USF researchers: Tobacco may prevent memory loss

Researchers with Bay Pines VA Healthcare and the University of South Florida this week announced they have found a compound derived from tobacco that may help memories of Alzheimer's disease patients.

Cotinine, they say, reduces plaques associated with dementia and prevented memory loss in mice with Alzheimer's disease. The findings were reported online in the Journal of Alzheimer's Disease.

"We found a compound that protects neurons, prevents the progression of Alzheimer's disease pathology, enhances memory and has been shown to be safe," said Valentina Echeverria, a Bay Pines VA Healthcare System researcher and assistant professor of molecular medicine at USF Health. "It looks like cotinine acts on several aspects of Alzheimer's pathology in the mouse model."

Currently, Alzheimer's disease drugs help delay the onset of symptoms, but none halt or reverse the processes of the disease, researchers said.

Previous studies have shown that people who smoke are less likely to suffer from Parkinson's and Alzheimer's disease, they said. Those studies have attributed this to a beneficial effect of nicotine.

The downside is that nicotine has harmful effects on cardiovascular functions and is addictive.

So, the researchers looked at the effects of cotinine, the major byproduct of nicotine metabolism, in Alzheimer's disease mice. They say cotinine is nontoxic and longer lasting than nicotine and its safety already has been demonstrated in human trials evaluating the compound's potential to relieve tobacco withdrawal symptoms.

Every day for five months, researchers gave cotinine to 2-month-old mice that had been genetically altered to develop memory problems mimicking Alzheimer's disease.

At the end of the study, the mice treated with cotinine performed better on tasks measuring their working memory and thinking skills than untreated Alzheimer's control mice.

Long-term cotinine treatment proved successful: the mice's performance was identical to that of normal mice without dementia, researchers said.

The compound's effects, scientists said, may extend beyond Alzheimer's patients.

They say the tobacco-derived compound also may relieve fear-induced anxiety and help blunt traumatic memories in mice afflicted with post-traumatic stress disorder.