Lowly Moss-Like Plant Seems to Copy Cannabis
Meet the new weed on the block, perhaps one better suited to medical rather than recreational use
By Emily Willingham on October 24, 2018 (Moss that acts like cannabis could help to relieve pain — interesting paper reported in The Times, March 12th 2019)
The recent discovery of another source of a cannabinoid comes from a plant that is a relative of the mosses called liverwort. One genus of the plant, Radula, boasts a handful of species that produce a chemical that is a lot like tetrahydrocannabinol (THC) from Cannabis sativa, or marijuana.
Why a liverwort, which lives and reproduces quite differently from a plant like Cannabis, would make this molecule remains a mystery. What we now know, however, is the cannabinoid from liverwort and the one in Cannabis are almost exactly the same and have quite similar effects in the mammalian brain.
Publishing October 24 in Science Advances, the researchers show through a variety of tests that PET from these Radula species looks and acts a lot like THC from Cannabis. “Curiosity-driven research can lead to interesting results,” says Daniele Piomelli, professor of anatomy and neurobiology at the University of California, Irvine, who was not involved in the study. “This is solid work, very credible, showing that this type of liverwort contains compounds that are akin both in structure and pharmaceutical activity to psychoactive cannabinoids in the cannabis plant.”
The team then examined how PET and THC compare in potency, and found PET to be less potent. They also discovered THC-like effects when PET was administered to mice–the animals responded similarly to both treatments, including moving more slowly and having lower body temperatures.
When the researchers evaluated the effects of PET compared with THC on inflammation pathways in mouse brains, they finally found a difference. Although PET’s psychoactive effects were less potent, it reduced certain molecules associated with inflammation, says study author Michael Schafroth, currently a postdoctoral researcher at The Scripps Research Institute.
In contrast, THC did not tamp down levels of these inflammation-related molecules, called prostaglandins. “These prostaglandins are involved in many processes (such as) memory loss, neuroinflammation, hair loss and vasoconstriction,” he says. That means PET is “highly interesting for medicinal applications, as we can expect fewer adverse effects while still having pharmacologically important effects.” The reduced potency of PET also might put a damper on any interest in the liverwort for recreational use, especially in an era of increasingly loosened cannabis regulation.
With a synthetic means to make this compound now established, the next step will be to investigate it in animal models of inflammatory diseases such as multiple sclerosis, Gertsch says, directly comparing it with the activity of THC.