Cannabidiol for Viral Diseases : Hype or Hope ?
Alex Mabou Tagne, Barbara Pacchetti, Mikael Sodergren, Marco Cosentino, and Franca Marino
Cannabis and Cannabinoid Research, 2020,1-11.
Doi : 10.1089/can.2019.0060
Background : The possibility of cannabidiol (CBD) to be used as an antiviral or to treat viral diseases has received limited attention so far, despite the growing number of claims that CBD could be used for the treatment of viral infection-related conditions.
Aim and Methods : Therefore, we systematically retrieved and critically evaluated the scientific literature available on PubMed and the claims on the Internet, to assess the current state of knowledge on the use of CBD in viral diseases, and to provide suggestions for future research directions.
Results : PubMed search referenced two original articles supporting the use of CBD for the treatment of hepatitis C and Kaposi sarcoma and one article reporting the ability of CBD to reduce neuro-inflammation in a virusinduced animal model of multiple sclerosis. Internet search found 25 websites claiming more indications for CBD. Remarkably, those claims were provided mostly by commercial websites and were not supported by appropriate scientific references.
Conclusion : Although preclinical studies suggest the potential effectiveness of CBD in viral diseases such as hepatitis C and Kaposi sarcoma, clinical evidence is still lacking. Anecdotal experiences of CBD use retrieved on the Internet, on the other side, lack any support from sound scientific evidence, although they might in some cases provide suggestions for conditions associated with viral infections that may deserve proper assessment in welldesigned clinical trials.
Keywords : cannabidiol; cannabinoid; antiviral effects; hepatitis C; herpes; Ebola
Cannabis (Cannabis sativa L., fam. Cannabaceae) and its derivatives are currently credited with treating a variety of medical conditions, including pain in adults, chemotherapy-induced nausea and vomiting, and spasticity associated with multiple sclerosis (MS).1 Many medical applications of cannabis and cannabinoids are related to their anti-inflammatory activity,which is, however, a double-edged sword under certain conditions. Particularly in viral infections, the anti-inflammatory activity of D9 tetrahydrocannabinol (D9-THC),2 the main component of cannabis, may jeopardize host immune responses to acute viral infections, leading to disease progression and death in the worst case.3,4 Nonetheless, D9-THC may be beneficial in viral infections where the host inflammatory response is pathogenic,3 although its psychoactive and addictive potential is a significant limitation to its therapeutic development.
Cannabidiol (CBD) is one of the main cannabinoids found in the cannabis plant that, unlike D9-THC, is devoid of psychotropic effects and addictive potential.5 Long neglected, CBD is currently gaining traction as a therapeutic vector for a vast range of pathological conditions.6 Recently, Epidiolex, a CBD-only drug, has been approved by Food and Drug Administration (FDA) to treat seizures in children with intractable forms of epilepsy.7 Since then, researchers have begun to search for more therapeutic applications for CBD.
Fragmentary evidence points to a possible use of CBD in viral infections. Indeed, several plant-derived compounds do have proven antiviral activity across a broad array of different chemical groups and structures.8,9 The main point is that plant secondary metabolites have evolved to become antimicrobial, and this includes many phenol-based compounds, such as those with terpenoid moieties.10 Despite the lack of research specifically on phytocannabinoids, there is a lot of scientific data on terpenoids.9,10 There is also a lot on the known targets of CBD, for instance, around its ability to induce apoptosis in mammalian cells.11 Apoptosis is well known to be a critical component of host responses to viral infections. 12 On the basis of this background, we critically reviewed the scientific literature to examine the current state of knowledge on the use of CBD in viral infections, and to provide suggestions for future research directions and perspectives. Since CBD-based products are popular and easily available to the general public,13 and the Internet is increasingly used as a source of health-related information, 14 we also consulted the Internet for anecdotal evidence or claims that CBD is being used or reported as an antiviral or in general as an aid in viral diseases.