The Emerging Role of Marine Natural Products for the Treatment of Parkinson's Disease.

Parkinson's Disease (PD), known as Parkinsonism, is a neurodegenerative disease that mainly affects the elderly and is characterized by an extensive and progressive loss of dopaminergic neurons in the Substantia Nigra pars compacta (SNpc). Owing to genetic, environmental, and lifestyle changes, the incidence of PD has recently risen among adults. The most widely used PD treatment strategies include the use of dopamine agonists, anticholinergics, and enzyme inhibitors. The aquatic flora and fauna have become the emerging source of novel, structurally diverse bioactive compounds and, at present, the researchers concentrate their efforts on isolating, characterizing, and identifying many secondary metabolites of different nature to treat various disorders, including, neuroprotective marine natural products (MNPs). The bioactive peptides, tannins, carotenoids, alkaloids, polyunsaturated fatty acids (PUFA), and sulfated polysaccharides from the MNP's and their synthetic derivatives have demonstrated important neuroprotective activity in preclinical studies through multiple mechanisms. An extensive literature survey was carried out, and published articles from PubMed, Scifinder, Google Scholar, Web of Science, and Scopus were carefully reviewed to compile information on the MNPs to treat PD. This current review focus on neuroprotective MNPs and their probable biological pathways to treat PD based on their structure and bioactivities reported from 1990 to 2020.