Human Proximal Tubule Epithelial Cells (HK-2) as a Sensitive In Vitro System for Ochratoxin A Induced Oxidative Stress.

Ochratoxin A (OTA) is a mycotoxin that is potentially carcinogenic to humans. Although its mechanism remains unclear, oxidative stress has been recognized as a plausible cause for the potent renal carcinogenicity observed in experimental animals. The effect of OTA on oxidative stress parameters in two cell lines of LLC-PK1 and HK-2 derived from the kidneys of pig and human, respectively, were investigated and compared. We found that the cytotoxicity of OTA on LLC-PK1 and HK-2 cells was dose- and time-dependent in both cell lines. Furthermore, increased intracellular reactive oxygen species (ROS) induced by OTA in both cell lines were observed in a time-dependent manner. Glutathione (GSH) was depleted by OTA at >48 h in HK-2 but not in LLC-PK1 cells. While the mRNA levels of glucose-6-phosphate dehydrogenase (G6PD) and glutathione peroxidase 1 (GPX1) in LLC-PK1 were down-regulated by 0.67- and 0.66-fold, respectively, those of catalase (CAT), glutathione reductase (GSR), and superoxide dismutase 1 (SOD) in HK-2 were up-regulated by 2.20-, 2.24-, and 2.75-fold, respectively, after 72 h exposure to OTA. Based on these results, we conclude that HK-2 cells are more sensitive to OTA-mediated toxicity than LLC-PK1, and OTA can cause a significant oxidative stress in HK-2 as indicated by changes in the parameter evaluated.

Ochratoxin A Levels in Tissues of Wild Boars (Sus scrofa) from Northern Italy.

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus and Penicillium, capable of contaminating several foodstuffs. OTA damages primarily the kidneys, and is suspected to be a carcinogenic substance, thus maximum levels for OTA in foodstuffs have been established in the EU. Italian Ministry of Health suggested a maximum level of 1 µg/kg OTA in pork meat and derived products. In this study, OTA concentrations in liver, kidney, and muscle of 64 wild boars (Sus scrofa) killed in two areas (area A and B) of Parma province (northern Italy), characterized by different habitat types, were assessed by HPLC-FLD technique. OTA was detected in 54% liver, 52% kidney, and 16% muscle samples. OTA levels were significantly higher in liver and kidney compared with muscle, and were above 1 µg/kg in 19 liver, 17 kidney, and 4 muscle samples. OTA levels in wild boars from area A resulted significantly higher with respect to those from area B, suggesting an environmental influence on OTA contamination in wild boars. This study seems to confirm that wild boar meat is a potential source of OTA, thus monitoring the presence of this mycotoxin in game meat might be recommended to prevent risks for human health.

Selenium Yeast Alleviates Ochratoxin A-Induced Apoptosis and Oxidative Stress via Modulation of the PI3K/AKT and Nrf2/Keap1 Signaling Pathways in the Kidneys of Chickens.

The purpose of this study was to investigate the protective effect and mechanism of yeast selenium (Se-Y) on ochratoxin- (OTA-) induced nephrotoxicity of chickens. A total of 80 one-day-old healthy chickens were randomly divided into 4 equal groups: control, OTA (50 µg/kg OTA), Se-Y (0.4 mg/kg Se-Y), and OTA+Se-Y (50 µg/kg OTA+0.4 mg/kg Se-Y). In the OTA chickens, differences in body weight, kidney coefficient, biochemical histological analysis, antioxidant capability, and the expression levels of the PI3K/AKT and Nrf2/Keap1 signaling pathway-related genes were observed. The levels of total superoxide dismutase (T-SOD), antioxidant capacity (T-AOC), catalase (CAT), and glutathione (T-GSH) significantly decreased, but the malondialdehyde (MDA) level of the kidneys significantly increased in the OTA treatment group. More importantly, treatment with Se-Y improved the antioxidant enzyme activities within the kidneys of chickens exposed to OTA. In addition, administration of OTA resulted in apoptosis and was associated with decreased expression of AKT, PI3K, and Bcl-2, which in turn enhanced expression of Caspase3, Bax, and P53. However, Se-Y improved the antioxidant defense system through activation of the Nrf2/Keap1 signaling pathway. Gene expression of Nrf2 and its target genes (HO-1, GSH-px, GLRX2, MnSOD, and CAT) was downregulated following OTA exposure. Conversely, Se-Y treatment resulted in a significant upregulation of the same genes. Besides, significant downregulations of protein expression of HO-1, CAT, MnSOD, Nrf2, and Bcl-2 and a significant upregulation of Caspase3 and Bax levels were observed after contaminated with OTA. Notably, OTA-induced apoptosis and oxidative damage in the kidney of chickens were reverted back to normal level in the OTA+Se-Y group. Taken together, the data suggest that Se-Y alleviates OTA-induced nephrotoxicity in chickens, possibly through the activation of the PI3K/AKT and Nrf2/Keap1 signaling pathways.

Protective effect of curcumin on ochratoxin A-induced liver oxidative injury in duck is mediated by modulating lipid metabolism and the intestinal microbiota.

Curcumin has antioxidant functions, regulates the intestinal microbial composition, and alleviates mycotoxin toxicity. The present study aimed to explore whether curcumin could alleviate ochratoxin A (OTA)-induced liver injury via the intestinal microbiota. A total of 720 mixed-sex 1-day-old White Pekin ducklings were randomly assigned into 4 groups: CON (control group, without OTA), OTA (fed a diet with 2 mg/kg OTA), CUR (ducks fed a diet with 400 mg/kg curcumin), and OTA + CUR (2 mg/kg OTA plus 400 mg/kg curcumin). Each treatment consisted of 6 replicates and 30 ducklings per replicate. Treatment lasted for 21 D. Results were analyzed by a two-tailed Student t test between 2 groups. Our results demonstrated that OTA treatment had the highest serum low-density lipoprotein (LDL) level among 4 groups. Compared with OTA group, OTA + CUR decreased serum LDL level (P < 0.05). OTA decreased liver catalase (CAT) activity in ducks (P < 0.05), while addition of curcumin in OTA group increased liver CAT activity (P < 0.05). 16S ribosomal RNA sequencing suggested that curcumin increased the richness indices (ACE index) and diversity indices (Simpson index) compared with OTA group (P < 0.05) and recovered the OTA-induced alterations in composition of the intestinal microbiota. Curcumin supplementation relieved the decreased abundance of butyric acid producing bacteria, including blautia, butyricicoccus, and butyricimonas, induced by OTA (P < 0.05). OTA also significantly influenced the metabolism of the intestinal microbiota, such as tryptophan metabolism and glyceropholipid metabolism. Curcumin could alleviate the upregulation of oxidative stress pathways induced by OTA. OTA treatment also increased SREBP-1c expression (P < 0.05). The curcumin group had the lowest expression of FAS and PPARG mRNA (P < 0.05) and the highest expression of NRF2 and HMOX1 mRNA. These results indicated that curcumin could alleviate OTA-induced oxidative injury and lipid metabolism disruption by modulating the cecum microbiota.

Detecting Neurodevelopmental Toxicity of Domoic Acid and Ochratoxin A Using Rat Fetal Neural Stem Cells.

Currently, animal experiments in rodents are the gold standard for developmental neurotoxicity (DNT) investigations; however, testing guidelines for these experiments are insufficient in terms of animal use, time, and costs. Thus, alternative reliable approaches are needed for predicting DNT. We chose rat neural stem cells (rNSC) as a model system, and used a well-known neurotoxin, domoic acid (DA), as a model test chemical to validate the assay. This assay was used to investigate the potential neurotoxic effects of Ochratoxin A (OTA), of which the main target organ is the kidney. However, limited information is available regarding its neurotoxic effects. The effects of DA and OTA on the cytotoxicity and on the degree of differentiation of rat rNSC into astrocytes, neurons, and oligodendrocytes were monitored using cell-specific immunofluorescence staining for undifferentiated rNSC (nestin), neurospheres (nestin and A2B5), neurons (MAP2 clone M13, MAP2 clone AP18, and Doublecortin), astrocytes (GFAP), and oligodendrocytes (A2B5 and mGalc). In the absence of any chemical exposure, approximately 46% of rNSC differentiated into astrocytes and neurons, while 40.0% of the rNSC differentiated into oligodendrocytes. Both non-cytotoxic and cytotoxic concentrations of DA and OTA reduced the differentiation of rNSC into astrocytes, neurons, and oligodendrocytes. Furthermore, a non-cytotoxic nanomolar (0.05 µM) concentration of DA and 0.2 µM of OTA reduced the percentage differentiation of rNSC into astrocytes and neurons. Morphometric analysis showed that the highest concentrations (10 µM) of DA reduced axonal length. These indicate that low, non-cytotoxic concentrations of DA and OTA can interfere with the differentiation of rNSC.

The effect of polyphenols and vitamin E on the antioxidant status and meat quality of broiler chickens fed diets naturally contaminated with ochratoxin A.

The aim of this study was to determine the effect of a polyphenol product (PP) (Proviox) and vitamin E on the antioxidant status and meat quality of broiler chickens fed diets contaminated with ochratoxin A (OTA). One hundred and twenty ROSS 308 broiler chickens were randomly divided into six groups (10 replications, 2 birds per replication). Group I received an uncontaminated and unsupplemented diet, diets of groups II to VI were contaminated with OTA at 172 µg and 200 µg/kg for the starter and grower period, respectively. Furthermore, diets of groups III, IV and V were supplemented with vitamin E at 100, 200 and 100 mg, respectively, and to diets of groups V and VI additionally 100 and 2200 mg PP was added, respectively. Supplementation with PP and vitamin E had no significant effects on the growth performance, dressing percentage or carcass trait parameters of broiler chickens. In chickens exposed to stress, dietary supplementation with vitamin E and/or PP improved the total antioxidant status (p ≤ 0.05), enhanced the blood activity of antioxidant enzymes (p ≤ 0.01) and increased the concentrations of non-enzymatic antioxidants (p ≤ 0.01) in the liver and breast muscles. Regardless of the administered antioxidants, chickens fed diets contaminated with OTA were characterised by lower dressing percentage (p ≤ 0.01), a higher proportion of the liver in the carcass (p ≤ 0.01), lower carcass fat content (p ≤ 0.01), and longer small intestines (p ≤ 0.01) and caeca (p ≤ 0.01). Dietary supplementation with PP improved the water-holding capacity of meat (p ≤ 0.01). The breast muscles of chickens fed diets supplemented with PP and vitamin E were characterised by higher (p ≤ 0.05) concentrations of eicosapentaenoic acid (C20:5). It was concluded that PP can be an insufficient component of diets for broiler chickens to improve growth performance and mitigate the negative effects of high dose of OTA in diets.

Predominant mycotoxins, mycotoxigenic fungi and climate change related to wine.

Wine is a significant contributor to the economies of many countries. However, the commodity can become contaminated with mycotoxins produced by certain fungi. Most information on mycotoxins in wine is from Spain, Italy and France. Grapes can be infected by mycotoxigenic fungi, of which Aspergillus carbonarius producing ochratoxin A (OTA) is of highest concern. Climate is the most important factor in determining contamination once the fungi are established, with high temperatures being a major factor for OTA contamination: OTA in wine is at higher concentrations in warmer southern Europe than northern. Contamination by fumonisins is a particular concern, related to Aspergillus niger producing these compounds and the fungus being isolated frequently from grapes. Aflatoxins can be present in wine, but patulin is seldom detected. Alternaria mycotoxins (e.g. alternariol) have been frequently observed. There are indications that T-2 toxin may be common. Also, the combined effects of mycotoxins in wine require consideration. No other mycotoxins are currently of concern. Accurate fungal identifications and mycotoxin detection from the fungi are important and a consideration of practical methods are required. There is a diversity of wines that can be contaminated (e.g. red, white, sweet, dry and fortified). The occurrence of OTA is higher in red and sweet than white wines. Steps to control mycotoxins in wine involve good agriculture practices. The effect of climate change on vines and mycotoxins in wine needs urgent consideration by well-constructed modelling studies and expert interpretation of existing data. Reliable models of the effect of climate change on vines is a priority: the health of vines affects mycotoxin contamination. A modelling study of OTA in grapes at higher temperatures over 100years is required. Progress has been made in reducing OTA in wine. The other mycotoxins require consideration and the effects of climate change will become crucial.

Daily uptake of mycotoxins - TDI might not be protective for nursed infants.

Exclusive breast feeding is recommended by international bodies for the first six months of life. Because of the presence of contaminants, breast feeding might lead to toxicologically relevant exposure of the nursed child. Exposure towards mycotoxins is of specific interest because of their widespread occurrence in food and of their toxicological profile. We calculated the relationship between maternal intake at the level of the existing TDIs and the exposure in the nursed infants of several mycotoxins to evaluate whether maternal exposure at the TDI is also safe for the nursed infant. If published information was not available we used in silico methods for estimating toxicokinetic parameters and the lactational transfer. A single dose and a continuous daily intake scenario were considered. Maternal intake at the TDI exceeds the age-adjusted TDI (TDI/3) values for infants in case of deoxynivalenol and patulin in the single dose scenario. Exceedance is particularly pronounced for ochratoxin A in the continuous daily intake scenario (29.2 fold above the child adjusted TDI). According to published data in infants impaired kidney function may result from this exceedance. When setting a TDI, the safety of the exclusively nursed infant should be considered in the continuous daily intake scenario.

Impact of mycotoxins on the intestine: are mucus and microbiota new targets?

There is an increasing awareness of the deleterious effects attributed to mycotoxins during their fate within the gut, particularly for deoxynivalenol (DON), zearalenone (ZEN), ochratoxin A (OTA), fumonisin B1 (FB1), aflatoxin B1 (AFB1), and patulin (PAT). Evidence indicates that disruption of the epithelial barrier is well established. However, intestinal barrier function on its luminal side involves two other partners, mucus and microbiota, which have rarely been considered in the context of mycotoxin exposure. The current review aimed at providing a summary of DON, ZEN, OTA, FB1, AFB1, and PAT effects on intestinal barrier function, with special focus on mucus and microbiota. DON, ZEN, OTA, FB1, AFB1, and PAT are known to markedly affect epithelial cell integrity and functions. Regarding mucus, DON is the most documentated mycotoxin. In vivo, toxicological impact of DON generally has only been assessed through goblet cell number. Evaluation of the mycotoxins/mucus interplay considering other indicators such as composition, thickness, and penetrability of mucus, mucin O-glycosylation thus warrants further attention. With respect to microbiota, few short-term studies to date have been reported indicating deleterious effects. However, long-term exposure to mycotoxins may also produce significant changes in microbiota composition and metabolic activity, which requires further experimentation. In conclusion, mucus and microbiota are key targets for dietary mycotoxins although assessment of induced effects is preliminary. A significant research effort is now underway to determine the adverse consequences of mycotoxins on mucus and microbiota considered as individual but also as tightly connected gut players.

Identification and safety evaluation of a product from the biodegradation of ochratoxin A by an Aspergillus strain.

BACKGROUND: Ochratoxin A (OTA) poses a serious health hazard throughout the world and is often reported in food commodities. At present, biological approaches to detoxifying OTA are now widely considered to be the most promising methods. RESULTS: In this study, a strain that was identified as Aspergillus niger was isolated, and it has a strong ability to detoxify OTA. The degradation product (compound 1) of OTA was treated with crude enzyme. The product has been isolated and identified as C11 H9 O5 Cl (ochratoxin α), which is a weak lipophilic molecule, in contrast to fat-soluble OTA. The cytotoxic response of compound 1 was revealed to be different to that of OTA. Compound 1 does not induce cellular oxidative damage in comparison with OTA, which may cause lipid peroxidation (MDA), reduce SOD activity and induce DNA damage. CONCLUSION: This study indicates that A. niger has the ability to detoxify OTA. The OTA degradation product, ochratoxin α, does not exert cytotoxic effects on cell metabolism. A. niger has prospective uses for the OTA decontamination of food and agricultural fields. © 2016 Society of Chemical Industry.

Lack of an Apparent Association between Mycotoxin Concentrations in Red Chili Peppers and Incidence of Gallbladder Cancer in India : an Ecological Study.

Our recent studies conducted in South America have shown that mycotoxin contamination of red chili peppers (RCPs) may be associated with an increased risk of gallbladder cancer (GBC). Whether this relationship exists in India, a country with a high incidence of GBC and high consumption of RCPs, is unclear. We therefore measured concentrations of aflatoxins (AFs) and ochratoxin A (OTA) in RCPs from areas of low, medium, and high incidence of GBC in India, and compared these concentrations with GBC incidence in each area. Twentyone RCP samples were collected from nine cities (eight from a lowincidence area, five from a mediumincidence area, and eight from a highincidence area). Concentrations of AFs and OTA were measured using highperformance liquid chromatography. No significant differences in mean concentrations of AFs and OTA were found in the three areas. AFB1 levels in the lowincidence area (10.81 ?g/kg) and highincidence area (12.00 ?g/kg) were more than 2.2 and 2.4 times higher compared with the maximum permitted level of AFB1 in spices (5.0 ?g/kg) set by the Commission of the European Communities, or that (4.4 ?g/kg) obtained in our previous study in Chile. Our results show that the mean concentrations of mycotoxins in RCPs are similar among the three areas in India with different incidences of GBC. Further studies with human subjects are needed to evaluate any association between AFB1 and GBC.

Influence of repeated ochratoxin A ingestion on milk production and its carry-over into the milk, blood and tissues of lactating cows.

An experiment was conducted to investigate the influence of repeated ingestion of ochratoxin A (OTA) on milk production of lactating Holstein cows over 28 days, and the carry-over of OTA from the diets into the milk and tissues of the cows. Nine cows were divided into three groups, labeled OTA5, OTA50 and OTA100, and fed a diet containing 5, 50 and 100 µg OTA/kg of dry matter, respectively. Body weight, feed intake and daily milk yield in cows were not different among the three groups during the OTA-intake period. OTA residues were neither detected in the tissues, such as liver, kidney, muscles, fat and jejunoileum, nor in the milk of any cows in the OTA intake groups. In contrast, a small amount of OTA (0.1 µg/kg) was detected in the blood plasma of one sample in the OTA50 group and multiple samples in the OTA100 group. The results of this study show that the ingestion of diets containing up to 100 µg/kg of OTA over 28 days does not affect feed intake or milk production of cows, and the dietary OTA is not carried over into milk and edible tissues such as the liver, muscles and fat.

Ochratoxin A Contamination of Red Chili Peppers from Chile, Bolivia and Peru, Countries with a High Incidence of Gallbladder Cancer.

Our previous study detected aflatoxins in red chili peppers from Chile, Bolivia, and Peru, each of which have a high incidence of gallbladder cancer (GBC). Since the aflatoxin B1 concentration was not so high in these peppers, it is important to clarify the presence of other mycotoxins. Here we attempted to determine any associations between the concentrations of aflatoxins and ochratoxin A (OTA) in red chili peppers, and the corresponding GBC incidences. We collected red chili peppers from three areas in Peru: Trujillo (a high GBC incidence area), Cusco (an intermediate GBC incidence area), and Lima (a low GBC incidence rate), and from Chile and Bolivia. Aflatoxins and OTA were extracted with organic solvents. The concentrations of aflatoxins B1, B2, G1, and G2, and OTA were measured by high-performance liquid chromatography. The values obtained were compared with the incidence of GBC in each area or country. All of the red chili peppers from the three areas showed contamination with aflatoxins below the Commission of the European Communities (EC) recommended limits (5 µg/kg), but the OTA contamination of two samples was above the EC recommended limit (15 µg/kg). The mean concentrations of OTA in the peppers from Chile (mean 355 µg/kg, range <5-1,059 µg/kg) and Bolivia (mean 207 µg/kg, range 0.8-628 µg/kg), which has a high incidence of GBC, were higher than that in Peru (14 µg/kg, range <5-47 µg/kg), which has an intermediate GBC incidence. The OTA contamination in the red chili peppers from Chile, Bolivia, and Peru was stronger than that of aflatoxins. Our data suggest that OTA in red chili peppers may be associated with the development of GBC.

Mycotoxicoses in children.

Mycotoxicoses are acute and chronic poisonings caused by mould toxins called mycotoxins. Although acute mycotoxicoses, caused by high mycotoxin levels in food are rare nowadays, they need to be described in order to inform physicians and other health care workers about their symptoms. Children are more sensitive to mycotoxins because of their lower body mass, higher metabolic rate, and underdeveloped organ functions and detoxication mechanisms. Some mycotoxicoses appear only in children, and some are more pronounced in children than in adults. Acute mycotoxicoses in children are reported poorly, mostly because they occur in the tropical regions with poor healthcare coverage. In developed countries healthcare authorities are more concerned about child exposure to low levels of mycotoxins with immunotoxic, genotoxic or carcinogenic properties.

Ochratoxin A in traditional dry-cured meat products produced from sub-chronic-exposed pigs.

The presence of ochratoxin A (OTA) was determined in traditional dry-cured meat products made from sub-chronically OTA-exposed pigs. The experimental group of pigs (n = 5) was treated with 300 µg OTA kg(-1) of feed during 30 days, whereas the control group (n = 5) remained untreated. After the household production of six types of dry-cured meat products based on traditional recipes, OTA residues were determined in final products produced from each treated and untreated animal using an immunoenzymatic technique (ELISA) and HPLC with fluorescence detection (HPLC-FD). The analytical methods showed acceptable analytical performance results and high correlation coefficients. Mean OTA concentrations ranged from 4.51 ± 0.11 µg kg(-1) in smoked ham to 6.87 ± 2.01 µg kg(-1) in home-made Slavonian sausage. The study demonstrated that pig exposure to OTA leads to the accumulation of OTA residues in muscle and adipose tissue used for the production, and consequently results in contamination of the final meat products.

Hepatocellular carcinoma and food contamination: aflatoxins and ochratoxin A as a great prompter.

Prolonged exposure to mycotoxins in the diet is related to cancer, among other diseases. Hepatocellular carcinoma (HCC) accounts for 70%-90% of primary liver cancers and is the third leading cause of cancer-related deaths worldwide. Secondary metabolites, like aflatoxins and ochratoxin A (OTA), produced by some fungi species stocked in an inappropriate manner are considered an important way to increase HCC incidence. Future epidemiologic studies of HCC should focus on good practices in food preparation, food storage and the consumption of OTA-containing foods.

An iTRAQ-based mitoproteomics approach for profiling the nephrotoxicity mechanisms of ochratoxin A in HEK 293 cells.

Nephrotoxicity is the most prominent of ochratoxin A (OTA) among the diverse range of toxicological effects. Previous work indicated that reactive oxygen species (ROS) play an important role in the pathogenesis of a variety of renal diseases, and its major endogenous source is mitochondria. No research has used global protein expression profiling to investigate potential toxicity mechanisms of OTA at the mitochondria level. An iTRAQ-based mitoproteomics approach was used to explore possible toxicity mechanisms of OTA and potential protective mechanisms of N-acetyl-L-cysteine (NAC) using the mitochondria of Human Embryonic Kidney 293 (HEK 293) cells. Our results showed that OTA induced a decrease in ΔΨm, and an increase in ROS and cell death. We identified a total of 1973 nonredundant proteins, among which 1398 proteins (70.86%) were overlapped. There were 66 significantly different proteins expressed in response to OTA, which were mainly involved in the perturbation of the mitochondrial electron transport chain (mETC), inhibition of protein synthesis, and induction of stress response and cell death. In addition, NAC could almost completely reverse the adverse effects of OTA at the protein level. Finally, a hypothetical model of OTA-induced mitochondria damage is proposed to provide a framework for the toxicity mechanism of OTA.

Ochratoxin a and mitotic disruption: mode of action analysis of renal tumor formation by ochratoxin A.

The mycotoxin and food contaminant ochratoxin A (OTA) is a potent renal carcinogen in rodents, but its mode of action (MoA) is still poorly defined. In 2006, the European Food Safety Authority concluded that there is a "lack of evidence for the existence of OTA-DNA adducts" and thus insufficient evidence to establish DNA reactivity as a MoA for tumor formation by OTA. In reviewing the available database on OTA toxicity, a MoA for renal carcinogenicity of OTA is developed that involves a combination of genetic instability and increased proliferative drive as consequences of OTA-mediated disruption of mitosis, whereby the organ- and site-specificity of tumor formation by OTA is determined by selective renal uptake of OTA into the proximal tubule epithelium. The proposed MoA is critically assessed with respect to concordance of dose-response of the suggested key events and tumor formation, their temporal association, consistency, and biological plausibility. Uncertainties, data gaps and needs for further research are highlighted.

Ochratoxin A levels in human serum and foods from nephropathy patients in Tunisia: where are you now?

Ochratoxin A is a natural mycotoxin with nephrotoxic properties that can contaminate food products. It has been detected in high amount in human serum collected from nephropathy patients, especially those categorized as having a chronic interstitial nephropathy of unknown etiology. In the present study, ochratoxin A levels were measured in commonly consumed food items and in serum samples from nephropathy and healthy subjects in Tunisia. To assess ochratoxin A, a high performance liquid chromatography method was optimized. The ochratoxin A assay showed very different scales of ochratoxin A serum and food contamination from 0.12 to 1.5 ng/mL and 0.11 to 6.1 ng/g respectively, and in healthy subjects and 0.11 to 33.8 ng/g for food and 0.12 to 3.8 ng/mL for serum in nephropathy patients suffering from chronic interstitial nephropathy of unknown etiology. The disease seems related to ochratoxin A serum levels and food contaminations, since the healthy group was significantly different from the nephropathy group (P<0.001) for both food and serum ochratoxin A contamination. Those results combined with data published already, emphasize the likely endemic aspect of ochratoxin A-related nephropathy occurring in Tunisia.