Aflatoxin

Aflatoxin B1 (AFB1), one of the most toxic chemical carcinogens, has been widely studied. It remains challenging to develop simple, accurate and sensitive analytical methods for the detection of AFB1 in food matrices. In this work, based on dual-signaling strategy, a ratiometric aptasensor was designed and verified for the accurate and sensitive detection of AFB1. The electrochemical method was first used as a model to verify the specific interaction between AFB1 and the aptamer, in which ferrocene (Fc) and methylene blue (MB) anchored DNA sequences were acted as dual signals...

Aflatoxin B1 (AFB1 ) is one of the most commonly found mycotoxins in food commodities, particularly cereals, oilseeds, spices and tree nuts. In the past decade, aptamers have come into limelight and emerged as a new biosensing element replacing antibodies in various detection formats. Herein we report a faster, more sensitive, high throughput method for the detection of AFB1 using AFB1 -specific aptamers. The assay format was based on a competitive reaction of the fluorescent tagged aptamer specific to AFB1 with the aflatoxin conjugate...

High voltage atmospheric cold plasma (HVACP) is a novel non-thermal decontamination technology that has potential for use in the food industry. In this study, HVACP was applied to treat pure aflatoxin B1 (AFB1) powder on a glass slide. AFB1 was degraded by 76% using a 5 min HVACP treatment in air having 40% relative humidity. The degradation products of AFB1 were separated and their molecular formulas were elucidated using liquid chromatography time of flight mass spectrometry (HPLC-TOF MS). Six main degradation products were observed...

Pseudomonas fluorescens strain 3JW1, which has a broad-spectrum antimicrobial activity, was studied to investigate whether it affects the amounts of aflatoxin B1 (AFB1) produced by Aspergillus flavus. It was found that the bacterium reduced the amounts of AFB1 in potato dextrose broth (PDB) and peanut medium by 97.8% and 99.4%, respectively. It also reduced AFB1 by ~183 μg/kg (55.8%) when applied onto peanut kernels. This strain reduced AFB1 via three mechanisms. First, it significantly inhibited A. flavus growth; second, our data showed that strain 3JW1 inhibits aflatoxin biosynthesis by A...

Exposure to molds and mycotoxins not only contributes to the onset of respiratory disease, it also affects the ocular surface. Very few published studies concern the evaluation of the effect of mycotoxin exposure on ocular cells. The present study investigates the effects of aflatoxin B₁ (AFB₁) and gliotoxin, two mycotoxins secreted by Aspergillus molds, on the biological activity of the human corneal epithelial (HCE) cells. After 24, 48, and 72 h of exposure, cellular viability and inflammatory response were assessed...

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...

Ginger has got increasing worldwide interests due to its extensive biological activities, along with high medical and edible values. But fungal contamination and mycotoxin residues have brought challenges to its quality and safety. In the present study, the relationship of content of mycotoxins accumulation and bioactive components variation in ginger after infection by toxigenic fungi were investigated for the first time to elucidate the influence of fungal contamination on the inherent quality of ginger. After being infected by Aspergillus flavus and Aspergillus carbonarius for different periods, the produced mycotoxins was determined by an immunoaffinity column clean-up based ultra-fast liquid chromatography coupled with tandem mass spectrometry, and the main bioactive components in ginger were analyzed by ultra performance liquid chromatography-photodiode array detection...

A simple and convenient cell-based electrochemical biosensor was developed to assess the individual and combined toxicity of deoxynivalenol (DON), zearalenone (ZEN), and Aflatoxin B1 (AFB1) on Hep G2 cells. The sensor was modified in succession with AuNPs (gold nanoparticles), cysteamine, and laminin. The cells interacting with laminin formed tight cell-to-electrode contacts, and collagen was used to maintain cell adhesion and viability. Electrochemical impedance spectroscopy (EIS) was developed to evaluate mycotoxin toxicity...

Localized surface plasmon resonance (LSPR) biosensors allow label-free detection of small molecules in molecular binding events; however, they are limited by a relatively low sensitivity and narrow dynamic range. Here, we report highly sensitive small-molecule detection by LSPR peak shift exploiting the G-quadruplex (GQx) structure-binding characteristic of known GQx binders to enhance the LSPR signal of a plasmonic aptasensor. Six known GQx binders (thiazole orange, malachite green, crystal violet, zinc protoporphyrin IX, thioflavin T, and berberine) were tested for their ability to enhance the LSPR signal...

Manufactured silver nanoparticles (Ag NPs) have long been used as antimicrobials. However, little is known about how these NPs affect fungal cell functions. While multiple previous studies reveal that Ag NPs inhibit secondary metabolite syntheses in several mycotoxin producing filamentous fungi, these effects are associated with growth repression and hence need sub-lethal to lethal NP doses, which besides stopping fungal growth, can potentially accumulate in the environment. Here we demonstrate that citrate coated Ag NPs of size 20 nm, when applied at a selected nonlethal dose, can result in a > 2 fold inhibition of biosynthesis of the carcinogenic mycotoxin and secondary metabolite, aflatoxin B1 in the filamentous fungus and an important plant pathogen, Aspergillus parasiticus, without inhibiting fungal growth...

Commercially available rice grains in Thailand were examined to isolate the monoverticillate Penicillium species responsible for toxic yellowed rice. Penicillium species were obtained from seven out of 10 rice samples tested. Among them, one Penicillium citreonigrum isolate and six Penicillium brocae isolates were morphologically identified. The P. citreonigrum isolate produced the mycotoxin citreoviridin on a yeast extract sucrose broth medium. Mycotoxin surveys showed that citreoviridin was not detected in any samples, but one out of 10 rice samples tested was positive for aflatoxin B₁ at a level of 5...

A series of prenylated flavonoids was obtained from antigenotoxic extracts and fractions of stem bark of Erythrina latissima E. Mey (Leguminosae). In addition to five constituents never reported before, i.e. (2S)-5,7-dihydroxy-2-(4-hydroxy-2-(prop-1-en-2-yl)-2,3-dihydrobenzofuran-6-yl)chroman-4-one (erylatissin D), (2S)-5,7-dihydroxy-2-(4-methoxy-2-(prop-1-en-2-yl)-2,3-dihydrobenzofuran-6-yl)chroman-4-one (erylatissin E), 5,7-dihydroxy-3-(4-methoxy-2-(prop-1-en-2-yl)-2,3-dihydrobenzofuran-6-yl)-4H-chromen-4-one (erylatissin F), (2S)-5,7,8'-trihydroxy-2',2'-dimethyl-[2,6'-bichroman]-4-one (erylatissin G) and (2S)-5,7-dihydroxy-8'-methoxy-2',2'-dimethyl-[2,6'-bichroman]-4-one (dihydroabyssinin I), 18 known flavonoids were identified...

Aflatoxin is a toxic, carcinogenic mycotoxin primarily produced by Aspergillus parasiticus and Aspergillus flavus. Previous studies have predicted the existence of more than 20 genes in the gene cluster involved in aflatoxin biosynthesis. Among these genes, aflK encodes versicolorin B synthase, which converts versiconal to versicolorin B. Past research has investigated aflK in A. parasiticus, but few studies have characterized aflK in the animal, plant, and human pathogen A. flavus. To understand the potential role of aflK in A...

Mycotoxins are toxic secondary metabolites produced by certain filamentous fungi (molds). These low molecular weight compounds (usually less than 1000 Daltons) are naturally occurring and practically unavoidable. They can enter our food chain either directly from plant-based food components contaminated with mycotoxins or by indirect contamination from the growth of toxigenic fungi on food. Mycotoxins can accumulate in maturing corn, cereals, soybeans, sorghum, peanuts, and other food and feed crops in the field and in grain during transportation...

An efficient method has been developed for the enantioselective synthesis of the aflatoxin system with multiple stereocenters via a sequence of organocatalytic Michael-acetalization-reduction-Nef reactions that proceed with high enantioselectivities (90-99% ee). The one-pot reaction sequence provides a facile entry to the aflatoxin system, including dihydroaflatoxin D2, which includes a formal total synthesis of aflatoxin B2. The first total synthesis of (-)- and (+)-microminutinin was also achieved via this protocol...

Mitochondrial fission, fusion, and mitophagy are interlinked processes that regulate mitochondrial shape, number, and size, as well as metabolic activity and stress response. The fundamental importance of these processes is evident in the fact that mutations in fission (DRP1), fusion (MFN2, OPA1), and mitophagy (PINK1, PARK2) genes can cause human disease (collectively >1/10,000). Interestingly, however, the age of onset and severity of clinical manifestations varies greatly between patients with these diseases (even those harboring identical mutations), suggesting a role for environmental factors in the development and progression of certain mitochondrial diseases...

Toxins of microbial origin frequently contaminate foodstuffs worldwide and pose a serious hazard to humans. This study reports on LCMS/MS quantification of multiple fungal and bacterial toxins, from household sampling of 50 traditionally prepared maize-fufu samples from Bamunka village, western highlands of Cameroon. Seventy-four metabolites including aflatoxin B1 (AFB1) (12/50: mean 0.9, range n.d-1.8 μg kg(-1)), cereulide (50/50: mean 37; range 1-236 μg kg(-1)), deoxynivalenol (DON) (50/50: mean 23, range 14-55 μg kg(-1)), fumonisin B1 (FB1) (50/50: mean: 151, range 48-709 μg kg(-1)), nivalenol (NIV) (50/50; mean 268, range 116-372 μg kg(-1)), patulin (PAT) (15/50:mean 105, range 12-890 μg kg(-1)) and zearalenone (ZEN) (50/50: mean 49, range 5-150) were detected; and of note every sample contained at least 27 toxic compounds...

Microcystins have been reported carcinogenic by animal and cell experimentation, but there were no data on the linkage between serum microcystins and hepatocellular carcinoma (HCC) risk in human. We conducted a clinical case-control study to investigate the association between serum microcystins and HCC risk after controlling several known risk factors, such as hepatitis B virus (HBV), alcohol, and aflatoxin. From December 2013 to May 2016, 214 patients newly diagnosed with HCC, along with 214 controls (frequency-matched by age and sex) were recruited from three hospitals in Chongqing, Southwest China...

Objective: To investigate the association between aflatoxin exposure and primary hepatocellular carcinoma (PHC) development. Methods: From December 2013 to May 2016, we selected 214 patients newly diagnosed with PHC as cases, and 214 patients as controls from three hospitals in Chongqing. Cases were confirmed with PHC diagnosis standard. And cases caused by clear reasons such as drug-induced liver injury, alcoholic liver damage, fatty liver and gallstones etiology, were excluded. Controls were included with no cancer and no digestive system disease, and recruited simultaneously with cases...

Combination of aptamers with DNAzymes attracted intense attention for development of DNA-based biosensors for detection of mycotoxins. In the present study a combination of aflatoxin B1 specific aptamer and HRP- (horseradish peroxidase-) mimicking DNAzyme was optimized for detecting aflatoxin B1. Detecting approach is based on the binding affinity of aflatoxin B1 to its specific aptamer and conversion of substrate to a detectable colorimetric signal by a linked DNAzyme. Compared to conventional methods for aflatoxin B1 detection, DNA-based assay has the advantages of low cost, long-term stability, and rapid, simple, and user-friendly steps...