Antidepressive Effects of Taraxacum Officinale in a Mouse Model of Depression Are Due to Inhibition of Corticosterone Levels and Modulation of Mitogen-Activated Protein Kinase Phosphatase-1 (Mkp-1) and Brain-Derived Neurotrophic Factor (Bdnf) Expression.

BACKGROUND Depression is a common disorder linked with high levels of chronicity, psycho-social and physical problems, and suicide. Here, we assessed the antidepressant effects of the hydromethanolic extract of Taraxacum officinale and investigated the underlying mechanism. MATERIAL AND METHODS Antidepressant effects were examined by use of the tail suspension test (TST). Concentrations of corticosterone, dopamine, noradrenaline, and adrenaline were examined by biochemical assays. The mRNA expression was assessed by quantitative RT-PCR. Phytochemical analysis was performed by LC/MS. RESULTS The results showed that the extract at the dosage of 50 and 100 mg/kg significantly (p<0.01) alleviated the TST-induced immobility in the mice, and the effects were comparable to the antidepressant drug Bupropion, which was used as the positive control. Investigation of the underlying mechanism revealed that the T. officinale extract exerts it effects by significantly (p<0.05) decreasing the levels of corticosterone and increasing the concentrations of dopamine, noradrenaline, and adrenaline. Further, the extract also increased the expression of brain-derived neurotrophic factor (Bdnf), which was associated with significant (p<0.05) decrease in the expression of mitogen-activated protein kinase phosphatase-1 (Mkp-1), indicative of the antidepressant potential of T. officinale. Finally, the active constituents of the extract, which include isoetin, hesperidin, naringenin, Kaempferol, sinapinic, and gallic acid, were also identified, which could potentially be responsible for its antidepressant effects. CONCLUSIONS In conclusion, T. officinale exerts significant antidepressant effects in a mouse model of depression by inhibition of corticosterone levels and modulation of Mkp-1 and Bdnf expression.