Whenever you enter a dispensary or walk through a cannabis garden in full bloom, the air is rich with the characteristic smell of marijuana. Thanks to terpenes, we are able to identify things in the environment with our most instinctive sense: smell.
The terpene, humulene, is one of many different aromatic compounds that inhabit the cannabis plant, and is also found in black pepper, hops, basil and ginseng.
The importance of terpenes can’t just be boiled down to smell. When people talk about the entourage effect observed in cannabis, they are talking about the delicate ways in which cannabinoids, terpenes and flavonoids work together synergistically to have a therapeutic or remedial effect. Terpenes are fundamentally important in the entourage effect phenomenon, as they are the second most abundant type of compound in cannabis.
Humulene, otherwise known as α-caryophyllene, is an example of the synergistic outcome we observe via the entourage effect. In an earlier article, we wrote about β-caryophyllene, which although is very similar to α-caryophyllene, exerts very different effects. However, when the two work in tandem, they produce powerful anti-inflammatory and even tumor reducing effects, and are known to work best when they are in the presence of each other.
What is humulene?
Humulene is the most abundant aromatic compound found in the Humulus Lupulus (hops) plant, and has this plant to thank for its scientific name. Aside from being found in hops, humulene is also found abundantly in cannabis, basil, sage, black pepper and ginseng. It has an earthy, woody aroma.
While the humulene molecule has the same chemical formula as β-caryophyllene, its atoms are arranged into a different structure, giving it a different effect. Humulene is often celebrated in modern science and biomedicine because it is found abundantly in many plants, and has therefore been the subject of a lot of research.
Interestingly, humulene doesn’t just have benefits for the humans ingesting it. It is biosynthesized in trichome heads, and it is thought that humulene is part of the cannabis plant’s defense mechanisms. The production of strong, aromatic compounds in trichome heads help the cannabis plant to deter pests and to prevent fungal infestations.
The therapeutic potential of humulene?
The most common and celebrated therapeutic effect of humulene is its anti-inflammatory properties. Its anti-inflammatory effect is said to be the strongest when it is working side by side with β-caryophyllene, its sesquiterpene. Aside from this, humulene is being investigated for its ability to fight tumors, to treat asthma, and for its antimicrobial qualities, especially in treating Golden Staph.
In 2009, researchers took to investigating the effects of humulene on allergic airway inflammation (asthma). The study was published in the British Journal of Pharmacology, where researchers administered both humulene and trans-caryophyllene (an isomer of humulene) to rodent models with asthma. While trans-caryophyllene had no marked or significant effects, humulene was found to have clinically significant anti-inflammatory effects. It is thought that this effect is mediated by reduction of inflammatory responses as a whole, and this effect and therefore be implied in other inflammatory conditions.
Humulene is an active terpene in many plants other than cannabis, including Balsam Fir. This plant is often distilled to extract its terpenes, and its essential oils have been used in aromatherapy for centuries. In a 2003 study aimed at the therapeutic potential of Balsam Fir, researchers concluded that humulene has tumor reducing effects. The way by which it does this is by reducing reactive oxygen species (ROS). Antioxidants are powerful anti-tumor agents for this exact reason, and by reducing ROS and free radicals, tumor size can be reduced.
This research is supported by a 2007 study, where researchers investigated the tumor reducing effects of humulene especially in conjunction with other phytocannabinoids. Interestingly, researchers found that humulene exerts most of its antiproliferative function when it is in the presence of β-caryophyllene, which is both a terpene and a cannabinoid. The anticancer activity of humulene can perhaps be credited to its synergy with other phytocannabinoids in the cannabis plant, a characteristic expression of the entourage effect.
In yet another study, humulene was researched for its antimicrobial properties, especially with respect to Staphylococcus aureus, a bacterial infection otherwise known as Golden Staph. Again, the plant being studied was Balsam Fir which naturally contains an abundance of humulene. Of the terpenes present in Balsam Fir essential oil, humulene, pinene and caryophyllene were found to exert powerful antimicrobial activity against S. aureus.
Strains rich in humulene
Virtually every strain of cannabis has a different aroma, different taste and overall different effects. Although cannabinoids play a huge role in the variation between strains, terpenes also contribute greatly to this diversity. In fact, every time a strain smells or tastes different, this is usually because of terpenes rather than cannabinoids.
With all of that in mind, some strains contain higher levels of humulene than others. In general, humulene is not found as abundantly as other terpenes in cannabis. Given the research cited earlier in the article, this might have to do with the fact that it is better when it works in conjunction with other terpenes and cannabinoids. It therefore doesn’t need to be present abundantly, but should be present with a handful of other compounds to make it clinically active.
Here are a few strains with higher levels of humulene:
The Death Star strain contains levels of humulene much higher the average cannabis strain. However, it also contains very high levels of caryophyllene, which we have discovered goes hand in hand with humulene. High levels of both cannabinoids suggests a powerful synergistic effect of these two special terpenes. This indica strain is most often medically for the treatment of stress and chronic pain.
Headband, another high humulene strain, is conveniently named for the light pressure it can bring to the head – kind of like wearing a headband! Again, this strain has high levels of caryophyllene. It may have anti-inflammatory and antimicrobial action as a result of the entourage effect, rather than purely for its high humulene levels.
Original Glue is most often celebrated for its potent psychedelic effects. Its thick covering of trichomes make it look almost frosted. Humulene is biosynthesized in the trichomes of cannabis, and therefore a thick dusting of trichomes suggests higher humulene levels. Just like with most humulene-rich strains, Original Glue also has potent levels of caryophyllene. This strain is most commonly used to treat stress, depression and stress-related headaches.
An example of the entourage effect
Humulene is perhaps one of the best examples of the entourage effect that we observe in the cannabis plant. Scientific research has supported the likelihood that humulene works in conjunction with its partner, caryophyllene. Together, these two terpenes exert powerful remedial effects. And in virtually every humulene-rich strain, we also observe higher-than-normal levels of caryophyllene.
The synergistic behavior between caryophyllene and humulene is exemplary of the entourage effect that cannabis writers, researchers and enthusiasts so often refer to. It is an expression of the teamwork and complexity we observe between active compounds of the marijuana plant. And fundamentally, this forms the basis of cannabis’ powerful remedial benefits.