What are flavonoids and what do they do?
When we consider the 200 or more bio-active compounds that have been discovered in cannabis, often the more widely understood phytocannabinoids and terpenes tend to steal the spotlight. But these aren’t the only important compounds produced by cannabis. Take flavonoids for example. They account for roughly 10% of these known compounds with around 20 varieties known to exist in cannabis.
Flavonoids are not unique to the cannabis plant. Scientists have identified thousands of them all throughout nature, from flowers to fruits and vegetables. However, there are some that are known to be found only within cannabis. These are known as cannaflavins. Similar to terpenes, flavonoids share a role in how we perceive cannabis through our senses. But there’s a lot more to flavonoids than what meets our nose and taste buds. In fact, flavonoids are among the most understudied compounds found within the plant. However, here’s what we do know about them.
Flavonoids exist throughout nature
Flavonoids are made up of groups of polyphenolic compounds that act as secondary metabolites to a myriad of plants and fungi. There are over 6,000 different types of flavonoids that have been discovered in the plant world, which are classified into three main groups:-
Flavonoids are further broken down into twelve separate categories:-
The word “flavonoid” actually stems from the Latin term flavus, referencing the colour yellow as it appears in nature. This makes sense considering a primary function of flavonoids is to provide colour pigmentation to plants, notably in flowers, for the purpose of attracting pollinators. Many plants, including a large majority of edible fruits and vegetables containing non-green pigmentation, owe their bright colours in part to flavonoids. Flavonoids are also partly responsible for protecting plants against the elements such as potentially harmful UV rays, pests, and diseases.
They are found in many foods and could be useful for treating chronic pain, Viral infections, Cancer, Alzheimer’s and many other conditions via interaction with our endocannabinoid system (ECS).
Flavonoids give cannabis character
We often attribute the flavours and aromas of cannabis to terpenes. However, flavonoids also play an important role in providing the distinguishing qualities we use to differentiate between strain varieties. Both odour and flavour are possible in cannabis due to the synergistic qualities that terpenes and flavonoids share with one another.
Moreover, flavonoids also affect the pigmentation of cannabis, just as they do with other flowers. Those beautiful, deep purple cannabis strains owe their coloration to the flavonoids known as anthoxanthins or anthocyanins. In other plants such as berries, anthocyanin may cause red, purple, or even blue coloration depending on pH levels.
Flavonoids are pharmacologically active compounds
If providing colour pigmentation, odour, flavour, and protection weren’t enough, research has shown that flavonoids are also highly pharmacologically active, including preliminary research indicating the medicinal benefits of the cannaflavins found exclusively in cannabis.
Flavonoids may be synergistic in cannabis
The “Entourage Effect” is a widely used term that describes the synergistic nature of the many pharmacologically active compounds in cannabis. Coined by S. Ben-Shabat and Dr. Raphael Mechoulam in 1998, the “Entourage Effect” has become commonplace in cannabis research. Dr. Mechoulam, as well as other scientists such as Ethan Russo and James MacPartland are among the few today working to uncover the mysteries of flavonoids as they exist in cannabis.
Our bodies are equipped with an endocannabinoid system, a vast network of receptors that cover almost every organ and system within us. Cannabinoids bind to these receptors to produce different effects, which are further influenced by terpenes and cannabinoids. The reason why certain combinations of these bio-molecules make us feel different is due to the synergistic properties of these various compounds. 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.
Major Flavonoids in Cannabis
Cannaflavin A, B & C
Cannaflavins are produced exclusively by the cannabis plant and belong to the flavone class of flavonoids. Flavones have been shown to be:
Anticancer in several animal models. Cannaflavins act on the inflammatory pathway of prostaglandins (lipids with hormone-like effects), meaning they are anti-inflammatory.
Cannaflavin A is fascinating and has been the most studied of the Cannaflavins. Cannaflavin A may interact with CBD and THC and may reduce inflammation.
Beta-Sitosterol
Beta-sitosterol is a white, waxy flavonoid with a chemical structure similar to cholesterol but can lower cholesterol levels. This flavonoid could be used with THCV to treat obesity and coronary heart disease. Beta-sitosterol is often found in avocados and nuts; some claim it has a yogurt-like smell/taste.
Kaempferol
Kaempferol has a yellow hue and can be found in kale, beans, tea, spinach, and broccoli. This flavonoid has a bitter flavour and could be helpful for the treatment of cancer. Kaempferol may also prevent cancerous tumours from metastasizing (spreading) throughout the body. Finally,
kaempferol helps the body produce new blood cells and affects the body’s antioxidant effects against harmful free radicals.
Quercetin
Quercetin is a flavonoid in almost all vascular plants (particularly capers, kale, apples, and red onions). It provides anti-inflammatory, antimutagenic (i.e., can prevent changes in DNA sequences), antiviral, antifungal, and antioxidant effects. Quercetin may also improve mental and physical performance. Quercetin has a bitter flavour and is found in beverages, including red wine.
Orientin
Orientin is a potent antioxidant with antibiotic, anti-inflammatory, and anti-cancer properties. It is common in both cannabis and tea plants, such as rooibos. Orientin has been described as having a sharp or bitter taste.
Luteolin
Luteolin is found in celery, thyme, green peppers, and chamomile tea. As with orientin, luteolin has a powerful antioxidant and anti-cancer effect but is perhaps less bitter, fruitier, and sweeter in flavour.
Vitexin & Isovitexin
Vitexin is found in passionflower, chaste berry, hawthorn, and pearl millet. Vitexin has pain-blocking properties and may help protect brain cells. There is much scientific interest in vitexin for its anti-Alzheimer effects. Isovitexin has a similar chemical structure and pharmacological properties as vitexin and could be beneficial for the same reasons.
Apigenin
Apigenin provides muscle relaxing, sedative, and anti-anxiety effects. Apigenin can also lower blood pressure and is found in chamomile tea, which may be why chamomile is frequently used as a sleep aid. This bitter-tasting flavonoid is also found in wheat sprouts, onions, oranges, and parsley.
Apigenin is active as an antioxidant and has numerous other therapeutic benefits. Apigenin is especially useful for organ transplant patients, particularly those who have suffered from renal injury and need a kidney transplant. Apigenin could combine with CBD to help treat kidney transplant patients and theoretically reduce the need for powerful immunosuppressant drugs.
Galangin
As the name suggests, Galangin is found in the root spice galangal, which is related to ginger and turmeric. Unlike ginger, galangal has a sharper, citrus, and pine flavour and is often used in Thai and Indian cuisines and medicine. Galangin has been shown to have antitumor, antibacterial and antiviral properties in vitro.
Naringin
Naringin occurs in citrus fruits and is especially prominent in grapefruit, contributing to its bitter flavour. Naringin is a versatile flavonoid that exhibits the following properties:-
Anti-inflammatory
Anti-cancer
Bone-regeneration – useful for arthritis and osteoporosis
Metabolic syndrome (obesity, diabetes, and high blood pressure (hypertension)
Protection against DNA damage and the genes that code for the body’s essential amino acids and proteins
Help treat conditions that affect the central nervous system (CNS), such as epilepsy, Alzheimer’s Disease, motor neurone disease (MND), neurofibromatosis, and Parkinson’s disease
Rutin
Rutin is another bitter flavonoid found in cannabis that is also present in citrus fruits, apples, and grains like buckwheat. Rutin can prevent blood clots.
Hesperetin
Hesperetin is a citrus-flavoured flavonoid but is more sweet than bitter. Hesperetin is found in sweet oranges and lemons. Hesperetin may be useful in treating lethal cardiac arrhythmias (fatal, irregular heartbeat).
Taxifolin
Taxifolin has an astringent flavour associated with tannin-rich foods and products like vinegar aged in cherry wood, tea, wine, cocoa, and milk thistle seeds. Taxifolin could help manage inflammation, tumours, microbial infections, oxidative stress, and cardiovascular and liver disorders.
Aromadendrene
Aromadendrene is a minty/woody tasting compound found in safflower, sweet marjoram, sweet bay, eucalyptus, and spearmint. When aromadendrene and the terpene cineole interact, they promote powerful antibacterial effects. There could also be an interaction with THC, contributing to its broncho dilatory effects (i.e., it opens up the throat and lungs to help the respiratory system take in more oxygen).
Catechin
Catechin is a flavan-3-ol and has a slightly acidic – but not bitter – taste. Catechin is found in peaches, green tea, vinegar, and barley grain. Catechin could be useful in treating diseases such as arthritis, cancer, cardiovascular disease (CVD), diabetes and obesity, infections, and neurologic and oral health.