Terahertz toroidal dipole metamaterial sensors for detection of aflatoxin B1

Terahertz metamaterial biosensors have attracted significant attention in the biological field due to their advantages of label-free,real-time and in situ detection.In this paper,a highly sensitive metamaterial sensor with semi-ring mirror symmetry based on toroidal dipole resonance is designed for a new metamaterial biosensor.It is shown that a refractive index sensitivity of 337.5 GHz per refractive index unit can be achieved under an analyte of saturated thickness near a 1.33 THz transmission dip.For biosensor samples where aflatoxin B1 is dropped on the metamaterial surface in our experiment,dip amplitudes of transmission varying from 0.1904 to 0.203 and 0.2093 are observed as aflatoxin B1 concentrations are altered from 0 to 0.001μg·ml-1 and to 0.01μg·ml-1,respectively.Furthermore,when aflatoxin B1 concentrations are 0.1μg·ml-1,1μg·ml-1,10μg·ml-1 and 100μg·ml-1,dip amplitudes of 0.2179,0.226,0.2384 and 0.2527 and dip redshifts of 10.1 GHz,20.1 GHz,27.7 GHz and 37.6 GHz are respectively observed.These results illustrate high-sensitivity,label-free detection of aflatoxin B1,enriching the applications of sensors in the terahertz domain.

Molecular mechanisms of aflatoxin neurotoxicity and potential neuroprotective agents

Aflatoxins(AFTs)represent one of the most notorious classes of deadly mycotoxins produced by certain fungi that are found on agricultural crops.Aflatoxins are highly toxic to mammals and are known to cause a series of detrimental effects,including neuro-,hepato-,nephron-,and immuno-toxicity.In this original review we summarize the mechanisms of aflatoxin-induced neurotoxicity and the clinical potential of novel neuroprotective agents.Aflatoxin B1(AFB1)is the most toxic congener among the 21 identified AFTs.Recent studies have shown that food borne exposure to AFB1 and/or its metabolites often leads to fatal neurotoxicity in animals and humans.Animal studies indicated that AFB1 exposure could induce abnormal behavioral changes,including anxiety,lethargy disorders,depression-like behavior,cognitive,learning and memory defects,and decreased feeding behavior.Mechanistically,AFB1 exposure has been associated with lipid peroxidation,ablation of non-enzymatic and enzymatic antioxidant defense systems and decreased neurotransmitter levels.AFB1 exposure has also been shown to induce DNA damage,apoptosis,pyroptosis,and mitochondrial dysfunction in the brain tissue.Several signaling pathways,including gasdermin D,toll like receptor 2(TLR2),TLR4,Akt,NF-κB,ERK/MAPK,protein kinase C(PKC),and mitochondrial apoptotic pathways have been shown to participate in AFB1-induced neuronal or astrocyte cell death.Targeting these pathways by small molecules(e.g.,quercetin,curcumin,and gallic acid,and dimethyl fumarate),Chinese herbal extracts(e.g.,Artichoke leaf extract,Chelidonium majus ethanolic extract,pumpkin extract,and Crocus sativus L.tea),and probiotic supplements could effectively improve AFB1-induced neurobehavioral abnormalities and neurotoxicity.To date,the precise molecular mechanisms of AFB1-induced neurotoxicity and potential neuroprotective agents remain unclear.In the present review,the clinical manifestations,molecular mechanisms,and potential neuroprotective agents of AFB1-induced neurotoxicity are summarized in the broadest overview.It is most hopeful that this broad reaching review provides valuable insights and stimulates broader discussion to develop the effective neuroprotective agents against aflatoxins.

Foodborne toxin Aflatoxin B_(1)induced glomerular podocyte inflammation through proteolysis of RelA,downregulation of miR-9 and CXCR4/TXNIP/NLRP3 pathway

Aflatoxin B_(1)(AFB_(1))is a naturally-occurring mycotoxin and recognized as the most toxic foodborne toxin,particularly causing damages to kidney.Glomerular podocytes are terminally differentiated epithelial cells.AFB_(1)induces podocyte inflammation,proteinuria and renal dysfunction.Studying the mechanism of AFB_(1)-induced podocyte inflammation and murine kidney dysfunction,we detected that AFB_(1)increased ubiquitindependent degradation of the transcription factor RelA through enhanced interaction of RelA with E3 ubiquitin ligase tripartite motif containing 7(TRIM7)in mouse podocyte clone-5(MPC-5)and mouse glomeruli.Reduction of RelA resulted in decreasing microRNA-9(miR-9)and activating the chemokine receptor 4(CXCR4),thioredoxin interacting protein(TXNIP),and NOD-like receptor pyrin domain-containing 3(NLRP3)signaling axis(CXCR4/TXNIP/NLRP3 pathway),leading to podocyte inflammation.We also determined that downregulation of miR-9 led to CXCR4 expression and the downstream TXNIP/NLRP3 pathway activation.Overexpression of miR-9 or deletion of CXCR4 suppressed AFB_(1)-induced CXCR4/TXNIP/NLRP3 pathway,resulting in alleviating podocyte inflammation and kidney dysfunction.Our findings indicated that ubiquitin-dependent proteolysis of RelA,downregulation of miR-9,and activation of CXCR4/TXNIP/NLRP3 pathway played an essential role in AFB_(1)-induced glomerular podocyte inflammation.Our study revealed a novel mechanism,via RelA,for the control of AFB_(1)’s nephrotoxicity,leading to an effective protection of food safety and public health.

Tissue inhibitor of metalloproteinase-3 expression affects clinicopathological features and prognosis of aflatoxin B1-related hepatocellular carcinoma

BACKGROUND The dysregulation of tissue inhibitor of metalloproteinase-3(TIMP3)was positively correlated with the progression of hepatocellular carcinoma(HCC).However,it is not clear whether TIMP3 expression is associated with the clinico-pathological features and prognosis of aflatoxin B1(AFB1)-related HCC(AHCC).A retrospective study,including 182 patients with AHCC,was conducted to explore the link between TIMP3 expression in cancerous tissues and the clinico-pathological characteristics and prognosis of AHCC.TIMP3 expression was detected by immunohistochemistry and its effects on the clinicopathological features and prognosis of AHCC were evaluated by Kaplan-Meier survival analysis and Cox regression survival analysis.Odds ratio,hazard ratio(HR),median overall survival time(MST),median tumor recurrence-free survival time(MRT),and corresponding 95%confidential interval(CI)was calculated to RESULTS Kaplan-Meier survival analysis showed that compared with high TIMP3 expression,low TIMP3 expression in tumor tissues significantly decreased the MST(36.00 mo vs 18.00 mo)and MRT(32.00 mo vs 16 mo)of patients with AHCC.Multivariate Cox regression survival analysis further proved that decreased expression of TIMP3 increased the risk of death(HR=2.85,95%CI:2.04-4.00)and tumor recurrence(HR=2.26,95%CI:1.57-3.26).Furthermore,decreased expression of TIMP3 protein in tissues with AHCC was significantly correlated with tumor clinicopatho-logical features,such as tumor size,tumor grade and stage,tumor microvessel density,and tumor blood invasion.Additionally,TIMP3 protein expression was also negatively associated with amount of AFB1-DNA adducts in tumor tissues.CONCLUSION These findings indicate that the dysregulation of TIMP3 expression is related to AHCC biological behaviors and affects tumor outcome,suggesting that TIMP3 may act as a prognostic biomarker for AHCC.

Contamination of aflatoxins as threat to the safety of herbal Unani drugs: an overview

Unani medicine is an oldest system of traditional medicine,where drugs of animal,mineral and herbal origin are used for centuries to cure diseases.Unani remedies are now available not only in drug stores,but also in food stores and super markets.Therefore the efficacy and safety of these drugs is very crucial.One of the most serious risks associated with these remedies is,consumer assumes that they are natural,so they are safe.But biological contamination(bacterial,fungal and insect)of herbal medicines is a serious concern.The Aspergillus flavus and Aspergillus parasiticus are the fungal species that occur naturally,release aflatoxins and is a threat to the natural drugs.The World Health Organization has recommended determination of aflatoxins in natural drugs(Unani)as one of the parameter of their safety studies as Aflatoxin contamination is concerned significantly with health and economic loss affecting humans,animals,and agriculture.Aflatoxin B1 is categorized as a group 1 carcinogen by The International Agency for Research on Cancer that causes a variety of health issues.Thus keeping in mind the deleterious health effects of aflatoxins,here,in this review we have made an attempt to summarize the aflatoxins with respect to their origin,occurrence,structure and properties to generate the awareness among the people dealing mainly with Unani herbal drugs.Besides these their toxicity and effects on health have also been discussed.The analytical methods for their determination and some measures to prevent their contamination are also suggested to improve the efficacy and safety of Unani herbal drugs.

Surface-enhanced Raman Scattering of Aflatoxin B1 on Silver by DFT Method

The structure, electrostatic properties, and Raman spectra of aflatoxin B1 （AFB1） and AFB1-Ag complex are studied by density functional theory with B3LYP/6- 311G（d,p）/Lan12dz basis set. The results show that the surface-enhanced Raman scattering （SERS） and pre-resonance Raman spectra of AFB1-Ag complex strongly depend on the adsorption site and the excitation wavelength found to enhance 102-103 order compared to of the incident light. The SERS factors are normal Raman spectrum of AFB1 molecule due to the larger static polarizabilities of the AFB1-Ag complex, which directly results in the stronger chemical enhancement in SERS spectra. The pre-resonance Raman spectra of AFB1-Ag complex are explored at 266, 482, 785, and 1064 nm incident light wavelength, in which the enhancement factors are about 10^2-10^4, mainly caused by the charge-transfer excitation resonance. The vibrational modes are analyzed to explain the relationship between the vibrational direction and the enhanced Raman intensities.

Biocontrol potential of reducing aflatoxin contamination by an atoxigenic strain of Aspergillus flavus. isolated from peanut

An Aspergillus section/Zam isolate （ NAFFHB396） was isolated from a peanut kernel. It was identified as Aspergillus flavus based on morphology and molecular characteristics. It produced yellow to green - colored conidia on CYA medium and colonies with bright orange in color on AFPA medium. NAFFHB396 was grouped with A. flavus NRRL21882 and NRRL3357 by phylogenetic analysis of partial calmodulin sequence data. It was found that 12 genes were absent in aflatoxin gene cluster in NAFF- HB396. HPLC result further showed that it was an atoxigenic isolate. Co - inoculation of NAFFHB396 with a high aflatoxin producer AF2202 at the ratio of 1：1 both on CYA medium and peanut kernel resul-ted in reduction of aflatoxin production by 88.7% and 99. 8% respectively. These results suggested that the atoxigenic NAFFHB396 obtained in this study had a great potential to be a biocontrol agent to reduce aflatoxin contamination of peanut in China.

Incidence, Types and Levels of Aflatoxin in Different Peanuts Varieties Produced in Busia and Kisii Central Districts, Kenya

Busia and Kisii Central districts are areas in western Kenya that have repeatedly reported high levels of stunting growth in children and an increase in hepatocellular carcinoma (HCC);an aspect often positively associated with chronic exposure to aflatoxins especially through consumption of foods such as peanuts. The objectives of the study were to determine the incidence, types and levels of aflatoxin in different varieties of peanuts produced in Busia and Kisii Central districts. One hundred and two (102) peanuts samples were collected from farmers’ in each district. Aflatoxin types and levels of aflatoxins were analyzed using high performance liquid chromatography (HPLC) technique. All the peanuts samples from Kisii Central and 97.06% samples from Busia were contaminated with aflatoxins. However, aflatoxin was not detected in 2.94% of samples from Busia district. The levels of total aflatoxin ranges were 0.1 to 268 μg/kg and 1.63 to 591.1 μg/kg in peanuts from Busia and Kisii Central respectively. Majority of peanuts samples had levels within Kenya Bureau of Standards (KEBS) and European Union (EU) regulatory limits for total aflatoxins. Improved variety (Valencia red) had significantly lower aflatoxin contamination compared to local varieties (Uganda local red, Homabay local and Local red). Aflatoxins B1, B2, G1 and G2 were found in peanuts;B1 was the most predominant in both districts (t = 12.4, df = 3, P = 0.034). The levels of aflatoxins especially in peanuts from Kisii Central district were high (591.1 μg/kg) where 44.6% of samples analyzed were unfit for even animal feed (USFDA regulatory limit). An assessment on the levels of aflatoxins should be done by the relevant stakeholders in other key foods in the areas for example maize. The most lethal aflatoxin type B1 was found to be the most predominant peanuts from both districts of study. This calls for frequent aflatoxin screening of peanuts from the districts particularly aflatoxin type B.

Aflatoxins,hepatocellular carcinoma and public health

Hepatocellular carcinoma(HCC) is one of the leading causes of cancer deaths worldwide,primarily affecting populations in the developing countries.Aflatoxin,a food contaminant produced by the fungi Aspergillus flavus and Aspergillus parasiticus,is a known human carcinogen that has been shown to be a causative agent in the pathogenesis of HCC.Aflatoxin can affect a wide range of food commodities including corns,oilseeds,spices,and tree nuts as well as milk,meat,and dried fruit.Many factors affect the growth of Aspergillus fungi and the level of aflatoxin contamination in food.Drought stress is one of the factors that increase susceptibility of plants to Aspergillus and thus aflatoxin contamination.A recent drought is thought to be responsible for finding of trace amounts of aflatoxin in some of the corn harvested in the United States.Although it's too soon to know whether aflatoxin will be a significant problem,since United States is the world's largest corn producer and exporter,this has raised alarm bells.Strict regulations and testing of finished foods and feeds in the United States should prevent a major health scare,and prevent human exposure to deleterious levels of aflatoxin.Unfortunately,such regulations and testing are not in place in many countries.The purpose of this editorial is to summarize the current knowledge on association of aflatoxin and HCC,encourage future research and draw attention to this global public health issue.

The aflatoxin B1 isolating potential of two lactic acid bacteria

Objective:To determine lactic acid bacteria's capability to enhance the process of binding and isolating aflatoxin B1 and to utilize such lactic acid bacteria as a food supplement or probiotic products for preventing absorption of aflatoxin Bl in human and animal bodies.Methods:In the present research,the bacteria were isolated from five different sources.For surveying the capability of the bacteria in isolating aflatoxin Bl,ELISA method was implemented,and for identifying the resultant strains through 16S rRNA sequencing method,universal primers were applied.Results:Among the strains which were isolated,two strains of Lactobacillus pentosus and Lactobacillus beveris exhibited the capability of absorbing and isolating aflatoxin Bl by respectively absorbing and discharging 17.4%and 34.7%of the aforementioned toxin existing in the experiment solution.Conclusions:Strains of Lactobacillus pentosus and Lactobacillus beveris were isolated from human feces and local milk samples,respectively.And both strains has the ability to isolate or bind with aflatoxin Bl.

Occurrence of Aflatoxin B_(1),deoxynivalenol and zearalenone in feeds in China during 2018-2020

Background:The current study was conducted to investigate the individual and combined occurrence of aflatoxin B_(1)(AFB_(1)),deoxynivalenol(DON)and zearalenone(ZEN)in feeds from various Provinces of China during 2018 to 2020.A total of 3,507 feed samples,including 2,090 feed ingredients and 1,417 complete feed samples,were collected from different areas of China for mycotoxins analysis.Results:The individual contamination of AFB_(1),DON and ZEN were present in more than 81.9%,96.4% and 96.9% of feed samples,respectively,with average concentration ranges of AFB_(1) between 1.2-27.4μg/kg,DON between 458.0-1,925.4μg/kg and ZEN between 48.1-326.8μg/kg.Notably,0.9%,0.5% and 0.1% of feed ingredients,and 1.2-12.8%,0.9-2.9% and 0-8.9% of complete feeds for pigs,poultry and ruminants with AFB_(1),ZEN and DON that exceeded China’s safety standards,respectively.Moreover,more than 81.5%of feed ingredients and 95.7% of complete feeds were co-contaminated with various combinations of these mycotoxins.Conclusion:This study indicates that the feeds in China were universally contaminated with AFB_(1),DON and ZEN during the past 3 years.These findings highlight the significance of monitoring mycotoxin contaminant levels in the domestic animal feed,and the importance of carrying out feed administration and remediation strategies for mycotoxin control.

Effects of Sterigmatocystin, Deoxynivalenol and Aflatoxin G_1 on Apoptosis of Human Peripheral Blood Lymphocytes in vitro

Objective To explore the effects of Sterigmatocystin (ST), Deoxynivalenol (DON) and Aflatoxin G1 (AFG1) on apoptosis of human peripheral blood lymphocytes (HPBLs) in vitro and thus to further elucidate the putative roles of these three mycotoxins on human immunosystem. Methods The effects of ST, DON and AFG1 on apoptosis of HPBLs were studied with cell culture, flow cytometric (FCM) DNA analysis and DNA agarose gel electrophoresis. Results DNA agarose gel electrophoresis results showed the characteristic 'ladder' pattern of apoptosis in HPBLs treated with ST, DON and AFG1. Flow cytometric DNA analysis revealed that typical subdiploid peaks of apoptosis in DNA histogram could be seen in all groups treated with the three mycotoxins. Significant time-effect and dose-effect relationships were found between the apoptosis rates and treatment time as well as concentrations of the three mycotoxins. Conclusion ST, DON and AFG1 can induce apoptosis of HPBLs in vitro and may have some negative effects on human immunosystem.

Hepatitis B virus x gene and cyanobacterial toxins promote aflatoxin B_1-induced hepatotumorigenesis in mice

AIM： To assess the combinative role of aflatoxin B1 （AFB1）, cyanobacterial toxins （cyanotoxins）, and hepatitis B virus （HBV） x gene in hepatotumorigenicity. METHODS： One-week-old animals carrying HBV x gene and their wild-type littermates were intraperitoneally （ip） injected with either single-dose AFB1 [6 mg/kg body weight （bw）], repeated-dose cyanotoxins （microcystin- LR or nodularin, 10 μg/kg bw once a week for 15 wk）, DMSO （vehicle control） alone, or AFB1 followed by cyanotoxins a week later, and were sacrificed at 24 and 52 wk post-treatment. RESULTS： AFB1 induced liver tumors in 13 of 29 （44.8%） transcjenic mice at 52 wk post-treatment, significantly more frequent than in wild-type mice （13.3%）. This significant difference was not shown in the 24-wk study. Compared with AFB1 exposure alone, MC-LR and nodularin yielded approximately 3-fold and 6-fold increases in the incidence of AFB1-induced liver tumors in wild-type animals at 24 wk, respectively. HBV x gene did not further elevate the risk associated with coexposure to AFB1 and cyanotoxins. With the exception of an MC-LR-dosed wild-type mouse, no liver tumor was observed in mice treated with cyanotoxins alone at 24 wk. Neither DMSO-treated transgenic mice nor their wild-type littermates had pathologic alterations relevant to hepatotumorigenesis in even up to 52 wk. CONCLUSION： HBV x gene and nodularin promote the development of AFB1-induced liver tumors. Co-exposure to AFB1 and MC-LR tends to elevate the risk of liver tumors at 24 wk relative to exposure to one of them. The combinative effect of AFB1, cyanotoxins and HBVx on hepatotumorigenesis is weak at 24 wk.

Biological control of aflatoxin contamination of crops

Aflatoxins produced primarily by two closely related fungi, Aspergillus flavus and Aspergillus parasiticus, are mutagenic and carcinogenic in animals and humans. Of many approaches investigated to manage aflatoxin contamination, bio-logical control method has shown great promise. Numerous organisms, including bacteria, yeasts and nontoxigenic fungal strains of A. flavus and A. parasiticus, have been tested for their ability in controlling aflatoxin contamination. Great successes in reducing aflatoxin contamination have been achieved by application of nontoxigenic strains of A. flavus and A. parasiticus in fields of cotton, peanut, maize and pistachio. The nontoxigenic strains applied to soil occupy the same niches as the natural occurring toxigenic strains. They, therefore, are capable of competing and displacing toxigenic strains. In this paper, we review recent development in biological control of aflatoxin contamination.

The Development of A Fluorescence Polarization Immunoassay for Aflatoxin Detection

A fluorescence polarization immunoassay （FPIA） was developed for the analysis ofaflatoxins （AFs） using an anti-aflatoxin B1 （AFB1） monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed an IC50 value of 23.33 ng/mL with a limit of detection of 13.12 ng/mL for AFB1. The cross-reactivities of AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2 with the antibody were 100%, 65.7%, 143%, 23.5%, 111.4%, and 2%, respectively. The group-specificity of anti-AFB1mAb indicated that the FPIA could potentially be used in a screening method for the detection of total AFs, albeit not AFG2 and AFM2. The total time required for analyzing 96 samples in one microplate was less than 5 rain. This study demonstrates the potential usefulness of the FPIA as a rapid and simple technique for monitoring AFs.

Aflatoxins metabolism, effects on epigenetic mechanisms and their role in carcinogenesis

Chronic consumption of aflatoxin-contaminated foods is a global problem in both developing and developed countries especially where there is poor regulation of their levels in foods. In the body, aflatoxins (AFBs) mainly AFB1 are biotransformed to various metabolites especially the active AFB1-exo-8,9-epoxide (AFBO). The AFB, AFBO and other metabolites interact with various biomolecules in the body including nucleic acids such as DNA and RNA and the various metabolic pathways such as protein synthesis, glycolytic pathway and electron transport chain involved in ATP production in body cells. The AFB interacts with DNA to form AFB-DNA adducts causing DNA breakages. The AFB and its metabolites induce the up regulation of nuclear receptors such as pregnane X receptor (PXR), constitutive androstane receptor (CAR), and aryl hydrocarbon receptor (AhR) through gene expression that regulates the metabolizing enzymes such as CYP450 involved in Phase I and Phase II metabolism of xenobiotics. AFB activates these nuclear receptors to produce the metabolizing enzymes. The AFB1 is metabolized in the body by cytochrome P450 (CYP450) enzyme isoforms such as CYP1A2, CYP1A2, CYP3A4/ CYP3A5, and CYP3A7 in fetus, glutathione S-transferase, aflatoxin B1-aldehyde reductase leading to reactive metabolites, some of which can be used as aflatoxin exposure biomarkers. These enzymes are involved in the Phase I and Phase II metabolic reactions of aflatoxins. The CYP1A2 is the principal metabolizer of aflatoxin at low concentrations while the reverse is true for CYP3A4. The accumulation of AFB and its metabolites in the body especially the AFB1-exo-8,9-epoxide depletes the glutathione (GSH) due to the formation of high amounts of epoxides and other reactive oxygen species (ROS). The AFB, AFB1-exo-8,9-epoxide and other metabolites also affect the epigenetic mechanisms including the DNA methylation, histone modifications, maturation of miRNAs as well as the daily formation of single nucleotide polymorphism (SNP) where AFB exposure may facilitate the process and induces G:C to T:A transversions at the third base in codon 249 of TP53 causing p53 mutations reported in hepatocellular carcinoma (HCC). The changes in epigenetic mechanisms lead to either epigenetic inactivation or epigenetic derepression and all these affect the gene expression, cellular differentiation and growth. AFB also through epigenetic mechanisms promotes tumorigenesis, angiogenesis, invasion and metastasis in hepatocellular carcinoma. However, the formation of the small amounts of AFB1 from AFB2 is suspected to cause the carcinogenicity of AFB2 in humans and animals. Chronic aflatoxins exposure leads to formation of reactive AFBO metabolites in the body that could activate and de-activates the various epigenetic mechanisms leading to development of various cancers.

Contamination of Aflatoxins in Different Kinds of Foods in China

Objective To study the contamination of total aflatoxins （AFs） in different kinds of foods including corn, peanut, rice, walnut, and pine nut in six provinces and two municipalities in China. Methods A total of 283 samples of corn, peanut, rice, walnut and pine nut were randomly collected from local markets in Fujian, Guangdong, Guangxi, Hubei, Jiangsu, and Zhejiang provinces, as well as in Shanghai and Chongqing municipalities. The samples were ground to which acetonitrile/water solution was added. After filtering, the extract was transferred into a MycoSepTM purifying column and was pressed slowly. Then the purified liquid was derivatized with trifluoroacetic acid （TFA） and assayed using high performance liquid chromatography （HPLC）. Results AFs were detected in 70.27% of corn samples, with a mean level of 27.44 μg/kg and the highest level of 1098.36 μg/kg. In peanut, the AFs detection rate was 23.08%, with a mean level of 0.82 μg/kg and the highest level of 28.39 μg/kg. Very few rice samples with AFs were detected. The AFs levels were very low in walnut and pine nut. Conclusion Corn is the food most seriously contaminated with AFs in China. AFBI is the main aflatoxin which is found as a contaminant in foods.

Knowledge of aflatoxin contamination in groundnut and the risk of its ingestion among health workers in Ibadan,Nigeria

Objective:To assess the awareness and knowledge of aflatoxin contamination in groundnut and the risk of its ingestion among health workers in Ibadan.Methods:The study was a descriptive cross-sectional study.Study instrument was a semi-structured self administered questionnaire. The respondents were health workers from a public health facility.Results:A total of 417 health workers participated out of which males were 60.2%.The mean age of respondents was(28.0±4.9) years old.Doctors made up 83.0%while others were nurses.95%of the respondents had previous awareness of aflatoxin and class room lectures was the most common source of information(56%).Occupation and religion both showed a significant association with previous awareness of aflatoxin(P<0.05).Knowledge regarding aflatoxin contamination in groundnut and the risk of its ingestion was obtained showing knowledge score range of 0 to 14.In all,80.6%had good scores of 11 to 14.None of the respondents had ever told their patients about the risk of aflatoxin ingestion. Conclusions:There is a need to explore the possibility of incorporating aflatoxin awareness into routine health talk to increase the level of awareness of patients and their relatives.

Toxicology,biosynthesis,bio-control of aflatoxin and new methods of detection

Mycotoxins and their derivatives since their discoveries and until the present time are behind unspecified economic and medical damages.Aflatoxins are classified according to their physical–chemical and toxicological characters in the most dangerous row of the mycotoxins.These aflatoxins are in part responsible,of irreversible medical disasters that are not easily manageable such as cancer of the liver and kidneys,and in the other part,of losses in the stored cereal products.Based on these crucial findings,monitoring of this toxin became imperative in post-harvest food products,during storage,during transformation chain and even during the long phases of conservation.Vigilance of this toxin is delivered by detection methods using very advanced technologies to respond in the shortest possible times.In addition,the knowledge of factors supporting the biosynthesis of aflatoxins such as the temperature,moisture content,concentration of nitrogen and carbon,and the molecules responsible for the genetic control of the synthesis will be reflected later in the choice of bio-control techniques.This control is currently based on new strategies using the bioactives substances of the plants,the lactic bacteria and some strains of actinomycetes that have good inhibiting activity against aflatoxins with fewer side effects on Man.On the other hand,this brief review summarizes the results of new studies demonstrating the toxicity of the toxin,new detection methods and bio-control.

Protective Effect of Procyanidin B2 on Acute Liver Injury Induced by Aflatoxin B1 in Rats

Objective This study aimed to explore the protective effect of procyanidin B2(PCB2)on acute liver injury induced by aflatoxin B1(AFB1)in rats.Methods Forty Sprague Dawley rats were randomly divided into control,AFB1,AFB1+PCB2,and PCB2 groups.The latter two groups were administrated PCB2 intragastrically(30 mg/kg body weight)for 7 d,whereas the control and AFB1 groups were given the same dose of double distilled water intragastrically.On the sixth day of treatment,the AFB1 and AFB1+PCB2 groups were intraperitoneally injected with AFB1(2 mg/kg).The control and PCB2 groups were intraperitoneally administered the same dose of dimethyl sulfoxide(DMSO).On the eighth day,all rats were euthanized:serum and liver tissue were isolated for further examination.Hepatic histological features were assessed by hematoxylin and eosin-stained sections.Weight,organ coefficient(liver,spleen,and kidney),liver function(serum alanine aminotransferase,aspartate aminotransferase,alkaline phosphatase,total bilirubin,and direct bilirubin),oxidative index(catalase,glutathione,superoxide dismutase,malondialdehyde,and 8-hydroxy-2′-deoxyguanosine),inflammation factor[hepatic interleukin-6(IL-6)m RNA expression and serum IL-6],and bcl-2/bax ratio were measured.Results AFB1 significantly caused hepatic histopathological damage,abnormal liver function,oxidative stress,inflammation,and bcl-2/bax ratio reduction compared with DMSO-treated controls.Our results indicate that PCB2 treatment can partially reverse the adverse liver conditions induced by AFB1.Conclusion Our findings indicate that PCB2 exhibits a protective effect on acute liver injury induced by AFB1.