February 19, 2015 | by Justine Alford
It’s probably the last thing you’d consider administering to children, but a new study has found that a psychedelic drug, called (R)-DOI, potently prevents the development of allergic asthma in mouse models of the disease, suggesting that the chemical could represent a novel treatment avenue for asthma in humans. But don’t worry, we won’t have asthmatics tripping left, right and center every time they puff their inhalers because even if this does eventually lead to an approved therapy, it’s effective at doses up to 100 times less than those that would influence behavior.
While people may raise one eyebrow at the idea, there is a lot of interesting research into the use of psychedelic drugs like LSD in the treatment of various medical conditions, mainly those related to the brain such as depression, anxiety and addiction. That’s primarily because these drugs increase the levels of a neurotransmitter called serotonin in the brain, our body’s natural mood balancer that is also implicated in the development of these disorders.
But serotonin isn’t just found in the brain; it also acts on other neurons throughout the body, such as those in the gastrointestinal tract to regulate appetite and digestion. Furthermore, it’s also been known for some time that it is involved in inflammation. Although asthma is an inflammatory disease, no one knew whether serotonin played a precise role in the disease.
To find out more, scientists from Louisiana State University began looking at vascular tissue cells (those related to blood circulation) in a dish. They found that activating a particular serotonin receptor, called (5-HT)2A, potently reduced inflammation. Taking this one step further, they found that activating these receptors in rodents also had anti-inflammatory activity in both blood vessels and tissues of the gut.
Since (R)-DOI is known to act by sticking to the (5-HT)2A receptor, the team wondered whether it could alleviate asthma symptoms, since these are driven in part by inflammation. The researchers tested their idea in a mouse model of human asthma, which involved making mice hypersensitive to egg white protein, or ovalbumin. When exposed to this protein, the mice develop asthma-like symptoms.
Thirty minutes prior to trial exposures, the researchers administered half of the mice with aerosolized (R)-DOI, and it was found to be remarkably effective compared to controls. As described in the American Journal of Physiology, not only did it prevent airway inflammation, it also reduced the excessive production of mucus and recruitment of immune cells known to be involved in asthma. Furthermore, the dose they used was between 50 and 100 times lower than those that would influence behavior.
“These drugs are known only for their effects in the brain,” said lead researcher Charles Nichols in a news release. “What we have demonstrated for the first time is that they are also effective in treating physiological diseases outside of the brain, a completely new and exciting role for this class of drug… We have identified an entirely new anti-inflammatory mechanism for the treatment of asthma in the clinic that could someday be administered in an inhaler or daily pill.”