Investigation of the potential toxic effects of potassium bromate in Allium cepa L. (Amaryllidaceae)

Additives used in various industries for different purposes bring many health and environmental problems. The solution of these problems is very time-consuming and costly. However brings with secondary problems. Therefore, the application of toxicity tests before using the additives and chemicals come to the fore and the problems that may arise can be predicted with these tests. In this study, the toxic effects of Potassium bromate (KBrO3) which is used in food sector especially in bread production and contaminated to humans by nutrition were tested on Allium cepa L. model system. KBrO3 was investigated at doses of 25, 50 and 100 mg/L in order to investigate the toxic effect and dose relationship. The toxic effect was evaluated using physiological, cytogenetic, biochemical and anatomical parameters and serious damages were determined depending on the dose. The frequency of micronucleus (MN) and chromosomal abnormalities tested as cytogenetic parameters was found to be significantly higher in 100 mg/L KBrO3 treated group compared to the control group. In addition, mitotic index (MI) percentage was significantly decreased in this group. Fragment and sticky chromosome formation are the most common types of chromosomal abnormalities in KBrO3 application groups. It was found that malondialdehyde (MDA) level, which is an indicator of lipid peroxidation, increased with increasing KBrO3 application dose and reached maximum level with a rate of 10 µmol/g FW. Catalase (CAT) and superoxide dismutase (SOD) activities as antioxidant enzymes were also found to be altered against KBrO3-induced lipid peroxidation. Physiological, cytogenetic and biochemical changes as well as anatomical changes in A. cepa root tissue were detected. Anatomical changes such as necrosis, cell deformation, flattened cell nucleus, substance accumulation and cell wall thickening in cortex cells were determined against KBrO3 application, and it was found that these changes reached maximum levels at 100 mg/L KBrO3 dose. As a result, it has been found that KBrO3 application causes various toxic effects and anatomical changes in A. cepa cells which is a eukaryotic model organism and these effects are dose dependent.