Nearly 6 million people die every year from tobacco-related illness, but breaking the addiction is easier said than done. Current smoking cessation therapies include the nicotine receptor agonist varenicline, the antidepressant bupropion, and various nicotine replacement therapies (gums, patches, and lozenges). However, more effective aids are needed, because only 15-30% of people who use these therapies remain tobacco-free in the long-term.
One alternative to drug-based therapy is a "nicotine vaccine". In fact, a number of nicotine vaccines are in clinical trials, but show varied success when compared to placebos.
Researchers at The Scripps Research Institute (TSRI) are taking a different approach. They knew a number of microorganisms were capable of degrading tobacco waste, and one bacterium, Pseudomonas putida, is extremely good at it.
“The bacterium is like a little Pac-Man”, says Kim Janda, professor of chemistry at TSRI, “it goes along and eats nicotine”.
Non-pathogenic P. putida uses a number of enzymes to degrade nicotine to fumaric acid. Song Xue, a graduate student at TSRI, investigated the enzyme NicA2 for its safety and efficacy as a smoking cessation drug, and the preliminary data appears quite promising.
When Xue and colleagues combined serum from mouse blood, nicotine, and NicA2, the half-life of nicotine dropped from 2 to 3 hours to between 9 and 15 minutes. On top of that, NicA2 remained stable in serum, produced no toxic metabolites, and proved to be heat stable for up to 3 weeks. These are all signs that NicA2 could one day help people kick the tobacco habit.