Photo/IllutrationThe Asahi Shimbun

A combination of three existing drugs can reduce the amount of a protein that accumulates in the brains of patients with Alzheimer’s disease, a Japanese research team found.

The team, headed by Haruhisa Inoue, a stem cell medicine professor at Kyoto University, used induced pluripotent stem (iPS) cells derived from patients to find the most effective combination in possible treatments for Alzheimer’s disease.

The three medicines combined were therapeutic agents for Parkinson’s disease, asthma and epilepsy.

The findings were published in the U.S. scientific journal Cell Reports on Nov. 22.

Although the cause of Alzheimer’s disease, the most common kind of dementia, remains unclear, a protein called amyloid beta is known to start accumulating in the brain before the onset of the disease.

Inoue and his colleagues expect the three drugs taken in combination will reduce the amount of accumulated amyloid beta, help delay the onset of the disease and cure the condition.

The team created cerebral cortex nerve cells from iPS cells derived from the skin and other parts of the body of patients to reproduce symptoms of the disease.

The scientists tested 1,258 types of existing drugs with cerebral cortex nerve cells from nine patients and four healthy individuals to find agents that are useful in lowering the accumulation of amyloid beta.

The most effective combination reduced the formation of amyloid beta by more than 30 percent on average in the cells from patients, the study found.

However, side effects of the agents and other potential problems need to be examined, so the possible combination therapy will not be available soon for patients.