Identification of a novel BACE1 inhibitor, timosaponin A-III, for treatment of Alzheimer's disease by a cell extraction and chemogenomics target knowledgebase-guided method
PHYTOMEDICINE
Authors: Wang, Hai-Qiao; Liu, Min; Wang, Liang; Lan, Fen; Zhang, Yi-Han; Xia, Jin-Er; Xu, Zhen-Dong; Zhang, Hai
Abstract
Background: Rhizoma Anemarrhenae (RA) has been conventionally used for treatment of Alzheimer's disease (AD) in Traditional Chinese Medicine, and thus, the active components from RA can be screened. Purpose: This research aimed to identify the active components of RA and their targets and further clarify the molecular mechanisms underlying its anti-AD activity. Methods: First, the potential active compounds from RA were screened by neurocyte extraction and microdialysis methods. Second, the potential targets were predicted by a chemogenomics target knowledgebase and further explored by surface plasmon resonance and enzyme activity assays. Third, the pharmacological effects were evaluated by employing APP/PS1 transgenic mice and SH-SY5Y-APP cells. ELISAs and Western blot analyses were used to evaluate the expression of key molecules in the amyloidogenic and NMDAR/ERK pathways. Results: Timosaponin A-III (TA-III) was screened and identified as a potential active component for the anti-AD activity, and BACE1 was proven to be a potential high-affinity target. Enzyme kinetic analysis showed that TA-III had strong noncompetitive inhibitory activity against BACE1. The in vitro and in vivo assays indicated that TA-III had pharmacological effects through improving memory impairment, reducing A beta aggregation via the amyloidogenic pathway and preventing neuronal impairment through downregulating the NMDAR/ERK signaling pathway. Conclusion: TA-III targets BACE1 to reduce A beta aggregation through down-regulating the NMDAR/ERK pathway for treating AD.
A Chronological Review of Potential Disease-Modifying Therapeutic Strategies for Alzheimer's Disease
CURRENT PHARMACEUTICAL DESIGN
Authors: Ettcheto, Miren; Busquets, Oriol; Espinosa-Jimenez, Triana; Verdaguer, Ester; Auladell, Carme; Camins, Antoni
Abstract
Late-onset Alzheimers disease (LOAD) is a neurodegenerative disorder that has become a worldwide health problem. This pathology has been classically characterized for its affectation on cognitive function and the presence of depositions of extracellular amyloid beta-protein (A beta) and intracellular neurofibrillary tangles (NFT) composed of hyperphosphorylated Tau protein. To this day, no effective treatment has been developed. Multiple strategies have been proposed over the years with the aim of finding new therapeutic approaches, such as the sequestration of A beta in plasma or the administration of anti-inflammatory drugs. Also, given the significant role of the insulin receptor in the brain in the proper maintenance of cognitive function, drugs focused on the amelioration of insulin resistance have been proposed as potentially useful and effective in the treatment of AD. In the present review, taking into account the molecular complexity of the disease, it has been proposed that the most appropriate therapeutic strategy is a combinatory treatment of several drugs that will regulate a wide spectrum of the described altered pathological pathways.