Avermectin disrupted hematopoietic development and lipid metabolism in zebrafish larvae.

Increased resistance to avermectin contributes to environmental stress. A notable concern is the limited assessment of pesticides, including avermectin, on the blood system. Zebrafish larvae have been used to assess the safety of avermectin on blood components. Findings revealed that 0.6 μg/mL avermectin impacted cellular elements of the blood, including hematopoietic stem cell (HSC), myeloid cell (MC), and erythrocyte (EC), each of which decreased by over 50 %. Whole-body hemoglobin levels in zebrafish larvae were reduced by 56.4 %, which may be an important factor in the abnormal erythropoiesis. Blood cells also serve as a key pathway for lipid transport, which is essential for vital biological functions. At 0.60 μg/mL, avermectin increased triglyceride, cholesterol, free cholesterol (FC), and low-density lipoprotein cholesterol (LDL-C) content in zebrafish larvae by 20.6 %, 21.8 %, 385.3 % and 40.0 %, respectively, while decreasing high-density lipoprotein cholesterol (HDL-C) content by 38.5 %. Nile red, BODIPY 493/503 and Oil red O staining showed that avermectin-induced lipid accumulation in zebrafish larvae. Molecular docking predicts that avermectin binds to proteins related to hematopoietic development (TAL1, LMO2), hemoglobin production (EPO/R, HBAA1, HBB1/2) and lipid transport (APOA1A, APOEB, DGAT2). In addition, avermectin interfered with the expression levels of related pathway genes.