Hydroxysafflor Yellow A Improves Motor Dysfunction in the Rotenone-Induced Mice Model of Parkinson's Disease

Dopamine D3 receptor (DRD3) is diminished in patients of Parkinson's disease (PD). Brain-derived neurotrophic factor (BDNF) is responsible for regulating expression of the DRD3 in the brain. Our previous study showed that hydroxysafflor yellow A (HSYA) could increase BDNF content in the striatum of PD mice. This experiment aimed to evaluate whether HSYA can improve the motor dysfunction induced by rotenone through regulating the BDNF/TrkB/DRD3 signaling pathway in mice. Male C57/BL6 mice were intraperitoneally treated with HSYA. Thirty minutes later, they were intragastrically administered with rotenone at a dose of 30 mg/kg. Pole, rotarod and open field tests were investigated at 28 d. Then, tyrosine hydroxylase (TH) in substantia nigra was observed by immunohistochemistry. Dopamine content was detected by high-performance liquid chromatography. The expressions of BDNF, phospho-tropomyosin-related kinase B (p-TrkB), tropomyosin-related kinase B (TrkB), phospho-phosphoinositide 3-kinase (p-PI3K), phosphoinositide 3-kinase (PI3K), phospho-protein kinase B (p-AKT), protein kinase B (AKT), and DRD3 were assayed by western blotting. Behavioral tests showed that rotenone-challenged mice displayed motor dysfunction. However, treatment with HSYA improved motor dysfunction induced by rotenone. HSYA treatment increased not only the number of TH-containing dopaminergic neurons in substantia nigra, but also the dopamine content in the striatum in PD mice. Moreover, the expressions of BDNF, p-TrkB/TrkB, DRD3, p-PI3K/PI3K, p-AKT/AKT were significantly increased in rotenone plus HSYA group. Our results indicated that HSYA improved motor dysfunction in rotenone-induced PD model and the pharmacological action of HSYA was related to regulating BDNF/TrkB/DRD3 signaling pathway, at least, in part.