Mamaki (Pipturus albidus) grows in Hawaii and is often made into tea. The plant also appears to have an effect against typical features of dementia and an appropriate supplement to the diet could potentially protect against the onset of the disease.
A Japanese research team from the Osaka Metropolitan University Graduate School of Medicine examined the effects of Mamaki on cognitive functions and neuropathology in mice in a recent study. The results are published in the specialist magazine “GeroScience”.
Counteract this in the preclinical stage
In dementia cases, changes in the brain can often be detected long before the onset of the disease, such as a cerebral accumulation of certain protein deposits (beta-amyloid, tau, alpha-synuclein and TDP-43), the researchers explain.
Since the accumulation begins decades before the onset of the disease, treatment should begin at the preclinical stage, with suitable agents having a broad effect against these etiological proteins, the team continued.
In addition, such an intervention would be necessary over a long period of time, which is why the prophylactic agents should be as easy to use, free of side effects and at the same time cost-effective, the experts emphasize. And last but not least, the agents should ideally also repair damaged neurons.
Effects of Mamaki examined
Although it is difficult for a single drug to meet these requirements, diets with different components are a possible approach, and the herb mamaki, native to Hawaii, could play an important role in this.
For the new study, the researchers examined the effects of Mamaki in four different mouse models of neurodegenerative dementia. The mice received either a hot water extract of the dried leaves, a simple powder from the leaves, or a simple powder from the fruits.
The experts then analyzed the effects on cognitive functions and neuropathologies in the animals.
Extremely positive effects can be proven
“The hot water extract of the leaves alleviated neuropathology, restored synaptophysin levels, suppressed microglial activation, and improved memory when administered orally for one month,” the researchers report.
The crushed leaf powder showed even greater effectiveness and the crushed fruit powder had the strongest effect, according to the research team. The fruit powder also significantly increased the expression of neurotrophic factor and neurogenesis, which helps repair damage to neurons.
Mamaki for dementia prevention
Overall, the researchers believe that the results indicate that crushed Mamaki leaves and fruits can make a promising contribution to a diet that prevents dementia. (fp)
