Phenolic profiling and in vitro antioxidant, anticholinesterase, and antimonoamine oxidase properties of aqueous extract of African star apple (Chrysophyllum albidum) fruit parts

African star apple is a tropical edible fruit that is widely consumed among Nigerians. This present study investigated the antioxidant, anticholinesterase, and antimonoamine oxidase properties of African star apple fruit parts (flesh pulp, seed coat, and back coat) in vitro. The aqueous extracts of different parts were prepared. Thereafter, the effect on cholinesterases (acetylcholinesterase [AChE] and butyrylcholinesterase [BChE]) and monoamine oxidase (MAO) activities and antioxidant potentials (1,1-diphenyl-2-picrylhydrazyl and hydroxyl) scavenging abilities and Fe2+ chelation abilities were investigated. Phenolic contents were also assayed for, and HPLC-DAD characterization of the phenolic constituents was carried out. The results revealed that the extracts inhibited AChE, BChE, and MAO activities and exhibited antioxidant properties. Also, there is abundance of caffeic acid, quercetin, chlorogenic acid and cyanidin as revealed by HPLC-DAD. In lieu of these findings, African star apple could be considered a cheap source of antioxidant and enzyme inhibitory compounds relevant in prevention/management of neurodegeneration. Practical application: The use of antioxidant, anticholinesterase and antimonoamine oxidase compounds has long been identified as useful therapeutic measures for the management of several neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Nevertheless, the several side effects of such synthetic compounds have limited their use and make natural biomolecules with similar therapeutic properties good alternatives. Here, we present the various fruit parts of African star apple as rich sources of antioxidants, as well as cholinesterase and monoamine oxidase inhibitors which could offer tremendous neuroprotective properties especially in the management of neurodegenerative diseases.