Mycotoxin Ochratoxin Research Articles

Determination of some mycotoxins from poultry feed in Baghdad city

The aims of this study were to determine some mycotoxins and to isolate the fungi from chicken feed samples from broiler and layer farms in Baghdad city. The isolation rate (percentage) of fungi from poultry feed samples was Aspergillus niger 17.7%, Aspergillus flavus 14.7%, Aspergillus fumigatus 12.4%, Aspergillus ochraceus 10.7%, Penicillium spp. 9.3%, Fusarium spp. 9.3%, Rhizopus spp. 8.4%, Mucar spp. 8.4%, Absidia spp. 7.6% and Chrysonilia sitophila 1.5%, while the most common yeast genera were Candida spp. 44.8%, Candida albicans 20.7%, Cryptococcus neoformans 17.3%, Geotricum candidum 12% and Trichosorom spp. 5.2%. The mycotoxins ochratoxin A (OTA), deoxynivalenol (DON), fumonisin B1 (FB1) and zearalenone (ZON) were detected, and the percentages of these mycotoxins were 43.1%, 27.2%, 21.1% and 8.6%, respectively. This study indicates that the presence of mold that produce mycotoxins in poultry feed increases the risk of mycotoxins in feed, meat, eggs, etc. of animals and therefore humans, and we need to raise awareness of the Ministry of Agriculture and Health to prevent these measures to reduce the mycotoxin levels in poultry products.

Assessment of ochratoxin A occurrence in poultry feed in eastern Algeria

ABSTRACT This study investigated the prevalence of the mycotoxin Ochratoxin A in poultry feed samples from Eastern Algeria, an important poultry production region. Ochratoxin A, produced by Aspergillus and Penicillium fungi, can contaminate feed, leading to toxicity issues for poultry and human beings consuming contaminated products. Analysis of 42 feed samples using the Enzyme-Linked Immunosorbent Assay (ELISA), found 62% contained detectable ochratoxin A levels exceeding the concentration of 1.50 ng g−1, varying between 2.23 ng g−1 and 3.23 ng g−1 with an average of 2.59 ng g−1. Although the widespread prevalence is below current regulatory limits, there is a need for continued monitoring to prevent contamination and toxin transfer to poultry meat and eggs. The study recommends expanding testing to more regions and implementing Ochratoxin A surveillance. This is a feed – and food – safety issue on a large scale, with implications for other countries in North Africa.

Saccharomyces cerevisiae NX2320 inhibit Aspergillus carbonarius by cell membrane disruption and oxidative stress-mediated autophagy in in vitro and during grape storage

Aspergillus carbonarius not only causes the decay of fresh fruit, but also produce the mycotoxin ochratoxin A. Biological control of pathogenic fungus by antagonistic microorganisms is a safe and effective method. However, information about the potential mechanism of antagonistic microorganisms to suppress A. carbonarius is limited. In this study, S. cerevisiae NX2320 inhibited the growth of A. carbonarius in PDA media and during grape storage. 2-phenylethanol (2-PE) produced by S. cerevisiae NX2320 may be the key substance for its antifungal mechanism. The result indicated that S. cerevisiae NX2320 and 2-PE inhibited OTA production, break the redox steady state, destroy membrane integrity, cause cell autophagy and control the production of mycotoxins. The results indicated that S. cerevisiae must be further investigated for potential application to control fungal and mycotoxin problems during grape storage.

Band Alignment Modulated Polarity-Switchable PEC Ratiometric Sensor through Coupling a pH-Responsive CuTCPP MOF with i-Motif Sensing tool.

In conventional ratiometric photoelectrochemical (PEC) sensors, the detection and reference signals are output sequentially from two independent photosensitive materials. In such a "two-to-two" ratiometric mode, unavoidable difference during dual-interface modification exists, resulting in questionable ratiometric signals and detection results. To address this issue, we propose a novel "one-to-two" ratiometric PEC sensor on a single electrode interface through pH-modulated band alignment engineering. The double ratiometric signals are generated by the synergistic action of a pH-responsive CuTCPP/WS2 photoelectric substrate material and the i-motif sensing tool. Specifically, a ternary heterostructure to generate a photoanodic detection signal is formed under alkaline conditions between CuTCPP/WS2 and signal label CdS QDs binding to the i-motif. While under acidic conditions, a photocurrent polarity conversion and signaling labels detachment, induced by the band realignment of CuTCPP/WS2 and the i-motif conformational switching, produce a reliable internal reference photocathodic signal. The feasibility of this two-wing signal generation strategy is validated by detecting mycotoxin ochratoxin A, which achieves accurate and reliable ratio detection results. Overall, this work provides guidance for the design of a PEC ratiometric determination system and exhibits great potential to be applied in practical analysis research.

Effects of Chrysin and Chrysin-7-sulfate on Ochratoxin A-Albumin Interactions and on the Plasma and Kidney Levels of the Mycotoxin in Rats.

The nephrotoxic mycotoxin ochratoxin A (OTA) is a common food contaminant. OTA binds to the Sudlow's Site I region of serum albumin with very high affinity, resulting in its slow elimination. The displacement of OTA from albumin may be beneficial due to the faster excretion of the mycotoxin, while it may also lead to the increased tissue uptake of OTA. Furthermore, it is challenging to displace the mycotoxin from albumin even with high-affinity Site I ligands. In this study, we tested the impacts of Site I and Heme site ligands on OTA-albumin interactions by applying fluorescence spectroscopic, ultracentrifugation, and modeling studies. Chrysin-7-sulfate (C7S) strongly displaced OTA from both human and rat albumins; therefore, the impacts of C7S (single intravenous administration) and the parent flavonoid chrysin (repeated peroral treatment) were examined on the plasma and kidney levels of OTA in rats. Chrysin barely influenced the concentrations of mycotoxin in plasma and kidneys. In the first few hours, C7S significantly decreased the plasma levels of OTA compared to the control animals; while after 24 h, only minor differences were noticed. Our study highlights the superior displacing ability of C7S vs OTA regarding human and rat albumins.

Ochratoxin A Induces Renal Cell Ferroptosis by Disrupting Iron Homeostasis and Increasing ROS.

Mycotoxin ochratoxin A (OTA) is a critical food safety concern due to its nephron-toxic effects and is detected in a wide range of food and feedstuffs. OTA nephrotoxicity is related to oxidative stress and damage. However, the mediator(s) of the excessive oxidative stress is unclear. The current study used human kidney cell lines to investigate whether and how intracellular iron contributed to OTA-induced ROS accumulation and how OTA-induced iron-dependent ferroptotic cell death. Our results showed that OTA treatment affected the cell viability and induced the typical characteristics of cell ferroptosis. Furthermore, gene and protein expression results indicated that OTA disrupted iron homeostasis by upregulating the expression levels of iron importer TFR1 and FTH, while downregulating the expression level of iron exporter FPN and dramatically increasing its negative regulator Hepcidin. The changes were consistent with the induction of intracellular iron accumulation and elevated levels of oxidative stress and lipid peroxidation. Additionally, co-treatment with OTA and an iron chelator significantly improved cell viability, reduced cellular total iron and ROS, and reversed OTA-induced changes in iron metabolism gene expression levels. Interestingly, the addition of a ROS scavenger also reversed cell death and changes in mRNA and protein expression levels of iron metabolism genes but to a lesser degree than that of the iron-chelating agent. Our results revealed that OTA induced ferroptosis in renal cells by disrupting iron homeostasis and increasing ROS.

Occurrence of ochratoxin A in breast milk and urine samples of nursing mothers in Bangladesh.

The mycotoxin ochratoxin A (OTA) is a potent nephrotoxin with carcinogenic properties and, thus, of concern as a food contaminant. Since food contaminant data are scarce in Bangladesh, we applied human biomonitoring to gain more insights into OTA exposure in the country's population. OTA concentrations in human milk and urine samples of nursing mothers were determined with the aim to assess also exposure to this mycotoxin in breastfed infants. Breastfeeding mothers (n = 74) from three districts of Bangladesh (Sylhet, Cumilla, and Mymensingh region) participated in this study. They provided demographic data, along with breast milk and urine samples. OTA levels were measured by a competitive enzyme-linked immunosorbent assay (ELISA) with a detection limit of 60ng/L for milk and 30ng/L for urine.OTA was detected in 62.2% of all breast milk samples (mean 74.8 ± 49.0ng/L, range < LOD-243.3ng/L) and in 51.4% of all urine samples (mean 44.3 ± 63.5ng/L, range < LOD-519.3ng/L). The differences observed between regions for mean breast milk or for urinary OTA levels were relatively small. No significant correlation was observed between OTA levels in breast milk and food consumption patterns among nursing mothers. Regarding infant exposure, the estimated average daily intake of OTA for all was 15.0ng/kg bw/day (range 4.5-45ng/kg bw/day). In 34.5% of these infants, their estimated daily OTA intake exceeded a preliminary TDI value set by EFSA (17ng/kg bw/day). The mean OTA intake was slightly higher (16.2 ± 7.8 ng/kg bw/day) in 1-2months babies than in older infants (< 2 to 12months), although the difference was not significant. Presence of OTA in most milk and urine samples of nursing mothers documents their widespread dietary mycotoxin exposure. Although based on a relatively small number of participants, the present analysis indicates non-negligible exposure of some nursed infants in Bangladesh. Therefore, further biomonitoring studies and investigations on major sources of OTA in food commodities are encouraged.

Farnesoid X Receptor Plays a Key Role in Ochratoxin A-Induced Nephrotoxicity by Targeting Ferroptosis In Vivo and In Vitro.

The mycotoxin ochratoxin A (OTA) causes nephrotoxicity, hepatotoxicity, and immunotoxicity in animals and humans. The farnesoid X receptor (FXR) is a member of the NR family and is highly expressed in the kidney, which has an antilipid production function. Ferroptosis is an iron-dependent form of regulated cell death involved in several pathophysiological cell death and kidney injury. The present study aims to evaluate the role of FXR and ferroptosis in OTA-induced nephrotoxicity in mice and HK-2 cells. Results showed that OTA induced nephrotoxicity as demonstrated by inducing the histopathological lesions and neutrophil infiltration of the kidney, increasing serum BUN, CRE, and UA levels, increasing Ntn-1, Kim-1, and pro-inflammatory cytokine expression, and decreasing IL-10 expression and the cell viability of HK-2 cells. OTA treatment also induced FXR deficiency, ROS release, MDA level increase, GSH content decrease, and 4-HNE production in the kidney and HK-2 cells. OTA treatment induced ferroptosis as demonstrated by increasing labile iron pool and lipid peroxidation levels as well as Acsl4, TFR1, and HO-1 mRNA and protein levels, decreasing GPX4 and FTH mRNA and protein expressions, and inducing mitochondrial injury. The FXR activator (GW4064) rescued the accumulation of lipid peroxides, intracellular ROS, and Fe2+, inhibited ferroptosis, and alleviated OTA-induced nephrotoxicity. The ferroptosis inhibitor (Fer-1) prevented ferroptosis and attenuated nephrotoxicity. Collectively, this study elucidates that FXR played a critical role in OTA-induced nephrotoxicity via regulation of ferroptosis, which provides a novel strategy against OTA-induced nephrotoxicity.

The nephrotoxin ochratoxin a impairs resilience of energy homeostasis of human proximal tubule cells

Despite a long history of research, the mode of action of the mycotoxin ochratoxin A (OTA) is still not clear. Based on our observation that OTA-exposed cells consume more glucose and produce more lactate than control cells, with this study, we want to suggest another possible mode of action of OTA, involving cellular metabolism and mitochondria. We exposed human proximal tubule cells (HK2 cells) to OTA and studied its influence on mitochondrial performance as well as on the expression of energy homeostasis-involved routing proteins (AMPK and TXNIP) and on glucose transporting and metabolizing proteins. OTA reduced the capacity of mitochondria to increase their oxygen consumption rate forcing the cells to switch to the ineffective anaerobic glycolysis which demands higher glucose availability. The higher glucose demand is met by augmented cellular glycogen degradation and increased glucose uptake capabilities by increasing glucose transporter expression. We conclude that OTA exposure leads to impaired mitochondria, which forces the cells to alter their metabolism in order to ensure energy supply. We suggest to consider a possible effect of OTA on metabolism and mitochondria and to have a closer look on OTA-induced changes in the metabolome as possible additional players in OTA toxicity.

Ochratoxin A-Imprinted nanoMIPs Prepared by Solid Phase Synthesis: Effect of Mimic Template on Binding Properties

The solid-phase polymerization synthesis (SPPS) represents one of the most innovative approaches to the preparation of nano-sized molecularly imprinted polymers. One of its main features consists of the use of a solid support on which the template molecule is covalently grafted. It implies that the imprinting process does not involve the target molecule as is, but, rather, a structural modification of it. It is known that the rationally designed mimic N-(4-chloro-1-hydroxy-2-naphthoylamido)-(L)-phenylalanine (CHNA-Phe) is able to generate, by bulk polymerization, imprinted materials capable of recognizing the mycotoxin Ochratoxin A (OTA). In this work, we wanted to verify whether the CHNA-Phe can be a useful mimic template in the SPPS technique. The binding isotherm were measured in the pH range of 4–8 and the binding affinities for CHNA-Phe and OTA were compared, showing that CHNA-Phe-imprinted nanoMIPs recognize, in buffered water, equally well OTA, and that the overall molecular recognition depends markedly from pH-related ionic interactions between the ligand and the binding site. There results confirm that in the SPPS method, it is possible and convenient to use as mimic templates a molecule whose three-dimensional structure is to some extent different from the target without substantial loss of selectivity or binding affinity.

Development of a Novel Magnetic-Bead-Based Automated Strategy for Efficient and Low-Cost Sample Preparation for Ochratoxin A Detection Using Mycotoxin–Albumin Interaction

The mycotoxin ochratoxin A (OTA) is toxic to humans and frequently contaminates wine and beer. Antibodies are essential recognition probes for the detection of OTA. However, they have several drawbacks, such as high costs and difficulty in preparation. In this study, a novel magnetic-bead-based automated strategy for efficient and low-cost OTA sample preparation was developed. Human serum albumin, which is an economical and stable receptor based on the mycotoxin-albumin interaction, was adapted and validated to replace conventional antibodies to capture OTA in the sample. Ultra-performance liquid chromatography-fluorescence detection was used in combination with this preparation method for efficient detection. The effects of different conditions on this method were investigated. The recovery of OTA samples spiked at three different concentrations ranged from 91.2% to 102.1%, and the relative standard deviations (RSDs) were 1.2%-8.2% in wine and beer. For red wine and beer samples, the LODs were 0.37 and 0.15 µg/L, respectively. This reliable method overcomes the drawbacks of conventional methods and offers significant application prospects.

The salicylate 1,2-dioxygenase from Pseudaminobacter salicylatoxidans DSM 6986T is a bifunctional enzyme that inactivates the mycotoxin ochratoxin A by a novel amidohydrolase activity

The salicylate 1,2-dioxygenase from the bacterium Pseudaminobacter salicylatoxidans DSM 6986T (PsSDO) is a versatile metalloenzyme that participates in the aerobic biodegradation of aromatic compounds, such as gentisates and salicylates. Surprisingly, and unrelated to this metabolic role, it has been reported that PsSDO may transform the mycotoxin ochratoxin A (OTA), a molecule that appears in numerous food products that results in serious biotechnological concern. In this work, we show that PsSDO, together with its dioxygenase activity, behaves as an amidohydrolase with a marked specificity for substrates containing a C-terminal phenylalanine residue, similar to OTA, although its presence is not an absolute requirement. This side chain would establish aromatic stacking interactions with the indole ring of Trp104. PsSDO hydrolysed the amide bond of OTA rendering the much less toxic ochratoxin α and L-β-phenylalanine. The binding mode of OTA and of a diverse set of synthetic carboxypeptidase substrates these substrates have been characterized by molecular docking simulations, which has permitted us to propose a catalytic mechanism of hydrolysis by PsSDO that, similarly to metallocarboxypeptidases, assumes a water-induced pathway following a general acid/base mechanism in which the side chain of Glu82 would provide the solvent nucleophilicity required for the enzymatic reaction. Since the PsSDO chromosomal region, absent in other Pseudaminobacter strains, contained a set of genes present in conjugative plasmids, it could have been acquired by horizontal gene transfer, probably from a Celeribacter strain.

Monitoring of mycotoxins and pesticides in winemaking

This study monitored concentrations of both pesticides 2,4-dichlorophenoxyacetic acid (2,4-D) and procymidone, and mycotoxin ochratoxin A (OTA) in stages of the winemaking process. Sampling was carried out in the usual vinification process of red wine in a winery between the steps to obtain must and alcoholic fermentation. The highest transference of contaminants in the process occurred in the crushing step to 2,4-D (100%) and maceration to OTA and procymidone (100%). Removal of contaminants in the winemaking process corresponded to 100%, with a half-life (T1/2) longer for procymidone (216.5 h) and shorter for 2,4-D (38.5 h) and OTA (96 h). The processing factors (PFs) (0) for the contaminants, together with the data obtained, characterize winemaking as a process of reducing mycotoxin and pesticides. Results highlight the importance of fermentation to reduce contaminants and that yeasts promote detoxification

Ochratoxin A and Deoxynivalenol Mycotoxin Profile in Triticale Seedlings with Different Susceptibility to the Root Rot

Cereals in the southeastern part of Kazakhstan can be affected by the crown and common root rot and spot blotches mostly caused by Bipolaris sorokiniana and Fusarium spp. Triticale is a man-made crop obtained from the crossing of wheat (Triticum sp.) × rye (Secale cereale L.) and it is mainly cultivated as a feed grain for livestock in Kazakhstan. Mycotoxins are secondary metabolites of fungi secreted by the toxigenic species Alternaria, Aspergillus, Fusarium, and Penicillium. The study aimed to determine the effect of the varietal factor and the type of mycotoxin on their content in 15-day triticale seedlings. The spread and development indices of root rot were calculated and the Liquid Chromatography coupled with tandem Mass Spectrometry (LC-MS/MS) was performed to determine the concentration of mycotoxins. The content of micro-toxins depended both on their type and the triticale variety (P-value <0.001). The maximum content of mycotoxins Ochratoxin A and Deoxynivalenol in some seedlings reached 100-120 mcg/mL, on average 12.4 and 15.1 mcg/mL, respectively. In Rondo, Fidelio 5, and Valentin varieties, the mycotoxin content was 11.2; 16.9, and 8.6 mcg/mL, with a spread of 79.0-93.0%, the development of common root rot reached 30.5-34.2%, while in Idea, TI 17, Nevo and Dokuckaevsky 9, the average mycotoxin content was lower, within 1.4-3.9 mcg/mL, with a spread of 50.0-65.0% and the development of common root rot reaching 20.5-25.0%. In the triticale Alnaiskii 5 variety, these indices equaled 0.7 mcg/mL; 55.0 and 19.2%, respectively. A high positive correlation (0.8) was found between the content of mycotoxins and the infestation of triticale seedlings with root rot.

Inhibition of cytochrome P450 enhances the nephro- and hepatotoxicity of ochratoxin A

The mycotoxin ochratoxin A (OTA) is a contaminant in food that causes nephrotoxicity and to a minor degree hepatotoxicity. Recently, we observed that OTA induces liver damage preferentially to the cytochrome P450 (CYP)-expressing pericentral lobular zone, similar to hepatotoxic substances known to be metabolically toxified by CYP, such as acetaminophen or carbon tetrachloride. To investigate whether CYP influences OTA toxicity, we used a single dose of OTA (7.5 mg/kg; intravenous) with and without pre-treatment with the pan CYP-inhibitor 1-aminobenzotriazole (ABT) 2 h before OTA administration. Blood, urine, as well as liver and kidney tissue samples were collected 24 h after OTA administration for biochemical and histopathological analyses. Inhibition of CYPs by ABT strongly increased the nephro- and hepatotoxicity of OTA. The urinary kidney damage biomarkers kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) were increased > 126-fold and > 20-fold, respectively, in mice treated with ABT and OTA compared to those receiving OTA alone. The blood biomarkers of liver damage, alanine transaminase (ALT) and aspartate transaminase (AST) both increased > 21- and 30-fold, respectively, when OTA was administered to ABT pre-treated mice compared to the effect of OTA alone. Histological analysis of the liver revealed a pericentral lobular damage induced by OTA despite CYP-inhibition by ABT. Administration of ABT alone caused no hepato- or nephrotoxicity. Overall, the results presented are compatible with a scenario where CYPs mediate the detoxification of OTA, yet the mechanisms responsible for the pericental liver damage pattern still remain to be elucidated.

Antioxidant and antiapoptotic effects of quercetin against ochratoxin A-induced nephrotoxicity in broiler chickens

The mycotoxin ochratoxin A (OTA) is produced by the fungi Aspergillus and Penicillium. The flavonoid quercetin (QUE) is distinguished by its antioxidant, anti-inflammatory, and antiapoptotic properties. This study was designed to determine whether QUE can protect broiler chickens against OTA-induced nephrotoxicity. Forty broiler chicks were randomly divided into four equal groups: control, OTA, QUE, and OTA + QUE. For 6 weeks, OTA (0.5 mg/kg) and/or QUE (0.5 g/kg) were added to the diet of chickens. The results demonstrated that OTA exposure increased serum levels of creatinine, uric acid, and blood urea nitrogen. OTA exposure also increased renal malondialdehyde content but decreased renal antioxidants. OTA-exposed chickens exhibited multiple pathological kidney lesions. Moreover, OTA exposure induced apoptosis in renal tissue, which was manifested by the up-regulation of proapoptotic genes and down-regulation of antiapoptotic genes via the suppression of the PI3K/AKT pathway. In addition, coadministration of QUE and OTA mitigated most of these nephrotoxic effects.

Ochratoxin A and Citrinin Differentially Modulate Bovine Mammary Epithelial Cell Permeability and Innate Immune Function.

Frequent detection of mycotoxins ochratoxin A (OTA) and citrinin (CIT) in ruminant feed and feedstuff can be a potential threat to feed safety, animal performance and health. Ineffective biodegradation of these mycotoxins by rumen microflora following ingestion of contaminated feeds can lead to their circulatory transport to tissues such as mammary gland as the result of their biodistribution throughout the body. The bovine mammary epithelium plays a pivotal role in maintaining milk yield and composition and contributes to innate immune defense of the udder. The present study is the first to investigate individual effects of OTA and CIT on barrier and innate immune functions of the bovine mammary epithelium using a bovine mammary epithelial cell line (MAC-T). Results indicated that OTA and CIT exposure for 48 h significantly decreased cell viability in a concentration-dependent manner (p < 0.05). A decrease in transepithelial electrical resistance and increase in paracellular flux of FITC-40 kDa dextran was significantly induced by OTA treatment (p < 0.05), but not by CIT after 48 h exposure. qPCR was performed for assessment of expression of tight-junction proteins, Toll-like receptor 4 (TLR4) and cytokines after 4, 24 and 48 h of exposure. Both OTA and CIT markedly downregulated expression of claudin 3 and occludin (p < 0.05), whereas CIT did not affect zonula occludens-1 expression. Expression of TLR4 was significantly upregulated by OTA (p < 0.001) but downregulated by CIT (p < 0.05) at 48 h. Expression of IL-6, TNF-a and TGF-β was significantly upregulated by OTA (p < 0.05), whereas IL-6 and TGF-β expression was downregulated by CIT (p < 0.01). These results suggest that OTA and CIT could potentially differentially modulate barrier and innate immune functions of mammary epithelium. The present study not only throws light on the individual toxicity of each mycotoxin on bovine mammary epithelium but also lays the foundation for future studies on the combined effects of the two mycotoxins.

Hypoalbuminemia affects the spatio-temporal tissue distribution of ochratoxin A in liver and kidneys: consequences for organ toxicity

Hypoalbuminemia (HA) is frequently observed in systemic inflammatory diseases and in liver disease. However, the influence of HA on the pharmacokinetics and toxicity of compounds with high plasma albumin binding remained insufficiently studied. The ‘lack-of-delivery-concept’ postulates that HA leads to less carrier mediated uptake of albumin bound substances into hepatocytes and to less glomerular filtration; in contrast, the ‘concept-of-higher-free-fraction’ argues that increased concentrations of non-albumin bound compounds facilitate hepatocellular uptake and enhance glomerular filtration. To address this question, we performed intravital imaging on livers and kidneys of anesthetized mice to quantify the spatio-temporal tissue distribution of the mycotoxin ochratoxin A (OTA) based on its auto-fluorescence in albumin knockout and wild-type mice. HA strongly enhanced the uptake of OTA from the sinusoidal blood into hepatocytes, followed by faster secretion into bile canaliculi. These toxicokinetic changes were associated with increased hepatotoxicity in heterozygous albumin knockout mice for which serum albumin was reduced to a similar extent as in patients with severe hypoalbuminemia. HA also led to a shorter half-life of OTA in renal capillaries, increased glomerular filtration, and to enhanced uptake of OTA into tubular epithelial cells. In conclusion, the results favor the ‘concept-of-higher-free-fraction’ in HA; accordingly, HA causes an increased tissue uptake of compounds with high albumin binding and increased organ toxicity. It should be studied if this concept can be generalized to all compounds with high plasma albumin binding that are substrates of hepatocyte and renal tubular epithelial cell carriers.

Transcriptomic analysis of inhibition by eugenol of ochratoxin A biosynthesis and growth of Aspergillus carbonarius

Aspergillus carbonarius is a saprophytic filamentous fungus that produces the mycotoxin ochratoxin A (OTA), a powerful hepatotoxin, nephrotoxin and teratogen, which causes global problems with food contamination during storage. Various methods were applied to assess the impact of eugenol on the OTA production and mycelial growth of A. carbonarius. The minimum inhibitory concentration (MIC) for eugenol treatment was 0.8 μL/mL. Eugenol treatment at 0.2 μL/mL (1/4 MIC) resulted in 87.7% decrease in OTA production in spite of only a 26.9% inhibition of mycelial growth, and actually caused marked morphological changes of spores and mycelia by Scanning electron microscopy (SEM). A total of 400 differentially expressed genes (DEGs) were detected by comparatively transcriptomic analysis of A. carbonarius in the presence or absence of eugenol, including 324 down-regulated and 76 up-regulated DEGs. The transcription of the clustered genes for OTA biosynthesis was significantly reduced under eugenol stress and further confirmed by RT-qPCR. LaeA, a global regulator for secondary metabolites biosynthesis, was markedly downregulated by eugenol. Eugenol disrupted cell integrity by the disturbance of the DEGs expression in relation with cellular structure, which was also proved by monitoring chitinase activity, malondialdehyde (MDA) and ergosterol content. Changes in superoxide dismutase (SOD) and catalase (CAT) activity, and glutathione (GSH) content showed that eugenol induced oxidative stress, which was also consistent with the changes in gene expression. These findings provide useful insights into the antifungal and antimycotoxigenic mechanisms of eugenol and improve understanding of the effects of eugenol on A. carbonarius.

Defining Mycotoxins Associated with Wheat Grains in Mosul Silo by ELISA

The study aimed to identify fungi-contaminated with some varieties of wheat grains locals, as well as isolate fungi-contaminated with grains imported wheat in Silo of Mosul city, and estimate the level of mycotoxins ochratoxin, zearalenone, and aflatoxin in them by ELISA method. Results showed that the local wheat variety, Ebaa 99, showed the highest percentage of appearance in Aspergillus flavus, was 63.15%, while the lowest appearance of fungi was Mucor spp. With a percentage of 2.47%, the variety Rasheed showed the highest percentage of A. flavus, which was 49.12%, while the lowest appearance was of Rhizopus spp. With a percentage of 2.29%, As well as in the variety Al-Baraka A. flavus showed the highest percentage, which was 5.453%, and the lowest percentage was Cladosporium spp by 9.43%. The contaminated fungi differed from the imported varieties and the percentage of their appearance. In the Canadian variety, the highest appearance of A. flavus was 63.72%, and A. dematatus was the least appearance with 5.42%. The fungus A. flavus also appeared in the American variety, with the highest appearance of 43.17%. The least appearance was Fusarium oxysporum at 5.34%. In the Australian variety, the highest appearance was found in A. flavus, at 54.03%, and the fungus Fusarium spp. was the least appeared fungi, at 1.96%. Estimation of mycotoxins indicates that the aflatoxin amount in the variety Ebaa 99 samples was 34.55 ppm, while its amount of ochratoxin and zearalenone was 21.75 ppm and 0.23 ppm, respectively. Canadian variety grains had the lowest aflatoxin content, with the highest ochratoxin. Australian variety grains had the lowest content of aflatoxin, ochratoxin, and zearalenone amount 12.29 ppm, 0.82 ppm, and 11.51 ppm, respectively.