Effect of astragaloside IV on PI3K/Akt signaling pathway in substantia nigra of mice with Parkinson′s disease / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effect of astragaloside IV on phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway in substantia nigra of mice with Parkinson′s disease.Methods:Forty-five SPF healthy male C57BL/6 mice, aged 8 weeks, weighing 19-25 g, were divided into 3 groups ( n=15 each) using a random number table method: control group (group C), Parkinson′s disease group (group PD) and astragaloside IV group (group A). The mouse model of Parkinson′s disease was developed by intraperitoneal injection of 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) 30 mg/kg everyday for 7 consecutive days.Astragaloside 20 mg/kg was intraperitoneally injected everyday at 30 min before MPTP injection for 7 consecutive days before the model was prepared in group A, and the equal volume of normal saline was given instead in group C. Behavior was measured at 1 day interval after completion of administration.The mice were then sacrificed, and the substantia nigra of the brain tissue were obtained for determination of the expression of tyrosine hydroxylase(TH), phosphorylated PI3K(p-PI3K), phosphorylated Akt(p-Akt), glial fibrillary acidic protein (GFAP) and brain-derived neurotrophic factor (BDNF) (by Western blot). Results:Compared with C group, the total distance of movement and latency of falling were significantly shortened, the hanging score was decreased, the step width was increased, the expression of TH, p-PI3K, p-Akt and BDNF in substantia nigra was down-regulated, and the expression of GFAP was up-regulated in PD group and A group ( P<0.05). Compared with PD group, the total distance of movement and the latency to fall were significantly prolonged, the hanging score was increased, the step width was reduced, and the expression of TH, p-PI3K, p-Akt and BDNF in the substantia nigra was up-regulated, and the expression of GFAP was down-regulated in group A ( P<0.05). Conclusions:The mechanism by which astragaloside IV improves motor dysfunction is related to the activation of PI3K/Akt signaling pathway, up-regulation of BDNF expression and inhibition of astrocyte activation in mice with Parkinson′s disease.