Cannabis is a complex plant with over 400 active compounds which mainly include cannabinoids, terpenes and flavonoids. However, of these compounds, often the most widely understood, like cannabinoids and terpenes tend to steal the spotlight. It is estimated that flavonoids account for 10% of these known compounds with around 20 varieties known to exist in cannabis.
What are Flavonoids?
Flavonoids are not unique to the cannabis plant. Scientists have identified thousands of them throughout nature, from plants, to fruits and vegetables. They belong to a group of plant chemicals known as phytonutrients. There are around 6000 different types of flavonoids broken down into 12 separate categories. Anthocyanidins, flavan-3-ols, flavonols, flavones, flavanones, and isoflavones are the flavonoids with the most dietary importance.
The word Flavonoid comes from the Latin word ‘Flavus’, referencing the color yellow as it appears in nature. Flavonoids cover a range of functions in plants although they primarily act as yellow pigments in leaves and petals to attract pollinating insects. They may also appear as bluish pigments to receive certain wavelengths of light, which allows the plant to be aware of the photoperiod. By filtering ultraviolet light many flavonoids also protect the plant.
On a cellular level they act as regulators of the cellular cycle. Some of them are synthesised in the plant’s roots and have crucial roles in establishing symbiotic fungi or mycorrhyzas, while at the same time they fight the infections caused by pathogenic fungi. They are also responsible for the color of certain fruits – think blue in blueberries or red in roses.
While flavonoids are present throughout nature, a few have been found unique to the cannabis plant. These are known as cannaflavins. Similar to terpenes they play a role in how we perceive cannabis through our senses. But there is a lot more to flavonoids than meets the eye. In fact they are among the most understudied compounds found within the cannabis plant.
What are Cannaflavins?
Cannabis contains flavonoids just like many other plants. The intense aromas, colors and flavors you might attribute to a particular strain are usually caused by the flavonoids and terpenes in that particular plant.
Cannabis flowers are full of different types of colors including shades of green, yellow, orange, red, and sometimes even blue and purple. These flavonoids are expressed throughout a cannabis plant’s life cycle, and play key roles in filtering UV light, as well as deterring pests and diseases.
Unfortunately, more research is needed to understand each of the cannaflavins and their effects. Of the more than 20 flavonoids found in cannabis uptil now, the following cannaflavins stand out for their concentration.
In the 1980s, Dr. Marilyn Barrett identified two diprenylated flavonoids in Cannabis which were previously unknown. She named them “Cannflavin” A and B.
In 2013 Mahmoud ElSohly and colleagues at the University of Mississippi identified a third, Cannflavin C. Dr. Marilyn Barrett made this discovery when she was looking for compounds that would counter the activity of an inflammatory mediator, prostaglandin E2 (PGE2), present in synovial cells cultured from the knee joints of patients undergoing surgery for rheumatoid arthritis.
Barrett and her co-workers found that a cannabinoid-free alcohol extract of Cannabis was inhibiting the release of these inflammatory prostaglandins from the cultured cells. To determine which component of the extract was having the anti-inflammatory effect, they divided the extract into fractions (using preparative thin layer chromatography) and measured the activity of each fraction in the cell culture assay.
The most active fraction, in turn, was divided into fractions and its most active fraction selected, and the process repeated until a pure compound was isolated. Using Mass Spectrometry, her team was able to confirm that they were working with a flavonoid, belonging to the class of flavones. Barretts team was able to confirm that Cannaflavin was 30 times more potent than aspirin in combating inflammation.
- Vitexin & Isovitexin
These cannaflavins also occur in plants such as the passion flower, hawthorne, pearl millet, Niagra Bamboo Leaves and the Chaste Tree. These compounds have been shown to have anti-oxidant, anti-cancer, anti-inflammatory, anti-hyperalgesic, and neuroprotective effects. Research has indicated that Vitexin & Isovitexin may be capable of inhibiting or delaying neural loss and could play a role in counteractive neurodegenerative diseases.
It has been shown to inhibit the secondary effects of ciclosporin A, an immunosuppressive administered during organ transplant to avoid rejection of the transplanted organ. It has also been proven that apigenin is one of the few substances capable of stimulating the monoamine transporter, altering the neurotransmitter levels. It has recently become clear that apigenin acts as an anxiolytic and sedative on the GABA receptors.
Studies have shown that Kaempferol has an antidepressant effect. It is attributed to have preventive action against coronary heart disease or cancer, as well as antioxidant and anti-inflammatory properties.
Found in almost all vascular plants, it inhibits viral enzymes and it can have antiviral effects. It also inhibits the production of prostaglandins, acting as an anti-inflammatory. A recent study suggests quercitin may have therapeutic applicability in treating fibromyalgia, due to its anti-inflammatory effects.
As has been shown, Cannabis has therapeutic effects in managing fibromyalgia, which could prove the synergy between quercitin and Cannabis. Similarly, quercitin inhibits the monoamine oxidase enzyme (MAO), which is involved in the metabolism of neurotransmitters and pharmaceuticals.
- Luteonin and Orientin
Both luteonin and orientin have shown to have pharmacologic effects as antioxidants, anti-inflammatories, antibiotics and as agents against cancer in preclinical studies. They can also have synergy with cannabinoids.
Beta-sitosterol is one of many sterols that come from plants (phytosterols) and have a structure like the cholesterol produced in the body.Beta-sitosterol is said to lower cholesterol levels and reduce the risk of some cancers. It also is said to relieve symptoms of benign prostatic hyperplasia (BPH). How beta-sitosterol works is not known. It may be related to cholesterol metabolismor anti-inflammatory effects. More research is needed to fully understand how it works.
The Entourage Effect
The compounds in cannabis work synergistically together to produce different effects. This is known as the entourage effect. Our bodies are equipped with an endocannabinoid system, a vast network of receptors that cover every organ and system in the human body. Cannabinoids bind to these receptors to produce different effects and these effects are modulated in part by the terpenes and flavonoids present in cannabis. Cannabidiol (CBD), for instance, modulates the effects of THC at the blood-brain barrier. Flavonoids are thought to have similar synergistic abilities. Whether they enhance the properties of cannabinoids or modulate their efficacy is not fully known and will require further research.