The Cannabis sativa L. plant has been the subject of increasing medical research in recent years, thanks to the large number of potential therapeutic compounds found within it. The most commonly and extensively researched of these compounds are the cannabinoids – namely cannabidiol (CBD) and Delta-9-tehtrhydrocannabinol (THC) – due to their prevalence within the plant. However, these are not the only compounds that have been found to have medicinal and therapeutic potential.
Cannflavins are a kind of flavonoid that is produced by the cannabis plant. More than 20 flavonoids have been identified in the cannabis plant, including cannflavins. Several pre-clinical studies have demonstrated that these compounds may have therapeutic potential, most notably as anti-inflammatories.
A scoping review, published in the journal Fitoterapia, aimed to understand the existing evidence of the medical potential of cannflavins and the challenges regarding clinical translation. The authors of the review identified relevant articles that referred to cannflavins regarding its production, isolation, and pre-clinical evidence.
Existing Research on the Potential of Cannflavins
A total of 26 relevant articles referring to cannflavins, including studies and articles regarding cultivation, extraction, pre-clinical and clinical research were included in the review. The majority of these studies detailed original research of cannflavin A. Fewer assessed cannflavin B, cannflavin C and isocannflavin B. The review highlighted that one of the greatest challenges to clinical translation of research is due to the low concentrations of cannflavins available to be extracted from individual cannabis plants. However, the recent discovery of a biosynthetic pathway may open up potential opportunities in the future to scale production and therefore research.
The existing literature demonstrates that cannflavins A and B have promising anti-inflammatory potential. Some studies showed that these cannflavins demonstrate inhibition of the production of prostaglandins that have been implicated in driving inflammation. Overactivity of these compounds is associated with inflammatory disease processes. Evidence shows that mice with knockout mPGES-1 display reduced inflammation, particularly within rheumatoid arthritis models.
Cannflavins A and B have also been found to inhibit the production of 5-lipo-oxygenase – the initial catalytic enzyme in the pathway for leukotriene synthesis from arachidonic acid. As Leukotrienes have been implicated in a wide range of inflammatory diseases, this inhibition may enhance the effects of cannflavins as anti-inflammatories in a clinical setting.
One study included in the review assessed the neoplastic potential of isocannflavin B in in vitro and in vivo models of pancreatic cancer. This study found that when co-administered with radiation in a smart radiotherapy biomaterial, isocannflavin B demonstrated a statistically significant reduction in pancreatic tumour size.
Pre-clinical research also suggests that isocannflavin B may play a role in inducing autophagy in hormone-responsive breast cancers. The implications of autophagy in the treatment of cancer are complicated however and clinical research is awaited.
The collection of studies included in this scoping review demonstrate that cannflavins may have significant therapeutic potential in a number of research areas. The anti-inflammatory and anti-cancer properties of these compounds present the greatest potential. However, the findings of these studies have yet to be translated into a clinical setting, which is crucial for developing our knowledge of the mechanisms by which these compounds work. The recent discovery of the biosynthetic pathway of cannflavins A and B may offer a promising opportunity to expand the clinical research into these compounds.
The authors acknowledge that, although the studies included in this review demonstrated promising results for the therapeutic potential of cannflavins, clinical validation of these findings is lacking. This review highlights that these areas of research require focused clinical evaluation in institutions with a track record of clinical transition across these research subjects.