Investigation of obesogenic effects of hexachlorobenzene, DDT and P,P-DDDE in male rat model

Obesity continues to be a global public health problem. Recent studies reported that some environmental pollutants may have obesogenic effects. Peroxisome proliferator activating receptor gamma (Pparγ) and uncoupling protein-1 (UCP1) genes play roles in adipogenesis. Their expression in white adipose tissue (WAT) and brown adipose tissue (BAT) is of importance. In the present study, we aimed to investigate obesogenic effects of dichlorodiphenyltrichloroethane (DDT), hexachlorobenzene (HCB) and dichlorodiphenyldichloroethylene (DDE). Secondly, we aimed to investigate the serum sex hormones (luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone), as well as testicular histology. Thirty-two adult male Sprague-Dawley rats were randomly divided into four groups: control, HCB, DDT and DDE. Organochlorine pesticides (OCPs; 5mg/kg) dissolved in corn oil were administered to the animals by oral gavage every other day for five weeks. Controls received vehicle alone. The body weights of the animals were monitored throughout the experiments. At the end, the animals were decapitated, BAT and WAT samples were collected to analyse Pparγ and UCP1 levels. Testes were dissected out for histological examination. Serum samples were collected to measure levels of LH, FSH, testosterone and serum cholesterol and triglyceride levels. Body weights of the animals did not significantly change among the groups. Serum cholesterol and triglyceride were similar. Serum LH and FSH levels were not significantly altered, but testosterone was significantly reduced in all groups (p<0.05). HCB administration significantly increased Pparγ expression only in WAT (p<0.05). DDT significantly decreased Pparγ and UCP1 expressions in both WAT and BAT (p<0.01). DDE significantly decreased Pparγ expression only in WAT (p<0.001). Testicular histology was found to deteriorated by OCPs. In conclusion, HCB-induced expression of Pparγ in WAT obesogenic activity of HCB. In addition, DDT and DDE-induced decreases in expression of Pparγ and UCP1 in WAT suggest that these two pesticides may reduce adipogenesis.