Objective To investigate the effects of deltamethrin (DM) subchronic exposure on hepatic lipid metabolism in male mice.

Methods Eighteen specific pathogen-free (SPF) male C57BL/6J mice (8-week-old) were randomly assigned to a control group (pure corn oil), a low-dose DM group (2.25 mg/kg), and a high-dose DM group (9.0 mg/kg), followed by oral gavage for 90 consecutive days. Hepatic morphological changes were observed via hematoxylin-eosin (HE) staining and Masson staining. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and superoxide dismutase (SOD), as well as the levels of total cholesterol (T-CHO), triglycerides (TG), reduced glutathione (GSH), and malondialdehyde (MDA) in the liver were measured. Western blotting analysis was performed to detect the expression levels of sterol regulatory elementbinding protein-1c (SREBP-1c) and peroxisome proliferator-activated receptor α (PPARα).

Results Compared with the control group, high-dose DM group showed significantly increased body weight and white adipose coefficient (P < 0.05). HE staining revealed focal inflammatory cell aggregation in liver tissues of high-dose DM group. Masson staining showed no significant fibrosis changes in any of DM dose groups. The liver ALT activity was increased in the low-dose and high-dose DM groups, and the AST activity was increased in the high-dose DM group (all P < 0.05). Compared with the control group, the level of cellular oxidative stress in the high-dose DM group was significantly increased (P < 0.05). Compared with the control group, the levels of hepatic T-CHO and TG in the high-dose DM group were increased (P < 0.05). The expression of SREBP-1c was up-regulated and the expression of PPARα was down-regulated in all DM dose groups (all P < 0.05).

Conclusion Sub-chronic DM exposure induces hepatic lipid metabolic disorder in mice, possibly through oxidative stress injury and imbalanced lipid synthesis-catabolism.