A rolling stone gathers no moss, but people might start gathering this moss if they want to get stoned.
Certain types of liverwort, a frightfully named plant species related to moss, reportedly produce a chemical that is similar to tetrahydrocannabinol (THC). First described in a 1994 study, the chemical is called perrottetinene (PET), and it's named after the liverwort species Radula perrottetii. This uncommon chemical only appears in a few types of liverwort, and the similarities to THC were only discovered in late 2018.
Noting that Radula preparations are sold online for a “cannabinoid-like legal high,” Swiss researchers studied the plant and published their findings in Science Advances last fall. The researchers found that PET molecules selectively bind to the same cannabinoid receptors as THC and do not bind to any proteins that THC does not. After being tested in mice, PET exerts a less-potent THC-like effect that includes pain relief, slower movement and lower body temperatures. The researchers described the PET high as being milder with fewer potential adverse effects and with the benefit of reduced neuroinflammation.
“This study not only provides a molecular basis on which to assess the mode of action and emerging recreational use of smoked Radula liverwort preparations as a legal high but also allows a direct comparison with THC fopotential therapeutic applications,” the researchers concluded. Likewise, the existence of another natural cannabinoid that binds to the CB1 receptor illustrates “the existence of convergent evolution of bioactive cannabinoids in the plant kingdom.”
In an analysis of the study, Scientific American wrote, “The pharmaceutical promise of liverwort could mean a higher profile for the modest moss and its kin” in terms of potential medical use.