Aflatoxin Cause DNA Damage

Verma, Ramtej J.

doi:10.1080/09723757.2004.11885899

Cited by 106 publications

(52 citation statements)

References 3 publications

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“…40 The accumulation of evidence suggests that aflatoxins may cause DNA damage, mutations, and suppress bone marrow functions. 41,42 The mechanism for this toxicity is thought to occur by a pathway, which involves the metabolism of aflatoxins into epoxide intermediates that go on to bind DNA and RNA. These intermediates interfere with DNA-dependent RNA polymerase, thereby inhibiting RNA and protein synthesis.…”

Section: Discussionmentioning

confidence: 99%

“…23 Studies with these mammals (cattle, guinea pigs, and rabbits) have shown that aflatoxins cause hemolysis of RBCs and may interact with RNA and DNA to cause a depression of hemopoiesis in primates. 24 Although this has not been documented to occur in humans, it is not unreasonable that aflatoxins may cause a similar effect in humans. The objective of this study is to examine the association between anemia and AF-ALB levels in the blood of pregnant women in Kumasi, Ghana.…”

Section: Introductionmentioning

confidence: 99%

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Association between Anemia and Aflatoxin B1 Biomarker Levels among Pregnant Women in Kumasi, Ghana

Shuaib¹,

Jolly²,

Ehiri³

et al. 2010

The American Society of Tropical Medicine and Hygiene

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Aflatoxins are fungal metabolites that contaminate staple food crops in many developing countries. Up to 40% of women attending a prenatal clinic in Africa may be anemic. In a cross-sectional study of 755 pregnant women, Aflatoxin B1-lysine adducts (AF-ALB) levels were determined by high-performance liquid chromatography. Participants were divided into quartiles “low,” “moderate,” “high,” and “very high.” Anemia was defined as hemoglobin levels < 11 g/dL. Logistic regression was used to examine the association of anemia with AF-ALB. The mean AF-ALB level was 10.9 pg/mg (range = 0.44–268.73 pg/mg); 30.3% of participants were anemic. The odds of being anemic increased 21% (odds ratio [OR], 1.21, P = 0.01) with each quartile of AF-ALB reaching an 85% increased odds in the “very high” compared with the “low” category (OR, 1.85; confidence interval [CI], 1.16–2.95). This association was stronger among women with malaria and findings were robust when women with evidence of iron deficiency anemia were excluded. This study found a strong, consistent association between anemia in pregnancy and aflatoxins.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Association between Anemia and Aflatoxin B1 Biomarker Levels among Pregnant Women in Kumasi, Ghana

Shuaib¹,

Jolly²,

Ehiri³

et al. 2010

The American Society of Tropical Medicine and Hygiene

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“…This mycotoxin is bioactivated by CYP enzymes to a more toxic form called AFB1-8,9-exo-epoxide (AFBO) that causes deleterious effects on both poultry and human health. 18,19 CYP1A, CYP2A6 and CYP3A enzymes have been reported as responsible for the bioactivation of AFB1 [20][21][22][23] in humans. The aim of the present study was to identify human ortholog activities in liver microsomes of four poultry species by the use of human CYP prototype substrates and AFB1and to compare the K M and V max constants obtained.…”

Section: Introductionmentioning

confidence: 99%

Enzymatic activity in turkey, duck, quail and chicken liver microsomes against four human cytochrome P450 prototype substrates and aflatoxin B1

2011

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Cytochrome P450 enzymes (CYP) are a group of monooxygenases able to biotransform several kinds of xenobiotics including aflatoxin B1 (AFB1), a highly toxic mycotoxin. These enzymes have been widely studied in humans and others mammals, but there is not enough information in commercial poultry species about their biochemical characteristics or substrate specificity. The aim of the present study was to identify CYPs from avian liver microsomes with the use of prototype substrates specific for human CYP enzymes and AFB1. Biochemical characterization was carried out in vitro and biotransformation products were detected by high-performance liquid chromatography (HPLC). Enzymatic constants were calculated and comparisons between turkey, duck, quail and chicken activities were done. The results demonstrate the presence of four avian ortholog enzyme activities possibly related with a CYP1A1, CYP1A2, CYP2A6 (activity not previously identified) and CYP3A4 poultry orthologs, respectively. Large differences in enzyme kinetics specific for prototype substrates were found among the poultry species studied. Turkey liver microsomes had the highest affinity and catalytic rate for AFB1 whereas chicken enzymes had the lowest affinity and catalytic rate for the same substrate. Quail and duck microsomes showed intermediate values. These results correlate well with the known in vivo sensitivity for AFB1 except for the duck. A high correlation coefficient between 7-ethoxyresorufin-Odeethylase (EROD) and 7-methoxyresorufin-O-deethylase (MROD) activities was found in the four poultry species, suggesting that these two enzymatic activities might be carried out by the same enzyme. The results of the present study indicate that four prototype enzyme activities are present in poultry liver microsomes, possibly related with the presence of three CYP avian orthologs. More studies are needed in order to further characterize these enzymes.

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“…These two toxins possess an unsaturated bond at the 8,9 position on the terminal furan ring. Aflatoxin B2 and AFG2 are essentially biologically inactive unless these toxins are first metabolically oxidized to AFB1 and AFG1 in vivo (Verma, 2004). AFM1 and AFM2 are hydroxylated derivatives of AFB1 and AFB2 that may be found in milk, milk products or meat (hence the designation M1).…”

Section: Introductionmentioning

confidence: 99%

“…AFM1 and AFM2 are hydroxylated derivatives of AFB1 and AFB2 that may be found in milk, milk products or meat (hence the designation M1). They are formed by the metabolism of B1 and B2 in the body of the animals following absorption of contaminated feeds (Gimeno, 2004;Verma, 2004;Wild & Gong, 2010). In animals, aflatoxins impair growth and are immunosuppressive.…”

Section: Introductionmentioning

confidence: 99%