Relative Genotoxic Effects of Cypermethrin, Alphamethrin and Fenvalerate on the Root Meristems of Allium cepa

Abstract

SummaryThe present investigation deals with the effects of 3 synthetic pyrethroid insecticides viz., Cypermethrin, Alphamethrin and Fenvalerate on the mitotic activity and mitotic chromosomes in the root meristems of Allium cepa. Root meristems were exposed to 4 different concentrations of each test compound for 1 h pulse treatment and allowed to different recovery periods.Cytological analyses revealed that the test compounds elicited varying degrees of cytotoxic, turbagenic (toxicity to spindle) and clastogenic effects. In the ultimate analysis, Cypermethrin and Alphamethrin have more turbagenic and weak clastogenic activity whereas Fenvalerate has relatively strong clastogenic activity in vitro.Key words Genotoxicity, Synthetic pyrethroid insecticides, Allium test.Use of pesticides has become a necessary evil in the crop protection management programmes. Synthetic pyrethroids are new generation pesticides, which include more than 1000 powerful broad-spectrum insecticides. In general, synthetic pyrethroids are less toxic to mammals than the organophosphate, carbamate and organochlorine pesticides. This coupled with the efficacy of synthetic pyrethroids made them logical alternative to organochlorines and carbamates in pest control programmes (Elliot et al. 1978, Leahey 1985, Litchfield 1985. Nevertheless, the wide usage of pesticides in agricultural practices and public health programmes gave rise to concerns on the deleterious effects of these chemicals on non-target organisms (Grover and Malhi 1985). Screening of pesticides for their genotoxic effects in various assay systems unfolded alarming implications.With very little information available on the genotoxicity and mutagenicity of pyrethroids, the present study is undertaken to assess the clastogenic and turbagenic effects of 3 synthetic pyrethroids using Allium test as the assay system (Fiskesjo 1985, Grant 1978, 1994, Sharma 1983. Materials and methodsRoot meristems raised from common onion (Allium cepa L. 2nϭ16) were used as assay system. Three insecticides tested in this study are [Cypermethrin (Devicyper 10% EC), a-S cyanophenoxybenzyl-2,2-dimethyl-3S-(2Ј,2Ј-dichlorovinyl)-1R-cyclopropanecarboxylate, Alphamethrin (Farsa 10% EC), a-S cyanophenoxybenzyl-2,2-dimethyl-3R-(2Ј,2Ј-dichlorovinyl)-1S-cyclopropanecarboxylate and Fenvalerate (Triumphcard 20% EC), a-cyano-(m-phenoxybenzyl)-2-(p-chlorophenyl)-3-methylbutyrate] (Fig. 1). Prior to the initiation of the experiment 1 per cent stock solutions were prepared by dissolving the test compounds in 1-2 drops of acetone and subsequently dilution in distilled water (volume/volume). Subsequent dilutions were made in phosphate buffer adjusted to pH 7.0. The range of test concentrations of each chemical was selected basing on cytotoxic threshold of each chemical (by LD 50 method) to the test system. Meristems of roots, 2-3 cm in length were exposed to the test solutions of different concentrations for 1 h followed by 0, 4, 12, 24

Cytogenotoxic effects of cypermethrin, deltamethrin, lambdacyhalothrin and endosulfan pesticides on Allium cepa root cells

“…Cypermethrin and alphamethrin were reported to elicit varying degrees of cytotoxic, turbagenic (toxicity to spindle) and clastogenic effects but generally more turbagenic and weak clastogenic (Rao et al, 2005). However, Asita and Makhalemele (2008) reported that alpha-thrin (active ingredient of alpha-cypermethrin) was only cytotoxic but not genotoxic at various concentrations in treated A. cepa.…”

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

“…Micronuclei are the results of acentric fragments, lagging chromosomes, chromosome breakage or whole chromosomes that fail to incorporate into one of the daughter nuclei during telophase of mitotic cells (Albertini et al 2000; Fenech 2007). It is suggested that loss of genetic material reveal genomic instability (Barale et al 1998) and may reveal cell death (Luzhna and Kovalchuk 2013).aberrations, which is in agreement withRao et al, (2005), while opposes Asita and Makhalemele (2008), who reported cypermethrin (Alpha-thrin) as cytotoxic, but not genotoxic at various concentrations. However, malathion is more genotoxic than cypermethrin.…”

“…(Rao et al 2005; Yekeen et al 2013; Dizdari and Kopliku 2013). Malathion toxicity to plants was clearly determined (Adam et al 1990; Bianchi et al 2015; Garza-León et al 2017).…”

Effect of cypermethrin insecticide on root chromosome morphometry of scallion (Allium fistulosum)

“…According to Rao et al (2005), high quantities of cypermethrin cause chromosomal aberrations in metaphase and chromosome bridge creation in anaphase. In this research, sticky chromosomes (Figure 6); chromosome bridge (Figure 7); chromosome agglutination (Figure 8); disrupted metaphase (Figure 9), and disturbed anaphase were identified as chromosomal aberrations (Figure 10).…”