Phytogenic Nanoparticles for Parkinson's Disease Therapy: Mechanistic Insights, Brain-Targeted Delivery and...

Parkinson's disease (PD) is a progressive neurodegenerative disorder, which causes the loss of dopaminergic neurons in the substantia nigra, resulting in both motor and non-motor impairments. Although crucial advancements in therapeutic strategies, the existing treatments primarily focus on symptom management and fail to address the underlying cause of the disease. Recent advancements in nanotechnology, particularly those that utilize phytogenic approaches, give promising strategies for managing and treating PD. In this review, the term phytogenic nanoparticles (NPs) refer broadly to nanoformulations in which plant-derived materials contribute either to nanoparticle synthesis or therapeutic functionality including plant extract-mediated green-synthesized nanoparticles, nanoparticles loaded or coated with purified phytochemicals and plant-derived exosome-like vesicles. Because these categories differ in composition, mechanism of action, reproducibility, safety and translational maturity, they are critically evaluated as distinct platforms throughout the review. These nanocarriers have shown the ability to improve drug stability, enhance bioavailability and increase brain exposure in experimental models, although the extent and mechanisms of blood-brain barrier (BBB) transport vary among formulations. Phytochemical-loaded nanoparticles demonstrated neuroprotective effects in preclinical models via modulation of oxidative stress and inflammation, inhibiting α-synuclein aggregation, and promoting autophagy, thereby offering a promising therapeutic avenue for neurodegenerative disorders. Phytogenic nanotechnology offers a promising approach for PD therapy through the improvement of drug stability, bioavailability and blood-brain barrier permeation. These NPs exhibit antioxidative, anti-inflammatory and neuroprotective effects, targeting important PD pathologies. Non-invasive delivery strategies, including intranasal drugs and microneedle patches, enhance therapeutic efficacy. This narrative review discusses the efficient management approach for PD via nanotechnological advancements.