Azoxystrobin induced genotoxicity in Pethia conchonius, a freshwater fish of river Teesta, India

Abstract

Abstract Purpose Azoxystrobin is one of the globally used strobilurin fungicides. Indiscriminate use of azoxistrobin can contaminate the water bodies by surface run-off. The bioaccumulation of azoxistrobin may adversely affect the aquatic organisms. This study has aimed to evaluate the genotoxic effects of azoxystrobin using Micronucleus (MN) and Comet assays in the fish Pethia conchonius as an experimental organism captured from the river Teesta of the northern part of West Bengal. Methods The 96h LC50 of azoxystrobin was estimated to be 0.514 mg/L. Three Sub-lethal concentrations (SLCs), namely SLC I = 0.025 mg/L, SLC II = 0.0514 mg/L and SLC III = 0.103 mg/L were used for the assay. The fishes were exposed to the above concentrations of azoxystrobin for 96h. The whole blood and gills were collected for MN and Comet assays, respectively at 24h interval. Results Nuclear abnormalities like micronuclei, notched and blebbed nuclei, and the DNA damage in terms of %Head DNA, %Tail DNA, Tail Length and Olive Tail moment were estimated by MN and Comet assays. The frequency of the nuclear abnormalities and DNA damages in the exposed groups were significantly (p˂0.05) higher than the control with increasing concentrations and the duration of exposure of azoxystrobin. The frequency of micronuclei (1.156 ± 0.011), notched (0.889 ± 0.011), blebbed (0.811 ± 0.011) nuclei and DNA damage parameters, %Head DNA (26.288 ± 1.981), %Tail DNA (73.712 ± 1.981), Tail Length (287.760 ± 11.641) and Olive Tail Moment (116.301 ± 7.636) were highest for SLC III at 96h of exposure. Conclusion The results strongly indicated that azoxystrobin is highly genotoxic in fish causing severe DNA damage.