A series of experiments by Chilean scientists imply that injections of a type of immune system-altering stem cell can stop binge drinking behavior in rats by reversing the neurological inflammation that comes with alcoholism.
According to their findings, published in Scientific Reports, rats that were bred to prefer alcohol over water and given free access to ethanol for 12 weeks reduced their intake – which was equivalent to a person drinking more than a pint of pure alcohol a day – by 93 percent only 48 hours after a single injection of specially engineered human mesenchymal stem cells (MSCs), compared to those injected with a control substance.
The reduced desire to drink lasted for more than four weeks without any further treatment.
Previous research has shown that MSCs have potent anti-inflammatory effects, and given that so many disease processes are mediated through inflammation, scientists are excitedly testing whether MSCs are effective therapeutic agents.
One such condition is chronic alcohol consumption, which causes the formation of cell-damaging molecules called reactive oxygen species. The brain, in turn, becomes acclimated to these toxic conditions, begins producing high levels of damaging inflammatory proteins, and – through complex and not fully understood pathways – craves more alcohol.
Recently, relapse when abstaining from addictive substances, including alcohol, has been linked to an above-normal concentration of a neurotransmitter called glutamate. Absorption of excess glutamate is the job of astrocytes, a type of brain cell that supports neurons, yet in a catch-22 scenario, inflammation from alcoholism impedes this activity.
Following an investigation that showed MSCs injected directly into the brains of booze-loving rats lowered alcohol intake and relapse drinking, the current study’s authors sought to develop and evaluate a stem cell treatment that could be administered through a regular, intravenous injection.
After creating a new type of MSC that excretes high levels of anti-inflammatory molecules, but is small enough to fit through the blood-brain barrier, they performed the willing consumption test described above.
Next, they examined whether MSC-treated rats who had unwillingly gone cold turkey would have different rates of alcohol binging relapse. A separate group of rats that had consumed ethanol freely for 12 weeks were injected with MSCs or the control substance, then allowed to drink either water or ethanol as desired for four more weeks.
At that point, the rats were deprived of ethanol for 2 weeks, then given unlimited access to the sauce for 60 minutes. During this short window, MSC rats drank 80 percent less alcohol than the control-treated mice.
To confirm these behavior changes were the result of altered inflammation pathways, and not some unforeseen effect of the stem cells, brain tissue samples were analyzed.
Astrocytes in rats that had received a single MSC injection began producing normal levels of inflammatory molecules and showed a boosted ability to transport glutamate. Moreover, levels of inflammation-perpetuating circulating reactive oxygen species were lowered.
Lead researcher Yedy Israel told ResearchGate that his group is currently looking for collaborators and funders to begin studying the stem cell treatment in humans.