Marijuana may be able to treat autoimmune disease, according to a recent study.

Researchers from the University of South Carolina have discovered a novel pathway through which marijuana's main active constituent, tetrahydrocannabinol (THC), can suppress the body's immune functions.

Marijuana is the most frequently used illicit drug in the United States, but as more states legalize the drug for medical and even recreational purposes, research studies are discovering new and innovative potential health applications for the drug.

"Marijuana is now regularly and successfully used to alleviate the nausea and vomiting many cancer patients experience as side effects to chemotherapy, combat the wasting syndrome that causes some AIDS patients to lose significant amounts of weight and muscle mass and ease chronic pain that is unresponsive to opioids, among other applications," researchers said in a statement.

The work builds on recent scientific discoveries that the environment in which humans live can actually trigger changes that occur outside of human DNA, but nevertheless can cause alterations to the function of genes controlled by DNA.

For the study, the investigators wanted to find out if the THC found in marijuana has the capacity to affect DNA expression through epigenetic pathways outside of the DNA itself.

The researchers found that THC can change critical molecules of epigenome called histones, leading to suppression of inflammation. These results suggest that one potential negative impact of marijuana smoking could be suppression of beneficial inflammation in the body. But they also suggest that, because of its epigenetic influence toward inflammation suppression, marijuana use could be efficacious in the treatment of autoimmune diseases such as arthritis, lupus, colitis, multiple sclerosis and the like, in which chronic inflammation plays a central role.

The findings were recently published online in the Journal of Biological Chemistry.