Although there is still a way to go, a team working on a new type of anti-smoking therapy based on a bacterial enzyme that devours nicotine before it can reach the brain are hopeful of success.
In the Journal of the American Chemical Society, scientists from The Scripps Research Institute (TSRI) in La Jolla, CA, report how the enzyme can be made in the lab and has a number of features that make it a promising candidate for drug development.
Kim Janda, senior author and professor of chemistry, says:
“Our research is in the early phase of drug development process, but the study tells us the enzyme has the right properties to eventually become a successful therapeutic.”
Prof. Janda and his team have been trying to create such an enzyme in the lab for over 30 years.
But it was not until they turned to nature that they found what they were looking for – a bacterium isolated from the soil of a tobacco field that consumes nicotine as its only source of carbon and nitrogen.
The bacterium – called Pseudomonas putida – relies on an enzyme called NicA2 to help it chomp away at nicotine, “like a little Pac-Man,” Prof. Janda says.
The team’s idea is to create an anti-smoking enzyme therapy that offers a more successful alternative to current smoking cessation aids, which they note fail in at least 80-90% of smokers.
The enzyme therapy would seek out and destroy nicotine before it reaches the brain, thus preventing the “reward” kick that the addictive substance gives.
In their paper, the Prof. Janda and colleagues describe how they analyzed the enzyme and tested its potential as an anti-smoking therapy.
One feature that makes the enzyme attractive is from the tests they ran; the researchers found it appears able to significantly reduce the time nicotine persists in the bloodstream.
To show this, they combined serum (a component of blood) from mice with an amount of nicotine that is equivalent to one cigarette. When they added the enzyme, instead of taking 2-3 hours for the nicotine level to halve, it took only 9-15 minutes.
Prof. Janda says with a few chemical modifications, they could make a version of the enzyme that would reduce the half-life of nicotine in the blood to the point where it does not even reach the brain.
The team also ran several tests to find out how well the enzyme stood up as a drug candidate and found the results encouraging.
The enzyme remained stable in the lab for over 3 weeks at 98 °F (37 °C) and showed no detectable toxic byproducts when it degraded the nicotine. They found it is also relatively stable in serum.
There is still some work to do to improve the enzyme’s potential as a drug candidate, note the researchers. For instance, they need to remove traces of its bacterial origin to reduce the chance of it triggering an immune reaction. First author and TSRI graduate student Song Xue says:
“Hopefully we can improve its serum stability with our future studies so that a single injection may last up to a month.”
Meanwhile, from another recently published study, Medical News Today also learned that even if you have no willpower, mindfulness meditation may help you quit smoking. The researchers who came to this conclusion say mindfulness meditation helps to reduce smoking by improving the brain’s self-control network and moderating stress-reactivity.