MRI evaluation of neuroprotective effects of Astragaloside Ⅳ on rotenone-induced late-stage Parkinson's disease mice

Astragaloside Ⅳ (AS-Ⅳ) improved the motor behavior of Parkinson's disease (PD) mouse but the alteration of imaging in the PD mice brain was unclear. PD models were established by unilateral injection of rotenone (ROT) into the substantia nigra pars compacta (SNc) of mice. AS-Ⅳ (20 mg/kg) was intraperitoneally injected once daily for 14 days. Pole and rotarod tests were performed to evaluate behavioral alterations at 32 weeks. Flow cytometry, electrophysiological recordings techniques, and MRI were performed to assess the neuroprotective effects of AS-Ⅳ. AS-Ⅳ ameliorated motor deficits and the incidence of dystonia in animal models of PD. AS-Ⅳ administration inhibited CD4⁺ T cell activation and increased dopaminergic neurons burst firing. Imaging studies have demonstrated that AS-Ⅳ alters the brain tissue microstructure in the substantia nigra (SN). After administering AS-Ⅳ, bilateral SN fractional anisotropy (FA) values increased, whereas mean diffusivity (MD) values decreased in mice, according to the diffusion tensor imaging (DTI) analysis. In addition, AS-Ⅳ treatment significantly reduced the T₂ values of the T₂-mapping. In summary, AS-Ⅳ improved motor impairments and efficiently performed neuroprotective functions in the ROT-induced mouse model.

Astragaloside Ⅳ; CD4(+)T cell; Diffusion tensor imaging (DTI); Parkinson’s disease; T(2)-mapping.