What can the Allium cepa test say about pesticide safety? A review

The increasing use of pesticides has caused global concerns about the toxic effects and adverse consequences of pesticides on humans and the environment. Among the ways to understand the impact of pesticides, the Allium cepa bioassay stands out. This test is suitable to evaluate different toxic, cytotoxic, genotoxic, and mutagenic outcomes. In this context, the present review aimed to summarize the history of using the A. cepa bioassay to investigate pesticide damages. Data on the experimental conditions were also discussed. The reviewed studies showed the toxicity profile of 113 active ingredients primarily tested in the laboratory, using water for exposure. The most used biomarkers were the mitotic index, chromosomal aberrations, and nuclear abnormalities. All active ingredients caused some toxicity levels in A. cepa, showing the efficiency and sensibility of this bioindicator and the adverse effect of pesticides on humans and the environment. Furthermore, it was evident that pesticides have great potential to damage the mitotic spindle and DNA because almost all active ingredients tested induced chromosomal aberrations and nuclear abnormalities. The current review showed that the A. cepa bioassay is an effective and appropriate model to evaluate pesticide toxicity, and it might indicate research gaps and recommendations for further studies.