Phytoconstituents as Potential Therapeutics against Enzymatic Targets for Neurodegenerative Diseases.

Neurodegenerative diseases are brought on by the loss of function of nerve cells in the brain or peripheral nervous system and afflict millions of people worldwide. Parkinson's disease and Alzheimer's disease are the two most common neurodegenerative diseases. These neurodegenerative diseases are multi-factorial, progressive, age-related, and influenced by two factors: genetic and environmental. Successful treatment of neurodegenerative diseases is yet a challenging task due to lack of selectivity, toxicity, and the growth of multi-drug-resistant cells to the currently available drugs. Plant-derived, natural secondary metabolites have a significant impact on the research and development of novel medications against neurodegenerative disease. Plant-derived natural products are frequently regarded as safe and relatively safer substitutes for synthetic drugs. The present review deals with the elucidation of plant-derived secondary metabolites, namely alkaloids, flavonoids, and terpenoids, as anti-neurological therapeutics with special reference to various enzymatic targets, such as β-secretase, γ-secretase, α-Secretase, acetylcholinesterase, monoamine oxidase, and phosphodiesterase-4.