People who enjoy the outdoors are probably familiar with the various stinging plants such as poison ivy, poison oak or stinging nettle (Urtica dioica), but how many knew that the potent poison dispensed on the leaves of stinging nettle contains the chemical serotonin? Serotonin in humans is made from enzymes and amino acids in the body and is the chemical responsible for regulating moods and emotions like anger and depression. Researchers have determined that people with serotonin levels below normal can suffer from aggressiveness or rage. In babies, low serotonin is believed to cause sudden infant death syndrome (SIDS). It was first discovered in 1948 and the human body manufactures it in the gastrointestinal tract. It is stored in the bloodstream.
Now, what does this have to do with plants? Well, there are several plants that are known to also produce serotonin, and one of them is the stinging nettle. The nettle plant has little fine hairs on its leaves and these hairs contain a combination of three chemicals. These three chemicals are used together as a defense. There is a histamine that makes the skin irritated by causing an allergic type reaction, and an acetylcholine which is a chemical that transmits messages to the nervous system. Acetylcholine makes the skin burn. Then there's serotonin. This chemical apparently works on the other two to assist them into performing their repelling duties.
Stinging nettle isn't the only plant to contain serotonin, in fact, walnut, mushrooms, tomatoes and various fruits also are known to produce serotonin. Perhaps this is why certain people seem to like different fruits and vegetables while other people might dislike them. It's interesting to think that so many plants contain the same chemicals that our own bodies produce and perhaps this could have something to do with our perception of taste or enjoyment...the serotonin content telling our brains that it's good to eat. Even the stinging nettle is edible and has a lot of folk remedy uses. The leaves are picked (using gloves for protection) and the stinging hairs scraped away. Then the leaves are cooked in a variety of recipes, or crushed and made into a solution that's rubbed onto the skin. Some people use nettle for treatment of arthritis pain. The chemicals in the nettle are thought to act on the pain receptors in the brain, effectively reducing the sensation of pain and giving the patient relief. But, as good as the stinging nettle plant might be for pain treatment or for satisfying hunger, it is definitely a plant to avoid while out hiking.
