CBD has shown great promise in aiding symptoms of migraines, as well as a great many other afflictions. CBD comes from the truly amazing miracle plant, cannabis.
Virtually every part of a plant is adapted to coexist with with the organisms in its immediate environment. And one of the amazing ways plants do this is by the production of phytochemicals (from Greek phyto, meaning “plant”), they are natural products and include phytochemicals known as terpenes. But what are terpenes?
Terpenes are flavorful and aromatic, they even mediate interactions between organisms. They might not be critical for a plant to grow and photosynthesize but they are indispensable for a plant to survive in its particular environment. Nowadays scientists are starting to learn that terpenes have a variety of functions on the brain and nervous systems of animals and insects, though few have been investigated with regards to their other ecological functions.
Based on fossil evidence the evolution of land plants and terpene production began ~388 MYA with ancient mosses and their relatives within intracellular oil bodies, surrounded by a single layer membrane. The oil bodies when damaged probably released terpenes that have been shown to have cytotoxic activity against the cells of fungi, insects, and invertebrate animals. Earliest fossils of such an occurrence are undigested plant tissue cells with a conspicuous disturbance, suggesting terpenes may have been acting as a deterrent to herbivores.
There are two major hypothesis as to why phytochemicals affect the human brain. It could be due to the cellular, biochemical, and molecular similarities between plants and humans, or do to the similarities of the human nervous system and that of insects, neither of these hypotheses are mutually exclusive and both could be accurate. (1)
Cannabis plants have a 4-8 month cycle in the wild, and exist as either females or males. Their growth patterns of flowering and senescence are dictated with the shortening and lengthening of the light and dark correlated with the season. The female plants produce clusters of flowers at the node of the leaf and stem, that produce up several pounds of seed per plant. Wild Cannabis is wind pollinated and the male plants die soon after shedding their pollen. However most modern cannabis is “sinsemilla”, meaning it is a female-only cultivation, the plants remain unfertilized and compensate the setting of seed by producing an excess of flowers.
Sinsemilla type Cannabis has increased trichome growth, and contains elevated levels of terpenes and cannabinoids. Terpenes and cannabinoids are present in all of the aerial parts of the Cannabis plant but are most concentrated in resinous trichomes. The terpene rich exudate is synthesized in capitate glandular trichomes and stored in spherical cells with a thin delicate membrane.
Terpenes have a variety of ecological roles. They may act as an attractant to certain insects, but only up to a certain point, for example if the membrane on the end of a trichome is sufficiently disturbed by an organism, the membrane could break and release the contents providing direct defenses to the plant. Terpenes also function as an intra- and inter- organismal signaling device and can be thought of as pheromones. Not only plants, but animals and insects use terpenes to signal each other. Scientists recently discovered that two different types of bacteria and fungi use terpenes to chemically signal each other as well.
The phytochemistry of Cannabis is intensely studied and terpenes could be one of the most important natural products from it medicinally. Terpenes are used in aromatherapy and perfume for their potent fragrances. Limonene a terpene, is what gives citrus its aromatic citrus flavor. Pinene the most common terpene has gives an essence of pine. Both of these terpenes and multiple others are common in Cannabis. By controlling the genetic drift Cannabis growers can grow strains for varying levels of terpenes and cannabinoids. The most commonly studied terpenes in Cannabis include, pinene, limonene, linalool, humulene, caryophyllene, and myrcene. Certain strains of Cannabis have distinctive flavors and aroma and this is due to terpene variation within each strain. Additionally each terpene has ecological functions that can be utilized medicinally.Fig. 1
Pinine is a colorless flammable liquid and is highly repellent to insects, it occurs in the tree sap of conifers. It is often modified and used in perfume (2).
Limonene gives a “citrus” aroma, it is a colorless liquid and is often used in cleaning products. There are variations of limonene isolated from the mint family that have a “piney” or “musky” aroma instead. Limonene can used as an insecticide on crops, and is used in flavoring for foods, and as an additive to cosmetics. (3)
Linalool has a “spicy floral” scent and is used in many commercial products. It is used in insecticidal sprays to keep mosquitos away, and is added to many soaps and shampoos. Certain types of linalool can smell “woody” or like lavender. (4)
Humulene is one of the principal essential oils from hops, and gives beer that “hoppy” flavor. Amazingly, it is emitted by plants can help influence the formation of organic aerosol formation in the atmosphere, a process that could be viewed as “cloud seeding” by the plants. (5)
Caryophyllene gives black pepper and clove their spicy flavor and aroma. It is present in Cannabis, hops, and rosemary as well. It is being studied for a variety of potential medicinal benefits including helping with inflammation. (6)
Myrcene is in spices like bay, parsley, Cannabis, and hops. It has a “peppery” and “herbal” flavor. (7)
These terpenes can be isolated from plants by different processes, including steam distillation. Many Cannabis products sold like vape pens are isolated cannabinoid oils. In processing the terpenes are removed from the oil. To give oils distinctive flavors, vendors actually add terpenes back into the oils to give them a particular flavor and aroma.
Terpenes are a plethora of volatile organic compounds, that stimulate olfactory sensations, the aroma of them is a veritable bouquet of sweet, spicy, and even earthy. Not only are they useful industrially but they provide plants with a variety of invaluable ecological roles. They are potently medicinal and so useful that we can’t overlook their importance to both the growing Cannabis industry as well as their ecological importance.
- Plants and the Human Brain, David Kennedy, Oxford Press, 2014. Print
- Pinene. https://en.wikipedia.org/wiki/Pinene
- Limonene. https://en.wikipedia.org/wiki/Limonene
- Linalool. https://en.wikipedia.org/wiki/Linalool
- Humulene. https://en.wikipedia.org/wiki/Humulene
- Caryophyllene. https://en.wikipedia.org/wiki/Caryophyllene
- Myrcene. https://en.wikipedia.org/wiki/Myrcene
Figure 1. Leafly Terpene Graphic. https://www.leafly.com/news/cannabis-101/infographic-what-are-cannabis-terpenes-and-how-do-they-affect-you
I’m an undergraduate environmental ecology student at The Evergreen State College. I’m especially passionate about synergistic agriculture, botany, and phytochemistry. I believe that the natural world holds many undiscovered medicines yet to be revealed through science. I’ve been a Cannabis enthusiast for over 10 years and believe the medicinal potential that it holds is vastly underestimated. The content I write is an exploration of bioprospecting natural medicines and is dedicated to validating the natural world.