Imidacloprid modifies the mitotic kinetics and causes both aneugenic and clastogenic effects in the macrophyte Bidens laevis L.

Abstract

Imidacloprid (IMI) is a neonicotinoid insecticide widely used in agricultural activities all around the world. This compound is transported from croplands to surrounding freshwater ecosystems, producing adverse effects on nontarget organisms. Because of the relevance of aquatic macrophytes in the above-mentioned environments and the lack of studies of potential effects of IMI on them, this work aimed to assess the mitotic process and potential genotoxicity in the aquatic macrophyte Bidens laevis L. Although the analysis of the Mitotic Index (MI) showed that IMI was not cytotoxic, the Cell Proliferation Kinetics (CPK) frequencies evidenced modifications in the kinetics of the mitotic process. Indeed, the anaphases ratio decreased at 10 and 100 μg/L IMI, while at 1000 μg/L an increase of prophases ratio and a decrease of metaphases ratio were observed. Regarding genotoxicity, IMI produced an increase of the abnormal metaphases frequency from 10 μg/L to 1000 μg/L as well as an increase in clastogenic anaphases-telophases frequency at 100 and 1000 μg/L. In addition, aneugenic anaphases-telophases and C-mitosis frequencies also increased at 1000 μg/L, confirming the effects on the mitotic spindle. Considering the genotoxic effects on B. laevis through two different mechanisms (aneugenic and clastogenic) and the wide spread use of IMI in agriculture, these mechanisms of toxicity on macrophytes should be considered among other recognized effects of this insecticide on aquatic biota.

Peppermint (Mentha piperita) extract modulates the genotoxic effects of Cypermethrin and Malathion insecticides on Allium cepa root cells

“…The decline in anaphase and telophase, and consequently MI, may be a direct result of mitotic arrest or slow mitosis due to onset obstruction of prophase (Briand and Kapoor 1989). The prevalence of metaphase stage induced by cypermethrin and malathion may result from metaphase arrest as a consequence of toxicity (Kabarity and Malallah 1980), failure to build spindle apparatus and microtubules (Komaki and Schnittger 2017) or delay of movement from metaphase to anaphase due to metaphase abnormalities (Lukaszewicz et al 2019).…”

“…The mitotic index (MI) expressed as a percentage following the method of Özmen and Sümer (2004). Cell proliferation kinetics (CPK) frequencies were calculated following the method of Lukaszewicz et al (2019). Chromosomal and mitotic aberrations (MAs) were recorded as percentage of mitotic aberrations.…”

Exposure of Pisum sativum L. Seeds to Methomyl and Imidacloprid Cause Genotoxic Effects in Pollen-Mother Cells

“…These findings suggest that these chemicals have the potential to cause meiotic abnormalities, as reported by previous researchers [ 50 , 51 , 52 ]. Specifically, these insecticides may cause chromosomal anomalies by inhibiting spindle proteins and inducing sister chromatid exchange [ 33 , 53 ]. Free radicals cause genomic instability in cells.…”

Insights into the Toxicity and Degradation Mechanisms of Imidacloprid Via Physicochemical and Microbial Approaches

“…Alters the biotransformation and the antioxidant enzyme activity in different tissues [34] 13. Aquatic macrophyte (Bidens laevis) 1-1000 µg•L −1 Alters the mitotic dynamics and causes aneugenic and clastogenic effects [35] 14.…”

“…The organs most affected by imidacloprid in the neotropical fish Prochilodus lineatus are the liver and the kidneys, followed by the gills, which alters their biotransformation and the antioxidant enzyme activity in different tissues [34]. Imidacloprid alters the mitotic dynamics and causes aneugenic and clastogenic effects in the aquatic macrophyte Bidens laevis [35].…”