Melatonin and Alzheimer's

Melatonin and Alzheimer's

INDIANAPOLIS--Melatonin may have the potential to treat Alzheimer'sdisease (AD) because of its capacity to reduce the development of a proteincomplex that is a hallmark of the disease. The results of this in vitro studywere published in the American Chemical Society's Biochemistry (40,49:14995-5001, 2001) (http://pubs.acs.org/journals/bichaw).

Researchers from the Indiana University School of Medicine added melatonin toanimal and human cell cultures that contained the building blocks of abnormalbrain amyloid fibrils as well as human apoE4--a protein associated with strongrisk for developing AD. "Inheritance of apoE4 is a strong risk factor forthe development of late-onset sporadic AD," the researchers wrote."Several lines of evidence suggest that apoE4 promotes formation ofbeta-sheet structures and amyloid fibrils. Deposition of amyloid fibrils is acritical step in the development of AD."

Researchers reported that the addition of melatonin to brain cells in thepresence of apoE inhibited fibril formation more effectively than with melatoninalone. This result was, however, structure-dependent upon melatonin, but notrelated to melatonin's antioxidant properties.

"Our results clearly demonstrate the ability of melatonin to inhibit theprocess of forming the 'signature' amyloid protein bundles seen in Alzheimer'sdisease," said Miguel Pappolla, M.D., study researcher. "This activityattributed to the 'indole' structure of melatonin appears to be specific. Theseexciting findings, however, mandate much more research before we canconvincingly state melatonin can halt or prevent Alzheimer's disease."

This study was supported by a grant from the National Institute on Aging (www.nia.nih.gov).