Welcome to China Mycotoxin Network! Today is Jan 22, 2020 Set home Add to Favorites 中文版 ENGLISH

Mycotoxin Introduction

Current Location:Home > Mycotoxin Introduction

    Mycotoxins are one of the main contaminants in agricultural products, people and livestock consuming the mycotoxin contaminated foodstuff can cause acute and chronic fungal toxin poisoning. Our country China is a largely agricultural based country, and residents mainly feed on wheat, corn, rice, and peanuts. Mildew annually causes about twenty-five thousand tons of inedible grain. As a result of fungal toxins exceeding the importing country limits, it often occurs that export cereals are given warnings or lower grades. The occurrence of food poisoning, chronic diseases and cancer can be related to intake food containing mycotoxins. In some regions of China, Henan, Guangxi, Hebei province, Anhui province and Jiangsu province, toxic events which are caused by livestock deoxynivalenol enolase came up to fifteen cases between 1985 and 1992. Especially at the end of spring and the beginning of summer in 1991, some provinces in china are subjected to surprisingly flood disaster. Anhui and Jiangsu province often encounters natural challenges which induces mycotoxin producing fungi in the grains.
    So far, there are more than 400 different mycotoxins having been discovered, in which more than 20 kinds has been isolated and identified. According to mycotoxin level of harm to agriculture and human health and the importance of social and economic development impact, Hesseltine conducted a review of more than three hundred countries in the world. The results show that Aflatoxin comes first, followed by ochratoxin A, Single trichothecene compound, citrinin, sterigmatocystins, patulin, cycloplazonlc acid and so on. When Hesseltine conducted of the investigation, fumonisin (fumonisins, FMs) has not been found. The survey also found that agricultural corns which are seriously polluted by Mycotoxin are peanuts and wheat.
 
1  Aflatoxin
 
    Aflatoxin is a kind of metabolite primarily produced by Aspergillus flavus and Aspergillus parasiticus. With the geographical and seasonal factors and crop growing, harvesting, storage conditions difference, the occurrence and extent of aflatoxin pollution vary. Grain and oil crops can be contaminated by toxigenic strains after harvest, storage period and the post-processing. Sometimes grain crops had been contaminated toxigenic strains early before the harvest.
    In the southern and eastern England, hundreds of thousands of turkeys died from eating moldy peanut flour in 1960. The autopsy poisoning dead chickens results found in liver hemorrhage, necrosis, renal enlargement, and pathological examination revealed degeneration of hepatocytes and biliary epithelial cell proliferation. Research findings show that turkey feed peanut flour contains a fluorescent substance, which causes turkey to die. It is confirmed that the substance is a metabolite of aflatoxin, named aflatoxin.
    Aflatoxin is recognized as a carcinogen by WHO in 1993.There are many kinds of aflatoxin, mainly including B1, B2, G1, G2, M1 and M2.They have different structures, and toxicity and hazards are quite different. In aflatoxin derivatives, B1 is the most toxic and cancerigenic, the most widely distributed in foods and the most harmful for food safety. Therefore, Aflatoxin B1 was identified as main pollution indicators in the food hygiene monitoring. Aflatoxin is the most toxic, but its toxicity usually changes along with doses of toxin, contact time, and animal species nutritional status and diet. In animal studies, high doses of intake of these toxins can lead to death. Long-term intakes of low doses of aflatoxin can lead to cancer, especially liver cancer. In the body, aflatoxin catalyzed by cytochrome P450 would react to produce the corresponding reactive derivative, and then exhibit toxicity. Part of the products are degraded by enzymes, thereby lose toxicity. Part of the derivative combines with cellular proteins and lipids, leading to cell death. When combined with the nucleic acid (DNA), it will lead to mutagenic and carcinogenic. Acute toxicity of Aflatoxin is 10 times as much as potassium cyanide, 68 times as much as arsenic.
 

2  Ochratoxin 

    Ochratoxin was originally isolated from ochratoxin strain out of South Africa, produced by Aspergillus ochraceus, Aspergillus alliaceus, and Pencillium viridicatum. However, Penicillium and other mold, including seven kinds of structurally similar compounds, ochratoxin A is one of the most toxic substances, which is the main natural contaminants in nature. In some countries, the contamination rate of Ochratoxin A is up to 2% to 30%. This compound mainly causes kidney toxicity. In the Balkan endemic nephropathy prevalence area, 6% ~ 18% people could be detected in the blood of ochratoxin A.
    The international agency for research on cancer (IARC) (1993) thinks that ochratoxin A is the mycotoxin closely related to human health and a probable human carcinogen. In addition to the potential genotoxicity and carcinogenicity, ochratoxin A is a kind of immune suppression, neurotoxic and teratogenic substances.

3  
Patulin 

   Patulin toxin (Pat), also called patulin and is an immunosuppressant produced by Aspergillus clavatus , Penicillium expansum,  and Pencillium aspergillus. Patulin toxin is a potent neurotoxin, which can be induced by experimental animal tumor, and has a damaging effect on the digestive system and skin tissue.. Penicillium urticae was isolated from the germination feed, which makes crows appear toxic symptom by Japan in 1953, Pat from which was detected. Poisoning dairy cattle appears mainly ascending paralysis, central nervous system edema and focal hemorrhage.  Pat also has the nature of teratogenic, mutagenic and carcinogenic, which can cause local subcutaneous injection site sarcoma in plant and animal cells and lead the formation of mitotic chromosomes blocked and cells binucleated. Pat has less genetic toxicity and has a cytotoxic effects on Hela cells and primary cultures of rat lung cells, can change the permeability of cell membrane, can inhibit the synthesis of macromolecules in cells of material, and can cause non protein thiol depletion in cells, lead to cell loss of activity.
 

4  Single trichothecene compound 

    Single trichothecene compound is a group of similar biological activity and chemical structure of toxic metabolites product produced by cephalosporin compounds (Ephalosporium), Fusarium (Fusarium), Stachybotrys (Stachybotrys) and Trichoderma (Trichodema) and other metabolic .
    Single trichothecene compounds can cause pigs, dogs, cats, ducks and other animals with acute poisoning. The main symptoms of poisoning animals are vomiting, weakness, bloody diarrhea and movement disorders. There can be observed bleeding or bleeding spots in the visible intestines, lymph nodes and multiple heart  and intestine containing a lot of dark red contents. Microscopic intestinal tract, lymph nodes, bleeding heart can be observed via the microscopic. Gastrointestinal epithelial cell necrosis, lymph nodes, bone marrow and liver cells are in the reduced condition. Some single trichothecene compounds may affect the immune system of animals changing their immune response and resulting in delayed-type hypersensitivity and reduced resistance to infection.
 
5  Zearalenone
 
    Zearalenone (ZEA), known as a toxin of F-2, is a metabolite, which is produced by strains of Fusarium. ZEA was isolated from the corns infected with Gibberellic Disease first, and produced by Fusarium graminearum, Fusarium culuorum, Fusarium eqlliseli, Fusarium solani, etc. It was reported in many countries that feeding the pig and cattle on grain and feed, which was contaminated by ZEA, can cause estrogen poisoning of animals.
    The acute toxic effect of ZEA on animal is very small, because when the concentration of ZEA in meals is low, ZEA has the physiological activity and no toxic effect. ZEA has the effect of estrogen, and mainly effects on reproductive system, especially the gilt is particularly sensitive to the poison. ZEA can cause the tumefaction of uterus and vagina and the atrophy of ovary of the prepubescent gilt, and lead to rectal prolapse in severe cases. If the human and gestational animal eats food containing ZEA, it can cause breast swelling, abortion, teras and stillbirth. Eating the food made by flour containing ZEA also causes symptoms of poisoning of the central nervous system, such as nausea, chills, headaches, depression, imbalance of supply, etc. ZEA causing excessive estrogen of pig was reported in Australia, Canada, Denmark, Britain, the United States, France, Germany, Japan and many other countries.  
 
6  Sterigmatocystin
 
    Sterigmatocystin is the final product of Aspergillus uersicolor or A. nidulans, also the middle-product when Aspergillus flavus or Aspergillus parasitic toxin synthesis. Sterigmatocystin have bad effect on liver and kidney, and cause necrosis of animal liver and kidney. Human’s and animal’s eating grains that been polluted by Sterigmatocystin will lose appetite, refuse feed, progressive emaciation, depression, weakness, death and other toxemic symptoms.
 
7  Fumonisins
 
    Fumonisins is a kind of mycotoxins produced by Fusarium moniliorme, Fusarium verticIllioides, Fusarium proliferatum or other Kamakura spore strains.Animal experiments show that fumonisins mainly damage on liver of horses. FB1 can cause server brain edema, early bilateral symmetry kind of necrosis on medulla oblongata, soften changing on cerebral white matter, which is called ELEM. After intravenous injection FB1 to horses, there will be obvious nerve poisoning symptoms, like mental tension, indifference, tilted staggered, tremor, imbalance, move slowly, lower lip and tongue paresis, cannot eat, etc. FB1 can also cause PPE, sheep's liver samples change and kidney disease, rat’s liver necrosis, heart indoor thrombosis.
    Damages on human of Fumonisins become more widely among countries, though that hasn’t been directly proved. However, food pollutions and the relationship between human or animals and cancer caused by Fumonisins become increasingly important.