Therapeutic Effects of Herbal Chemicals in Traditional Chinese Medicine on Alzheimer's Disease

Alzheimer's disease (AD) is the most common type of dementia that leads to increasing death and mental disability among humans. Current therapy of AD mainly relies on the use of acetylcholinesterase inhibitors (AChEIs) or antagonists of N-methyl-D-aspartate receptors (NMDARs), which only relieve the symptoms of the disease but not halt its progression. Nevertheless, Traditional Chinese medicines (TCM) are highly prized as many bioactive components isolated from TCM are beneficial for treating AD. In this review, we summarize the latest information on TCM and the bioactive components according to their mechanistic role in alleviating AD. They act as modulators of alpha- and beta-secretases, and inhibitors of beta-amyloid (A beta) aggregation. Some of them suppress A beta-induced neuronal cytotoxicity and inflammation. Hence, this work has demonstrated the feasibility of applying TCM in AD therapy and the possibility of screening of constituents in TCM in the near future.