Cytogenotoxic effects of alphamethrin and carbofuran based on mitotic index and chromosomal aberrations in Allium cepa root tip cells

Abstract

Abstract. Mili C, Kalita CK, Deka MJ, Das P, Tayung K. 2025. Cytogenotoxic effects of alphamethrin and carbofuran based on mitotic index and chromosomal aberrations in Allium cepa root tip cells. Cell Biol Dev 9: 71-77. Synthetic pesticides are widely used by farmers to protect crops from insect damage, which results in adverse effects on the environment. This study aimed to examine the cytogenotoxic potential of two pesticides, alphamethrin and carbofuran, using Allium cepa assay. The half maximum effective concentration (EC₅₀) was found to be 10 µg/mL for alphamethrin and 5 µg/mL for carbofuran. The toxicity was assessed with different concentrations of 1/10?×?EC₅₀; 1/5?×?EC₅₀; EC₅₀; 2?×?EC₅₀; and 3?×?EC₅₀ for both pesticides. Both pesticides demonstrated significant cytogenotoxic effects, evident from inhibited root growth, reduced mitotic index (MI), and increased chromosomal aberrations in onion (Allium cepa L.) root meristem cells. For alphamethrin, the lowest MI (12.24%) was observed at 20 µg/mL, while the highest chromosomal aberration frequency (CAF = 0.34) occurred at 30 µg/mL. Carbofuran exhibited a minimum MI of 14.90% at 10 µg/mL and the highest CAF (0.44) at 15 µg/mL. Moreover, the root growth inhibition demonstrated a dose-dependent pattern, while the MI showed neither a dose- nor a time-dependent pattern. The chromosomal aberrations observed were stickiness, vagrant, laggard chromosomes, C-metaphase, nuclear lesions, and spindle disturbance. These results underscore the urgent need for strong regulation and safer substitutes to minimize the ecological and health risks associated with widespread synthetic pesticide usage.