Genotoxicity and metabolic pathway of aflatoxin isolate in contaminated poultry feed
- International Journal of Avian & Wildlife Biology
Godwin M Ubi,1 Edu N,1 Eyogor,1 Paul B Ekpo,1 Nneka C Emmanuel,3 Affiong O Ambang,4 Joyce F Akpan,5 Success E Kalu,5 Imaobong S Essien2
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Aflatoxin is a nephrotoxic mycotoxin found in stale food which when consumed has some carcinogenic potentials. Aflatoxin presence has been identified in many foodstuffs all over the globe and with significantly higher frequency and concentrations coming from poultry feeds especially the locally formulated ones as a result of high cost of poultry feedstuff. Though foodstuffs are often contaminated with more than one mycotoxin, the focus of most research had centred on aflatoxin due to its wide occurrence and toxicology effect on the agro-morphometric parameters of poultry. The present studies reveals the major genes affected by aflatoxin ingestion in contaminated feed to include Tumour protein gene (TP53), Albumin protein gene (Alb), Spermatogenesis associated protein 5 (SPATA5), cytochrome p450 subfamily 3 polypeptide 4 and 7 protein genes (CYP3A4 and CYP3A7), glutathione s-transferase mu-1 protein gene (GSMU1) and minor genes such as the epoxide hydrolase 1 gene (EPHX 1), LACE 1 gene, XRCC1gene and cyclin 2 gene (CCGN2) whose expressions and functionality in the poultry has been silenced or activated leading to genotoxicity, highlights the biosynthesis and metabolic pathway of aflatoxins in poultry system and the toxin–protein interactions of aflatoxin ingested through contaminated poultry feed stuff as well as its co-occurrence with other mycotoxins in organisms as well on their combined toxicity. The metabolic pathway of aflatoxins B1, B2, G1 and G2 ingestion of aflatoxin in contaminated poultry feeds begins with the production of methyl-sterigmatocystin enzyme which pave the way for the complex, Sterigmatocystin which upon dimethylation produces versicolonin A (an enzyme which disrupts the colon) and versicolonin. The two enzymes reacts to form versiconial hemiactal acetate and producing 1‘5 Hydroxyaverantin both of which distorts the expression and functionality of Mycotoxin mixtures involving aflatoxin produced additive and synergistic effects in poultry birds suggesting that aflatoxins represent a significant health hazard. Hence, special attention should be given to poultry feedstuff screening and purification to prevent the associated toxicity that includes genotoxicity and the production of cancer-promoting mycotoxins.
tumour protein gene, albumin protein gene, CYP3A4 & CYP3A7, Aspergillusflavus, Aspergilusparasiticus