Acute toxicity of three herbicide formulations of Astyanax altiparanae (Characiformes, Characidae), an emerging neotropical fish model species.

Herbicides are used in agriculture to control harmful crop weeds, prevent algae proliferation, and enhance macrophyte growth. Herbicide contamination of water bodies might exert toxic effects on fish in different development stages. Sperm, embryos, and adults of Astyanax altiparanae were used as a model to examine the detrimental effects of the following herbicide formulations: Roundup Transorb® (glyphosate), Arsenal® NA (imazapyr), and Reglone® (diquat). The lethal concentration 50 (LC50) values for adults using glyphosate and imazapyr were 3.14 mg/L and 4.59 mg/L, respectively, while the LC50 was higher than 28 mg/L for diquat. For the initial stages of embryo development, LC50 values were 16.52 mg/L glyphosate, 9.33 mg/L imazapyr, and 1084 mg/L diquat. Inhibition of sperm motility was noted at 252 mg/L glyphosate, 137 mg/L imazapyr, and 11,300 mg/L diquat, with an average sperm viability of 12.5%, 73.2%, and 89.3%, respectively, compared to 87.5% detected to control. A. altiparanae exhibited different sensitivities to the herbicide formulations investigated in the developmental stages evaluated. Roundup Transorb® exposure was more toxic for adults, while Arsenal® NA was most harmful for early embryonic development and inhibited sperm motility. Reglone® demonstrated low toxicity for A. altiparanae compared to Roundup Transorb® and Arsenal® NA. A. altiparanae may be considered an emerging fish model for toxicological studies for the neotropical region due to its wide distribution and biological characteristics.

NMR spectroscopy spotlighting immunogenicity induced by COVID-19 vaccination to mitigate future health concerns.

In this review, the disease and immunogenicity affected by COVID-19 vaccination at the metabolic level are described considering the use of nuclear magnetic resonance (NMR) spectroscopy for the analysis of different biological samples. Consistently, we explain how different biomarkers can be examined in the saliva, blood plasma/serum, bronchoalveolar-lavage fluid (BALF), semen, feces, urine, cerebrospinal fluid (CSF) and breast milk. For example, the proposed approach for the given samples can allow one to detect molecular biomarkers that can be relevant to disease and/or vaccine interference in a system metabolome. The analysis of the given biomaterials by NMR often produces complex chemical data which can be elucidated by multivariate statistical tools, such as PCA and PLS-DA/OPLS-DA methods. Moreover, this approach may aid to improve strategies that can be helpful in disease control and treatment management in the future.

Assessment of occupational and dietary exposures of feed handling workers to mycotoxins in rural areas from São Paulo, Brazil.

In the current study, the occupational and dietary exposures of feed handling workers (N = 28) to aflatoxins (AFs), fumonisins (FBs), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEN), toxins T-2 and HT-2 were assessed for the first time in animal-producing farms and feed factories from São Paulo, Brazil. Mycotoxins in food (n = 244) and airborne dust (n = 27), as well as biomarkers in urine (n = 97) samples were determined by liquid chromatography coupled with tandem mass spectrometry. FBs were detected in all airborne dust samples, with concentrations ranging from 7.85 to 16,839 ng/m3. The mean probable daily intake (PDI) based on food data were 0.005, 0.769, 0.673 and 0.012 µg/kg of body weight (bw)/day for AFs, FBs, DON and ZEN, respectively. Mean PDI values obtained through urinary biomarkers were 0.29, 0.10, 0.50, 9.72 and 0.10 µg/kg body weight/day for AFB1, DON, OTA, FB1 and ZEN, respectively. The analyses based on urinary biomarkers revealed a potential health concern for OTA and FBs, although no potential health concern was observed with PDI calculated through food data. Results of this trial stress the need for preventive measures to avoid health risks of workers in Brazilian animal-producing farms and feed industries.

Oncogenic and tumor suppressor pathways in subchronic aflatoxicosis in rats: Association with serum and urinary aflatoxin exposure biomarkers.

In this study, the changes in oncogenic and tumor suppressor signaling pathways in liver and their association with serum and urinary biomarkers of aflatoxin exposure were evaluated in Wistar rats fed diets containing aflatoxin B1 (AFB1) for 90 days. Rats were divided into four groups (n = 15 per group) and assigned to dietary treatments containing 0 (control), 50 (AFB50), 100 (AFB100) and 200 µg AFB1 kg-1 diet (AFB200). Multiple preneoplastic foci of hepatocytes marked with glutathione-S-transferase-placental form (GST-P) were identified in AFB100 and AFB200 groups. Hepatocellular damage induced by AFB1 resulted in overexpression of cyclin D1 and ß-catenin. The liver expression of retinoblastoma (Rb) and p27Kip1 decreased in AFB100 and AFB200 groups, confirming the favorable conditions for neoplastic progression to hepatocellular carcinoma. All samples from rats fed AFB1-contaminated diets had quantifiable AFB1-lysine in serum or urinary AFM1 and AFB1-N7-guanine, with mean levels of 20.42-50.34 ng mL-1, 5.31-37.68 and 39.15-126.37 ng mg-1 creatinine, respectively. Positive correlations were found between AFB1-lysine, AFM1 or AFB1-N7-guanine and GST-P+, ß-catenin+ and cyclin D1+ hepatocytes, while Rb + cells negatively correlated with those AFB1 exposure biomarkers. The pathways evaluated are critical molecular mechanisms of AFB1-induced hepatocarcinogenesis in rats.

Mycotoxin occurrence in breast milk and exposure estimation of lactating mothers using urinary biomarkers in São Paulo, Brazil.

In this study, the occurrence of aflatoxins (AFs), fumonisins (FBs), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEN) and some of their metabolites were assessed in breast milk and urine of lactating women (N = 74) from Pirassununga, São Paulo, Brazil. Exposure estimations through urinary mycotoxin biomarkers was also performed. Samples were collected in four sampling times (May and August 2018, February and July 2019) and analyzed by liquid chromatography coupled to tandem mass spectrometry. Aflatoxin M1 (AFM1) was not detected in breast milk. However, two samples (3%) presented FB1 at 2200 and 3400 ng/L, while 4 samples (5%) had OTA at the median level of 360 ng/L. In urine, AFM1 and aflatoxin P1 (AFP1) were found in 51 and 11% of samples, respectively (median levels: 0.16 and 0.07 ng/mg creatinine, respectively). Urinary DON (median level: 38.59 ng/mg creatinine), OTA (median level: 2.38 ng/mg creatinine) and ZEN (median level: 0.02 ng/mg of creatinine) were quantified in 18, 8 and 10% of the samples, respectively. Mean probable daily intake (PDI) values based on urinary biomarkers were 1.58, 1.09, 5.07, and 0.05 µg/kg body weight/day for AFM1, DON, OTA, and ZEN, respectively. Although a low mycotoxin occurrence was detected in breast milk, the PDI for the genotoxic AFs was much higher than those reported previously in Brazil, while PDI values obtained for OTA and DON were higher than recommended tolerable daily intakes. These outcomes warrant concern on the exposure of lactating women to these mycotoxins in the studied area.

Combinations of emerging technologies with fermentation: Interaction effects for detoxification of mycotoxins?

Consumption of foods containing mycotoxins, as crucial groups of naturally occurring toxic agents, could pose significant health risks. While the extensive scientific literature indicates that prevention of contamination by toxigenic fungi is one of the best ways to reduce mycotoxins, detoxifying strategies are useful for improving the safety of food products. Nowadays, the food and pharmaceutical industries are using the concept of combined technologies to enhance the product yield by implementing emerging techniques, such as ultrasound, ohmic heating, moderate electric field (MEF), pulsed electric field (PEF) and high-pressure processing, during the fermentation process. While the application of emerging technologies in improving the fermentation process is well explained in this literature, there is a lack of scientific texts discussing the possibility of mycotoxin degradation through the interaction effects of emerging technologies and fermentation. Therefore, this study was undertaken to provide deep insight into applying emerging processing technologies in fermentation, mechanisms and the prospects of innovative combinations of physical and biological techniques for mycotoxins' detoxification. Among various emerging technologies, ultrasound, ohmic heating, MEF, PEF, and cold plasma have shown significant positive effects on fermentation and mycotoxins detoxification, highlighting the possibility of interactions from such combinations to degrade mycotoxins in foods.

Application of new technologies in decontamination of mycotoxins in cereal grains: Challenges, and perspectives.

Emerging decontamination technologies have been attracted considerable attention to address the consumers' demand for high quality and safe food products. As one of the important foods in the human diet, cereals are usually stored for long periods, resulting in an increased risk of contamination by different hazards. Mycotoxins comprise one of the significant contaminants of cereals that lead to enormous economic losses to the industry and threats to human health. While prevention is the primary approach towards reducing human exposure to mycotoxins, decontamination methods have also been developed as complementary measures. However, some conventional methods (chemical treatments) do not fulfill industries' expectations due to limitations like safety, efficiency, and the destruction of food quality attributes. In this regard, novel techniques have been proposed to food to comply with the industry's demand and overcome conventional methods' limitations. Novel techniques have different efficiencies for removing or reducing mycotoxins depending on processing conditions, type of mycotoxin, and the food matrix. Therefore, this review provides an overview of novel mycotoxin decontamination technologies such as cold plasma, irradiation, and pulse light, which can be efficient for reducing mycotoxins with minimum adverse effects on the quality and nutritional properties of produce.

In vitro and in vivo capacity of yeast-based products to bind to aflatoxins B1 and M1 in media and foodstuffs: A systematic review and meta-analysis.

The aflatoxins are hepatotoxic and carcinogenic metabolites produced by Aspergillus species during growth on crop products. In this regard, a systematic review to collect the quantitative data regarding the in vitro capacity of yeasts-based products to bind to aflatoxin B1 (AFB1) and/or aflatoxin M1 (AFM1) was performed. After screening, 31 articles which met the inclusion criteria was included and then the pooled decontamination of aflatoxins in the defined subgroups (the type of foods, pH, contact time, temperature, yeast species, and aflatoxin type) was calculated by the random effect model (REM). The overall binding capacity (BC) of aflatoxins by yeast was 52.05% (95%CI: 49.01-55.10), while the lowest and highest aflatoxins' BC were associated with Yeast Extract Peptone (2.79%) and ruminal fluid + artificial saliva (96.21%), respectively. Regarding the contact time, temperature, pH and type of aflatoxins subgroups, the binding percentages varied from 50.83% (>300 min) to 52.66% (1-300 min), 50.71% (0-40 °C) to 88.39% (>40 °C), 43.03% (pH: 3.1-6) to 44.56% (pH: 1-3) and 59.35% (pH > 6), and 48.47% (AFB1) to 69.03% AFM1, respectively. The lowest and highest aflatoxins' BC was related to C. fabianii (18.45%) and Z. rouxii (86.40%), respectively. The results of this study showed that variables such as temperature, yeast, pH and aflatoxin type can be considered as the effective factors in aflatoxin decontamination.

Effect of Lactobacillus rhamnosus on growth of Listeria monocytogenes and Staphylococcus aureus in a probiotic Minas Frescal cheese.

This study aimed to evaluate the effect of Lactobacillus rhamnosus GG on growth of Staphylococcus aureus and Listeria monocytogenes, inoculated alone or in combination on surface of Minas Frescal cheeses, during storage for 21 days at 7 °C. Survival percentages of each individual bacterial species after exposure to in vitro simulated gastrointestinal conditions (SGC) were also determined. The addition of L. rhamnosus did not affect (P > 0.05) pH, moisture, fat, protein and texture profile of Minas Frescal cheeses. L. rhamnosus was able to survive in suitable counts (>6 Log CFU/g) in cheeses from the 7th day of storage, with high survival (>74.6-86.4%) after SGC. An inhibitory effect of L. rhamnosus on L. monocytogenes was observed in cheeses (decrease of 1.1-1.6 Log CFU/g) and after SGC (20% reduction in the survival). No inhibitory effect of L. rhamnosus was observed on S. aureus counts (P > 0.05), and this microorganism did not survive the exposure to SGC. In conclusion, the addition of L. rhamnosus in Minas Frescal cheese has a potential for L. monocytogenes inhibition. Further studies are necessary to elucidate the mechanisms involved in the inhibition process and determine the survival ability of the bacterial species evaluated in in vivo experiments.

Electron beam irradiation to reduce the mycotoxin and microbial contaminations of cereal-based products: An overview.

The contamination of food commodities in various conditions along the production chain is the point of concern, especially among recent years. While different conventional methods for microbial and mycotoxin decontamination of cereal and cereal-based products were introduced, approaching of newly introduced techniques such as Electron Beam Irradiation (EBI) attracted notable attention. EBI is classified as a non-thermal method for decontamination with several advantages over conventional thermal treatments, including environmental friendly, time effective, and lower detrimental effects on the nutritional value of food products. By contrast, the high needed investment for providing accelerators and low penetration power of the electron beam are among the limitations for the use of EBI in food industries. Importantly, the effectiveness of this method increased when applied in combination with other traditional approaches. In this paper, a review of available data regarding the application of EBI in reducing of the mycotoxin and microbial contaminations of cereal-based products is presented, indicating potential applications of this technique to significantly reduce the microbial load and main mycotoxins, especially when combined with fermentation methods. This promising technology can be considered as one of available alternatives in microbial and mycotoxin decontamination of cereal and cereal-based products.

Dietary exposure assessment and risk characterization of mycotoxins in lactating women: Case study of São Paulo state, Brazil.

The exposure and risk characterization of lactating women to aflatoxins (AFs), fumonisins (FBs), ochratoxin A (OTA) and zearalenone (ZEN) due to consumption of different types of food products in Pirassununga, São Paulo, Brazil, was assessed. Lactating women (N = 74) provided samples of foods stored and available at their households between April-August/2018, totaling 184 samples. Mycotoxins were determined in food samples by liquid chromatography-tandem mass spectrometry. According to findings, 20% (n = 36) of all food samples were contaminated with AFs at median concentrations ranging from 9.2 to 18.5 µg/kg, while OTA was detected only in three samples (rice, bread and pasta) at concentrations of 22.3, 23.8 and 48.7 µg/kg, respectively. ZEN was detected in 34 samples (18%) at median levels of 62-195 µg/kg, and FBs at median levels of 58-1546 µg/kg was observed in 22 samples (12%). Moreover, the concentration of AFs, OTA, ZEN and FBs exceeded their respective maximum permitted levels in 11 (6%), 3 (2%), 8 (4%) and 5 (3%) from total samples, respectively. Twenty-eight samples (15%) were contaminated with two or three types of mycotoxins. Corn products contributed for the highest mean probable daily intakes (PDI) of AFs (0.119 ± 0.193 µg/kg body weight (bw)/day), ZEN (0.325 ± 0.097 µg/kg bw/day) and FBs (2.936 ± 1.541 µg/kg bw/day), while wheat-based products contributed for the highest PDI of OTA (0.035 ± 0.028 µg/kg bw/day). The Margin of Exposure (MoE) value for AFs (3.72) demonstrated a high cancer risk (MoE < 10,000), and the Hazard Quotient (HQ) obtained for OTA (24.66), ZEN (4.24) and total FBs (5.01) also resulted in a non-tolerable risk (HQ > 1) via consumption of the investigated food products. Results of this trial indicate high exposure levels of lactating women to dietary mycotoxins in the studied area, which warrant concern about the possible transfer of residual mycotoxins into breast milk.

Enniatin B1-induced lysosomal membrane permeabilization in mouse embryonic fibroblasts.

The mycotoxin enniatin B1 (ENN B1) is widely present in grain-based feed and food products. In the present study, we have investigated how this lipophilic and ionophoric molecule can affect the lysosomal stability and chaperone-mediated autophagy (CMA) in wild-type (WT) and in lysosome-associated membrane proteins (LAMP)-1/2 double-deficient (DD) mouse embryonic fibroblasts (MEF). The cell viability and lysosomal pH were assessed using the Neutral Red (NR) cytotoxicity assay and the LysoSensor® Yellow/Blue DND-160, respectively. Changes in the expression of the CMA-related components LAMP-2 and the chaperones heat shock cognate (hsc) 70 and heat shock protein (hsp) 90 were determined in cytosolic extracts by immunoblotting. In the NR assay, LAMP-1/2 DD MEF cells were significantly less sensitive to ENN B1 than WT MEF cells after 24 h exposure to ENN B1 at levels of 2.5-10 µmol/L. Exposure to ENN B1 at concentrations below the half maximal effective concentration (EC50) (1.5-1.7 µmol/L) increased the lysosomal pH in WT MEF, but not in LAMP-1/2 DD cells, suggesting that lysosomal LAMP-2 is an early target of ENN B1-induced lysosomal alkalization and cytotoxicity in MEF cells. Additionally, cytosolic hsp90 and LAMP-2 levels slightly increased after exposure for 4 h, indicating lysosomal membrane permeabilization (LMP). In summary, it appeared that ENN B1 can destabilize the LAMP-2 complex in the lysosomal membrane at concentrations close to the EC50, resulting in the alkalinization of lysosomes, partial LMP, and thereby leakage of CMA-associated components into the cytosol.

Fumonisins at Doses below EU Regulatory Limits Induce Histological Alterations in Piglets.

Fumonisins (FBs) are mycotoxins produced by Fusarium species that can contaminate human food and animal feed. Due to the harmful effects of FBs on animals, the European Union (EU) defined a recommendation of a maximum of 5 mg FBs (B1 + B2)/kg for complete feed for swine and 1 µg FBs/kg body weight per day as the tolerable daily intake for humans. The aim of this study was to evaluate the toxicity of dietary exposure to low doses of FBs, including a dose below the EU regulatory limits. Four groups of 24 weaned castrated male piglets were exposed to feed containing 0, 3.7, 8.1, and 12.2 mg/kg of FBs for 28 days; the impact was measured by biochemical analysis and histopathological observations. Dietary exposure to FBs at a low dose (3.7 mg/kg of feed) significantly increased the plasma sphinganine-to-sphingosine ratio. FBs-contaminated diets led to histological modifications in the intestine, heart, lung, lymphoid organs, kidney, and liver. The histological alterations in the heart and the intestine appeared at the lowest dose of FBs-contaminated diet (3.7 mg/kg feed) and in the kidney at the intermediate dose (8.1 mg/kg feed). At the highest dose tested (12.2 mg/kg feed), all the organs displayed histological alterations. This dose also induced biochemical modifications indicative of kidney and liver alterations. In conclusion, our data indicate that FBs-contaminated diets at doses below the EU regulatory limit cause histological lesions in several organs. This study suggests that EU recommendations for the concentration of FBs in animal feed, especially for swine, are not sufficiently protective and that regulatory doses should be modified for better protection of animal health.

Studies Into ß-Glucan Recognition in Fish Suggests a Key Role for the C-Type Lectin Pathway.

Immune-modulatory effects of ß-glucans are generally considered beneficial to fish health. Despite the frequent application of ß-glucans in aquaculture practice, the exact receptors and downstream signalling remains to be described for fish. In mammals, Dectin-1 is a member of the C-type lectin receptor (CLR) family and the best-described receptor for ß-glucans. In fish genomes, no clear homologue of Dectin-1 could be identified so far. Yet, in previous studies we could activate carp macrophages with curdlan, considered a Dectin-1-specific ß-(1,3)-glucan ligand in mammals. It was therefore proposed that immune-modulatory effects of ß-glucan in carp macrophages could be triggered by a member of the CLR family activating the classical CLR signalling pathway, different from Dectin-1. In the current study, we used primary macrophages of common carp to examine immune modulation by ß-glucans using transcriptome analysis of RNA isolated 6 h after stimulation with two different ß-glucan preparations. Pathway analysis of differentially expressed genes (DEGs) showed that both ß-glucans regulate a comparable signalling pathway typical of CLR activation. Carp genome analysis identified 239 genes encoding for proteins with at least one C-type Lectin Domains (CTLD). Narrowing the search for candidate ß-glucan receptors, based on the presence of a conserved glucan-binding motif, identified 13 genes encoding a WxH sugar-binding motif in their CTLD. These genes, however, were not expressed in macrophages. Instead, among the ß-glucan-stimulated DEGs, a total of six CTLD-encoding genes were significantly regulated, all of which were down-regulated in carp macrophages. Several candidates had a protein architecture similar to Dectin-1, therefore potential conservation of synteny of the mammalian Dectin-1 region was investigated by mining the zebrafish genome. Partial conservation of synteny with a region on the zebrafish chromosome 16 highlighted two genes as candidate ß-glucan receptor. Altogether, the regulation of a gene expression profile typical of a signalling pathway associated with CLR activation and, the identification of several candidate ß-glucan receptors, suggest that immune-modulatory effects of ß-glucan in carp macrophages could be a result of signalling mediated by a member of the CLR family.

Assessment of mycotoxin exposure and risk characterization using occurrence data in foods and urinary biomarkers in Brazil.

This study aimed to assess the exposure of Brazilian residents (N = 86) from rural areas to multiple mycotoxins and characterize the associated risk in two sampling periods (SP) (April-May and December/2016). Mycotoxins in food and urine samples were determined by liquid chromatography coupled to tandem mass spectrometry. Mean probable daily intake (PDI) values based on occurrence data in foods in both SP varied from 0.007 to 0.013, 0.069 to 1.002, 0.119 to 0.321 and 0.013-0.156 µg kg-1 body weight (bw) day-1 for aflatoxins (AFs), deoxynivalenol (DON), fumonisins (FBs) and zearalenone (ZEN), respectively. Mean PDI values based on urinary biomarkers were 0.001, 84.914, 0.031, 0.377 and 0.002 µg kg-1 bw day-1 for AFB1, DON, ochratoxin A (OTA), FB1 and ZEN, respectively. Hazard quotient (HQ) calculated using food data revealed a potential health concern for ZEN in 2nd SP. HQ > 1 based on urinary biomarkers were observed for DON in the two SP. Although OTA was not detected in any food sample, the HQ based on urinary OTA levels was >1 in the 1st SP. Margin of exposure values for AF from food and urine data in the 1st SP were below 10,000, indicating potential health risks.

ß-Glucan successfully stimulated the immune system in different jawed vertebrate species.

Several reports have shown the positive effects of ß-glucans on the immune. Howeverthese studies have a broad experimental design including ß-glucans compounds. Consequently, a study using the same ß-glucan molecule, administration route and experimental design is needed to compare the effects of ß-glucan across vertebrate species. For this end, during 28 days we fed four different vertebrate species: mice, dogs, piglets and chicks, with two ß-glucan molecules (BG01 and BG02). We measured the serum interleukin 2 as an indicator of innate immune response, the neutrophils and monocytes phagocytosis index as a cellular response and antibody formation as an adaptive response. The results clearly showed that the different ß-glucan molecules exhibited biologically differently behaviors, but both molecules stimulate the immune system in a similar pattern in these four species. This finding suggests that vertebrates shared similar mechanisms/patterns in recognizing the ß-glucans and confirms the benefits of ß-glucans across different vertebrate species.

Co-occurrence of mycotoxins in maize food and maize-based feed from small-scale farms in Brazil: a pilot study.

A limited survey was conducted to assess the co-occurrence of aflatoxins (AF) B1, B2, G1, and G2; fumonisins (FB) B1 and B2; ochratoxin A (OTA); zearalenone (ZEN); and deoxynivalenol (DON) in maize food (N = 26) and animal feed (N = 45) collected from 21 small-scale farms from the states of São Paulo (SP) and Santa Catarina (SC), Brazil. Samples evaluated were maize meal and maize flour for human consumption available in the farm households, and maize-based feed intended for broiler chicks, laying hens, and dairy cows. Analyses of mycotoxins were performed by ultra-performance liquid chromatography coupled with tandem mass spectrometry. The median levels of mycotoxins found in maize food were 2.5 µg/kg (total AF), 120 µg/kg (total FB), 13 µg/kg (ZEN), and 57 µg/kg (DON). All values were below the Brazilian tolerance limits, except for total FB in one sample of maize flour. In feed samples, median levels of total AF, total FB, ZEN, and DON were 100 µg/kg, 680 µg/kg, 160 µg/kg, and 200 µg/kg, respectively. The co-occurrence of two or more mycotoxins was confirmed in 35% and 51% of maize food and feed, respectively. Results indicate a low human exposure to mycotoxins in the small-scale farms evaluated and a higher exposure of farm animals to mycotoxins in the feed.

Aflatoxin in foodstuffs: Occurrence and recent advances in decontamination.

Aflatoxins are highly toxic compounds produced as secondary metabolites by some Aspergillus species, whose occurrence have been reported predominantly in several types of foods of low moisture content, while aflatoxin biotransformation products have been reported mainly in milk and milk products. This review deals with the occurrence of aflatoxins in some of the major food products in the last 5 years including regulatory aspects, and recent advances in detoxification strategies for contaminated foods. Aflatoxin contamination in cereals including corn and peanut is still a public health problem for some populations, especially in African countries. Despite that most of physical and chemical methods for aflatoxin detoxification may affect the nutritional properties of food, or are not safe for human consumption, gamma-radiation and ozone applications have demonstrated great potential for detoxification of aflatoxins in some food matrices. Biological methods based on removal or degradation of aflatoxins by bacterial and yeast have good perspectives, although further studies are needed to clarify the detoxification mechanisms by microorganisms and determine practical aspects of the use of these methods in food products, especially their potential effects on sensory characteristics of foods.

Aflatoxin B1 residues in human livers and their relationship with markers of hepatic carcinogenesis in São Paulo, Brazil.

In this study, hepatic biopsies from autopsy cases in São Paulo, Brazil, showing hepatocellular carcinoma (HCC, n = 8), cirrhosis associated with viral hepatitis (VC, n = 20), cirrhosis associated with alcoholism (AC, n = 20), and normal livers (NL or controls, n = 10) were subjected to determination of aflatoxin B1 (AFB1) and its main metabolites, and of markers of hepatic carcinogenesis Only non-metabolized AFB1 was detected in 13 samples (27.1%, N = 48) of liver disorders (HCC, VC and AC), at levels between 10.0 and 418.0 pg/g (mean: 76.6 ± 107.7 pg/g). Immuno-labeling of p53, cyclin D1, p21, ß-catenin, and Prohibitin (PB) increased mainly in HCC patients, in relation to the controls. AFB1+ samples of HCC presented higher expressions of p53, cyclin D1, p21, and ß-catenin compared with AFB1-livers. In contrast, p27, p16, and Rb immuno-labeling decreased in HCC, VC, and AC samples, compared with NL, with lowest values in AFB1+ samples for all liver disorders. Compared with NL, gene expression of cyclin D1 and PB in AFB1+ samples of HCC and AC were also higher, along with higher gene expression of p21 in VC and AC AFB1+ livers. Results indicated that patients with liver disorders were exposed to dietary aflatoxins, and that residual AFB1 in liver negatively affected the p53 and protein Rb pathways in HCC. Moreover, the presence of AFB1 in cirrhotic livers warrants concern about the potential contribution of dietary aflatoxin to disease progression during VC and AC.