Quercetin mitigates anxiety-like behavior and normalizes hypothalamus-pituitary-adrenal axis function in a mouse model of mild traumatic brain injury.

Mild traumatic brain injury (mTBI) is a major public health risk for developing anxiety-related disorders and hypothalamus-pituitary-adrenal (HPA) axis dysregulation in humans. Extensive research has shown that dietary intake or supplementation of the natural flavonoid quercetin might be useful for treating anxiety-related symptoms. The objectives of this study were to determine whether quercetin treatment can attenuate anxiogenic-like behaviors and normalize HPA axis function in mice with mTBI. Animals subjected to mTBI were treated daily with quercetin (50 mg/kg) or diazepam (positive control, 3 mg/kg) for 14 days. Four behavioral tests (open field, plus maze, light-dark box, and zero maze) were used to assess anxiety-related behaviors in mice. To evaluate HPA axis function, adrenocorticotropic hormone and corticosterone were measured in the serum of mice after the anxiety tests. Quercetin treatment was found to significantly reduce anxiety-like behaviors in mTBI-induced mice. A strength of this study is the consistency of results among anxiety tests. The dysregulation of the HPA axis in mTBI-induced mice treated with quercetin was also attenuated, with decreased levels of adrenocorticotropic hormone and corticosterone. The effects of quercetin were comparable with those of diazepam treatment. Taken together, these results suggest that quercetin might be useful for treating anxiety-related symptoms and HPA axis hyperreactivity in patients with mTBI.