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Researchers Found a THC-Like Compound in This Plant

And other crazy science news this week.
marijuana leaves on pink background

A THC-like compound was found in moss that only grows in Japan, New Zealand, and Costa Rica

In the 1960s, biochemist Raphael Mechoulam was investigating the chemical compounds in weed and found that only one had any effect on the monkeys he was testing on. “To confirm it, he took a big dose of THC home with him and asked his wife, Dalia, to add it to her cake recipe,” says a profile of Mechoulam from 2016. (It was the only time the so-called ‘father of cannabis’ got high.)

We know now that THC is the stuff in weed that actually gets you high, and researchers have also been exploring the therapeutic options of THC for a variety of medical and health benefits. The problem is that at large doses, THC can be extremely inebriating and it’s also a controlled substance—making it tough for researchers to do large-scale clinical trials.


Until now, it was thought that cannabis was the only plant that produces THC. But in a new study in Science Advances, researchers report that liverwort contains a substance similar to THC that might act in similar ways, but without some of the downsides.


University of Bern/Stefan Fischer

Liverworts are not plants from Herbology class in Harry Potter (despite reminding me of gilly weed). They are small green plants that usually grow in moist places, like a moss. There are over 9000 species of liverworts and they’re super old—liverwort fossils have been found from 473 million and 471 million years ago.

As far back as 1994, a Japanese phytochemist Yoshinori Asakawa found that a liverwort plant called Radula perrottetii contained something like THC; its molecular structure is similar but not quite exactly the same. He named it perrottetinene.

Word must have gotten out because Jürg Gertsch, a professor at Institute of Biochemistry and Molecular Medicine at the University of Bern, noticed liverwort was being sold online. “Some started to sell it on the internet as a legal high,” he tells me. “The reports of users were contradictory. Some said it has effects and other said it does not. As a researcher interested in psychoactive compounds I regularly read the anecdotal chats for drug users on the internet, and it’s where I came across this liverwort for the first time.”

In the new study, Gertsch and his collaborators used animal models to see what perrottetinene does in the body. They found that it does reach the brain, and that it activates the cannabinoid receptors, just like THC does. Like THC, it can also reduce inflammation.


The perrottetinene lowers inflammation by inhibiting prostaglandins, which contribute to inflammation—similar to what our body’s own endocannabinoids do. More studies need to be done on it, but perrottetinene seems to have a better pharmacological safety profile. It's not as psychoactive (meaning it won't get you as high) and probably would come with less side effects, including memory problems, reduced attention and confusion.

And we're lucky to have found it. “It's astonishing that only two species of plants," Gertsch says in a release, "separated by 300 million years of evolution, produce psychoactive cannabinoids."

We could one day rate movies based on chemicals people emit into the air

I first watched the Terminator at a very young age—probably before I was ready to handle the violence of the movie. I wasn’t permanently damaged, but I do remember being somewhat haunted by what I saw.

Whether or not you agree kids should be shielded from seeing a jacked Arnold Schwarzenegger go after women named Sarah Connor, this is why we put ratings on movies. Parents are given age recommendations for content that could be upsetting. But these ratings are highly subjective: Do they actually reflect the amount of intensity a person feels when they’re watching a movie? Or is it just what we guess people will feel?

Researchers at the Max Planck Institute for Chemistry in Mainz have come up with a very unique way to answer these questions. The researchers measured what was in the air during 135 screenings of eleven different movies, encompassing 13,000 audience members. They found that the concentration of a certain chemical people give off correlated with movie ratings. “ Evidently, the more nervous and tense people are,” the more of this chemical people give off, a release says. “This can be used to deduce how “stressful” a film might be for children and adolescents.”


The compound they found is called isoprene, which is a gas that’s regularly found in the air in small amounts. Plants give it off during photosynthesis, and so the highest concentrations researchers normally measure it are in the Amazon rainforest. But humans also emit isoprene on our breath, and it's thought to be a byproduct of natural cholesterol synthesis in the body.

“The isoprene we produce internally gets stored in our muscles and when we move our legs and arms we mobilize the isoprene into the bloodstream from where it comes out on our breath,” Jonathan Williams, group leader at the Max Planck Institute for Chemistry, explains.

During an intense movie, if you squirm in your seat, jump with fear, or tense your muscles, you generate pulses of isoprene in the air. Isoprene measurements could one day, Williams thinks, reveal what a movie’s emotional impact on children and teens would be.

Besides being a very cool way to give out a PG-13 rating, Williams and his collaborators’ idea reveals that there might be other chemical fingerprints of internal processes that leave our body through our breath and skin that we could investigate.

“We have shown in our previous study that certain chemicals vary according to the type of film scene shown,” he tells me. “We are broadcasting information in chemical form all the time. Maybe about what we have eaten, whether we have washed, or how we are feeling.”


How grief changes the body

The first months after someone loses a spouse, a person is at higher risk for heart problems and premature death. Somehow, their grief impacts the body, and a new study in Psychoneuroendocrinology examines one potential contributing factor: an increase in inflammation.

We always hear that chronic inflammation is bad but what exactly is it? When your body notices something inside of it that shouldn’t be there, like a foreign bacteria or virus, it sets off an inflammatory response and white blood cells accumulate to kill the invaders. This is a healthy and normal reaction, but if inflammation becomes chronic, it can have the opposite effect, leading to a decline in health and disease.

Higher levels of inflammation are predictors of quality of life, morbidity, and many causes of mortality in older adults, says Chris Fagundes, psychoneuroimmunologist at Rice University. Elevated chronic inflammation is associated with cardiovascular disease, as well as other diseases of older adulthood. It’s thought that chronic systemic inflammation could be also an important biological mechanism underlying depression and fatigue.

In the new study, Fagundes and others looked at the effects of grief on inflammation. They interviewed 99 people whose spouses recently died, and took blood samples to look for markers of inflammation. Some of the people had more symptoms of grief than others: like “pining for the deceased, difficulty moving on, a sense that life is meaningless and inability to accept the reality of the loss,” a release says.


When the researchers compared the inflammation levels of those who expressed more grief, they found those people had higher levels of inflammation—and sometimes much higher. Widows and widowers with elevated grief symptoms had up to 17 percent higher levels of bodily inflammation, Fagundes tells me. “Of those in the top one third of the clinical cut-off group, they had 53 percent higher levels of inflammation compared with the rest of the total sample population,” he says.

The results show in a very real way how human behaviors and activities and have physical effects on the body. “We also know that depression is linked to higher levels of inflammation, and those who lose a spouse are at considerably higher risk of major depression, heart attack, stroke and premature mortality,” Fagunes says in a release. “However, this is the first study to confirm that grief—regardless of people's levels of depressive symptoms—can promote inflammation, which in turn can cause negative health outcomes."

Your weekly health and science reading list

Why sex is not binary. By Anne Fausto-Sterling in The New York Times.
Defining gender as just man or a women isn't just culturally incorrect—it's scientifically incorrect.

Miscarrying at work: The physical toll of pregnancy discrimination. By Jessica Silver-Greenberg and Natalie Kitroeff in The New York Times.
An investigation that found pregnant women's requests for lighter jobs are refused, with devastating consequences.

Designer babies aren’t futuristic. They’re already here. By Laura Hercher in MIT Tech Review.
Using pre-implantation genetic testing, parents can make sure they don't pass on diseases to their kids.

The main suspect behind an ominous spike in a polio-like illness. By Ed Yong in The Atlantic
"The condition looked remarkably like polio—the viral disease that is on the verge of being eradicated worldwide. But none of the kids tested positive for poliovirus. Instead, their condition was given a new name."

Real-life 'zombie' animals walk the earth thanks to thousands of parasites. By Kim Kelly in Gizmodo.
Just in time for Halloween, Kelly interviews Matt Simon on his book Plight of the Living Dead about all the real-world zombies that live among us.

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