Cannabis in the Time of Coronavirus Disease 2019: The Yin and Yang of the Endocannabinoid System in Immunocompetence

A Scientometric Visualization Analysis for Molecular Mechanisms of Substance Abuse and Its Neurotoxicity From 1997 to 2021

Substance abuse has become a global problem due to drug-induced addiction and neurotoxicity, which causes a huge physical, social, and financial burden. Various kinds of drugs can hijack the users’/abusers’ behavior and associated neurocircuitry. To summarize recent scientific advances on drug abuse, we reviewed relevant publications to analyze research progress and such trends through bibliometric ways. Based on retrieval strategies, a total of 681 scientific records published from 1997 to 2021 were screened and included in the Web of Science (WoS) database. Further scientometric analysis revealed that annual publication output increased across this period, with the United States of America (USA) contributing a significant number of reasons. Research has focused on neurotransmitter, oxidative stress, mitochondrial system injury, and other neurotoxic mechanisms. Neuroimmune, neurotoxic targets, and new psychoactive substances have been hot topics in recent years, which deserve continued research in the future. Specific research on molecular mechanisms has progressed across this period, with an emphasis on the root cause of toxicity and molecular targets for therapy. Moreover, collaborations of international multi-disciplinary research teams have been efficient and need to be encouraged for addiction research and the development of appropriate therapeutic processes.

Bridging Disciplines: Applications of Forensic Science and Industrial Hemp

Forensic laboratories are required to have analytical tools to confidently differentiate illegal substances such as marijuana from legal products (i.e., industrial hemp). The Achilles heel of industrial hemp is its association with marijuana. Industrial hemp from the Cannabis sativa L. plant is reported to be one of the strongest natural multipurpose fibers on earth. The Cannabis plant is a vigorous annual crop broadly separated into two classes: industrial hemp and marijuana. Up until the eighteenth century, hemp was one of the major fibers in the United States. The decline of its cultivation and applications is largely due to burgeoning manufacture of synthetic fibers. Traditional composite materials such as concrete, fiberglass insulation, and lumber are environmentally unfavorable. Industrial hemp exhibits environmental sustainability, low maintenance, and high local and national economic impacts. The 2018 Farm Bill made way for the legalization of hemp by categorizing it as an ordinary agricultural commodity. Unlike marijuana, hemp contains less than 0.3% of the cannabinoid, Δ9-tetrahydrocannabinol, the psychoactive compound which gives users psychotropic effects and confers illegality in some locations. On the other hand, industrial hemp contains cannabidiol found in the resinous flower of Cannabis and is purported to have multiple advantageous uses. There is a paucity of investigations of the identity, microbial diversity, and biochemical characterizations of industrial hemp. This review provides background on important topics regarding hemp and the quantification of total tetrahydrocannabinol in hemp products. It will also serve as an overview of emergent microbiological studies regarding hemp inflorescences. Further, we examine challenges in using forensic analytical methodologies tasked to distinguish legal fiber-type material from illegal drug-types.

Potential Neuroprotective Effect of Cannabinoids in Covid-19 Patients

The global pandemic caused by the SARS-CoV-2 virus began in early 2020 and is still present. The respiratory symptoms caused by COVID-19 are well established, however, neurological manifestations that may result from direct or indirect neurological damage after SARS-CoV-2 infection have been reported frequently. The main proposed pathophysiological processes leading to neurological damage in COVID-19 are cerebrovascular disease, and indirect mechanisms of inflammatory / autoimmune origin. A growing number of studies confirm that neuroprotective measures should be maintained in COVID-19 patients. On the other hand, cannabinoids have been the subject of various studies that propose them as potential promising drugs in chronic neurodegenerative diseases due to their powerful neuroprotective potential. In this review we address the possible mechanism of action of cannabinoids as a neuroprotective treatment in patients infected by SARS-CoV-2. The endocannabinoid system is found in multiple systems within the body, including the immune system. Its activation can lead to beneficial results, such as a decrease in viral entry, a decrease in viral replication, and a decrease in pro-inflammatory cytokines such as IL-2, IL-4, IL-6, IL-12, TNF-α or IFN-c through CB2R expression induced during inflammation by SARS-CoV-2 infection in the central nervous system.

Implications of Cannabis and Cannabinoid Use in COVID-19: Scoping Review

ABSTRACT Objective: to identify and synthesize studies on the effects of cannabis use and its relation with SARS-CoV-2, as well as the therapeutic possibilities of using cannabinoids in the prevention and treatment of COVID-19. Methods: scoping review, in the BVS, PubMed, SCIELO, CINAHL, SCOPUS, Web of Science, MedNar, CAPES and ProQuest databases, with no language restriction and year limitation. Narrative synthesis was performed. Results: cannabis use causes changes in the respiratory and vascular system, it reduces the production of cytokines, which affects the users’ immune system, increasing the susceptibility to infection and progression of COVID-19. However, studies have suggested the use of cannabinoids in the prophylaxis and treatment of COVID-19, due to their anti-inflammatory effect. Conclusions: the use of inhaled cannabis increases the progression and severity of the infection. On the other hand, the benefits of cannabinoids seem promising to modulate the immune system, but it needs further studies.

A review of natural products, their effects on SARS-CoV-2 and their utility as lead compounds in the discovery of drugs for the treatment of COVID-19

During the COVID-19 pandemic lasting now for well more than a year, nearly 247 million cases have been diagnosed and over 5 million deaths have been recorded worldwide as of November 2021. The devastating effects of the SARS-CoV-2 virus on the immune system lead to the activation of signaling pathways involved in inflammation and the production of inflammatory cytokines. SARS-CoV-2 displays a great deal of homology with other coronaviruses, especially SARS-CoV and MERS-CoV which all display similar components which may serve as targets, namely the Spike (S) protein, the main protease (M^Pro) which is a chymotrypsin-like protease (CL^Pro) and RNA-directed RNA polymerase (RdRp). Natural constituents found in traditional herbal medicines, dietary supplements and foods demonstrate activity against SARS-CoV-2 by affecting the production of cytokines, modulating cell signaling pathways related to inflammation and even by direct interaction with targets found in the virus. This has been demonstrated by the application of fluorescence resonance energy transfer (FRET) experiments, assays of cytopathic effect (CPE) and in silico molecular docking studies that estimate binding strength. Glycyrrhizin, flavonoids such as quercetin, kaempferol and baicalein, and other polyphenols are the most common constituents found in Traditional Chinese Medicines that modulate inflammation and cell signaling pathways, and bind viral targets demonstrating valuable effects against SARS-CoV-2. However, the bioavailability of these natural products and their dependence on each other in extracts make it difficult to assess their actual utility in the treatment of COVID-19. Therefore, more can be learned through rational drug design based on natural products and from well-designed clinical trials employing specific doses of standardized combinations.

The potential of cannabinoids and inhibitors of endocannabinoid degradation in respiratory diseases

The global incidence of respiratory diseases and complications is increasing. Therefore, new methods of treatment, as well as prevention, need to be investigated. A group of compounds that should be considered for use in respiratory diseases is cannabinoids. There are three groups of cannabinoids - plant-derived phytocannabinoids, synthetic cannabinoids, and endogenous endocannabinoids including the enzymes responsible for their synthesis and degradation. All cannabinoids exert their biological effects through either type 1 cannabinoid receptors (CB₁) and/or type 2 cannabinoid receptors (CB₂). In numerous studies (in vitro and in vivo), cannabinoids and inhibitors of endocannabinoid degradation have shown beneficial anti-inflammatory, antioxidant, anti-cancer, and anti-fibrotic properties. Although in the respiratory system, most of the studies have focused on the positive properties of cannabinoids and inhibitors of endocannabinoid degradation. There are few research reports discussing the negative impact of these compounds. This review summarizes the properties and mechanisms of action of cannabinoids and inhibitors of endocannabinoid degradation in various models of respiratory diseases. A short description of the effects selected cannabinoids have on the human respiratory system and their possible use in the fight against COVID-19 is also presented. Additionally, a brief summary is provided of cannabinoid receptors properties and their expression in the respiratory system and cells of the immune system.

β-Caryophyllene, A Natural Dietary CB2 Receptor Selective Cannabinoid can be a Candidate to Target the Trinity of Infection, Immunity, and Inflammation in COVID-19

Coronavirus disease (COVID-19), caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an ongoing pandemic and presents a public health emergency. It has affected millions of people and continues to affect more, despite tremendous social preventive measures. Identifying candidate drugs for the prevention and treatment of COVID-19 is crucial. The pathogenesis and the complications with advanced infection mainly involve an immune-inflammatory cascade. Therefore, therapeutic strategy relies on suppressing infectivity and inflammation, along with immune modulation. One of the most promising therapeutic targets for the modulation of immune-inflammatory responses is the endocannabinoid system, particularly the activation of cannabinoid type 2 receptors (CB2R), a G-protein coupled receptor which mediates the anti-inflammatory properties by modulating numerous signaling pathways. To pharmacologically activate the CB2 receptors, a naturally occurring cannabinoid ligand, beta-caryophyllene (BCP), received attention due to its potent anti-inflammatory, antiviral, and immunomodulatory properties. BCP is recognized as a full selective functional agonist on CB2 receptors and produces therapeutic effects by activating CB2 and the nuclear receptors, peroxisome proliferator-activated receptors (PPARs). BCP is regarded as the first dietary cannabinoid with abundant presence across cannabis and non-cannabis plants, including spices and other edible plants. BCP showed tissue protective properties and favorably modulates numerous signaling pathways and inhibits inflammatory mediators, including cytokines, chemokines, adhesion molecules, prostanoids, and eicosanoids. Based on its pharmacological properties, molecular mechanisms, and the therapeutic potential of BCP as an immunomodulator, anti-inflammatory, organ-protective, and antiviral, we hypothesize that BCP could be a promising therapeutic and/or preventive candidate to target the triad of infection, immunity, and inflammation in COVID-19. In line with numerous studies that proposed the potential of cannabinoids in COVID-19, BCP may be a novel candidate compound for pharmaceutical and nutraceutical development due to its unique functional receptor selectivity, wide availability and accessibility, dietary bioavailability, nonpsychoactivity, and negligible toxicity along with druggable properties, including favorable pharmacokinetic and physicochemical properties. Based on reasonable pharmacological mechanisms and therapeutic properties, we speculate that BCP has potential to be investigated against COVID-19 and will inspire further preclinical and clinical studies.

Addictions in the COVID-19 era: Current evidence, future perspectives a comprehensive review

BACKGROUND

In the context of the COVID-19 worldwide pandemic, an up-to-date review of current challenges in addictions is necessary. While large scale disasters may have an impact on substance use and addictions, the use of some substances is also likely to modify the risk of COVID-19 infection or course. Many countries have imposed lockdowns. Whether this quarantine or the end of lockdown measures will have an impact on substance use is discussed. The aim of this review is to gather knowledge for clinicians and to guide public health policies during/after lockdown.

METHODS

PubMed was reviewed in August 6th (2020), to determine the current evidences and observations concerning the addictions and SARS-CoV2. We used all the names of the severe acute respiratory syndrome of coronavirus 2 (SARS-CoV2 previously 2019 nCoV), the name of the coronavirus disease 2019 (COVID-19), and common substances of abuse. For the physiopathological parts, searches were conducted using key words such as "infection" or "pneumonia". For the lockdown effects, key words such as "quarantine", "disaster" or "outbreak" were used.

RESULTS

Overall, pathophysiological data showed an increased risk of infections for individuals with Substance Use Disorders (SUD) and a possible protective role of nicotine. During lockdown, there is a substantial risk of increasing SUDs. Individuals with opioid use disorder are particularly at risk of relapse or of involuntary withdrawal. After lockdown, increase of use may be observed as far as years after. Individuals with addictions are at higher risk of multimorbidity and mortality during COVID outbreak.

CONCLUSION

This review describes useful strategies in clinical practice, including a systematic assessment of addiction comorbidity during this almost worldwide lockdown/pandemic. This review also highlights important areas for future research.

Opportunities, Challenges and Pitfalls of Using Cannabidiol as an Adjuvant Drug in COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may lead to coronavirus disease 2019 (COVID-19) which, in turn, may be associated with multiple organ dysfunction. In this review, we present advantages and disadvantages of cannabidiol (CBD), a non-intoxicating phytocannabinoid from the cannabis plant, as a potential agent for the treatment of COVID-19. CBD has been shown to downregulate proteins responsible for viral entry and to inhibit SARS-CoV-2 replication. Preclinical studies have demonstrated its effectiveness against diseases of the respiratory system as well as its cardioprotective, nephroprotective, hepatoprotective, neuroprotective and anti-convulsant properties, that is, effects that may be beneficial for COVID-19. Only the latter two properties have been demonstrated in clinical studies, which also revealed anxiolytic and antinociceptive effects of CBD (given alone or together with Δ9-tetrahydrocannabinol), which may be important for an adjuvant treatment to improve the quality of life in patients with COVID-19 and to limit post-traumatic stress symptoms. However, one should be aware of side effects of CBD (which are rarely serious), drug interactions (also extending to drugs acting against COVID-19) and the proper route of its administration (vaping may be dangerous). Clearly, further clinical studies are necessary to prove the suitability of CBD for the treatment of COVID-19.

The Immunopathology of COVID-19 and the Cannabis Paradigm

Coronavirus disease-19 caused by the novel RNA betacoronavirus SARS-CoV2 has first emerged in Wuhan, China in December 2019, and since then developed into a worldwide pandemic with >99 million people afflicted and >2.1 million fatal outcomes as of 24th January 2021. SARS-CoV2 targets the lower respiratory tract system leading to pneumonia with fever, cough, and dyspnea. Most patients develop only mild symptoms. However, a certain percentage develop severe symptoms with dyspnea, hypoxia, and lung involvement which can further progress to a critical stage where respiratory support due to respiratory failure is required. Most of the COVID-19 symptoms are related to hyperinflammation as seen in cytokine release syndrome and it is believed that fatalities are due to a COVID-19 related cytokine storm. Treatments with anti-inflammatory or anti-viral drugs are still in clinical trials or could not reduce mortality. This makes it necessary to develop novel anti-inflammatory therapies. Recently, the therapeutic potential of phytocannabinoids, the unique active compounds of the cannabis plant, has been discovered in the area of immunology. Phytocannabinoids are a group of terpenophenolic compounds which biological functions are conveyed by their interactions with the endocannabinoid system in humans. Here, we explore the anti-inflammatory function of cannabinoids in relation to inflammatory events that happen during severe COVID-19 disease, and how cannabinoids might help to prevent the progression from mild to severe disease.

Cannabis sativa L. as a Natural Drug Meeting the Criteria of a Multitarget Approach to Treatment

Cannabis sativa L. turned out to be a valuable source of chemical compounds of various structures, showing pharmacological activity. The most important groups of compounds include phytocannabinoids and terpenes. The pharmacological activity of Cannabis (in epilepsy, sclerosis multiplex (SM), vomiting and nausea, pain, appetite loss, inflammatory bowel diseases (IBDs), Parkinson's disease, Tourette's syndrome, schizophrenia, glaucoma, and coronavirus disease 2019 (COVID-19)), which has been proven so far, results from the affinity of these compounds predominantly for the receptors of the endocannabinoid system (the cannabinoid receptor type 1 (CB1), type two (CB2), and the G protein-coupled receptor 55 (GPR55)) but, also, for peroxisome proliferator-activated receptor (PPAR), glycine receptors, serotonin receptors (5-HT), transient receptor potential channels (TRP), and GPR, opioid receptors. The synergism of action of phytochemicals present in Cannabis sp. raw material is also expressed in their increased bioavailability and penetration through the blood-brain barrier. This review provides an overview of phytochemistry and pharmacology of compounds present in Cannabis extracts in the context of the current knowledge about their synergistic actions and the implications of clinical use in the treatment of selected diseases.

The Relevance of Complementary and Integrative Medicine in the COVID-19 Pandemic: A Qualitative Review of the Literature

Background: During the COVID-19 pandemic people are facing risks of adverse health effects due to the restrictions implemented such as quarantine measures, reduced social contact, and self-isolation. In this qualitative review, we collected data on potential preventive and therapeutic health benefits of Complementary and Integrative Medicine (CIM) that might be useful during the COVID-19 pandemic. We have reviewed the scientific literature to summarize CIM practices that could be beneficial for improving physical and mental health and well-being of the population under the current pandemic circumstances. It must be noted that this review is not SARS-CoV-2 specific and we explicitly do not intend to make any SARS-CoV-2 specific health claims in this article. Methods and Findings: A qualitative, non-systematic literature review was conducted in Medline to identify literature describing preventive and therapeutic CIM approaches for strengthening mental and physical health. For a variety of CIM approaches clinical evidence was identified, indicating beneficial effects. CIM approaches include specific dietary measures and selected micronutrients, physical activity, techniques from Mind-Body Medicine, single botanicals or botanical compounds, and spending time in nature among others. The effects of CIM measures on conditions like obesity and hypertension are of special relevance here, as these conditions are considered as risk factors for a severe course of COVID-19. Moreover, a possibly direct effect of CIM approaches on immune functions and clinical parameters in respiratory tract infections, such as influenza, were identified. The findings of this review could be helpful for clinicians, patients, and the general population during the current pandemic when discussing and/or considering CIM options. Conclusions: CIM offers a variety of preventive and therapeutic options for strengthening physical and mental resilience, which could also be useful in the current COVID-19 pandemic. The evidence of CIM approaches with a potential benefit in the COVID-19 pandemic in different areas is worth to be analyzed. While this qualitative review has several obvious limitations, it might serve as useful starting point for further research on this topic.

The interaction between the endocannabinoid system and the renin angiotensin system and its potential implication for COVID-19 infection

Background

Coronavirus disease 2019 (COVID-19) is spreading fast all around the world with more than fourteen millions of detected infected cases and more than 600.000 deaths by 20th July 2020. While scientist are working to find a vaccine, current epidemiological data shows that the most common comorbidities for patients with the worst prognosis, hypertension and diabetes, are often treated with angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs).

Body

Both ACE inhibitors and ARBs induce overexpression of the angiotensin converting enzyme 2 (ACE-2) receptor, which has been identified as the main receptor used by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to enter into the alveolar cells of the lungs. While cannabinoids are known to reduce hypertension, the studies testing the hypotensive effects of cannabinoids never addressed their effects on ACE-2 receptors. However, some studies have linked the endocannabinoid system (ECS) with the renin angiotensin system (RAS), including a cross-modulation between the cannabinoid receptor 1 (CB1) and angiotensin II levels.

Conclusion

Since there are around 192 million people using cannabis worldwide, we believe that the mechanism underlying the hypotensive properties of cannabinoids should be urgently studied to understand if they can also lead to ACE-2 overexpression as other antihypertensive drugs do.