Simultaneous screening, identification, quantitation, and activity evaluation of six acetylcholinesterase (AChE) inhibitors in Coptidis Rhizoma by online UPLC-DAD coupled with AChE biochemical detection

Abstract

Acetylcholinesterase (AChE) inhibition is a common treatment in the early stages of dementia and neurodegenerative diseases, including Alzheimer's disease (AD). Coptidis Rhizoma (CR), a traditional Chinese medicine (TCM), contains numerous isoquinoline alkaloids that substantially inhibit AChE played neuroprotective effects in the treatment of cognitive diseases. We established a method using an ultra-high-performance liquid chromatography-diode array detector coupled with AChE biochemical detection (UPLC-DAD-AChEBCD) to screen and identify AChE inhibitors (AChEIs), measure AChEIs content and activity, and evaluate the quality of CR derived from different plant species and growth year. The chromatographic fingerprint and AChEIs activity profiles of CR were simultaneously obtained by UPLC-DAD-AChEBCD, and six alkaloids including groenlandicine, coptisine, epiberberine, jatrorrhizine, berberine, and palmatine, were identified by UPLC-electrospray ionization-tandem mass spectrometry. Data analysis based on AChEIs content and total activity of 12 batches of CR indicated differences among different species and growth year. Therefore, the online method could be used to rapidly identify AChEIs in complex matrixes and screen potential agents for neurodegenerative prevention and treatment, as well as provide information for the identification and quantitation of active markers directly associated with herbal medicine quality.