Neuroprotective Potential of Curcuminoids in Modulating Alzheimer's Disease via Multiple Signaling Pathways

Alzheimer's disease (AD) is a progressive and frequent neurodegenerative disease in elderly people. In the 21st century, owing to the increasing prevalence of AD, there is a crucial need for finding better and more effective pharmacotherapeutic approaches. This review article demonstrated various sources and possible metabolic pathways of curcuminoids obtained from Curcuma longa herb, to prevent and treat AD, but the information related to the metabolic fate of curcuminoids is deficient. Different in vitro and in vivo research studies demonstrating the mechanisms by which curcuminoids attenuated AD have been summarized. Administration of curcuminoids has been indicated to inhibit hyperphosphorylation of tau protein, deposition, and oligomerization of amyloid beta plaques in several AD models. Curcuminoids also inhibit acetylcholinesterase activity, chelate metals and form complexes, have antioxidant properties, mediate neuroinflammatory signaling pathways by altering the activity of microglial cells, and modulate other related signaling pathways such as the heme-oxygenase pathway and the insulin signaling pathways. Briefly curcuminoids exhibit the capability to be more productive and efficacious compared to many recent treatments due to their antioxidant, delayed neuron degeneration, and anti-inflammatory potential. Although their effectiveness as a curative agent is considered to be reduced due to their low bioavailability, if the issue of curcuminoids' low bioavailability is resolved then curcuminoid-based medications are hopefully on the horizon against AD.