A Pyrethroid Pesticide, Permethrin, Alters Lipid Metabolism and Voluntary Activities in Mice

Abstract

Exposure to pesticides previously reported to be linked with excessive weight gain and disturbed lipid metabolism. Permethrin, a pyrethroid pesticide, was reported to alter adipogenesis in vitro. However, in vivo effects of permethrin on lipid metabolism and physical activities are unclear. Thus, the purpose of this study was to investigate the effect of permethrin exposure on development of obesity in a mouse model. We tested three different doses of permethrin (0.05, 0.5, & 5 mg/kg body weight/day) in low-fat (4% w/w of diet) or high-fat (20% w/w of diet) diets in female C57BL/6J mice for 12 weeks. Body weight, food intake and physical activities were monitored during the experiment. Serum markers were measured after sacrifice. Permethrin treatment (0.5 mg/kg/day) increased weight gain in low-fat fed animals, while no significant differences were found between high-fat fed groups. Animals fed high-fat diet exhibited reduced activity levels than low-fat fed animals. Permethrin (5 mg/kg/day) treatment markedly decreased activities in low-fat fed groups. Serum parameters further showed permethrin treatment (0.5 mg/kg/day) elevated glucose, triglycerides, free fatty acid, and cholesterol levels in mice fed low-fat diet. These results suggest that oral exposure to permethrin may cause obesity, which may link to altered lipid metabolism and voluntary activities. Supported by NIH R21ES023676