Cytogenotoxic effect of glow stick content on meristematic root cells of Allium cepa L.

Abstract

The use of chemiluminescent glow sticks in commercial longline fishing has led to an accumulation of these devices on beaches at the Costa dos Coqueiros region, Bahia state, northeastern Brazil, and local residents thereat have been using the content of the sticks on their skin, allegedly with cosmetic and medicinal purposes. Aiming to evaluate the toxic effects of the stick liquid content, we exposed Allium cepa bulbs to aqueous solutions of such content at concentrations 0.007%, 0.010% and 0.013%. After a 72-h exposure, root tips grown in these solutions were collected and fixed, and we then analyzed meristematic root cells under microscopy to assess cytotoxic and genotoxic parameters. Data was analyzed by Fisher’s exact test. The mitotic index of root cells decreased significantly at the tested concentrations (p < 0.001), while the frequency of interphase nuclear abnormalities increased significantly (p < 0.001). The most frequent nuclear abnormalities included fragmented nuclei, vacuolated nuclei, elongated nuclei, notched nuclei, nuclear buds, binucleated cells and micronuclei. Our results suggest that the glow stick chemical content has cytotoxic and genotoxic effects on meristematic root cells of Allium cepa.