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Background and purpose: Aflatoxins are highly toxic compounds that can cause acute and chronic toxicity in humans and animals. This study aimed to evaluate the expression of BDNF and GFAP, histopathological changes, and oxidative stress factors in brain tissue exposed to aflatoxin G1 (AFG1) in male rats. Experimental approach: Twenty-eight male Wistar rats were used. Animals were randomly divided into 4 groups of 7 each. The control group received 0.2 mL of corn oil and the treatment groups were exposed to AFG1 (2 mg/kg) intra-peritoneally for 15, 28, and 45 days. The tissue was used for histopathological studies, and the level of TAC, SOD, and MDA, and the expression of BDNF and GFAP genes were evaluated. Findings/Results: Real-time PCR results showed that AFG1 increased GFAP expression and decreased BDNF expression in AFG1-treated groups compared to the control group. The tissue level of TAC and SOD over time in the groups receiving AFG1 significantly decreased and the tissue level of MDA increased compared to the control group. Histopathological results showed that AFG1 can cause cell necrosis, a reduction of the normal cells number in the hippocampal region of CA1, cerebral edema, shrinkage of nerve cells, formation of space around neuroglia, and diffusion of gliosis in the cerebral cortex after 45 days. Conclusion and implication: AFG1, by causing pathological complications in cortical tissue, was able to affect the exacerbation of nerve tissue damage and thus pave the way for future neurological diseases.

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Background and purpose: Previous studies have shown the adverse effects of aflatoxin G1 on testicular tissue and the process of spermatogenesis. The aim of this study was to investigate changes in the expression of Cyclin D1, the estrogen receptor ERα and the levels of nitric oxide (NO), superoxide dismutase (SOD), and malondialdehyde (MDA) in testicular tissue following exposure to AFG1. Materials and methods: Twenty four mice were divided into four groups (n=6 per group); a control group (saline) and three treatment groups to receive AFG1 for 7, 15, and 28 days intraperitoneally. Histopathological changes caused by this toxin along with the expression of Cyclin D1 and Erα, as well as Nitric oxid (NO), superoxide dismutase (SOD), and malondialdehyde (MDA) levels in testicular tissue were measured. Results: The expression of Cyclin D1 in testicular tissue in AFG1 receiving groups increased in a time-dependent manner and the expression of ERα decreased in testicular tissue in AFG1 receiving groups (P

Background: Among aflatoxins, the subtype aflatoxin G1 is one of the most toxic, commonly found in cereals, legumes, dairy and non-alcoholic beers. Aflatoxins have been known as nephrotoxic compounds. In this study, changes in the expression of aquaporin-1, the histopathology of renal tissue and plasma biochemical factors after exposure to aflatoxin G1 were investigated in mice. Methods: Twenty-four adult male mice (weighing 20±2 g) were divided into four groups of six. The control group received the vehicle (0.2 ml) and the three experimental groups were injected intraperitoneally with aflatoxin G1 at 20 μg/kg for 7, 15 or 35 days, respectively. On days 7, 15 and 35, blood samples were drawn from the mice for biochemical analysis of plasma and the kidney tissues were sampled for real-time PCR and histopathological studies. Results: The real PCR results showed a reduction in aquaporin-1 expression in the experimental groups compared to those in the controls (P

Background and purpose: Aflatoxin (AF) is a mycotoxin produced by various strains of the Aspergillus family. AFG1 as one of the most important types is highly found in cereals and grains. AF affects sperm production or even its quality. This study was designed to test the effects of AFG1 on mice testicular tissue. Experimental approach: Twenty-four Albino mice were divided into four groups of 6 each; a control group (0.2 mL corn oil and ethanol), three treatment groups with different periods (20 μg/kg AFG1 for 7, 15, and 35 consecutive days). All treatments were applied intraperitoneally. Biosynthesis of cyclin D1, p21, and estrogen receptor alpha (ERα) proteins was evaluated by immunohistochemistry (IHC) staining. Levels of cyclin D1, p21, and ERa mRNA were evaluated by the real-time polymerase chain reaction (RT-PCR) technique. Tubular differentiation index (TDI), reproductive index (RI), and spermiogenesis indices were also analyzed. Findings/Results: AFG1 increased the percentage of seminiferous tubules with negative TDI, RI, and SPI compared to the control group (P < 0.05). RT-PCR and IHC analyses illustrated time-dependent enhancement in p21 expression and cyclin D1 biosynthesis in AFG1-treated groups significantly (P < 0.05). While the protein and mRNA levels of ERa were significantly (P < 0.05) decreased in a time-dependent manner. Conclusion and implications: The chronic exposure to AFG1 reduced the expression and synthesis of ERa, increased the expression and synthesis of p21 and cyclin D1, impaired apoptosis, which in turn could impair spermatogenesis.

The present study sought to evaluate the interaction between aflatoxin G1 and free DNA in vitro through different analytical techniques. The UV–visible spectra results showed that the structure of DNA might be changed with a new aflatoxin G1-DNA complex forming, which indicated that the interacting mode between them was the intercalating mode. The DNA melting temperature increased by 12.80 °C, suggesting that the DNA double helix structure was more compact and stable through intercalation. The circular dichroism (CD) spectra results indicated that the interaction of aflatoxin G1 with DNA induced the DNA base stacking changes. The results of agarose gel electrophoresis and fluorescence microscope further verified that the interacting mode between aflatoxin G1 and DNA was intercalation mode. According to the fluorescence spectrum data, the binding constant was calculated 6.24 × 104 L·mol−1. The thermodynamic results demonstrated that the reaction of aflatoxin G1 intercalating to DNA was a spontaneous reaction. The elimination results suggested that aflatoxin G1 could be enriched and removed by DNA intercalation through magnetic beads separation, with the removal efficiency of 93.73%. The study results would provide a theoretical basis for establishing a new aflatoxin removal method based on DNA intercalation. [ABSTRACT FROM AUTHOR]

The present study sought to evaluate the interaction between aflatoxin G1 and free DNA in vitro through different analytical techniques. The UV–visible spectra results showed that the structure of DNA might be changed with a new aflatoxin G1-DNA complex forming, which indicated that the interacting mode between them was the intercalating mode. The DNA melting temperature increased by 12.80 °C, suggesting that the DNA double helix structure was more compact and stable through intercalation. The circular dichroism (CD) spectra results indicated that the interaction of aflatoxin G1 with DNA induced the DNA base stacking changes. The results of agarose gel electrophoresis and fluorescence microscope further verified that the interacting mode between aflatoxin G1 and DNA was intercalation mode. According to the fluorescence spectrum data, the binding constant was calculated 6.24 × 104 L·mol−1. The thermodynamic results demonstrated that the reaction of aflatoxin G1 intercalating to DNA was a spontaneous reaction. The elimination results suggested that aflatoxin G1 could be enriched and removed by DNA intercalation through magnetic beads separation, with the removal efficiency of 93.73%. The study results would provide a theoretical basis for establishing a new aflatoxin removal method based on DNA intercalation. [ABSTRACT FROM AUTHOR]

Background and purpose: Previous studies have shown the adverse effects of aflatoxin G1 on testicular tissue and the process of spermatogenesis. The aim of this study was to investigate changes in the expression of Cyclin D1, the estrogen receptor ERα and the levels of nitric oxide (NO), superoxide dismutase (SOD), and malondialdehyde (MDA) in testicular tissue following exposure to AFG1. Materials and methods: Twenty four mice were divided into four groups (n=6 per group); a control group (saline) and three treatment groups to receive AFG1 for 7, 15, and 28 days intraperitoneally. Histopathological changes caused by this toxin along with the expression of Cyclin D1 and Erα, as well as Nitric oxid (NO), superoxide dismutase (SOD), and malondialdehyde (MDA) levels in testicular tissue were measured. Results: The expression of Cyclin D1 in testicular tissue in AFG1 receiving groups increased in a time-dependent manner and the expression of ERα decreased in testicular tissue in AFG1 receiving groups (P<0.05). Also, AFG1 decreased the level of SOD in testicular tissue in a time-dependent manner and increased the levels of MDA and NO. Atrophy of the seminiferous tubules and extensive intercellular edema were seen in treatment groups compared to the control group. Conclusion: AFG1 disrupts the process of cell division by atrophy of spermatozoa tubules in testicular tissue. It also reduced the expression of ERα receptors and increased the expression of Cyclin D1 along with decreasing the level of SOD in testicular tissue and increased MDA and NO levels. These factors can cause disorders in the process of spermatogenesis. [ABSTRACT FROM AUTHOR]

Background: Among aflatoxins, the subtype aflatoxin G1 is one of the most toxic, commonly found in cereals, legumes, dairy and non-alcoholic beers. Aflatoxins have been known as nephrotoxic compounds. In this study, changes in the expression of aquaporin-1, the histopathology of renal tissue and plasma biochemical factors after exposure to aflatoxin G1 were investigated in mice. Methods: Twenty-four adult male mice (weighing 20±2 g) were divided into four groups of six. The control group received the vehicle (0.2 ml) and the three experimental groups were injected intraperitoneally with aflatoxin G1 at 20 µg/kg for 7, 15 or 35 days, respectively. On days 7, 15 and 35, blood samples were drawn from the mice for biochemical analysis of plasma and the kidney tissues were sampled for real-time PCR and histopathological studies. Results: The real PCR results showed a reduction in aquaporin-1 expression in the experimental groups compared to those in the controls (P<0.05). Also, the plasma concentrations of urea and creatinine were significantly increased in the experimental groups compared to those in the controls (P<0.05). Also, the serum sodium and potassium levels had decreased significantly compared to the controls (P<0.05). Various damages were observed in the ureters and glomeruli among the experimental groups compared to those in the controls. Conclusion: Aflatoxin G1 had adverse effects on the renal tissue by reducing the expression of aquaporin-1. Subsequently, there were biochemical manifestations in the serum, consisting of changes in the concentrations of urea, creatinine, sodium and potassium, confirming the histopathological toxicity of aflatoxin G1. [ABSTRACT FROM AUTHOR]

Introduction: AFG1 after B1 is the most important aflatoxin found in beans and grains. Remarkably, aflatoxin cause a decrease in production and quality of sperm. In the current study, the effect of AFG1 on spermatogenesis, spermiogenicity, synthesis of P21 and cyclin D1 proteins in testicular tissue was investigated. Materials and Methods: 24 male albino mice were divided into 4 groups; control group intraperitoneally received 0.2 ml corn oil and experimental groups received AFGI (20 g for 7, 15, and 35 days, respectively. After 7, 15 and 35 days, the testicular tissue samples were taken, and after preparing tissue sections, hematoxylin and eosin (H&E) staining was performed. Histomorphometric parameters and the immunohistochemical analysis of proteins of P21 and cyclin D1 were investigated. Data analysis was carried out using one-way ANOVA at the significance level of p<0.05. Results: The results of this study showed that the diameter of the spermatozoa tubes and the thickness of the germinal epithelium in the experimental groups significantly decreased (P <0.05), which was time dependent. The percentage of semen tubes with differentiation coefficients, tubular replacement as well as negative spermiogenesis increased in mice receiving AFG1. Conspiciously, injection of AFG1 in experimental group mice resulted in increased synthesis of P21 and cyclin D1 proteins. Conclusion: AFG1 interrupted cell division by increasing the amount of protein synthesis of Cyclin D1 and P21 protein, which in turn could be a disorder in the process of spermatogenesis. However, increase differentiation indices, tubular differentiation, and spermiogenesis in testicular tissue, which consequently lead to a decrease in sperm production and quality. [ABSTRACT FROM AUTHOR]

Occurrence of aflatoxins (AFs) AFB1, AFB2, AFG1, AFG2 and ochra toxin A (OTA) was studied in 65 samples of stored and freshly harvested wheat, barley and maize collected in Tunisia. The mycotoxins were simultaneously extracted and quantified by high performance liquid chromatography. Determination of AF-producing (sectionFlavi)and OTA-producingAspergillusspecies (sectionsNigriandCircumdati) was conducted in these samples by species-specific polymerase chain reaction (PCR). Results showed that most of maize samples were contaminated with AFs, data after storage showing lower values than those collected at harvest. All contaminated maize samples contained AFG1 and AFG2, among which 27.78% also had AFB1 and AFB2. This AFs pattern was consistent with theA. parasiticustoxin profile.A. flavushowever showed the highest frequency in maize but was also found in barley and wheat where no AFs were detected. In contrast, OTA was neither found in maize nor in barley and only one wheat sample contained OTA.A. nigerwas the only OTA-producing species detected. [ABSTRACT FROM PUBLISHER]

A reliable and easy method has been developed for the determination of aflatoxins B1 and G2 in maize samples. High performance liquid chromatography coupled with FLD (HPLC-FLD) with photochemical derivatization was used. Mycotoxins were extracted from maize using a QuEChERS-based extraction procedure. The optimized analytical conditions were evaluated in terms of recoveries, reproducibility, LOD, LOQ and linearity for aflatoxin B1 and aflatoxin G1 in maize. Extraction, chromatographic and detection conditions were optimized in order to increase sample sensitivity. The linearity was analyzed in the range of 0.4-20 μg/kg and the correlation coefficients (R2) were higher than 0.99 for aflatoxins B1 and G1. Blank samples were spiked at 1.0, 2.0 and 4.0 μg/kg, and the average recovery for aflatoxin G1 was 96.96±1.72% and for aflatoxin B1 it was 86.80±1.24%. RSDs were lower than 25% for both mycotoxins. LOD for both aflatoxins was 0.5 μg/kg and LOQ was 1.0 μg/kg, respectively.

To detect and monitor G-group aflatoxins in agricultural products, we generated class-specific monoclonal antibodies that specifically recognized aflatoxins G1 and G2. Of the final three positive and stable hybridomas obtained, clone 2G6 produced amonoclonal antibody that had equal sensitivity to aflatoxins G1 and G2, and did not cross-react with aflatoxins B1, B2, or M1. Its IC50 values for aflatoxins G1 and G2 were 17.18 ng⋅mL-1 and 19.75 ng⋅mL-1, respectively. Using this new monoclonal antibody, we developed a competitive indirect enzyme-linked immunosorbent assay (CI-ELISA); the method had a limit of detection of 0.06 ng⋅mL-1. To validate this CI-ELISA, we spiked uncontaminated peanut samples with various amounts of aflatoxins G1 and G2 and compared recovery rates with those determined by a standard HPLC method. The recovery rates of the CI-ELISA ranging from 94% to 103% were comparable to those of the HPLC (92% to 102%). We also used both methods to determine the amounts of G-group aflatoxins in five peanut samples contaminated by aflatoxin B1-positive, and their relative standard deviations ranged from 8.4% to 17.7% (under 20%), which demonstrates a good correlation between the two methods. We further used this CI-ELISA to assess the ability of 126 fungal strains isolated from peanuts or field soils to produce G-group aflatoxins. Among these, seven stains producing different amounts of G-group aflatoxins were identified. Our results showed that the monoclonal antibody 2 G6-based CI-ELISA was suitable for the detection of G-group aflatoxins present in peanuts and also those produced by fungi. [ABSTRACT FROM AUTHOR]

The natural occurrence of ochratoxin A, ochratoxin B, aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 (OTA, OTB, AFB1, AFB2, AFG1, AFG2) in red wines was investigated by HPLC/FLD after immunoaffinity column clean-up in 57 market samples produced in Sicily (Italy). The results showed a very low incidence of these mycotoxins in analysed samples, confirming the high degree of quality and safety of Sicilian red wines. The results indicated 71.9% and 64.9% positive samples for OTA and OTB respectively, with an average level of 0.13 μg l–1, well below the European maximum permitted levels (MLs). The aflatoxin most frequently detected in the samples was AFG1, present in 57.9% of samples, while the other aflatoxins were rarely present. Recovery experiments were carried out on eight mycotoxin-free red wines spiked with OTA, OTB, AFB1, AFB2, AFG1 and AFG2 at two different levels. The limits of detection (LODs) in wines were 0.02 µg l–1 for OTA, 0.04 µg l–1 for OTB, 0.03 µg l–1 for AFG1, AFG2 and AFB2, and 0.05 µg l–1 for AFB1. A good correlation was found, with good performances in term of precision for the method. [ABSTRACT FROM AUTHOR]

Background and Purpose: Aflatoxins are highly toxic compounds that can cause acute and chronic toxicity in humans and animals. This study aimed to evaluate the expression of BDNF and GFAP, histopathological changes, and oxidative stress factors in brain tissue exposed to aflatoxin G1 (AFG1) in male rats., Experimental Approach: Twenty-eight male Wistar rats were used. Animals were randomly divided into 4 groups of 7 each. The control group received 0.2 mL of corn oil and the treatment groups were exposed to AFG1 (2 mg/kg) intra-peritoneally for 15, 28, and 45 days. The tissue was used for histopathological studies, and the level of TAC, SOD, and MDA, and the expression of BDNF and GFAP genes were evaluated., Findings/results: Real-time PCR results showed that AFG1 increased GFAP expression and decreased BDNF expression in AFG1-treated groups compared to the control group. The tissue level of TAC and SOD over time in the groups receiving AFG1 significantly decreased and the tissue level of MDA increased compared to the control group. Histopathological results showed that AFG1 can cause cell necrosis, a reduction of the normal cells number in the hippocampal region of CA1, cerebral edema, shrinkage of nerve cells, formation of space around neuroglia, and diffusion of gliosis in the cerebral cortex after 45 days., Conclusion and Implication: AFG1, by causing pathological complications in cortical tissue, was able to affect the exacerbation of nerve tissue damage and thus pave the way for future neurological diseases., (Copyright: © 2022 Research in Pharmaceutical Sciences.)

To detect and monitor G-group aflatoxins in agricultural products, we generated class-specific monoclonal antibodies that specifically recognized aflatoxins G1 and G2. Of the final three positive and stable hybridomas obtained, clone 2G6 produced a monoclonal antibody that had equal sensitivity to aflatoxins G1 and G2, and did not cross-react with aflatoxins B1, B2, or M1. Its IC50 values for aflatoxins G1 and G2 were 17.18 ng·mL−1 and 19.75 ng·mL−1, respectively. Using this new monoclonal antibody, we developed a competitive indirect enzyme-linked immunosorbent assay (CI-ELISA); the method had a limit of detection of 0.06 ng·mL−1. To validate this CI-ELISA, we spiked uncontaminated peanut samples with various amounts of aflatoxins G1 and G2 and compared recovery rates with those determined by a standard HPLC method. The recovery rates of the CI-ELISA ranging from 94% to 103% were comparable to those of the HPLC (92% to 102%). We also used both methods to determine the amounts of G-group aflatoxins in five peanut samples contaminated by aflatoxin B1-positive, and their relative standard deviations ranged from 8.4% to 17.7% (under 20%), which demonstrates a good correlation between the two methods. We further used this CI-ELISA to assess the ability of 126 fungal strains isolated from peanuts or field soils to produce G-group aflatoxins. Among these, seven stains producing different amounts of G-group aflatoxins were identified. Our results showed that the monoclonal antibody 2 G6-based CI-ELISA was suitable for the detection of G-group aflatoxins present in peanuts and also those produced by fungi.

Cytochrome P450 2A13 (CYP2A13) is an extrahepatic enzyme that mainly expresses in human respiratory system, and it is reported to mediate the metabolic activation of aflatoxin B1. Due to the structural similarity, AFG1 is predicted to be metabolized by CYP2A13. However, the role of CYP2A13 in metabolic activation of AFG1 is unclear. In present study, human bronchial epithelial cells that stably express CYP2A13 (B-2A13) were used to conduct the effects of AFG1 on cytotoxicity, apoptosis, DNA damages, and their response protein expression. Low concentrations of AFG1 induced significant cytotoxicity and apoptosis, which was consistent with the increased expressions of pro-apoptotic proteins, such as C-PARP and C-caspase-3. In addition, AFG1 increased 8-OHdG and γH2AX in the nuclies and induced S phase arrest and DNA damage in B-2A13 cells, and the proteins related to DNA damage responses, such as ATM, ATR, Chk2, p53, BRCA1, and γH2AX, were activated. All the above effects were inhibited by nicotine (a substrate of CYP2A13) or 8-MOP (an inhibitor of CYP enzymes), confirming that CYP2A13 mediated the AFG1-induced cytotoxicity and DNA damages. Collectively, our findings first demonstrate that CYP2A13 might be an efficient enzyme in metabolic activation of AFG1 and helps provide a new insight into adverse effects of AFG1 in human respiratory system. [ABSTRACT FROM AUTHOR]

Aflatoxins have been shown to be hepatotoxic, carcinogenic, mutagenic and teratogenic to different species of animals. Besides, at low concentrations, Selenium (Se4+) is antimutagenic and anticarcinogenic while it is toxic, mutagenic and carcinogenic at high concentrations. In this study, we aimed to evaluate the effect of Se4+ against aflatoxin GAFG1 (AFG1) on blood cultures in relation to induction of sister chromatid exchange (SCE). The results showed that at 0.4 and 0.8 parts per million (ppm) concentration of AFG1, the frequency of SCE increased in cultured human lymphocytes. When different concentration of Se4+ (0.08 and 8 ppm) were added to AFG1, the frequencies of SCE decreased. Howewer, when 800 ppm concentration of Se4+ together with 0.08 ppm AFG1 were added to cell division inhibited in the cultures. Results suggested that Se4+ could effectively inhibit AFG1-induced SCE. Besides, the protective role of Se4+ against AFG1-induced SCE is probably related to its doses. [ABSTRACT FROM PUBLISHER]

Abstract: Different local and exported white cheese samples were collected from different markets in Jeddah during September 2008. Trace and heavy metals including Pb, Zn, Mn, Cu, Fe and Cd were analyzed using atomic absorption spectrometry. The concentration of the tested metals was in the range, Fe++ >Zn+++ >Mn++ >Pb++ >Cu++ >Cd++. The mean concentration of 7.63, 7.19, 0.5, 0.47, 0.16 and 0.14μg/g was recorded for Fe, Zn, Mn, Pb, Cu and Cd, respectively. The concentration of iron ranged from 3.5 to 11.9μg/g, zinc from 3.4 to 10.5, manganese from 0.12 to 1.0, lead from 0.14 to 1.14, and copper from 0.09 to 0.22. Yeasts and fungi were counted on Sabouraud and Potato Dextrose media and incubation was carried out at 25°C for 7 and 5days, respectively. Yeast count and fungi count of cheese were ranged from 0.1 to 0.44CFU/g and from 0.123 to 1.11CFU/g, respectively. Three out of 20 samples of cheese were contaminated with toxigenic fungi with 5% contamination level. Aflatoxin G1 was recorded in three samples using immunoadsorbent column chromatography with a range from 7 to 13ppm. [ABSTRACT FROM AUTHOR]

Abstract: Aflatoxins (AF) are the mycotoxin with the carcinogenic effect produced by the fungi like Aspergillus flavus, including AFB1, B2, G1, G2, M1, and so on. The detection rate of Aflatoxin G1 (AFG1) is very high in the diet of residents in the high incidence area of the gastric carcinoma and esophageal carcinoma in China, which is the main polluting mycotoxin of the local grain. However, there were no available data regarding the gastric toxicity of AFG1 up to now. In the present study, The toxicity of AFG1 in vitro-cultured human primary adult esophageal epithelial cells was explored by employing the methods of Western blot, semi-quantitative RT-PCR and observing the effect of AFG1 on the expression of the HLA-I molecules of the human esophageal epithelial cells and the antigen processing relative genes TAP-1 and LMP-2. The results showed that AFG1 treatment could decrease both the protein expression of HLA-ABC of the cell surface and the mRNA expression of HLA-A and HLA-B. Moreover, In the AFG1 treatment groups of different densities, both the TAP-1 mRNA and protein expression level of the human esophageal epithelial cells decreased. Furthermore, the LMP-2 protein expression level of the human esophageal epithelial cells decreased, while the mRNA expression level was not obviously changed by AFG1 treatment. It is indicated that the decrease of the HLA-I expression of the cell surface was probably dependent on the decrease of the TAP-1 and LMP-2 expression to a great extent. The decrease of LMP-2 expression resulted in the decrease of HLA-I expression and stability in the cell membrane and finally led to the defect in the antigen presentation, which hindered its identification by the T lymphocytes, made it escape the immune surveillance, and then caused the tumor genesis. [Copyright &y& Elsevier]

Abstract: The nadA gene is present at the end of the aflatoxin gene cluster in the genome of Aspergillus parasiticus as well as in Aspergillus flavus. RT-PCR analyses showed that the nadA gene was expressed in an aflatoxin-inducible YES medium, but not in an aflatoxin-non-inducible YEP medium. The nadA gene was not expressed in the aflR gene-deletion mutant, irrespective of the culture medium used. To clarify the nadA gene’s function, we disrupted the gene in aflatoxigenic A. parasiticus. The four nadA-deletion mutants that were isolated commonly accumulated a novel yellow-fluorescent pigment (named NADA) in mycelia as well as in culture medium. When the mutants and the wild-type strain were cultured for 3 days in YES medium, the mutants each produced about 50% of the amounts of G-group aflatoxins that the wild-type strain produced. In contrast, the amounts of B-group aflatoxins did not significantly differ between the mutants and the wild-type strain. The NADA pigment was so unstable that it could non-enzymatically change to aflatoxin G1 (AFG1). LC–MS measurement showed that the molecular mass of NADA was 360, which is 32 higher than that of AFG1. We previously reported that at least one cytosol enzyme, together with two other microsome enzymes, is necessary for the formation of AFG1 from O-methylsterigmatocystin (OMST) in the cell-free system of A. parasiticus. The present study confirmed that the cytosol fraction of the wild-type A. parasiticus strain significantly enhanced the AFG1 formation from OMST, whereas the cytosol fraction of the nadA-deletion mutant did not show the same activity. Furthermore, the cytosol fraction of the wild-type strain showed the enzyme activity catalyzing the reaction from NADA to AFG1, which required NADPH or NADH, indicating that NADA is a precursor of AFG1; in contrast, the cytosol fraction of the nadA-deletion mutant did not show the same enzyme activity. These results demonstrated that the NadA protein is the cytosol enzyme required for G-aflatoxin biosynthesis from OMST, and that it catalyzes the reaction from NADA to AFG1, the last step in G-aflatoxin biosynthesis. [Copyright &y& Elsevier]

Background and Purpose: Aflatoxin (AF) is a mycotoxin produced by various strains of the Aspergillus family. AFG1 as one of the most important types is highly found in cereals and grains. AF affects sperm production or even its quality. This study was designed to test the effects of AFG1 on mice testicular tissue., Experimental Approach: Twenty-four Albino mice were divided into four groups of 6 each; a control group (0.2 mL corn oil and ethanol), three treatment groups with different periods (20 μg/kg AFG1 for 7, 15, and 35 consecutive days). All treatments were applied intraperitoneally. Biosynthesis of cyclin D1, p21, and estrogen receptor alpha (ERα) proteins was evaluated by immunohistochemistry (IHC) staining. Levels of cyclin D1, p21, and ERα mRNA were evaluated by the real-time polymerase chain reaction (RT-PCR) technique. Tubular differentiation index (TDI), reproductive index (RI), and spermiogenesis indices were also analyzed., Findings/results: AFG1 increased the percentage of seminiferous tubules with negative TDI, RI, and SPI compared to the control group ( P < 0.05). RT-PCR and IHC analyses illustrated time-dependent enhancement in p21 expression and cyclin D1 biosynthesis in AFG1-treated groups significantly ( P < 0.05). While the protein and mRNA levels of ERα were significantly ( P < 0.05) decreased in a time-dependent manner., Conclusion and Implications: The chronic exposure to AFG1 reduced the expression and synthesis of ERα, increased the expression and synthesis of p21 and cyclin D1, impaired apoptosis, which in turn could impair spermatogenesis., Competing Interests: The authors declared no conflict of interest in this study., (Copyright: © 2021 Research in Pharmaceutical Sciences.)

The present study sought to evaluate the interaction between aflatoxin G 1 and free DNA in vitro through different analytical techniques. The UV-visible spectra results showed that the structure of DNA might be changed with a new aflatoxin G 1 -DNA complex forming, which indicated that the interacting mode between them was the intercalating mode. The DNA melting temperature increased by 12.80 °C, suggesting that the DNA double helix structure was more compact and stable through intercalation. The circular dichroism (CD) spectra results indicated that the interaction of aflatoxin G 1 with DNA induced the DNA base stacking changes. The results of agarose gel electrophoresis and fluorescence microscope further verified that the interacting mode between aflatoxin G 1 and DNA was intercalation mode. According to the fluorescence spectrum data, the binding constant was calculated 6.24 × 10 4 L·mol -1 . The thermodynamic results demonstrated that the reaction of aflatoxin G 1 intercalating to DNA was a spontaneous reaction. The elimination results suggested that aflatoxin G 1 could be enriched and removed by DNA intercalation through magnetic beads separation, with the removal efficiency of 93.73%. The study results would provide a theoretical basis for establishing a new aflatoxin removal method based on DNA intercalation.

Environmental conditions during ripening of dry-cured meat products favour growth of fungal population on their surface. Some of these moulds can produce mycotoxins. Paprika is one of the ingredients usually used in the formulation of raw-cured sausages, and its addition could influence the growth and production of mycotoxins of the moulds present in these products. In this work the effect of Spanish smoked paprika "Pimentón de la Vera" on growth of Aspergillus parasiticus and Penicillium nordicum and production of aflatoxins B 1 (AFB 1), G 1 (AFG 1) and ochratoxin A (OTA) respectively, was evaluated. Moulds were grown in a culture medium made from lyophilized fresh pork meat added with 4% salt and different concentrations of Spanish smoked paprika (1, 2 and 3%) at several water activity values (0.98, 0.94 and 0.87) and temperature (20–25 °C), to simulate conditions usually found during ripening of dry-cured meat products. Mould growth was evaluated by measuring the diameter of the colony every 24 h, and the production of mycotoxins by UHPLC-MS/MS every 2 days, during 10 days of incubation. Addition of paprika favours growth of the two mould species tested. However, the synthesis of mycotoxins was reduced at 0.94 and 0.98 a w when at least a 2% of paprika was added. Therefore, the addition of Spanish smoked paprika at 2–3% in the formulations may help to minimize AFs and OTA production in dry-cured meat products such as loins or "chorizo" sausages. • Paprika provokes a reduction of lag phases of A. parasiticus and P. nordicum. • Growth of A. parasiticus and P. nordicum increases when paprika is added. • 2% of paprika reduced aflatoxins and OTA concentration at 0.94 and 0.98 a w. • Addition of paprika could help to control the mycotoxins hazard in dry-cured meat products. [ABSTRACT FROM AUTHOR]

To detect and monitor G-group aflatoxins in agricultural products, we generated class-specific monoclonal antibodies that specifically recognized aflatoxins G₁ and G₂. Of the final three positive and stable hybridomas obtained, clone 2G6 produced a monoclonal antibody that had equal sensitivity to aflatoxins G₁ and G₂, and did not cross-react with aflatoxins B₁, B₂, or M₁. Its IC50 values for aflatoxins G₁ and G₂ were 17.18 ng·mL(-1) and 19.75 ng·mL(-1), respectively. Using this new monoclonal antibody, we developed a competitive indirect enzyme-linked immunosorbent assay (CI-ELISA); the method had a limit of detection of 0.06 ng·mL(-1). To validate this CI-ELISA, we spiked uncontaminated peanut samples with various amounts of aflatoxins G₁ and G₂ and compared recovery rates with those determined by a standard HPLC method. The recovery rates of the CI-ELISA ranging from 94% to 103% were comparable to those of the HPLC (92% to 102%). We also used both methods to determine the amounts of G-group aflatoxins in five peanut samples contaminated by aflatoxin B₁-positive, and their relative standard deviations ranged from 8.4% to 17.7% (under 20%), which demonstrates a good correlation between the two methods. We further used this CI-ELISA to assess the ability of 126 fungal strains isolated from peanuts or field soils to produce G-group aflatoxins. Among these, seven stains producing different amounts of G-group aflatoxins were identified. Our results showed that the monoclonal antibody 2 G6-based CI-ELISA was suitable for the detection of G-group aflatoxins present in peanuts and also those produced by fungi.

Aflatoxin G1 (AFG1) is one of the main toxic contaminants in pistachio nuts and causes potential health hazards. Hence, AFG1 reduction is one of the main concerns in food safety. Kefir-grains contain symbiotic association of microorganisms well known for their aflatoxin decontamination effects. In this study, a central composite design (CCD) using response surface methodology (RSM) was applied to develop a model in order to predict AFG1 reduction in pistachio nuts by kefir-grain (already heated at 70 and 110°C). The independent variables were: toxin concentration (X1: 5, 10, 15, 20 and 25 ng/g), kefir-grain level (X2: 5, 10, 20, 10 and 25%), contact time (X3: 0, 2, 4, 6 and 8 h), and incubation temperature (X4: 20, 30, 40, 50 and 60°C). There was a significant reduction in AFG1 (p < 0.05) when pre-heat-treated kefir-grain used. The variables including X1, X3 and the interactions between X2-X4 as well as X3-X4 have significant effects on AFG1 reduction. The model provided a good prediction of AFG1 reduction under the assay conditions. Optimization was used to enhance the efficiency of kefir-grain on AFG1 reduction. The optimum conditions for the highest AFG1 reduction (96.8%) were predicted by the model as follows: toxin concentration = 20 ng/g, kefir-grain level = 10%, contact time = 6 h, and incubation temperature = 30°C which validated practically in six replications.