Approaches for the treatment of neurodegenerative diseases related to natural products

Neurodegenerative diseases (NDs) represent one of the most important public health problems, and worldwide, hundreds of millions of people are affected by NDs, displaying strong evidence to these diseases is one of the most significant challenges to public health. Neurological disorders include several common diseases of the central and peripheral nervous system such as Alzheimer's disease and other dementia, epilepsy, headache disorders, multiple sclerosis, Parkinson's disease, and others. The discovery of substances capable of preventing or treating neurological disorders has been the goal of researchers for several years. New therapies and new molecules should be explored. In this context, natural compounds represent an important source for the development of new drugs. For example, between 1981 and 2014, from a total of 12 new approved molecules for the treatment of Parkinson's disease, only one was a synthetic drug, being the others biological, derived or inspired in a natural product. In the same line, > 50% of all new antidepressant molecules were synthetic/mimetic of a natural product. Anticholinesterases like physostigmine and neostigmine, opioids alkaloids, galantamine, are some examples of drugs utilized from derived plants for the treatment of neurological disorders, highlighting the relevance of studying and searching for new natural products for the treatment of neurological disorders. This chapter aimed to summarize the most important compounds originated from natural sources that were targets of clinical studies, associated with neurological and psychiatric disorders, obtaining a total of 13 articles, in the last 10 years. Also, we characterized these compounds structurally. Considering the vast diversity of plants, few herbal medicines or botanical drugs were approved for human use, in the last centuries, only few innovative therapeutic products have been developed, especially in the field of neurological diseases.