Melatonin, exercise show potential as Alzheimer's treatments

Tuesday, October 2, 2012. The June, 2012 issue of the journal Neurobiology of Aging published a report by researchers in Spain that describes a benefit for exercise and the hormone melatonin in a mouse model of Alzheimer's disease.

Scientists from the Barcelona Biomedical Research Institute, the University of Granada and the Autonomous University of Barcelona studied the effects of the therapies in mice with three mutations that result in the characteristics of Alzheimer's disease. The animals, which were in the initial phases of the disease, were divided to receive 10 milligrams melatonin per kilogram body weight, a daily exercise regimen consisting of unrestricted use of a running wheel, or both treatments. Alzheimer's mice that received neither therapy and a group of mice that did not have the mutations served as controls.

Engaging in exercise reduced behavioral and psychological symptoms, including anxiety, emotionality and a lack of exploration. Both melatonin and exercise resulted in decreases in cognitive impairment, brain oxidative stress, amyloid beta and mitochondrial DNA reductions. Combined treatment with exercise and melatonin resulted in additional mitochondrial benefit. Melatonin alone reduced hyperphosphorylated tau protein (found in the brains of Alzheimer's disease patients). "After six months, the state of the mice undergoing treatment was closer to that of the mice with no mutations than to their own initial pathological state," reported lead researcher Coral Sanfeliu of the Barcelona Biomedical Research Institute. "From this we can say that the disease has significantly regressed."

While the recommendation of melatonin for humans with Alzheimer's disease may be premature at this stage, coauthor Darío Acuña-Castroviejo of the University of Granada noted that "Other studies which use melatonin as medication show its high level of effectiveness."

"Even though many more studies and clinical tests are still required to assess the doses of melatonin which will be effective for a wide range of diseases, the antioxidant and anti-inflammatory properties of melatonin mean that its use is highly recommended for diseases which feature oxidative stress and inflammation," he added.

"For years we have known that the combination of different antiaging therapies such as physical exercise, a Mediterranean diet, and not smoking adds years to one's life," Dr Sanfeliu stated. "Now it seems that melatonin, the sleep hormone, also has important anti-aging effects".