Flavonoids in Medical Cannabis: The Overlooked Plant Compounds

What Are Cannabis Flavonoids?

• Flavonoids are a large family of polyphenolic compounds found throughout the plant kingdom and in significant concentrations in cannabis
• Over 20 flavonoids have been identified in cannabis, including quercetin, apigenin, kaempferol, and the cannabis-specific cannflavins A and B
• Flavonoids are responsible for some of the colour pigmentation in cannabis flower and leaves and contribute to the plant’s overall aroma profile
• They are present in lower concentrations than cannabinoids and terpenes but are increasingly recognised as pharmacologically active contributors to the entourage effect

While cannabinoids and terpenes attract most scientific attention, the flavonoids in medical cannabis represent a rich and largely unexplored source of therapeutic activity.

The Pharmacological Activities of Cannabis Flavonoids

• Cannflavin A and B are anti-inflammatory compounds unique to cannabis that were found in a 1985 study to inhibit prostaglandin E2 synthesis more potently than aspirin
• Quercetin demonstrates antioxidant, antiviral, and anti-inflammatory properties that are relevant to many conditions treated with medical cannabis
• Apigenin binds to GABA-A receptors in the brain, producing anxiolytic effects that complement the action of CBD and linalool
• Kaempferol has been shown in preclinical studies to possess neuroprotective and anticancer properties, adding to the therapeutic breadth of full-spectrum cannabis products

The pharmacological activities of cannabis flavonoids span anti-inflammation, neuroprotection, anxiolysis, and antioxidant defence, making them important contributors to the therapeutic profile of whole-plant preparations.

Why Flavonoids Matter for Product Selection

• Full-spectrum cannabis products retain their flavonoid content; cannabis isolates and some broad-spectrum products lose them during extraction
• CO2 supercritical extraction at low temperatures preserves flavonoids better than high-temperature hydrocarbon extraction methods
• Patients seeking maximum entourage effect should look for products that specify flavonoid content or use gentle extraction processes
• Heat (including vaporisation at high temperatures) can degrade flavonoids; temperatures below 200°C are recommended to preserve them

Flavonoid preservation should be a consideration in both product manufacturing and patient administration, as these compounds make a meaningful contribution to the overall therapeutic profile of cannabis.

Research Directions and Clinical Future

• A 2019 study successfully synthesised cannflavin A and B, opening the door to scaled production and clinical trials
• Researchers at the University of Guelph identified the biosynthetic pathway for cannflavins, enabling their production without cultivating cannabis
• Cannabis flavonoids are an active area of pharmaceutical development, with several companies exploring cannflavin-derived drug candidates
• Clinical trials specifically designed to isolate and test cannabis flavonoid fractions are likely to be a significant growth area in cannabis medicine over the next decade

Cannabis flavonoids represent a genuine frontier in cannabis science, with the potential to yield new pharmaceutical entities and deepen our understanding of why whole-plant preparations often outperform isolated cannabinoids.