Acupoint stimulation by microneedle alleviates motor dysfunction through modulating striatal dopamine and choline levels and reducing neuroinflammation in the Parkinson's disease mouse model

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the basal ganglia. Despite the development of numerous drugs to treat PD, the limitations of these drugs have led to the exploration of various therapies. Previous clinical trials and in vivo studies have demonstrated that stimulation of acupuncture points (acupoints) effectively improve PD phenotype. Recently, microneedles (MNs) have emerged as promising therapeutic tools and may offer a novel approach for easy acupoint stimulation. This study explored the effects of MN patches attached to acupoints on PD phenotypes. The MN patches were attached to the Fengchi (GB20) and Yanglingquan (GB34) acupoints in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP)-induced mice for 12 consecutive days. Following this treatment, tissue analysis was performed using immunohistochemistry and Western blot. Mice with MN patches showed significantly improved motor function in the pole and rotarod tests. In the SN of a mouse with MN patches attached, the expression of Heme Oxygenase 1 (HO-1)/Nuclear factor erythroid-2-related factor 2 (Nrf2) was increased, and dopaminergic neurons damaged by MPTP were protected. In the brain tissues of mice with MN patches, the balance of dopaminergic and cholinergic neurons was regulated, and the hyperactivation of microglia and astrocytes was inhibited. Furthermore, the levels of cytokines in the plasma of mice with MN patches were significantly decreased. Collectively, the stimulation of GB20 and GB34 acupoints by MN patches may be a novel therapy for delaying PD.