Di-(N-butyl)-phthalate-induced Oxidative Stress And Depression-like Behavior In Mice With Or Without Ovalbumin Immunization

Recently, the relationship between human health and environmental pollutant is of increasing interest. Di-(n-butyl) phthalate (DBP) is one important plasticizer used in industry, and exists widely in our daily life. Therefore, humans and animals can be exposed to these ubiquitous compounds via different routes. Moreover, although epidemiological evidence suggests a link between allergies and depression, no in vivo evidence exists. Therefore, our study aimed to investigate the relationship between atopic allergy and depression, and the role of DBP in depression.BALB/c mice were randomly divided into eight groups:saline, ovalbumin (OVA)-immunized, DBP (0.45or45mg/kg/d) alone, DBP (0.45or45mg/kg/d) OVA-immunized, hydrocortisone (30mg/kg/d) alone, and hydrocortisone (30mg/kg/d)-exposed OVA-immunized. Three kinds of indexes were tested in this research: behavior (The Open-field Test, Tail Suspension Test, and Forced Swimming Tests), viscera coefficients (brain and spleen), oxidative damage of the brain (Reactive Oxygen Species [ROS], Malondialdehyde [MDA], and Glutathione [GSH]), as well as levels of IgE and IL-4in the serum.The results were shown as follows:with the increasing DBP concentrations, the mice depression symptoms were increased in the saline and OVA groups. Moreover, the OVA groups were related with more serious depression degrees when compared with the same DBP concentration exposure saline groups. Oxidative stress may be having an association with the increase in DBP in the different groups in a dose-dependent way. The concentrations of IL-4and IgE are showed an association with low-dose DBP stimulation, which was changed to high-dose inhibition with increasing DBP exposure. This is inferred that possibly spleen injury, which was seen at the high DBP concentrations, was responsible for it.Development of an atopic allergy can cause depressive symptoms in mice, and DBP is implicated as a causative agent in this process. Oxidative damage of the mice brains and cytokine of their serum induction may be potential mechanisms of DBP-induced depression.