engleski

Cyto/genotoxic and oxidative stress response in bisphenol A treated onion (Allium cepa L.) root meristem cells

The aim of this study was to test cytotoxicity, genotoxicity, and oxidative stress as a mechanism of toxicity of bisphenol A (BPA) using Allium test. Allium test is considered as a good model for detecting environmental mutagens and good correlation in cytogenetic studies of Allium test with other test organisms is confirmed. Onion bulbs (Allium cepa L.) were germinated for 24 h, and afterwards, rooted bulbs (n = 10) were exposed to BPA in concentration range 1-50 mg/L or to distilled water (negative control) for 72 h. Following 72 h exposure, morphometry (the root length and the fresh weight) was assessed. In root meristem cells mitotic index (MI) and frequency of micronuclei (MNi) were determined using a light microscope analysing minimum 500 cells per slide. In root homogenate as oxidative stress parameters the level of glutathione (GSH) and protein carbonyls (PC) was assessed spectrophotometrically. The results were analysed by use of one-way ANOVA followed by Dunnett’s test. Statistical significance level was set at p < 0.05. After 72 h exposure to BPA (1-50 mg/L) a concentration-dependent decrease in the root length, root fresh weight as well as decrease in the percentage of MI of meristem cells was observed. Even the lowest concentration of BPA (1 mg/L) inhibited the root growth while the root fresh weight was reduced after exposure to BPA at 5 mg/L compared to negative control. The lowest BPA concentration (1 mg/L) decreased the percentage of MI as well as the number of cells in each of the cell cycle phase. With the increase of BPA concentration, an increase in MNi formation was observed. A decrease in GSH level was observed already after exposure to the lowest BPA concentration (1 mg/L) while an increase of PC was observed after exposure to BPA in concentration 10 mg/L. Based on the obtained results, it can be concluded that BPA induces cyto/genotoxic effects in root meristem cells and that oxidative stress is involved in its toxicity.

bisphenol A ; mitotic index ; micronuclei ; glutathione ; meristem cells

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