If you're familiar with the distinct aroma of hops in beer, then you're already somewhat aware of humulene (α-humulene, also known as α-caryophyllene), one of the more prominent terpenes found in cannabis. Humulene was first identified in essential oils from the conical flowers of the common hops plant (Humulus lupulus) and was thus named after it. However, we also find this terpene in other pungent edibles from all over the world such as basil, clove, ginger, ginseng, sage, and Vietnamese coriander.
Humulene is a monocyclic sesquiterpene consisting of three isoprene units that contain three nonconjugated C═C double bonds. It is an isomer of β–caryophyllene and the two terpenes are often together in many plants, but humulene does not have a cyclobutane ring like β–caryophyllene does. It's known for having an earthy aroma with notes of wood, herbs, and spices, and we consistently find high levels of humulene in cannabis strains such as Skywalker OG, Girl Scout Cookies, Sour Diesel, and White Widow.
Common hops and other plants with high levels of the terpene humulene have been used in traditional Chinese medicine for generations to suppress one's appetite, treat inflammation, manage pain, and fight bacterial infections, and recent scientific studies have proven just how effective it is. For instance, a 2006 study conducted at the University of Quebec found α-humulene taken from the essential oil of balsam fir trees to be “active against” the Staphylococcus aureus bacteria strain. Also, the Federal University of Santa Catarina in southern Brazil conducted a study in 2007 that found humulene to effectively reduce inflammation, and another study in 2008 that determined that the terpene acts as an antinociception, which means it blocks feelings of pain.
Humulene is also being studied for its potential in treating cancerous tumors. In 2003 the French National Institute of Health and Medical Research found humulene to be the only chemical compound present in balsam fir oil to be “active against all the solid tumor cell lines.” The study concluded that humulene seems to aid in the production of Reactive Oxygen Species (ROS), which contributes to apoptosis (programmed cell death) in cancer when adequate levels are present.