Neonicotinoid insecticide imidacloprid impairs lipid metabolism in 3T3‐L1 cells

Abstract

Exposures to environmental pollutants including several classes of insecticides have been positively or negatively linked to obesity epidemic. Imidacloprid, a relatively new insecticide belongs to a class called neonicotinoid, has been increasingly used to control agricultural insect pests, structural pests, and ectoparasites significantly affecting human and animal health. Although medical and public interests towards the environmental exposure to insecticides are growing, information about imidacloprid exposure affecting human and animal health is very limited. To elucidate mechanism of impairing lipid metabolism, we tested the effect of imidacloprid on adipogenesis in 3T3‐L1 cells. 3T3‐L1 pre‐adipocytes were differentiated by the addition of insulin (1μg/ml), dexamethasone (1μM), IBMX (10mM), and 10% FBS in DMEM medium. Cells were treated with or without imidacloprid (10 and 20μM). No cytotoxicity was observed in concentration of 20μM imidacloprid for 6 days of differentiation as reported elsewhere. Lipid accumulation was measured by Oil‐red O staining and intracellular triacylglyceride contents were analyzed. Level of mRNA and protein expression of the lipid metabolism related transcription factors were measured by RT‐PCR and Western Blot analysis, respectively. Imidacloprid significantly increased adipocyte differentiation as well as lipid accumulation in 3T3‐L1 cells.