Researchers at the University of Oslo have identified the molecule they believe explains why passion fruit extract appeared to slow Alzheimer's disease in their earlier work. It is called alpha-amyrin, and according to the team's new paper in Advanced Science, it protects central processes in the brain - most notably the mitochondria, the tiny structures inside cells that generate the energy neurons need to function.
"After four years of hard work, we have managed to uncover what the passion fruit's secret is," said Associate Professor Evandro Fei Fang-Stavem of the University of Oslo and Akershus University Hospital, who added that the molecule might be usable in a medicine against Alzheimer's if it also proves effective in future clinical trials.
The mitochondrial angle matters because of how Alzheimer's is thought to unfold. The disease involves a build-up of protein waste in the brain that damages nerve cells until they die, and ageing brain cells become less able to clear that debris away. As the waste accumulates, the brain's energy factories struggle to keep up. Co-author Cao described brain cells as particularly vulnerable to this cascade, depending as they do on mitochondria producing enough energy - which is why a compound that shields the mitochondria is considered a significant lead.
The important qualifier is in Fang-Stavem's own phrasing: the potential of alpha-amyrin as a treatment rests on clinical trials that have yet to happen. What the Oslo group has done is narrow a promising fruit extract down to a single identified molecule, which is the step that makes serious drug development possible. For families living with Alzheimer's today, this is early-stage science rather than a therapy, but it does give researchers a specific target to pursue.