Study On The Toxicity And Exposure Levels Of Deoxynivalenol And Its Derivatives In Wheat And Maize

3-acetyle-deoxynivalenol(3-ADON),15-acetyle-deoxynivalenol(15-ADON)and Deoxynivalenol(DON)belonging to B group produced by Fusarium graminearum and Fusarium culmorum have been suggested significant effects on human,animals and plants.Due to resistance to heat,high pressure,acid and alkali,they are difficult to be degraded in nature.Thus,progressed and unprogressed food is easily polluted by them.Chronic and acute toxicities such as hepatotoxicity,nephrotoxicity,neurotoxicity,immunotoxicity potentially caused by DON,3-ADON and 15-ADON were considered.Mycotoxin leads to food destruction and economy losses every year.Thus,the study on the toxicity of DON and its derivatives has become a focus in recent years.To investigate pollution of DON,3-ADON,15-ADON on wheat and maize in China,and provide a more scientific basis for the determination of DON and its derivatives of limit standard in wheat and maize,the contents of DON,3-ADON,15-ADON were detected with UPLC-MS/MS method for 579 wheat samples from main wheat-producing provinces(Hubei,Henan,Jiangsu,Hubei and Anhui),and for 606 maize samples from main maize-producing provinces(Jilin,Liaoning,Heilongjiang,Inner Mongolia and Shandong).From the overall situation,the total contents of DON and its derivatives in wheat and maize ranged from LOQ-6436.11μg/kg,with the relevance ratio of 99.92%.The relevance ratio of DON,3-ADON,15-ADON was 99.92%,8.95%and 39.92%,respectively.The DON exceeding standard rate was 3.29%,15-ADON and DONs exceeding 1000 μg/kg were 0.25%and 5.06%,respectively.Judging from different varieties,the total contents of DON and its derivatives in the national wheat samples were mainly distributed in 12.16-6436.11μg/kg(P25-P75).The detection rates of DON,3-ADON,15-ADON from wheat samples were 100%,4.15%and 0.52%,respectively.The over-standard rate of DON was 3.63%,and neither 3-ADON nor 15-ADON exceeded 1000μg/kg.By analyzing the distribution ratio of DON and its derivatives in wheat,DON showed a higher incidence of 95.51%,the combined detection rate of DON+3-ADON was 3.97%,the combined detection rate of DON+15-ADON was 0.35%,and the detection rate of DON+3-ADON+15-ADON was only 0.17%.The total contents of DON and its derivatives in the national maize samples were mainly distributed in 50.45-323.24μg/kg(P25-P75).The relevance ratio of DON,3-ADON and 15-ADON from maize samples was 99.83%,13.53%and 76.40%,respectively.Among them,the DON exceeding standard rate was 2.97%.The 15-ADON and DONs exceeding 100μg/kg were 0.50%and 6.44%respectively.To compare the distribution of DON and its derivatives in maize,a large number of the maize samples were contaminated with DON+15-ADON(64.19%)and DON(22.11%).The samples with a combination of DON+3-ADON and DON+3-ADON+15-ADON accounted for 1.32%and 12.21%,respectively.The undetectable rate of maize was only 0.17%.Joint FAO/WHO Expert committee on Food Additives(JECFA)established that the temporary maximum daily tolerable intake(PMTDI)of DON and its derivatives was 1μg/kg BW/d,and DON,3-ADON and 15-ADON coexisted in wheat and maize.Currently,Chinese food safety standards did not include 3-ADON and 15-ADON,so the toxic effects of the three toxins are attracting more and more attention.The toxicity differences of DON,3-ADON and 15-ADON on intestinal cells Caco-2 were analyzed and compared,for providing theoretical basis for food safety limit standards.CCK-8 assay was used to determine the activity of Caco-2 cells at different concentrations of DON,3-ADON and 15-ADON(0.1μM,0.2μM,0.5μM,1μM,2μM,5μM,10μM)at different times(24h,48h,72h).The 50%inhibition of cellular proliferation values(IC50)ranged from 1.46 to 6.17μM,from 7.84μM to 13.19μM and from 1.44 to 3.86μM for DON,3-ADON and 15-ADON,respectively.It can be concluded that the cytotoxicity of Caco-2 on intestinal cells is 15-ADON≈DON>3-ADON.