Antioxidant-oxidant balance and vital parameter alterations in an eukaryotic system induced by aflatoxin B2 exposure.

This study was performed to evaluate the toxic effects of aflatoxin B2 (AFB2) on antioxidant-oxidant balance and vital parameters such as physiological, cytogenetic, and anatomical alterations in Allium cepa L. root tip cells. Toxic effects of AFB2 on vital parameters were investigated by using the changes in weight gain, germination percentage, chromosomal aberrations (CAs), mitotic index (MI), micronucleus frequency (MN), and anatomical structure. Malondialdehyde (MDA) and reduced glutathion (GSH) levels and superoxide dismutase (SOD) and catalase (CAT) activities in root cells were investigated as antioxidant-oxidant parameters. For this aim, A. cepa bulbs were seperated into five groups as negative control, positive control, and AFB2 treatment groups. In results, while the rate of germination percentage, weight gain, and MI rates decreased, MN and CA frequency increased in AFB2-treated groups compared with the negative control. Most common CAs observed in AFB2-treated groups were fragment and chromosome bridges. It was determined that in 160 μg L-1 AFB2-treated group there was a 70.8% increase in MDA and a 78.1% decrease in GSH level compared with the negative control group and these changes indicate oxidative damage. In 160 μg L-1 AFB2 treatment group, SOD and CAT activities decreased importantly due to inhibition. In anatomical examinations, it was determined that AFB2 treatment caused some anatomical damages in A. cepa root cells such as necrosis, cell deformation, and thickening in cell wall. This study showed that AFB2, which has the least data among aflatoxins, causes serious in vivo toxic effects in A. cepa root cells.