Anti-cholinesterase inhibitory activities of different varieties of chili peppers extracts

Alzheimer’s disease (AD) is one of the leading neurological disorders that degrade learning,memory and cognitive functions of a nervous system, eventually leaving a person with aninability to perform any function on his/her own. One of several AD causes involves loss ofpresynaptic markers of a cholinergic system due to cholinesterase enzymes, acetylcholinesterase(AChE) and butyrylcholinesterase (BChE), which degrade neurotransmitters, acetylcholine(ACh). Currently, the investigation in natural products that can act as functional foods is ofan interesting matter to promote health benefits. Chili pepper is previously reported to containvarious bioactive compounds that can promote several health benefits. Nevertheless, limitedinformation regarding the control of AD through inhibition of AChE and BChE are available.Therefore, the aim of this experiment was to investigate the cholinesterase inhibitory activitiesof Thai local chili peppers including Yellow pepper, Bird pepper, Green pepper, CayennePepper, Jinda-green pepper, Jinda-red pepper, Young pepper, Chili Spur pepper and Sweetpepper using a colorimetric high throughput screening methodology. As results, all chilipeppers (in exception of Yellow pepper) exhibited AChE inhibitory activities under the rangeof 5-26% inhibition with Young pepper extract exhibiting the highest inhibition. Interestingly,all chili peppers (in exception of Young pepper) exhibited the BChE inhibitory activities underthe range of 2-24% inhibition with Jinda-green pepper extract exhibiting the highest inhibition.Both AChE and BChE inhibitory activities were in dose-dependent manners. These resultspossibly that the bioactive compounds such as capsaicin, myricetin, quercetin and luteolin inchili pepper might function as anti-cholinesterase agents, since these compounds have beenpreviously reported to be capable of effectively inhibiting cholinesterase enzymes in vitro.The information received from this study would support further investigation on potentialnatural bioactive compounds from chili pepper with anti-AD property through inhibition ofcholinesterase enzymes.