Cannflavins - From plant to patient: A scoping review

Introduction: Cannflavins are a group of prenylflavonoids derived from Cannabis sativa L.. Cannflavin A (CFL-A), B (CFL-B) and C (CFL-C) have been heralded for their anti-inflammatory properties in pre-clinical evaluations. This scoping review aims to synthesise the evidence base on cannflavins to provide an overview of the current research landscape to inform research strategies to aid clinical translation.

Methods: A scoping review was conducted of EMBASE, MEDLINE, Pubmed, CENTRAL and Google Scholar databases up to 26th February 2020. All studies describing original research on cannflavins and their isomers were included for review.

Results: 26 full text articles were included. CFL-A and CFL-B demonstrated potent anti-inflammatory activity via inhibition of 12-o-tetradecanoylphorbol 13-acetate induced PGE2 release (CFL-A half maximal inhibitory concentration (IC50): 0.7 μM; CFL-B IC50: 0.7 μM) and microsomal prostaglandin E synthase-1 (CFL-A IC50: 1.8 μM; CFL-B IC50: 3.7 μM). Outcomes were also described in preclinical models of anti-oxidation (CFL-A), anti-parasitic activity (CFL-A, CFL-C), neuroprotection (CFL-A) and cancer (Isocannflavin B, a CFL-B isomer). In-silico screening identified that CFL-A has binding affinity with viral proteins that warrant further investigation.

Conclusions: Cannflavins demonstrate a number of promising therapeutic properties, most notably as an anti-inflammatory agent. Low yields of extraction however have previously limited research to small pre-clinical investigations. Identification of cannflavin-rich chemovars, novel extraction techniques and recent identification of a biosynthetic pathway will hopefully allow research to be scaled appropriately. In order to fully evaluate the therapeutic properties of cannflavins focused research now needs to be embedded within institutions with a track-record of clinical translation.

Keywords: Cannabis; Cannflavins; Drug discovery; Inflammation; Pharmacognosy.