Vitamin B3 reduces Alzheimer's symptoms, lesions

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An over-the-counter vitamin in high doses prevented memory loss in

mice with Alzheimer's disease, and UC Irvine scientists now are

conducting a clinical trial to determine its effect in humans.

Nicotinamide, a form of vitamin B3, lowered levels of a protein called

phosphorylated tau that leads to the development of tangles, one of two

brain lesions associated with Alzheimer's disease. The vitamin also

strengthened scaffolding along which information travels in brain

cells, helping to keep neurons alive and further preventing symptoms in

mice genetically wired to develop Alzheimer's.

"Nicotinamide has a very robust effect on neurons," said Kim Green,

UCI scientist and lead author of the study. "Nicotinamide prevents loss

of cognition in mice with Alzheimer's disease, and the beauty of it is

we already are moving forward with a clinical trial."

The study appears online Nov. 5 in the Journal of Neuroscience.

Nicotinamide is a water-soluble vitamin sold in health food stores.

It generally is safe but can be toxic in very high doses. Clinical

trials have shown it benefits people with diabetes complications and

has anti-inflammatory properties that may help people with skin

conditions.

Nicotinamide belongs to a class of compounds called HDAC inhibitors,

which have been shown to protect the central nervous system in rodent

models of Parkinson's and Huntington's diseases and amyotrophic lateral

sclerosis. Clinical trials are underway to learn whether HDAC

inhibitors help ALS and Huntington's patients.

In the nicotinamide study, Green and his colleague, LaFerla,

added the vitamin to drinking water fed to mice. They tested the

rodents' short-term and long-term memory over time using water-maze and

object-recognition tasks and found that treated Alzheimer's mice

performed at the same level as normal mice, while untreated Alzheimer's

mice experienced memory loss.

The nicotinamide, in fact, slightly enhanced cognitive abilities in

normal mice. "This suggests that not only is it good for Alzheimer's

disease, but if normal people take it, some aspects of their memory

might improve," said LaFerla, UCI neurobiology and behavior professor.

Scientists also found that the nicotinamide-treated animals had

dramatically lower levels of the tau protein that leads to the

Alzheimer's tangle lesion. The vitamin did not affect levels of the

protein beta amyloid, which clumps in the brain to form plaques, the

second type of Alzheimer's lesion.

Nicotinamide, they found, led to an increase in proteins that

strengthen microtubules, the scaffolding within brain cells along which

information travels. When this scaffolding breaks down, the brain cells

can die. Neuronal death leads to dementia experienced by Alzheimer's

patients.

"Microtubules are like highways inside cells. What we're doing with

nicotinamide is making a wider, more stable highway," Green said. "In

Alzheimer's disease, this highway breaks down. We are preventing that

from happening."

Source: University of California -

Irvine

http://esciencenews.com/articles/2008/11/04/vitamin.b3.reduces.alzheimers.symptoms.lesions