Melatonin Could One Day Treat Multiple Sclerosis

Multiple sclerosis (MS) flare ups are caused by changes in melatonin levels in the spring and summer seasons, according to findings published in Cell.

Researchers from Brigham and Women’s Hospital in Boston, Massachusetts studied 139 patients with relapsing remitting MS in order to determine the relationship between seasonal changes in disease activity in MS and melatonin levels. The investigators examined improvement in symptoms and seasonal factors as proposed links to MS disease activities, such as vitamin D levels, UV incidence, and upper respiratory tract infections.

“We wanted to see what environmental factors would reveal to us about this disease,” study leader Francisco Quintana, PhD, from the Ann Romney Center for Neurologic Diseases, explained in a press release. “We knew that MS disease activity changed with the seasons. What we’ve uncovered offers an explanation for why that is the case.”

The researchers determined melatonin was the key factor consistently linked to severity of MS disease activity. Levels of melatonin are higher during longer days in the spring and summer and lower in the shorter fall and winter days. This theory was tested in mice and human cell models, and the researchers determined that melatonin affected pathogenic T cells that attack and destroy regulatory T cells (which are the mechanism that keeps the pathogenic T cells in line).

“We found that melatonin has a protective effect,” continued Quintana. “It dampens the immune response and helps keep the bad guys — or pathogenic T cells – at bay.”

The researchers found that in the fall and winter, there was 32 percent reduction in the number of MS relapses compared to the spring and summer months. The researchers said that the higher melatonin levels in the darker, shorter months contribute to improving clinical symptoms.

The researchers suggest that melatonin supplements, sold over the counter, may help patients but come at the risk of various side effects such as drowsiness. In the future, MS treatment may include melatonin or its derivatives, the researchers believe.

“Extreme caution should be exercised because our data do not show that melatonin or its analogs are effective in treating MS,” Quintana concluded. “Until a clinical trial is conducted and an appropriate drug and dosage is established, it is not recommended to use melatonin for the treatment of MS.”