Plants synthesize alkaloids to repel herbivorous animals that graze on them. These phytochemicals often taste bitter and can prove to be toxic if ingested in large amounts.
Ironically, alkaloids and similar chemicals that drive off or kill certain animals will not harm other forms of life. The latter can even use the plant compounds for its own benefit.
This is the case for editan and utazi. Grown in southern Nigeria, the bitter-tasting leaves of the vegetables are not only consumed without harm, but also with relish. A popular vegetable soup dish is named after editan, and its leaves are also used in traditional African medicine.
A 2016 study by the Rivers State University Of Science And Technology found that editan provides important nutrients to the body. The study recommended further analysis of the chemical contents of the editan leaves and their specific effects on human health. (Related: Eating more citrus fruits is an easy way to prevent dementia.)
Drawing from that and other earlier studies, researchers from the Federal University of Technology Akure (FUTA) examined the alkaloids found in the leaves of editan and utazi for potential modulating effects on neurodegenerative diseases. Other alkaloids were previously shown to slow down the onset of brain disorders, such as Alzheimer's disease, by suppressing the actions of enzymes related to neurodegeneration.
For their experiment, they collected fresh editan and utazi leaves, which they processed into extracts with concentrated levels of alkaloids. The profiles of these phytochemicals were analyzed through a modified form of gas chromatography.
Both extracts underwent testing for their antioxidant activity. First, they were applied to ferrous ions (Fe2+) to determine their efficiency at chelating the iron-based particles. Next, the extracts were subjected to a free radical scavenging test.
Finally, an in vitro test evaluated the inhibitory potential of the alkaloids against enzymes that are associated with neurodegeneration. These enzymes were acetylcholinesterase, butyrylcholinesterase, and monoamine oxidase.
The researchers reported that the alkaloids found in editan and utazi possessed considerable antioxidant activity. Both extracts cleaned up considerable amounts of ferrous ions and free radicals that would otherwise harm cells and tissues.
Ferrous ions and free radicals trigger oxidative stress, a reaction that damages cells and tissues. If oxidative stress takes place in the brain, it could increase the risk of neurodegenerative diseases.
Furthermore, the editan and utazi extracts displayed inhibitory effects against all three neurodegenerative enzymes. Increasing the dosage – and the amount of alkaloids – improved an extract's suppression of the enzyme's harmful activities.
For editan, the minimum inhibitory concentration against acetylcholinesterase was 115.60 micrograms per milliliter (mg/ml), 169.48 mcg/ml against butyrylcholinesterase, and 73.72 mcg/ml versus monoamine oxidase. Utazi performed much better as smaller doses of its alkaloid could achieve the same effect as editan.
According to the gas chromatography analysis of the extracts, both editan and utazi contained large amounts of choline. An essential nutrient made from lecithin, choline plays important roles in the development and growth of the brain and the nervous system. It is the precursor to acetylcholine, a neurotransmitter that controls the activation of muscles.
The researchers concluded that editan and utazi contained natural alkaloids that protected against neurodegenerative diseases by halting harmful enzymes and reactions while also increasing choline levels in the body. They believe the consumption of these vegetables could help patients suffering from Alzheimer's disease, Parkinson's disease, and similar disorders.