of ASX on the myocardium.

Human Biomonitoring of Mycotoxins in Blood, Plasma and Serum in Recent Years: A Review

This manuscript reviews the state-of-the-art regarding human biological monitoring (HBM) of mycotoxins in plasma serum and blood samples. After a comprehensive and systematic literature review, with a focus on the last five years, several aspects were analyzed and summarized: a) the biomarkers analyzed and their encountered levels, b) the analytical methodologies developed and c) the relationship between biomarker levels and some illnesses. In the literature reviewed, aflatoxin B1-lysine (AFB1-lys) and ochratoxin A (OTA) in plasma and serum were the most widely studied mycotoxin biomarkers for HBM. Regarding analytical methodologies, a clear increase in the development of methods for the simultaneous determination of multiple mycotoxins has been observed. For this purpose, the use of liquid chromatography (LC) methodologies, especially when coupled with tandem mass spectrometry (MS/MS) or high resolution mass spectrometry (HRMS), has grown. A high percentage of the samples analyzed for OTA or aflatoxin B1 (mostly as AFB1-lys) in the reviewed papers were positive, demonstrating human exposure to mycotoxins. This review confirms the importance of mycotoxin human biomonitoring and highlights the important challenges that should be faced, such as the inclusion of other mycotoxins in HBM programs, the need to increase knowledge of mycotoxin metabolism and toxicokinetics, and the need for reference materials and new methodologies for treating samples. In addition, guidelines are required for analytical method validation, as well as equations to establish the relationship between human fluid levels and mycotoxin intake.

Ochratoxin A in human blood plasma samples from apparently healthy volunteers in Nanjing, China

This study was conducted to investigate the exposure to ochratoxin A (OTA) of populations living in Nanjing, China. Plasma samples were collected from 147 healthy adults (age 18-63 years) and analyzed for OTA by a reliable and sensitive ultra-high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method (limit of detection 0.04 ng/mL). After enzymatic hydrolysis by β-glucuronidase/arylsulfatase, OTA was detected in 80.9% plasma samples with mean concentration of 0.26 ± 0.59 ng/mL (range 0.04-6.59 ng/mL). The estimated daily intakes of OTA based on plasma concentrations (mean 0.51 ng/kg bw/day, max 12.99 ng/kg bw/day) were lower than the tolerable daily intake published by European Food Safety Authority (EFSA) or Joint FAO/WHO Expert Committee on Food Additives (JFECFA) indicative of rare risks related to the OTA exposure in the investigated area. This study provides a valuable insight on human exposure to OTA in China. Further studies in children and elder people and in adult cohorts from other regions are recommended.

A self-assembled electrochemical immunosensor for ultra-sensitive detection of ochratoxin A in medicinal and edible malt

Trace residue of mycotoxins in complex medicinal and edible food matrices has brought huge challenges for the development of ultrasensitive analytical methods. Here, a green electrochemical immunosensor for the ultrasensitive detection of ochratoxin A (OTA) was fabricated by self-assembling a compact 2-mercaptoacetic (TGA) monolayer on the surface of the working Au electrode to form the Au/TGA/bovine serum aibumin (BSA)-OTA/anti-OTA monoclonal antibody composite probes for selective and ultra-sensitive detection of OTA based on indirect competitive principle and differential pulse voltammetry analysis. The electrochemical impedance spectroscopy and cyclic voltammetry methods were introduced to characterize the assemble situation of the TGA-modified Au electrode and optimize some critical parameters for the green electrochemical immunoseonsor. Under the optimal conditions, the developed immunosensor exhibited much lower limit of detection (0.08 ng/mL) in the range of 0.1-1.0 ng/mL for OTA compared with other direct or disposable electrochemical immunosensors. Real application in the spiked malt samples verified high accuracy with no matrix interferences of the proposed immunoseonsor. This is a meaningful study on a self-assembled electrochemical immunoseonsor for ultra-sensitive and rapid detection of OTA in malt samples, which suggested a general simple-to-use sensing platform and prospect as an economical and green tool for ultra-sensitive detection of much more trace-level of toxic small molecules in other complex matrices to ensure their quality and safety.

Toxicological and Medical Aspects of Aspergillus-Derived Mycotoxins Entering the Feed and Food Chain

Due to Earth's changing climate, the ongoing and foreseeable spreading of mycotoxigenic Aspergillus species has increased the possibility of mycotoxin contamination in the feed and food production chain. These harmful mycotoxins have aroused serious health and economic problems since their first appearance. The most potent Aspergillus-derived mycotoxins include aflatoxins, ochratoxins, gliotoxin, fumonisins, sterigmatocystin, and patulin. Some of them can be found in dairy products, mainly in milk and cheese, as well as in fresh and especially in dried fruits and vegetables, in nut products, typically in groundnuts, in oil seeds, in coffee beans, in different grain products, like rice, wheat, barley, rye, and frequently in maize and, furthermore, even in the liver of livestock fed by mycotoxin-contaminated forage. Though the mycotoxins present in the feed and food chain are well documented, the human physiological effects of mycotoxin exposure are not yet fully understood. It is known that mycotoxins have nephrotoxic, genotoxic, teratogenic, carcinogenic, and cytotoxic properties and, as a consequence, these toxins may cause liver carcinomas, renal dysfunctions, and also immunosuppressed states. The deleterious physiological effects of mycotoxins on humans are still a first-priority question. In food production and also in the case of acute and chronic poisoning, there are possibilities to set suitable food safety measures into operation to minimize the effects of mycotoxin contaminations. On the other hand, preventive actions are always better, due to the multivariate nature of mycotoxin exposures. In this review, the occurrence and toxicological features of major Aspergillus-derived mycotoxins are summarized and, furthermore, the possibilities of treatments in the medical practice to heal the deleterious consequences of acute and/or chronic exposures are presented.

Red orange and lemon extract prevents the renal toxicity induced by ochratoxin A in rats

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.

An immunoassay for ochratoxin A using tetramethylrhodamine-labeled ochratoxin A as a probe based on a binding-induced change in fluorescence intensity

In an immunoassay, ochratoxin A (OTA) competitively displaces the bound tetramethylrhodamine (TMR)-OTA fluorescent probe from the antibody, causing a decrease in fluorescence.

Efficacy of the Combined Protective Cultures of Penicillium chrysogenum and Debaryomyces hansenii for the Control of Ochratoxin A Hazards in Dry-Cured Ham

The ecological conditions during the ripening of dry-cured ham favour the development of moulds on its surface, being frequently the presence of Penicillium nordicum, a producer of ochratoxin A (OTA). Biocontrol using moulds and yeasts usually found in dry-cured ham is a promising strategy to minimize this hazard. The aim of this work is to evaluate the effect of previously selected Debaryomyces hansenii and Penicillium chrysogenum strains on growth, OTA production, and relative expression of genes involved in the OTA biosynthesis by P. nordicum. P. nordicum was inoculated against the protective cultures individually and combined on dry-cured ham for 21 days at 20 °C. None of the treatments reduced the growth of P. nordicum, but all of them decreased OTA concentration. The lower production of OTA could be related to significant repression of the relative expression of otapksPN and otanpsPN genes of P. nordicum. The efficacy of the combined protective cultures was tested in 24 dry-cured hams in industrial ripening (an 8 month-long production). OTA was detected in nine of the 12 dry-cured hams in the batch inoculated only with P. nordicum. However, in the batch inoculated with both P. nordicum and the combined protective culture, a considerable reduction of OTA contamination was observed. In conclusion, although the efficacy of individual use P. chrysogenum is great, the combination with D. hansenii enhances its antifungal activity and could be proposed as a mixed protective culture to control the hazard of the presence of OTA in dry-cured ham.

GPx1-mediated DNMT1 expression is involved in the blocking effects of selenium on OTA-induced cytotoxicity and DNA damage

Ochratoxin A (OTA) is a potent nephrotoxin. Selenium (Se) is an essential micronutrient for humans and animals, and plays a key role in antioxidant defense. To date, little is known about the effect of Se on OTA-induced DNA damage. In this study, the protective effects of Se (from selenomethionine) against OTA-induced cytotoxicity and DNA damage were investigated by using PK15 cells as a model. The results showed that OTA at 4.0 μg/mL induced cytotoxicity and DNA damage. Se at 0.5, 1, 2 and 4 μM significantly blocked OTA-induced cytotoxicity and DNA damage. Furthermore, Se blocked the increases of DNMT1, DNMT3a and HDAC1 mRNA and protein expression, reversed the decreases of glutathione peroxidase 1 (GPx1) mRNA and protein expression, and promoted the increases of SOCS3 mRNA and protein expression induced by OTA. Overexpression of GPx1 by pcDNA3.1-GPx1 inhibited the OTA-induced DNMT1 expression, promoted OTA-induced SOCS3 expression, and prevented the OTA-induced cytotoxicity and DNA damage. In contrast, knock-down of GPx1 by using a GPx1-specific siRNA had the opposite effects. The results suggest that GPx1-mediated DNMT1 expression is involved in the blocking effects of selenium on OTA-induced cytotoxicity and DNA damage.

Ochratoxin A exposure causes meiotic failure and oocyte deterioration in mice

Ochratoxin A (OTA) is a mycotoxin produced by fungi and occurs naturally in various foodstuffs and some animal-derived products. This mycotoxin can cause deleterious effects on kidney, liver, central nervous, and immune system. However, potential mechanisms regarding how OTA disrupts the mammalian oocyte quality have not been clearly defined. In this study, we proved that OTA weakened oocyte quality by impairing oocyte meiotic maturation. We found that female mice treated with 1 mg/kg body weight OTA by intraperitoneal (IP) injection for 7 days displayed ovarian dysfunction and decreased offspring number. We also found that OTA treatment at 7.5 μM for 16 h decreased the rate of first polar body extrusion by disrupting spindle and chromosome alignment. In addition, OTA caused oxidative stress by inducing the accumulation of reactive oxygen species and consumption of antioxidants during meiosis, consequently resulting in oocytes apoptosis. Mitochondrial damage and insufficient energy supply were also observed in OTA-pretreated oocytes, which led to the meiotic failure of oocyte. Moreover, the epigenetic modifications were also affected, showing with altered 5 mC, 5hmC, H3K9ac, and H3K9me3 levels in mice oocytes. In summary, these results showed that OTA could decrease oocyte maturation and fertility by inducing oxidative stress and epigenetic changes.

Analyses of biomarkers of exposure to nephrotoxic mycotoxins in a cohort of patients with renal tumours

The Czech Republic occupies the first place in the world in the frequency of renal and other urinary tract tumours, but their aetiology is unknown. To explore whether carcinogenic and nephrotoxic mycotoxins may contribute to kidney diseases in the Czech population, biomarkers of ochratoxin A (OTA) and citrinin (CIT) exposure were determined in biological specimens from a cohort of 50 patients with malignant renal tumours. Biomarker analyses in blood and urine samples used validated targeted methods for measuring OTA and CIT plus dihydrocitrinone (DH-CIT) after enrichment of analytes by specific immunoaffinity clean-up. OTA and CIT plus its metabolite DH-CIT were frequently detected in patient urine samples (OTA 62%; CIT 91%; DH-CIT 100%). The concentration ranges in urine were 1-27.8 ng/L for OTA, 2-87 ng/L for CIT and 2-160 ng/L for DH-CIT. The analyses of blood samples revealed also a frequent co-occurrence of OTA and CIT, in the ranges of 40-870 ng/L serum for OTA and 21-182 ng/L plasma for CIT. This first analysis of biomarkers in blood and urine samples of Czech patients revealed no major differences in comparison with published data for the general healthy Czech and European populations. Nonetheless, a frequent co-occurrence of CIT and OTA biomarkers in patient samples may be of interest with regard to potential interactions with other risk factors for renal disease.

Mycotoxin contamination of food and feed in the Gulf Cooperation Council countries and its detection

Mycotoxins are secondary metabolites produced by different fungal spices and are found in diverse agricultural crops worldwide; they pose a severe threat to public health. Mycotoxins can cause either acute or chronic symptoms, depending on the type and dose of mycotoxin one has been exposed to. Thus, a continuous monitoring of mycotoxins is needed. Since the discovery of mycotoxins, numerous countries, including the Gulf Cooperation Council (GCC) countries, have established mycotoxin-specific regulations for feed and food. Although a number of studies in GCC countries have investigated the presence of mycotoxins, till date, there are no reviews focusing on the mycotoxin contamination of the food and feed from this region. This review is the first study to present an up-to-date overview of the occurrence of mycotoxins in feed and food in the GCC countries and to discuss the techniques used for mycotoxin analysis.

Environmental exposures in young adults with declining kidney function in a population at risk of Mesoamerican nephropathy

OBJECTIVES

There is an epidemic of Mesoamerican nephropathy (MeN) in Central America, where sugarcane production is prominent. Numerous causes are proposed, but to date limited evidence supports any one hypothesis. A nested case-control study using biosamples from a rural, community-based follow-up study of 350 young adults from Northwest Nicaragua at risk of MeN was conducted with the aim of characterising the associations between urinary concentrations of metals, pesticides and mycotoxins from samples collected in the first 6 months and decline in kidney function over 2 years.

METHODS

Urine samples collected at baseline (pre-sugarcane harvest) and the first 6 month follow-up (post-sugarcane harvest) visit were tested. Twelve metals and metalloids (aluminium, total arsenic, cadmium, chromium, cobalt, copper, lead, manganese, mercury, selenium, silicon and strontium) were analysed by inductively coupled plasma-mass spectrometry. Twelve pesticides or their metabolites (2,4-dichlorophenoxyacetic acid, 3-phenoxybenzoic acid, 4-fluoro-3-phenoxybenzoic acid, chloro-3,3,3-trifluoro-1-propen-1-yl-2,2-dimethylcyclopropanecarboxylic acid, cis/trans 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid, ethylenethiourea, glyphosate, 4-chloro-2-methylphenoxy acetic acid, 3-hydroxy-pyrimetanil, 5-hydroxytiabendazole, hydroxy-tebuconazole and 3,5,6-trichloro-2-pyridinol) and two mycotoxins (ochratoxin A (OTA) and citrinin (CIT)) were analysed by liquid chromatography coupled-mass spectrometry. Differences in the creatinine-corrected urinary concentrations of the measured exposures between outcome groups (participants with stable vs declining kidney function) were examined.

RESULTS

Elevated levels of aluminium and total arsenic as well as metabolites of several pesticides were detected across the population. No differences were identified between the declining and stable groups in the levels of metals or pesticides tested. OTA and CIT were below the limit of detection.

CONCLUSIONS

The tested metals, metalloids, pesticides and mycotoxins were not associated with loss of kidney function in participants at-risk of MeN.

Antifungal activity of selected natural preservatives against the foodborne molds Penicillium verrucosum and Aspergillus westerdijkiae

The present study examines the inhibitory effect of the essential oil (EO) of Origanum vulgare, its active components carvacrol and thymol, and a few active components of other EOs, namely, eugenol, trans-cinnamaldehyde and 1,8-cineole, against Penicillium verrucosum CBS 302.48, Aspergillus westerdijkiae CBS 112803 and Aspergillus westerdijkiae CBS 112804. Therefore, the minimum inhibitory concentration (MIC) was determined by broth macrodilution of each antifungal agent. Regarding their antifungal activity, the following ranking in order of decreasing inhibitory action is: trans-cinnamaldehyde > carvacrol = thymol > O. vulgare EO > eugenol > 1,8-cineole. The combined effects of the natural preservatives were studied by checkerboard assay. The results are based on the fractional inhibitory concentration indices (FICIs), which are interpreted as 'synergy', 'no interaction' or 'antagonism'. The indices ranging from 0.8 to 1.3 and thus show no interaction. In addition, the dependence of the natural inhibitors on different pH values (pH 7.0, 5.6, 4.5 and 3.5) and water activity (0.99, 0.92, 0.90 and 0.87 aw) was investigated. All tested natural preservatives are tolerant to the different examined milieu conditions, with the lowest MICs recorded at pH 3.5 and 0.87 aw.

Astaxanthin Protects OTA-Induced Lung Injury in Mice through the Nrf2/NF-κB Pathway

The aim of this research was to evaluate the potential protective mechanism of astaxanthin (ASTA) against oxidative damage and inflammation caused by ochratoxin (OTA) in mouse lung. We divided mice into a control group (CG), an OTA group (PG), an astaxanthin group (AG), and an OTA+ASTA group (JG). Oxidative indices (malondialdehyde (MDA), total superoxide dismutase (T-SOD), and reduced glutathione (GSH)) and inflammatory markers (interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α)) were assayed in the lung, and the lung-weight-to-body-weight ratio was calculated. Apoptosis was detected in pathological sections by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. Oxidative damage and inflammation were detected in the lung of mice after exposure to OTA. Besides, Nrf2- and NF-κB-pathway-associated proteins were detected by Western blot. In contrast with OTA, ASTA significantly raised the expression of Nrf2, HO-1, and MnSOD, while the expression of other proteins (Keap1, TLR4, and NF-κB) was significantly decreased. These results indicate that ASTA exerted protective effects against OTA-induced oxidative damage and inflammation in the lung by regulating the Nrf2 and NF-κB pathways.