Curcumin ameliorates chronic Toxoplasma gondii infection-induced affective disorders through modulation of proinflammatory cytokines and oxidative stress

Long-term infection with Toxoplasma gondii is associated with affective disorders (i.e., anxiety and depression) in adults. We aimed to explore the effects of curcumin (CR) on anxiety- and depressive-like behaviors in mice infected with T. gondii. 

Animals were studied in five groups: Control, Model, Model + CR20, 40, and 80 (with IP injection of 20, 40, and 80 mg/kg CR).  T. gondii infection was prolonged for four weeks. The animals were then treated with CR or vehicle for two weeks and evaluated by behavioral tests at the end of the study. Hippocampal levels of oxidative stress biomarkers (superoxide dismutase; SOD, glutathione; GSH, and malondialdehyde; MDA) and gene expression and protein levels of hippocampal proinflammatory mediators (interleukin-1β; IL-1β, IL-6, IL-18, and tumor necrosis factor- α; TNF-α) were determined. 

Behavioral tests confirmed that long-term infection with T. gondii led to anxiety- and depressive-like behaviors. Antidepressant effects of CR were linked to modulation of oxidative stress and cytokine network in the hippocampal region of infected mice. These results showed that CR reduced anxiety and depression symptoms via regulation of oxidative stress and proinflammatory cytokines in the hippocampus of T. gondii-infected mice. 

Therefore, CR can be used as a potential antidepressant agent against T. gondii-induced affective disorders.