Cellular toxicity mechanisms of lambda-cyhalothrin in Venus verrucosa as revealed by fatty acid composition, redox status and histopathological changes

Abstract Lambda-cyhalothrin (λ-cyh), a synthetic pyrethroid type II, is one of the most toxic xenobiotics to aquatic organisms, which leads to a number of complex toxicological syndromes. The present study aimed to assess the adverse effects of λ-cyh, on fatty acid (FA) composition, redox status, and the histopathology aspect of Venus verrucosa digestive gland under an exposure to a series of concentrations (100, 250 and 500 µg/L). An increase of saturated fatty acid (SFAs) levels and a decrease of polyunsaturated fatty acids (PUFAs) content, mainly eicosapentaenoic (C20: 5n − 3, EPA) and docosahexaenoic (C22: 6n − 3, DHA) acids, were observed in λ-cyh-treated digestive gland. Moreover, our data indicated an alteration in arachidonic acid (C20:4n − 6, ARA) level. The exposure to the highest dose of λ-cyh promoted oxidative stress with an increase of malondialdehyde (MDA), advanced oxidation protein product (AOPP), metallothionein (MT) and hydrogen peroxide (H2O2) levels. A significant decrease in enzymatic (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) and non-enzymatic (reduced glutathione (GSH), vitamin C and non-protein-SH (NPSH)) antioxidants was showed in treated groups. Moreover, acetylcholinesterase (AChE) activity was inhibited with the increase in λ-cyh concentration. Our biochemicals results have been confirmed by the histopathological observations. Overall, our results indicated the toxic effect of λ-cyh on the redox status of V. verrucosa digestive gland and highlighted the usefulness of determining FA composition in the better understanding of λ-cyh toxicity.