Abstract
INTRODUCTION: Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra. The precise molecular mechanisms underlying neuronal loss in PD remain unknown, and there are currently no effective treatments for PD-associated neurodegeneration. Echinacoside (ECH) is known for its neuroprotective effects, which include scavenging cellular reactive oxygen species and promoting mitochondrial fusion. However, the blood-brain barrier (BBB) limits the bioavailability of ECH in the brain, posing a significant challenge to its use in PD treatment. METHODS: We synthesized and characterized PEGylated ECH liposomes (ECH@Lip) and peptide angiopep-2 (ANG) modified liposomes (ECH@ANG-Lip). The density of ANG in ANG-Lip was optimized using bEnd.3 cells. The brain-targeting ability of the liposomes was assessed in vitro using a transwell BBB model and in vivo using an imaging system and LC-MS. We evaluated the enhanced neuroprotective properties of this formulation in a the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD model. RESULTS: The ECH@ANG-Lip demonstrated significantly higher whole-brain uptake compared to ECH@Lip and free ECH. Furthermore, ECH@ANG-Lip was more effective in mitigating MPTP-induced behavioral impairment, oxidative stress, dopamine depletion, and dopaminergic neuron death than both ECH@Lip and free ECH. CONCLUSION: The formulation used in our study significantly enhanced the neuroprotective efficacy of ECH in the MPTP-induced PD model. Thus, ECH@ANG-Lip shows considerable potential for improving the bioavailability of ECH and providing neuroprotective effects in the brain.