A quit-smoking drug based on a protein found in soil could help addicts quit without any withdrawals، research suggests، as the Daily Mail said.
Trials on addicted rats showed the medication broke down nicotine in their bodies before it reached their brains - stopping them receiving a 'hit'.
This gave the rodents more willpower when faced with nicotine and reduced signs of withdrawal، such as irritable behaviours.
Scientists at the Scripps Research Institute، who created the drug and plan to test it on humans، have yet to name it. This is a very exciting approach because it can reduce nicotine dependence without inducing cravings and other severe withdrawal symptoms،' lead author Dr Olivier George said.
'And it works in the bloodstream، not the brain، so its side effects should be minimal.'
The researchers allowed rats free access to nicotine dissolved in salt for 21 hours a day for 12 days، which caused them to become addicted.
The rodents were then given access to nicotine only every two days، which led to withdrawal symptoms. These symptoms included aggressive behaviours، like biting and boxing، as well as defensive actions، such as burying and jumping.
And when the animals were given nicotine again، they took more of it - a sign of addiction.
Half of the rats were then injected with the protein NicA2-J1، which breaks down nicotine and is found in soil bacteria.
Blood samples showed the rodents who were injected with the protein had less nicotine in their bodies، which suggested NicA2-J1 was breaking the addictive substance down.
The treated rats also showed less signs of irritability، according to the study published in the journal Science Advances.
'It’s as if they were smoking 20 cigarettes but receiving the nicotine dose of only one or two، so that made their withdrawal process much less severe،' study author Dr Marsida Kallupi said.
Perhaps surprisingly، blocking nicotine from reaching the brains of addicted rats did not cause side effects.
'It’s like quitting "cold turkey" - the subject will feel horrible،' Dr George said.
'However، what’s unique about this enzyme is it removes enough nicotine to reduce the level of dependence، but leaves enough to keep the animals from going into severe withdrawal.'
In a second part of the experiment، the rodents were taken off nicotine for 10 days، before being given an injection of the substance to reawaken their dependency.
They rodents were then given free access to nicotine again.
Results showed the animals who were treated with NicA2-J1 resisted nicotine much more than the untreated rodents.
The researchers plan to investigate the effects of NicA2-J1 in human smokers and hope to test whether the drug Chantix also blocks nicotine from reaching rats' brains.
Chantix is widely considered the most effective anti-smoking treatment.
Smoking is the leading cause of disease and preventable death worldwide.
Three out of five people who try a cigarette become daily smokers، previous research suggests.
And up to 80 per cent of smokers who try to quit relapse.
Preventing nicotine from reaching the brain has long been considered a promising target for drugs that help smokers quit.
However، up until now، previous medications and vaccines have not reduced nicotine levels in the blood enough to be effective.