A Japanese research team has succeeded in curbing a protein associated with Alzheimer’s disease using genetically modified rice, raising hopes for the development of new oral medicines.
The brains of Alzheimer’s disease patients contain deposits called senile plaques, formed by a type of protein known as beta amyloid. It is believed that an accumulation of beta amyloid in the brain leads to Alzheimer’s disease through a series of stages.
The Japanese research team including University of Tokyo professor Shoichi Ishiura had been working on oral vaccines to produce antibodies that attacked beta amyloid, thereby preventing a buildup of the protein. In past methods, they had ground up the leaves of sweet pepper plants that had been modified to contain beta amyloid and given them to mice with Alzheimer’s disease. This resulted in the amount of beta amyloid in their brains decreasing.
In the latest experiments they had six mice eat rice containing beta amyloid genes once every 10 days for 16 months. To further boost the immune systems of the mice, they gave each one a beta amyloid injection. As the level of antibodies recognizing beta amyloid increased, the beta amyloid level in the brain decreased. In further experiments with mazes, the mice showed improvements in memory.
Vaccines using beta amyloid injections have been halted in the United States due to the side-effect of meningitis. Ishiura says oral administration of vaccines could prevent such problems.
The group’s research was published in the science journal Vaccine.
(Mainichi Japan) August 29, 2011