Study sheds new light on cannabis metabolism

A UBC study has shed new light on the metabolic processes that occur in the flowers of the cannabis plant, which are consumed for the psychoactive and medicinal properties of their specialized metabolites.

“Cannabis is in the news all the time these days and used in many medicinal and recreational products available in our society today, so it’s important to figure out how the cannabis plant is making the products (i.e. cannabinoid metabolites and terpenes) in the first place,” said Sam Livingston, a PhD candidate in botany and co-lead author of the study.

Cannabinoids are substances like CBD and THC that interact with specialized receptors in the brain.

Livingston explained that although there had been some studies in the past that used visible light to examine the glandular trichomes — hair-like structures that secrete products involved with plant metabolism — of cannabis, those studies had a difficult time gleaning information about the plant at the cellular and tissue level.

As a result, there were no preconceived expectations for the research. Co-lead author Dr. Teagen Quilichini was the one who devised the idea of using UV light to examine the composition of the plant.

The team developed a specialized imaging technique that took advantage of glandular trichome intrinsic autofluorescence — a property of the trichomes that causes them to emit light when exposed to certain other kinds of light. Using that technique, the researchers were able to demonstrate that the stalked glandular trichomes in cannabis flowers possessed blue autofluorescence correlated with high cannabinoid levels.

The next step of the study is to examine the cannabis plant’s ability to store cannabinoid metabolites, as those products are technically toxic to the plant. As a result, there has to be some biological mechanism to ensure that these cells that are constantly pumping these products within themselves continue to do so efficiently and doesn’t result in cell death.

Although the research was focused on examining the cannabis plant from a purely biological perspective, Livingston believes the findings could be expanded to analyze the role of cannabis in medicinal and industrial domains.

Once researchers are able to deduce the composition methodology of the plant — how the metabolites are produced and stored — they may be able to practice selective breeding when wanting to create a specific strain of cannabis.

“Part of our work is to find our which trichomes make rich cannabinoids and terpenes,” said Livingston. “It’s possible that this could be scaled up to a more medicinal or industrial approach.”