In Search of Preventative Strategies: Novel Anti- Inflammatory High-CBD Cannabis Sativa Extracts Modulate ACE2 Expression in COVID-19 Gateway Tissues
Bo Wang, Anna Kovalchuk, Dongping Li, Yaroslav Ilnytskyy, Igor Kovalchuk and Olga Kovalchuk
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 19 April 2020
doi : 10.20944/preprints202004.0315.v1
Abstract : With the rapidly growing pandemic of COVID-19 caused by the new and challenging to treat zoonotic SARS-CoV2 coronavirus, there is an urgent need for new therapies and prevention strategies that can help curtail disease spread and reduce mortality. Inhibition of viral entry and thereby spread constitute plausible therapeutic avenues. Similar to other respiratory pathogens, SARS-CoV2 is transmitted through respiratory droplets, with potential for aerosol and contact spread. It uses receptor-mediated entry into the human host via angiotensin-converting enzyme II (ACE2) that is expressed in lung tissue, as well as oral and nasal mucosa, kidney, testes, and the gastrointestinal tract. Modulation of ACE2 levels in these gateway tissues may prove a plausible strategy for decreasing disease susceptibility. Cannabis sativa, especially one high in the antiinflammatory cannabinoid cannabidiol (CBD), has been proposed to modulate gene expression and inflammation and harbour anti-cancer and anti-inflammatory properties. Working under the Health Canada research license, we have developed over 800 new Cannabis sativa lines and extracts and hypothesized that high-CBD C. sativa extracts may be used to modulate ACE2 expression in COVID- 19 target tissues. Screening C. sativa extracts using artificial human 3D models of oral, airway, and intestinal tissues, we identified 13 high CBD C. sativa extracts that modulate ACE2 gene expression and ACE2 protein levels. Our initial data suggest that some C. sativa extract down-regulate serine protease TMPRSS2, another critical protein required for SARS-CoV2 entry into host cells. While our most effective extracts require further large-scale validation, our study is crucial for the future analysis of the effects of medical cannabis on COVID-19. The extracts of our most successful and novel high CBD C. sativa lines, pending further investigation, may become a useful and safe addition to the treatment of COVID-19 as an adjunct therapy. They can be used to develop easy-to-use preventative treatments in the form of mouthwash and throat gargle products for both clinical and at-home use. Such products ought to be tested for their potential to decrease viral entry via the oral mucosa. Given the current dire and rapidly evolving epidemiological situation, every possible therapeutic opportunity and avenue must be considered.
Keywords : COVID-19; SARS-CoV2; ACE2 receptor; medical cannabis; CBD
Currently, there is a global pandemic of COVID-19 disease caused by the SARS-CoV2 zoonotic coronavirus. The disease started with a fast-growing outbreak in Wuhan, China, in December 2019, and by April of 2020 spread throughout the entire world, affecting over 1.42 million people and killing over 82,000. Worldwide, death rates vary between 2 and 10 percent.
SARS-CoV2 possesses fast human-human transmission, with a doubling time of around 6-7 days and a Ro of around 2.2 1,2. Similar to other respiratory pathogens, SARS-CoV2 is transmitted through respiratory droplets from coughing and sneezing. However, aerosol transmission and close contact transmission cannot be ruled out as a means of disease spread 2. While COVID-19 symptoms are many, they can be broken up into several categories: typical influenza-like symptoms, such as fever, fatigue, myalgia, and headache; respiratory symptoms, such as dry cough and dyspnea; and gastrointestinal symptoms, such as diarrhea and nausea 3. Anosmia and ageusia, the loss of the senses of smell and taste, respectively, are also common. Overall, COVID- 19 has a broad clinical spectrum, ranging from asymptomatic and mild disease to pneumonia that often progresses to respiratory failure, major organ failure, and death 2,4. Up to 20% of cases are severe and require hospital-admission, and, currently, there exists no vaccine for this virus, nor any known approved drug therapy.
SARS-CoV2 was first isolated from human airway epithelial cells 5 and found to be similar to the severe acute respiratory syndrome coronavirus (SARS-CoV) 6, and hence was named SARS-CoV2. It is now well accepted that angiotensin-converting enzyme II (ACE2) is the cell receptor of SARS-CoV2 and the main route for receptor-mediated entry of the virus into the human host 7. Since ACE2 plays a pivotal role in cellular entry, ACE2 expressing cells serve as critical viral gateways 8.
To date, ACE2 expression was found in lung tissue, nasal mucosa, kidney, testes, and the gastrointestinal tract. High levels of ACE2 were seen in lung and intestinal epithelia 9. An in-depth analysis of The Cancer Genome Atlas (TCGA) and Functional Annotation of The Mammalian Genome Cap Analysis of Gene Expression (FANTOM5 CAGE) datasets revealed that ACE2 is expressed in oral mucosa and is enriched in the epithelial cells of the tongue. ACE2 expression in oral, lung, and intestinal epithelia may thus constitute important routes of SARS-CoV2 entry into hosts 10.
A recent study by Xu and colleagues reported high levels of ACE2 expression in oral epithelial tissues and suggested that the oral cavity could be regarded as a high-risk target for SARS-CoV2 infectious susceptibility, and thereby an important target for prevention strategies 10. Similarly, numerous studies have reported high levels of ACE2 in the lower respiratory tract, and higher levels of ACE2 expression, such as those seen in smokers and patients with chronic obstructive pulmonary disease (COPD), were associated with higher COVID-19 predisposition and more severe disease 11.
Modulation of ACE2 levels in gateway tissues may thus prove a plausible strategy to decrease disease susceptibility. These strategies ought to be accessible, easy to use, and, ideally, should fall into the generally regarded as safe (GRAS) category. Cannabis sativa, especially one high in the anti inflammatory cannabinoid cannabidiol (CBD), has been proposed to modulate gene expression and inflammation and is under investigation for several potential therapeutic applications against cancer and various inflammatory diseases 12,13. Working under the Health Canada research license, we have developed over 800 new Cannabis sativa lines and extracts, as well as a method of using them as a means to regulate gene expression and molecular cascades that drive inflammation and other vital cellular processes (PCT/IL2019/051340; US16/711,647; PCT/IL2019/051342; US16/713,029; PCT/IL201 /051341; US16/711,655; PCT/IL2019/051343; US16/713,030). Serendipitously, we noted that cannabis may also affect ACE2. Here, we hypothesized that high-CBD C. sativa extracts may be used to modulate ACE2 expression in COVID- 19 target tissues.