A team of Japanese researchers has found a new drug combination that reduces amyloid beta protein, believed to play a key role in causing Alzheimer’s disease, by using stem cells derived from patients, Kyoto University announced Tuesday.
The scientists believe their findings, published in the online edition of the Cell Reports journal the same day, is a promising step to eventually find a drug to treat Alzheimer’s — a progressive disease characterized by memory loss that affects tens of millions of people worldwide. There is so far no known cure or established treatment for Alzheimer’s.
For its experiment, the team created so-called induced pluripotent stem cells (iPS cells) from individuals, including patients with Alzheimer’s, and then cultivated them in vitro to replicate diseased brain tissue.
The researchers created cortical neurons derived from iPS cells from five patients with familial Alzheimer’s; four patients with sporadic Alzheimer’s, which means there is no family history of the disease; and four healthy individuals.
They then tested 1,258 drugs on the tissue, and identified that the most effective combination to reduce the amyloid beta content was a drug cocktail combining three existing drugs — bromocriptine, which is used to treat Parkinson’s disease; cromolyn, used for asthma; and topiramate, which is used for epilepsy treatment.
The team said in its report that the “cocktail showed a significant and potent” effect and “promises to be useful” for the development of drugs to treat Alzheimer’s.
Haruhisa Inoue, a professor with the Center for iPS Cell Research and Application at Kyoto University who was part of the team, expressed hope that the combination would prove more effective than existing options.
“I hope to tap into the merits of (using) existing drugs that have a track record for safety over a long period of time,” Inoue said in an email to The Japan Times.
By using the three tested drugs simultaneously, the experiment showed that the accumulation of amyloid beta deposits was reduced by more than 30 percent, the team said. Overproduction of amyloid beta in the brain is said to be a key factor in Alzheimer’s.
“There was an effect at the cellular level, but we are not sure yet on the effect on humans,” Inoue said.
The center said it is the first time in the world a combination of existing drugs has been shown to reduce levels of the amyloid beta protein.
Other researchers have also tried to develop a drug to lower amyloid beta the protein. But their efforts have failed during the clinical trial stage due to the side effects of drug candidates, prompting researchers to look for a safer approach.
Able to be reprogrammed to grow in human tissues and organs, iPS cells are recognized as a promising tool for drug development and regenerative medicine.
Alzheimer’s is the most common type of dementia, which pertains to a broad category of symptoms affecting the brain including memory loss and impaired judgment caused by nerve cell damage.
According to Alzheimer’s Disease International, the number of people with dementia was estimated at 46.8 million globally in 2015, with that figure set to increase to 131.5 million by 2050.