Reviewed: Ryz NR, Remillard DJ, Russo EB. Cannabis roots: A traditional therapy with future potential for treating inflammation and pain. Cannabis Cannabinoid Res. August 2017;2(1):210-216. doi: 10.1089/can.2017.0028.

The many uses of cannabis (Cannabis spp., Cannabaceae) leaves, flowers, seeds, stalks, and trichomes (resin glands) for food, fuel, fiber, medicine, and other purposes are well known. However, the medicinal use of cannabis roots, which was documented as early as 77 CE by Roman naturalist Pliny the Elder, has been largely neglected by the modern medical research community. The authors of this review summarize the medical history and traditional use of cannabis roots, as well as the limited pharmacological data on the composition of cannabis root.

Cannabis root preparations have been mentioned in the Pên-ts’ao Ching, an ancient Chinese pharmacopeia; Persian medicinal texts from the 12th century; accounts of European physicians dating back to 1542 and US Eclectic physicians; as well as ethnobotanical reports of traditional practices in South America, Indonesia, and Réunion Island.

Historically, cannabis root was taken orally as a hot water decoction or used topically as a “cataplasm” or poultice. In addition, the ground-up roots were mixed with wine and taken orally, or mixed with fat or butter and taken orally or applied topically. Cannabis root has been used for painful joints; gout; fever and inflammation; difficult childbirth and postpartum hemorrhaging; burns and calluses; as both an emetic and anti-emetic; to treat infections; and as a veterinary vermicide. Historical records also mention cannabis root as a treatment for “tumors,” but the authors note that it is unclear if these reports were referring to cancerous tumors; historically, the word “tumor” often was used to refer to any abscess, sore, ulcer, or swelling, including inflammation associated with joint pain.

Active compounds in cannabis roots include the triterpenoids friedelin and epifriedelanol. Both are abundant in many plants, algae, lichen, mosses, coal, and mineral wax. To date, researchers have not isolated friedelin or epifriedelanol specifically from cannabis roots. Friedelin from other plant sources has been found in vivo and in vitro to have various activities, including anti-inflammatory, anti-pyretic, analgesic, estrogenic, antioxidant, hepatoprotective, and cytotoxic.

An oil fraction of wild cannabis roots from Jammu, India (misspelled as “Jammy, India” in the journal article), was found to have the characteristic minty aroma of carvone (found at 77.7%) and dihydrocarvone (23.3%). These monoterpenes, which are also found in spearmint (Mentha spicata, Lamiaceae) and dill (Anethum graveolens, Apiaceae) oils, have antinociceptive (blocking the detection of pain stimuli) effects in vivo and are being investigated for their potential therapeutic use in patients with osteoarthritis. N-(p-hydroxy-β-phenylethyl)-p-hydroxy-trans-cinnamamide, also found in cannabis roots, has also been shown to have analgesic activity in vivo. No pharmacological data are available on the cannabis root alkaloids cannabisativine or anhydrocannabisativine. Cannabis roots also contain choline and several sterols, including sitosterol, campesterol, and stigmasterol. Cannabis roots, unlike its flowering tops and resin glands, have no appreciable amounts of cannabinoids.

Although there have been no reports of the cardiac activity of cannabis roots, a 1971 article in the Journal of the American Medical Association discussed a case from 1931 that linked “Indian hemp” roots, which were used as a treatment for dropsy, with bradycardia (slow heart rate). However, the authors of this review note that the 1931 treatment most likely referred to dogbane (Apocynum cannabinum, Apocynaceae), which was commonly called “Indian hemp” in the 1930s and earlier, has known cardiac glycosides, and was used historically to treat dropsy in folk and Native American medicine.

When considering therapeutic compounds in and possible uses of cannabis roots, it is important to keep in mind the great variability of the plant in different climates, growth conditions, and among its different chemovars and varieties. Just as different chemovars have been identified in relation to their cannabinoid content, different root chemovars may emerge. Many cannabis dispensaries in the United States now offer body lotions, salves, lip balms, and other products made from cannabis or hemp (non-intoxicating cannabis) roots. Great care must be taken when sourcing roots for any medicinal purpose because they readily accumulate heavy metals from soil, including iron, chromium, and cadmium.

—Mariann Garner-Wizard