What is the mechanism of action of aflatoxin?

Aflatoxin B1(AFB1), the main metabolite produced by moulds of genus Aspergillus, exerts its effects after conversion to the reactive compound AFB1-epoxide, by the action of cytochrome P450-dependent enzymes. This epoxide can form derivatives with cellular macromolecules, including proteins, RNA and DNA.

How does aflatoxin cause cancer?

Aflatoxin B1, which is a genotoxic hepatocarcinogen, which presumptively causes cancer by inducing DNA adducts leading to genetic changes in target liver cells. AFB1 is metabolized by cytochrome-P450 enzymes to the reactive intermediate AFB1-8, 9 epoxide (AFBO) which binds to liver cell DNA, resulting in DNA adducts.

How does aflatoxin affect your cells and play a role in the development of cancer?

The mechanism of aflatoxin-induced carcinogenesis is thought to involve tumor promotion or progression. There is evidence that aflatoxin is involved in the activation of proto-oncogenes and mutations in the tumor suppressor gene p53.

How does aflatoxin cause mutagenesis?

Aflatoxin forms DNA adducts and is mutagenic, whilst chronic HBV infection can increase cell proliferation resulting in fixation of DNA adducts as mutations, perhaps at codon 249 of the p53 gene, and selective clonal expansion of these mutant cells due to a functional growth advantage of these cells (see above).

What is the function of aflatoxin?

Aflatoxins, on a world scale, are one of the most important groups of mycotoxins (Lanyasunya et al., 2005). Aflatoxins target the liver immune system, kidney and other body organs. Aflatoxin B1 is the most potent known naturally occurring carcinogen.

How many types of aflatoxin are there?

four
There are four main types of aflatoxins: B1, B2, G1, and G2. Aflatoxin B1 is the major toxin produced, and is regulated in the United States at 20 ppb in agricultural products that may be used in human food.

How do you prevent aflatoxins?

You can reduce your aflatoxin exposure by buying only major commercial brands of nuts and nut butters and by discarding nuts that look moldy, discolored, or shriveled. To help minimize risk, the U.S. Food and Drug Administration (FDA) tests foods that may contain aflatoxins, such as peanuts and peanut butter.

What causes aflatoxin?

Aflatoxins are toxins produced by the mold Aspergillus flavus that can grow on pet food ingredients such as corn, peanuts, and other grains. At high levels, aflatoxins can cause illness (aflatoxicosis), liver damage, and death in pets. The toxins can be present even if there is no visible mold on the pet food.

Where is aflatoxin found?

Aflatoxins are a family of toxins produced by certain fungi that are found on agricultural crops such as maize (corn), peanuts, cottonseed, and tree nuts. The main fungi that produce aflatoxins are Aspergillus flavus and Aspergillus parasiticus, which are abundant in warm and humid regions of the world.

What type of mutation does aflatoxin cause?

Aflatoxin causes DNA damage and with prolonged exposure to aflatoxin, cells accumulate DNA mutations and thus are at increased risk of developing into cancer cells.

What are the types of aflatoxins?

There are four main types of aflatoxins: B1, B2, G1, and G2. Aflatoxin B1 is the major toxin produced, and is regulated in the United States at 20 ppb in agricultural products that may be used in human food.

How are aflatoxins used to study human health?

Aflatoxins have been extensively studied with respect to their mechanisms of toxicity. An understanding of metabolism, DNA adduct induction, mutagenicity and carcinogenicity has been paralleled by the development of biomarkers of aflatoxin exposure and biological effects (e.g. mutations) applied to human populations.

Which is a protective mechanism for aflatoxin in mice?

Detoxification of AFB-8,9-epoxide by a specific alpha class glutathione S-transferase is an important protective mechanism in mice, and it accounts for the resistance of this species to the carcinogenic effects of AFB.

How does aflatoxin B1 affect the TP53 gene?

The DNA damage (point mutation) caused on the TP53 gene due to exposure to aflatoxin B1 can result to the triggering of a number of cellular responses and these would determine whether the cell will be able to eliminate the damage or to active apoptosis processes.

How is aflatoxin converted to an epoxid in the liver?

Aflatoxin is converted to aflatoxin-8,9-epoxid in the liver of humans or animals. In humans, the effects caused by ingestion of this mycotoxin can be chronic or acute, including hepatotoxic and immunotoxic effects, an increase in reactive oxygen species, and modifications in DNA strands and protein structure (EATON; GALLAGHER, 1994). …