Phytomolecules from conventional to nano form: Next-generation approach for Parkinson's disease.

The incidence of neurodegenerative diseases is increasing exponentially worldwide. Parkinson's disease (PD) is a neurodegenerative disease caused by factors like oxidative stress, gene mutation, mitochondrial dysfunction, neurotoxins, activation of microglial inflammatory mediators, deposition of Lewy's bodies, and α- synuclein proteins in the neurons leading to neuroinflammation and neurodegeneration in the substantia nigra. Hence the development of efficacious neuro-therapy is in demand which can prevent neurodegeneration and protect the nigrostriatal pathway. One of the approaches for managing PD is reducing oxidative stress due to aging and other co-morbid diseased conditions. The phytomolecules are reported as safe and efficacious antioxidants as they contain different secondary metabolites. However, the limitations of low solubility restricted permeability through the blood-brain barrier, and low bioavailability limits their clinical evaluation and application. This review discusses the therapeutic efficacy of phytomolecules in PD and different nanotechnological approaches to improve their brain permeability.