Saponins extracted from lychee seeds helped improve cognitive function and prevented neuronal injury in rats induced with Alzheimer’s Disease (AD), a new study reports.
Researchers from Southwest Medical University in Sichuan found that rats induced with AD and given lychee seed saponins (LSS) performed as well and, in some cases better, in memory tests compared to rats given a conventional durg treatment.
“The study showed that rats fed with LSS performed similarly, or even more, effective against AD than [the drug] Donepezil,” wrote the research team in the journal Nutrients.
“These results suggest that LSS can improve the ability of spatial learning and memory of the AD rats,” they added.
They also noted that brain tissue analysis led them to believe that LSS may also have a protective affect against neuronal injury.
The study involved two main groups of rats – 12 for sham operation group injected with normal saline (NS) solution in the lateral ventricle, and 68 rats injected with Amyloid β-peptide Aβ (25–35) to induce AD.
The treatments started 21 days after the AD induced procedure, with the AD rats divided further into five groups – group one treated with NS, group two was dosed with donepezil (0.42mg a day), and groups three to five given LSS in 120, 240, and 480mg by intragastric (IG) administration once a day for 28 days.
Meanwhile, the sham group had an equal volume of NS solutions by IG for 28 days as a negative control.
A Morris water maze tested for all five groups’ spatial learning and memory functions. In the hidden platform test, findings showed that the AD rats took more time to find the platform, compared to the control rats.
However, all three LSS and the donepezil groups took less time to find the hidden platform compared to AD rats treated with NS.
In a spatial probe test, compared to NS-treated AD rats, all LSS groups made more crossings and spent more time in the designated platform. The donepezil group’s spatial probe test result was similar to LSS 480mg.
Protective effects on neuron injuries caused by Amyloid β-peptide Aβ (25–35) also showed on brain tissues of rats from LSS and donepezil groups, which led researchers to conclude that LSS in AD rats improved not only cognitive function, but also prevented neuronal injury induced by Aβ (25–35).
“LSS significantly improved cognitive function and prevented neuronal injury in the AD rats via regulation of the apoptosis pathway,” researchers concluded.
“Therefore, LSS may be developed as a nutritional supplement and sold as a drug for AD prevention and/or treatment.”