Aflatoxins are highly toxic and carcinogenic compounds produced by molds such as Aspergillus flavus and Aspergillus parasiticus, contaminating crops like peanuts, corn, and tree nuts under favorable conditions.
Among these, Aflatoxin G2 (AFG2) is one of the significant types alongside B1, B2, and G1, posing severe health risks including liver cancer and immunosuppression. Although less potent than Aflatoxin B1, AFG2 remains a concern due to its stability and ability to persist in food products even after processing.
Effective management of aflatoxin contamination involves early detection through various methods and control measures during pre- and post-harvest stages.
Integrating biocontrol strategies and chemical treatments is crucial for mitigating aflatoxin levels, thereby protecting human and animal health.
Aflatoxins are a group of highly toxic and carcinogenic compounds produced as secondary metabolites by certain molds, primarily Aspergillus flavus and Aspergillus parasiticus. [10., 22.]
They are one type of mycotoxin, which are a larger group of toxic chemical compounds produced by molds.
These mycotoxins are formed when the molds colonize foods like peanuts, corn, cottonseed, tree nuts, and spices under favorable temperature and humidity conditions. [10., 21.]
The main aflatoxins are B1, B2, G1, and G2, with aflatoxin B1 (AFB1) being the most potent and carcinogenic. [4.]
Their production occurs when the mold's growth is stressed, such as during drought conditions or improper crop storage.
Aflatoxins are among the most carcinogenic substances known - they can cause acute toxicity leading to liver failure, hemorrhaging, and even death in severe cases. [8.] Chronic exposure increases the risk of developing liver cancer, as aflatoxins can bind to DNA and cause mutations, particularly in the p53 tumor suppressor gene. [10., 12.]
They can also suppress the immune system, and can cause stunted growth in children. [11., 15., 16.]
Worryingly, aflatoxins are highly stable and can persist in foods and animal feeds even after processing and cooking. They bioaccumulate in the body over time, especially in the liver, due to their lipophilic nature and resistance to metabolic breakdown. [1., 13., 14.]
Aflatoxin B1 is metabolized to the reactive aflatoxin-8,9-epoxide, which binds to DNA and proteins, initiating carcinogenesis. [16.]
Animals fed contaminated feed can pass aflatoxin metabolites into meat, milk, and eggs, posing risks to humans consuming these products.
Anti-aflatoxin biomarkers are a group of compounds or metabolites that can be measured in biological samples to assess exposure to aflatoxins, which are toxic and carcinogenic metabolites produced by certain molds.
These biomarkers provide a direct measure of internal exposure and can help evaluate the associated health risks.
A variety of biomarkers have been used to identify the presence of aflatoxins in humans and animals.
Aflatoxin B1, known as one of the most potent and toxic aflatoxins, is one such biomarker.
Aflatoxins are metabolic compounds produced by molds like Aspergillus flavus and Aspergillus parasiticus. They are highly toxic and carcinogenic compounds that contaminate various crops, including cotton, groundnut, maize, and chilies.
Among the different types of aflatoxins, G2 (AFG2) along with aflatoxins B1, B2, and G1, poses significant health risks, including liver cancer and immunosuppression.
These toxins are resilient, persisting in food products even after processing, and can bioaccumulate in the body through dietary consumption or environmental exposure.
Effective management of aflatoxin contamination involves early detection through cultural, chromatographic, and molecular methods, and control measures during pre- and post-harvest stages.
Biocontrol strategies using atoxigenic strains of Aspergillus and various chemical and physical treatments are crucial in mitigating aflatoxin levels in food and feed, thus protecting human and animal health.
While chronic exposure to aflatoxins as a group has been linked to liver cancer, oxidative stress, and fetal growth abnormalities, the specific health effects of AFG2 exposure are not as well-characterized. [1.]
Available evidence suggests that AFG2 is less mutagenic and genotoxic compared to the potent aflatoxin B1, but it still possesses some level of mutagenic and potentially carcinogenic potential.
However, the degree of genotoxicity and carcinogenic potency of AFG2 relative to other aflatoxins remains unclear, with limited or inadequate evidence for its carcinogenicity according to some sources.
While AFG2 exhibited no effects in certain genotoxicity assays, it is generally acknowledged to be less genotoxic than AFB1 but more genotoxic than aflatoxin metabolites like AFM1.
Various biological samples can be employed to detect and quantify anti-aflatoxin biomarkers, particularly blood, urine and nasal secretions.
Blood samples are typically collected via venipuncture in a clinical setting, while urine and nasal secretion samples may be collected from the comfort of home.
It is important to consult with the ordering provider prior to sample collection, as certain protocols may be recommended beforehand.
Because of the high level of toxicity of aflatoxins, optimal test results indicate undetectable levels of aflatoxins.
Elevated levels of aflatoxins indicate recent or current exposure to aflatoxins. However, because they are known to bioaccumulate, testing positive for the presence of aflatoxins may indicate a persistent historical exposure. [6., 15.]
Low or undetectable levels of aflatoxins are considered ideal.
In addition to the direct measurement of anti-aflatoxin biomarkers, other biomarkers can provide complementary information about aflatoxin exposure and its potential health effects.
Aflatoxin exposure is known to induce oxidative stress, which can lead to cellular damage and contribute to the development of various diseases.
Biomarkers such as malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) can be measured to assess oxidative stress levels and the associated risk of aflatoxin-related toxicity. [17.]
Since the liver is a primary target organ for aflatoxin toxicity, monitoring liver function biomarkers like alanine aminotransferase (ALT), aspartate aminotransferase (AST), and bilirubin can provide insights into the extent of hepatic injury and potential liver damage caused by aflatoxin exposure.
Aflatoxin exposure can trigger inflammatory responses, and biomarkers such as C-reactive protein (CRP), interleukins (e.g., IL-6, IL-8), and tumor necrosis factor-alpha (TNF-α) can be measured to evaluate the inflammatory status and associated health risks.
Aflatoxins B1, B2, G1, and G2 are the four major aflatoxins produced by the fungi Aspergillus flavus and Aspergillus parasiticus. Testing for all four provides a comprehensive assessment of aflatoxin contamination.
Aflatoxin B1 (AFB1) is considered the most potent and carcinogenic aflatoxin . It is crucial to test for AFB1 due to its severe toxicity and strong link to hepatocellular carcinoma (liver cancer).
While less potent than AFB1, aflatoxins G1 and B2 are also known carcinogens and can contribute to the overall toxicity of aflatoxin-contaminated food and feed products. [9., 19.]
Co-occurrence and co-exposure to multiple aflatoxins are common in various food commodities like cereals, nuts, and spices. Testing for all four major aflatoxins provides a comprehensive assessment of the overall aflatoxin burden.
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