A recent study conducted by research scientists at PBG BioPharma found cannabis leaves contained flavonoids in amounts comparable to those in ginkgo leaves, which is among one of the best sources of flavonoids.
Flavonoids have anti-inflammatory and anti-oxidant properties, which give them the potential to be a food supplement that protects against toxicity from pesticides used when growing the plant. Additionally, flavonoids aid learning, cognition, and healthy brain activity by reducing oxidative stress. They protect against obesity and diabetes by reducing blood sugar, and have also shown to reduce blood pressure and cholesterol.
A total of twenty-six flavonoids have been identified in cannabis plants1–3, among which Cannflavin A and B are notable in their medicinal potential4. The other most common flavonoids are glycosides of orientin, vitexin, isovitexin, quercetin, luteolin, kaempferol, and apigenin1–3. These flavonoids are also found in ginkgo leaves, red wine, essential oils, vegetables, and herbal tea.
Although cannabis leaves have ten times fewer cannabinoids (1-2%) compared to inflorescences, they contain several times more flavonoids (around 1%)5. Flavonoids share a wide range of biological effects with cannabinoids and terpenoids that include anti-inflammatory, anti-cancer, and neuroprotective properties6.
In traditional herbal medicine, cannabis leaves were used to treat malaria, asthma, panting, roundworm, scorpion stings, hair loss, and greying of hair7–9. Leaves were often powdered and consumed with tea or warm alcohol, pulverized and consumed as juice, or smoked9.
References
Clark, M. N. & Bohm, B. A. Flavonoid variation in Cannabis L. Botanical Journal of the Linnean Society 79, 249–257 (1979).
Flores-Sanchez, I. J. & Verpoorte, R. PKS Activities and Biosynthesis of Cannabinoids and Flavonoids in Cannabis sativa L. Plants. Plant and Cell Physiology 49, 1767–1782 (2008).
Pollastro, F., Minassi, A. & Fresu, L. G. Cannabis Phenolics and their Bioactivities. Current medicinal chemistry 25, 1160–1185 (2018).
Werz, O. et al. Cannflavins from hemp sprouts, a novel cannabinoid-free hemp food product, target microsomal prostaglandin E2 synthase-1 and 5-lipoxygenase. PharmaNutrition 2, 53–60 (2014).
Jin, D., Dai, K., Xie, Z. & Chen, J. Secondary Metabolites Profiled in Cannabis Inflorescences, Leaves, Stem Barks, and Roots for Medicinal Purposes. Scientific Reports 10, 3309 (2020).
Andre, C. M. & Evers, Y. L. and D. Dietary Antioxidants and Oxidative Stress from a Human and Plant Perspective: A Review. Current Nutrition & Food Science (2010).
Brand, E. & Wiseman, N. Concise Chinese materia medica. (Paradigm Publications, 2008).
Smith, F. P. & Stuart, G. A. Chinese materia medica: vegetable kingdom. (American Presbyterian Mission Press, 1911).
Editorial Committee. Great Encyclopedia of Chinese Medicinals (Zhong yao da ci dian). (Shanghai Technology Press, 1977).
