According to the study published in the journal Science, neuroscientists at Case Western Reserve U. School of Medicine have found a promising drug that reversed the cognitive, social and olfactory deficits and improved the neuronal circuit function in mice caused by the onset of Alzheimer’s disease (AD). Bexarotene, FDA approved for cancer treatment, is the miraculous drug of this study. Scientists knew that the bexarotene activates a protein that helps switch on the ApoE gene. Thus, they hypothesized that bexarotene would enhance normal A-beta clearance mechanism by inducing ApoE expression.

Although the exact cause of the disease is yet unknown, the build-up protein called Amyloid-beta (A-beta), which leads to the development of amyloid plaques, is one of the two hallmarks of the disease, the other being the abnormal tangles created by Tau protein. A-beta itself is not problematic; in fact, all human brains produce A-beta, but, in healthy individuals, enzymes break the fragments down with help from a protein

called Apolipoprotein E (ApoE).
According to the Alzheimer’s Association, 5.4 million Americans are living with AD today. One in eight Americans aged 65 and over, and nearly half of people aged 85 and older have the disease. Every 69 seconds, another American develops AD. It is estimated that by 2050, approximately 16 million Americans will be suffering from AD.

AD is the sixth leading cause of death in the United States and the only cause of death among the top 10 in America without a way to prevent, cure or even slow its progression. Between 2000 and 2008, mortality rates for AD increased by 66 percent, whereas the mortality rates for other major diseases, including heart diseases, decreased.

For years, scientists and doctors have searched for the cure of this disease, which has resulted in no fruitful outcomes. According to the National Institute of Health, as of 2012, more than 1,000 clinical trials have been or are being conducted to find ways to treat AD, but so far we have been able to treat only symptoms of the disease.

The results of the study were impressive; in two months old mice with Alzheimer’s-like condition, within 6 hours of administering the drug, brain interstitial fluid Aβ40 and Aβ42 levels were rapidly reduced, with 25% reduction by 24 hours. There was a 30% reduction in soluble Aβ levels throughout 14 days treatment and 40% reduction in insoluble Aβ level 72 hours post drug administration with progressive decrease over subsequent 14 days. Total Aβ plaques were reduced by nearly 75% after 14 days of treatment. Similar results were obtained in older mice, indicating that the bexarotene works efficiently in both early and later stages of AD in mouse model.

The drug rapidly restored cognition and memory, which were assessed by contextual fear conditioning. Also, mice treated with bexarotene for 90 days exhibited improved hippocampal function, which was assessed by Morris water maze performance. Furthermore, just 72 hours post treatment with bexarotene nest construction behavior was restored in mice. And finally, 9 days treatment of bexarotene significantly improved the odor habituation behavior in mice.

Ultimately, bexarotene has the potential to help more than 36 million people suffering from Alzheimer’s disease worldwide. Plus, the drug has a good safety and side-effect profile. According to the authors of the study, there is a plan to launch a clinical trial of the drug as soon as possible.