Washington’s smoke signals: Science of cannabis

With the passage of I-502 in 2012, development of marijuana legislation and marijuana research has surged to unprecedented levels. In an attempt to clearly translate new laws and research, the Reporter and Courier-Herald will examine these issues in a four-part series. Part four of this series addresses information about the cannabis plant and the chemicals it produces.

While research on the long-term health effects of marijuana use and Tetrahydrocannabinol or THC have only just begun, the cannabis plant itself has been thoroughly studied. The anatomy of the plant is well-known; the iconic five-leaf plant is easily recognizable in popular culture. The science of growing and processing the cannabis plant is also well documented and studied, giving both businesses and medical dispensaries innumerable ways to utilize the plant. On a chemical level, we know how THC affects the human brain and can even synthesize those same chemicals in a lab. Consider this your Cannabis 101 class – the science behind the plant.

The cannabis plant

One of the first things people learn about cannabis and marijuana is there are countless different strains of marijuana.

However, there are three general subspecies of cannabis: cannabis sativa, cannabis indica, and cannabis ruderalis. The current cannabis market for medical cannabis and recreational marijuana focus on cannabis sativa and cannabis indica for their chemical content.

Cannabis sativa tends to grow closer to the equator and in warmer climates. The plant is tree-like, growing tall and thin with thin leaves.

When the sativa plant is dried and smoked, it is reputed to give users an uplifting or energetic high.

Cannabis indica is naturally grown further away from the equator in colder climates. The plant is shorter and bushier than its cousin with wider leaves.

Highs from the indica plant tend to be more relaxing and calming, and may induce the stereotypical stoner “couch lock”, where users feel unmotivated to move from their current position, whether it be on the floor, a chair or draped over the arm of a couch watching cartoons.

While many cannabis and marijuana users will stand by the various effects of cannabis sativa versus cannabis indica, marijuana producer and processor Jonathan Swartz of Sylica Phoenix would dispute this.

“Indicas and sativas have a reputation for producing a certain effect,” Swartz said. “But I would challenge anyone to prove and demonstrate an indica or sativa that is purely an indica or sativa, so they can say this is what the effect is.”

The confusion, Swartz said, comes from the fact many cannabis plants have been mixed genetically, crossing sativa genes with indica genes.

“We have Grape-Wreck; Grape Ape (an indica strain) and Train Wreck (a sativa strain) mixed together,” said Swartz. “People think it is an indica but no, it’s a hybrid with apparently indica characteristics.”

Peter Pessiki of Integrity Labs, which tests cannabis and marijuana products for quality control, said that it is not yet known why sativa strains and indica strains produce different effects, although researchers guess there are secondary chemicals in the plant may cause the different effects.

Products sold in stores or dispensaries typically come from the female plant. In order to control cannabis sub-strains, which in turn controls the THC and chemical content of the plant, male plants have to be carefully controlled in order to prevent the accidental pollination of an entire female batch.

According to Swartz, when a female plant is pollinated, it ends the plant’s flowering process early, halts THC production and produces seeds, all of which the market would prefer to avoid in plants meant to be used for products.

The female flower buds are typically harvested from the terminal cola, which is located at the top of the plant. However, buds can be found at many sites along the plant.

The buds themselves are composed of tight bunches of small leaves and calyxes, tear-shaped nodules that contain the glands that secrete THC and other chemicals, known as cannabinoids.

These glands, or trichomes, are found in abundance in the buds, but can also be found on the stem and leaves of the cannabis plant as well.

Processing the plant

The cannabis plant can be processed several different ways to get it ready for consumption.

Many do-it-yourself websites, like Marijuana Growers HQ, explain that drying the cannabis plant after harvesting it is extremely important.

One way to dry the plant is to hang it on a line, use mesh screens, or a drying cage.

A different process is needed for extracts and edibles.

According to CannLabs, another cannabis testing company, many cannabis processors soak the plant in a solvent, such as butane, isopropyl alcohol or ethanol, to begin the extraction process.

THC and other cannabinoids in the cannabis plant bond to the liquid solvent and are pulled off the plant.

The plant materials, sans cannabinoids, are then filtered out of the solvent mixture.

The solvent is also removed, leaving only the cannabinoids from the plant ready to be mixed into food products like chocolates or brownies, or even put into gel capsules for consumption.

Sylica Phoenix uses butane for their extraction process, and their end-product is 80 percent plus THC extract.

Other methods for extracting cannabinoids from the cannabis plant include using carbon dioxide (CO2), water and dry sieves, each resulting in different potency and chemical content.

Cannabinoids and other chemicals

Cannabinoids are the active chemicals in cannabis. The University of Washington Alcohol and Drug Abuse Institute has said there are 66 classified cannabinoids, although several cannabis information websites claim there are more than 85 cannabinoids in the plant.

The most commonly-known cannabinoid is tetrahydrocannabinol, or THC, the psychoactive chemical many researchers believe is responsible for the high users receive when consuming marijuana.

However, you can’t just chow down on a raw cannabis plant to get buzzed.

The cannabis plant creates a chemical called tetrahydrocannabinolic acid, or THCA.

According to Pessiki, THCA is not psychoactive because the chemical is attached to a carboxylic acid.

“With that group on there, it does not have any of the psychological effects,” Pessiki said. “It doesn’t get you stoned.”

Pessiki said THCA must undergo a form of combustion in order to activate the chemical.

“By heating it, you lose carbon dioxide, CO2, and once it spits out that CO2 molecule, it is now active and ready to interact with your brain,” he said.

When THCA becomes active, it turns into THC delta-9, which is a more specific way to refer to psychoactive THC.

Swartz said consuming cannabis and THCA without combustion, “is like eating grass.”

A lesser-known cannabinoid is cannabidiol. According to the National Institute on Drug Abuse, cannabidiol (CBD) has been used for medical treatments and for treating epilepsy. CBD is a non-psychoactive cannabinoid, meaning it won’t get a user high like THC, and has been used to treat pain, psychosis and addiction to other substances.

When THC and CBD are consumed, these cannabinoids affect the endocannabinoid system in a person’s brain.

According to the National Institute on Drug Abuse, human brains already produce cannabinoid chemicals naturally.

These natural cannabinoids and cannabis cannabinoids are very similar in shape on a molecular level, which is why THC and CBD can affect the human brain.

The natural cannabinoid that is similar to THC is called anandamide.

The natural cannabinoids, however, are weaker versions than THC and CBD, and are broken down in the brain more easily.

Because THC and CBD are stronger chemicals, they affect the brain for longer than the natural chemicals.

Other chemicals found in cannabis include terpenes. According to scientific staff at Integrity Labs, terpenes give cannabis strains specific odors, which range from typical skunk smell of marijuana to the citrus scent of Night Train, according to the Medical Marijuana Strains website.

Flavinoids are also found in cannabis, and when smoked, can give the user unique tastes, from a woody and earthy taste to key lime pie.