Researchers at the Dental College of Georgia and Medical College of Georgia have found early evidence that CBD could help reduce the cytokine storm and excessive lung inflammation, the major causes of death in patients with COVID-19.
The new animal model study led by Dr. Babak Baban suggests that CBD may positively impact acute respiratory distress syndrome (ARDS), one of the most dangerous symptoms that occur in patients with COVID-19. This finding could help patients who show signs of respiratory distress to avoid extreme interventions like mechanical ventilation as well as death from ARDS. Clinical reports suggest that the cytokine storm associated with ARDS is the leading cause of mortality in severe cases of some respiratory viral infections, including COVID-19.
A major problem with the novel virus is the immune response that can quickly disable the lungs. Mechanical ventilators can take over these vital functions for a while, but the evidence indicates that 30-50% of patients who get to the point of mechanical ventilation don’t survive.
Having in mind that CBD has demonstrated potent anti-inflammatory effects in a variety of pathological conditions, the scientist considered this research to be a logical step towards finding a possible solution for severe COVID-19 and other virus-induced ARDS.
Their results suggest a potential protective role for CBD during ARDS that may extend CBD as part of the treatment of COVID-19 by reducing the cytokine storm, protecting pulmonary tissues, and re-establishing inflammatory homeostasis.
ARDS in COVID-19
ARDS is a serious inflammatory lung condition responsible for the highest rate of medical complications and mortality among critically ill patients. In the case of viral respiratory infections, symptoms are usually mild, self-limiting, and confined to the upper airways. In more severe respiratory viral infections, the infection can affect the bronchoalveolar units of lower respiratory tracks, causing ARDS.
Currently, other than supportive measures, there is no definitive cure for ARDS, which presents an urgent need for creative and effective therapeutic modalities to treat this complex condition.
Numerous studies report that cannabinoids may function as immune modulators, limiting the adverse effects of inflammatory diseases. Endocannabinoids are produced in the respiratory system and cannabinoids induced bronchial dilation suggests a significant therapeutic potential for cannabinoids in the treatment of respiratory diseases, including ARDS. Importantly, several reports demonstrated that CBD can block Interleukin 6 (IL-6) in several models of inflammatory diseases. IL-6 are signaling molecules promptly produced in response to infections and tissue injuries, contributing to host defense through the stimulation of acute-phase responses, hematopoiesis, and immune reactions.
In this study, the scientist had two objectives: to develop a murine model to simulate viral infection-induced ARDS and to test the potential of cannabinoids in mitigating ARDS symptoms. They used polyribocytidylic acid in a murine model to simulate the viral disease state and clinical symptoms of ARDS.
Developing the murine model
The scientists used 12 weeks old wild-type mice, who were divided into three experimental groups of sham, control, and treatment. All mice were anesthetized with isoflurane. The sham group received phosphate-buffered saline (PBS) while control and treatment groups were administered Poly(I:C) intranasally in three once-daily doses.
CBD (isolate, tetrahydrocannabinol-free Cannabidiol Ltd., Dublin, Ireland) was delivered intraperitoneally (5 mg/kg), first dose 2 h after the second Poly(I:C) treatment and every other day for a total of three doses to the treatment group. Sham and control groups received PBS only. All mice were sacrificed at 8 days after the first Poly(I:C) application. Vital signs including temperature and blood oxygen saturation were measured before and after any treatment. Blood and lung tissues were harvested and subjected to analysis.
Intranasal administration of Poly(I:C) induced ARDSlike symptoms very similar to those of severe COVID19. Poly(I:C) reduced the blood oxygen saturation by 10% from – 81.6% to – 72.2%, and the histological examination of lung tissues demonstrated that Poly(I:C) caused a significant perivascular and peribronchiolar interstitial inflammatory infiltrate compared with the normal tissue. Poly(I:C) produced structural damages to the lung, including, not limited to, fibrosis, hypertrophy, and pulmonary edema evidenced by the widened interstitial space surrounding the airways and vasculature.
These symptoms were totally or partially reversed and returned to the level and condition of the normal after treatment with CBD. Furthermore, CBD treatment reduced the expression of IL-6 and lowered the frequencies of neutrophils in the lung.
CBD treatment reversed all the inflammatory indices and partially re-established homeostasis. In the blood, CBD treatment enhanced the lymphocyte frequencies while reducing the number of neutrophils and monocytes as well as the level of proinflammatory cytokines significantly. In the lung, CBD treatment downregulated the number of infiltrating neutrophils and macrophages markedly and reduced the level of cytokines significantly.
Present findings propose a potential immunotherapeutic role for CBD in the treatment of severe respiratory viral infections and ARDS. The current data support the notion that the anti-inflammatory function of CBD may reduce cytokine storm and mitigate the effects of exaggerated inflammation. Recent reports suggest that the interaction between the immune system and COVID-19 is a two-phased process of immune activation and immune dysregulation. Increasingly, clinical and preclinical studies show regulatory functions of CBD: inhibiting leukocyte migration and limiting inflammatory cytokine production.
Considering all potential regulatory effects of CBD as well as the vast distribution of the endocannabinoid system in the body, it is plausible that CBD may be used as a therapeutic candidate in the treatment of various inflammatory conditions including COVID-19 and other virus-induced ARDS, conclude the scientist.
More studies are required to expand and validate this therapeutic strategy.