Cannabis terpenes, the part of cannabis plants responsible for its smell and taste, may be able to relieve pain both by themselves and with cannabinoids. The results were published in Scientific Reports by researchers from the University of Arizona.
Researchers have been questioning whether cannabis can provide pain relief by an ‘entourage effect’- that is, different parts of the plant working together to have a greater effect on pain relief than any of its individual constituents alone. To this end, the researchers behind the current paper set out to see how cannabis terpenes can modulate pain.
For the study, the researchers focused on how four cannabis terpenes: alpha-humulene, geraniol, linalool, and beta-pinene, worked in mice to reduce pain. They examined each terpene by itself and with WIN55,212-2, a synthetic cannabinoid agonist that stimulates the body’s cannabinoid receptors.
In doing so, they found that all the terpenes activated CB1R cannabinoid receptors similarly to tetrahydrocannabinol (THC). They also found that all four terpenes lowered pain sensitivity, pain sensation, and body temperature. The terpenes additionally reduced movement and catalepsy, a freezing behavior linked to the psychoactive effects of cannabinoids.
The researchers noticed that when each terpene was combined with WIN55,212-2, mice had even greater reductions in pain sensation. This, they say, shows that different parts of the cannabis plant may work together to produce enhanced effects.
“It was unexpected, in a way,” says Dr. John Streicher, lead author of the research. “It was our initial hypothesis, but we didn’t necessarily expect terpenes, these simple compounds that are found in multiple plants, to produce cannabinoid-like effects.”
The researchers are now researching how terpenes can be used with opioids for different kinds of cancer-related pain. In the long-term, they hope to develop a dose-reduction strategy using terpenes and other cannabinoids or opioids for pain relief with fewer side effects at lower dosage points than current options.