Allium cepa chromosome aberration and micronucleus tests applied to study genotoxicity of extracts from pesticide-treated vegetables and grapes

Abstract

The Allium cepa assay is an efficient test for chemical screening and in situ monitoring for genotoxicity of environmental contaminants. The test has been used widely to study genotoxicity of many pesticides revealing that these compounds can induce chromosomal aberrations in root meristems of A. cepa. Pesticide residues can be present in fruit and vegetables and represent a risk for human health. The mutagenic and carcinogenic action of herbicides, insecticides and fungicides on experimental animals is well known. Several studies have shown that chronic exposure to low levels of pesticides can cause birth defects and that prenatal exposure is associated with carcinogenicity. This study evaluated the potential application of plant genotoxicity tests for monitoring mutagens in edible vegetables. The presence of pesticides and genotoxic compounds extracted from 21 treated vegetables and eight types of grapes sampled from several markets in Campania, a region in Southern Italy, was monitored concurrently. The extracts were analysed for pesticides by gas chromatography and high-performance liquid chromatography, and for genotoxicity using two plant tests: the micronucleus test and the chromosomal aberration test in A. cepa roots. Thirty-three pesticides were detected, some of which are not approved. Genotoxicity was found in some of the vegetables and grapes tested. Allium cepa tests proved to be sensitive in monitoring genotoxicity in food extracts. The micronucleus test in interphase cells gave a much higher mutagenicity than the chromosomal aberration test in anaphase–telophase cells.

Keywords:

• Allium cepa test
• genotoxicity
• pesticides
• vegetables

Acknowledgements

This paper is dedicated to the memory of the conceivers of the research, Domenica Biscardi and Raffaele De Fusco, memorable friends and researchers of the University of Naples and Salerno. The authors express their deepest appreciation to Dr. Giovanni Petrone of D’Aniello Laboratory of Sant’Egidio Montalbino, Salerno, Italy, for his assistance in this research.