The investigation on cholinesterases and BACE1 inhibitory activities in various tea infusions

Abstract

Alzheimer’s disease (AD) is a chronic neurological disease related to the decline in brain and nervous system functions. At present, inhibitions of cholinesterases (ChEs) including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) to enhance neurotransmitters and retardation of Β-amyloid formation through Β-secretase (BACE1) inhibition are 2 hypotheses for AD prevention and treatment. Hence, this study aims to investigate inhibitory activities against ChEs of various tea varieties of Camellia sinensis and herbal teas. At this step, the screening methodology for ChEs inhibitory activities in various tea varieties in order to provide a fast, inexpensive and convenient method for the detection of anti-cholinesterase activity was optimized. Then, selected tea with high ChEs was further examined regarding its BACE1 activity. As results, all tea samples displayed both anti-AChE and -BChE activities with the broad ranges of 6 - 85 % and 0 - 72 % inhibitory activities, respectively. Interestingly, C. sinensis teas exhibited higher ChEs inhibitory activities than herbal teas, in exception of Pandanus amaryllifolius (pandan) tea, which exhibited comparable inhibitory activities as C. sinensis teas. Pandan leaves were found to exhibit anti-BACE1 activity with 98 % inhibition. Besides, preliminary in vivo study showed that pandan leaves extract was able to rescue climbing defect observed in AD Drosophila melanogaster model, indicating the potential roles of pandan leaves in AD prevention.