Inhibitory Effect of Mannan on the Toxicity Produced in Mice Fed Aflatoxin B1 Contaminated Corn

Abstract

Aflatoxin B(1) (AFB(1)) is a potent mutagenic and carcinogenic agent found in numerous agricultural and dairy products consumed by humans. Therefore, we evaluated the capacity of mannan to cope with its genotoxic potential. We prepared a diet constituted of corn (90%) plus the recommended amount of other nutrients, as well as with the tested compounds (mannan and/or AFB(1)). Mice were fed this diet during 4 weeks as follows: one group with AFB(1)-contaminated corn (0.25 mg/kg of corn), three groups with mannan (50, 250, and 500 mg/kg of corn) plus AFB(1) (0.25 mg/kg), another group with only mannan (500 mg/kg), and the last group with an uncontaminated diet and no mannan added. We determined the weight, the micronucleated normochromatic erythrocyte rate (MNNE), the polychromatic/normochromatic index, and the sister chromatid exchange rate (SCE). We also examined the recovery response of mice during 4 additional weeks, when they were fed only the normal diet without AFB(1) or mannan. The results in the first period revealed the following: a) mice fed with mannan alone presented values in the range determined for the control group; b) mice fed AFB(1) had a significant weight decrease, as well as a significant increase in the rate of MNNE and SCE; and c) animals fed the combined regimen (AFB(1) plus mannan) presented a 25% weight increase with respect to the animals treated with AFB(1) alone, as well as a significant reduction in the level of MNNE and SCE with the two high doses tested. In the second (recovery) period, the control and the mannan fed groups maintained values similar to those exhibited in the previous phase, and the AFB(1) group as well as the groups fed the regimen combined with mannan showed an improvement in all evaluated parameters; the best response was that found in mice fed AFB(1) plus 500 mg/kg of mannan. Our study established an antigenotoxic effect of mannan that could be due to its adsorbent capacity.

Use of lactic acid bacteria and yeasts to reduce exposure to chemical food contaminants and toxicity

“…Control and S. cerevisiae-fed mice had a low MNNE rate, whereas mice fed only with AFB1 showed a significant MNNE increase. The same authors conducted a similar study in which they treated mice with AFB1-contaminated corn (0.25 mg/kg of corn) and mannan (50-500 mg/kg) instead of dosing with S. cerevisiae (Madrigal-Santillán et al, 2007). The results demonstrated an antigenotoxic effect of this component of the yeast wall, with the best response found in mice fed with AFB1 plus 500 mg/kg of mannan.…”

Antioxidant and Anticlastogenic Capacity of Prickly Pear Juice

“…Two blood smears were made from the tail of each animal, fixed in methanol for 5 min and stained for 20 min with a 4% Giemsa solution made in phosphate-buffered saline, at a pH of 6.8 [18]. One thousand erythrocytes per animal were scored to determine the rate of MNPE.…”

Investigation on the Protective Effect of α-Mannan against the DNA Damage Induced by Aflatoxin B1 in Mouse Hepatocytes

“…Man in particular, is a highly branched oligosaccharide constituted by a main chain of mannoses linearly joined through α-1–6 bonds, and with α-1–2 and 1–3 bonds in the branches. In an earlier report we showed that the administration of Man for four weeks to mice fed with AFB 1 contaminated corn reduced the frequency of micronuclei and SCE about 70 % [ 11 ]. Other authors have demonstrated a significant in vitro antimutagenic effect of the compound by reduction of the damage induced by ofloxacin and acridine orange in the chloroplast DNA of Euglena gracilis [ 12 ].…”