Bioaccumulation And Toxic Effects Of Chlorantraniliprole And Flubendiamide In Zebrafish (Danio Rerio)

Chlorantraniliprole and flubendiamide are two of the early registered diamides,which are new insecticides with broad-spectrum.high insecticidal efficiency and no cross resistance.Due to the widespread use in agriculture,diamides are ubiquitous in the environment,thereby posing potential toxicity risk to organisms.However,as diamides are widely used in the field,the environmental safety issues caused by them are increasingly concerned.Among them,the toxicity risk of diamides in aquatic ecosystem has received more and more attention,but relevant researches are limited.The toxic effects of chlorantraniliprole and flubendiamide on zebrafish have been studied from acute toxicity,bioaccumulation,growth toxicity,histopathology,oxidative stress and apoptosis,to provide theoretical guidance for the risk assessment of diamides in aquatic ecosystem.The main findings are as follows:(1)The semi-static test method was used to explore the acute toxicity of chlorantraniliprole and flubendiamide to adult zebrafish.Results showed that the LC50 values of chlorantraniliprole to zebrafish at 24,48,72 and 96 h were 53.10,42.42,39.73 and 36.93 mg/L,respectively,which proved that acute toxicity of chlorantraniliprole to zebrafish is low.LC50 of flubendiamide to adult zebrafish was greater than 30 mg/L,so flubendiamide has low toxicity in zebrafish,and chlorantraniliprole is more toxic to zebrafish than flubendiamide.The bioaccumulation behavior of chlorantraniliprole and flubendiamide in zebrafish was studied by LC-MS/MS.The results showed that the bioconcentration factor of chlorantraniliprole and flubendiamide in zebrafish was 0.614?2.534 and 1.125?2.011,respectively,which indicated that chlorantraniliprole and flubendiamide showed low bioaccumulation in zebrafish(2)Growth index evaluation,physiological and biochemical analysis,histopathological assessment and expression analysis of apoptosis-related genes were used to explore the toxic effects of chlorantraniliprole at concentrations of 0.1,1,10 mg/L and flubendiamide at concentrations of 0.1.0.5,1 mg/L on zebrafish.The results showed that the weight,length and k-factors of zebrafish after chlorantraniliprole and flubendiamide treatment were not significantly different from those of the control group.After 7 and 14 days of treatment with 1 and 10 mg/L chlorantraniliprole,the hepatosomatic index of zebrafish increased significantly,and 1 mg/L flubendiamide caused a significant increase in hepatosomatic index of zebrafish after 14 days,indicating that chlorantraniliprole and flubendiamide can cause damage in liver of zebrafish.The results of oxidative stress measurement showed that chlorantraniliprole can cause significant changes in SOD,CAT and GPx in the liver of zebrafish,and the content of MDA and GSH changed significantly,indicating that oxidative stress occurred in the liver of zebrafish.MDA content in zebrafish liver was significantly increased after treatment with flubendiamide,and after 14 days of 1 mg/L flubendiamide treatment,the CAT was significantly increased,and the content of GSH was significantly decreased,indicating that flubendiamide can cause oxidative damage to the zebrafish liver.After histopathological observation,obvious pathological changes occured in liver of zebrafish,including swelling and vacuole formation,and the degree of liver injury gradually increased with the increase of the treatment concentration.What's more,flubendiamide caused swelling,vacuolation,and degeneration of zebrafish liver.The expression of apoptosis-related genes in the zebrafish liver also showed changes.The expression of Apaf-1,P53,PUMA,Caspase-3 and Caspase-9 genes all up-regulated,and Bcl-2/Bax was significantly lowered,indicating that chlorantraniliprole and flubendiamide can induce apoptosis in zebrafish liver.The results of the study indicate that both chlorantraniliprole and flubendiamide can accumulate in zebrafish and produce varying degrees of toxic effects on zebrafish.This study can lay a foundation for clarifying the potential risks of chlorantraniliprole and flubendiamide to aquatic ecosystems,and provide an important theoretical basis for the systematic assessment of the environmental safety of two pesticides.