In vitro neuroprotective properties of some commonly consumed green leafy vegetables in Southern Nigeria

Green leafy vegetable is one of the major cuisines in Southern Nigeria and they are not only consumed for their palatability, but also for their nutritional and medicinal properties as reported in folklore. Notable among them are afang (Gnetum africanum), editan (Lasianthera africana) and utazi (Gongronema latifolium). In this study, we investigated the effect of aqueous extracts from afang, editan and utazi leaves on cholinesterases [acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)] and monoamine oxidase (MAO) activities. Fe2 + chelating abilities were also determined as an assessment of their neuroprotective potentials in vitro. We also assayed for their total phenol contents while the constituent phenolics were characterized using high performance liquid chromatography coupled with diode array detector (HPLC-DAD). The results revealed that the extracts inhibited AChE, BChE and MAO activities and also chelated Fe2 + in concentration dependent manner. The HPLC-DAD characterization showed that gallic, caffeic and ellagic acids and rutin were the dominant phenolic compounds in the extracts; nevertheless, utazi had the highest distribution of identified phenolics while afang had the least. The ability of the aqueous extracts of the vegetables to inhibit key enzymes (AChE, BChE and MAO) relevant to neurodegeneration, as well chelate metal ion could help suggest their possible neuroprotective properties. These vegetables could be use as dietary intervention in the management of neurodegenerative diseases such as Alzheimer's and Parkinson's diseases.