“Staphylococcal enterotoxin‐B (SEB) is one of the most potent bacterial superantigens that exerts profound toxic effects by inducing cytokine storm. When SEB is inhaled, it can cause Acute Respiratory Distress Syndrome (ARDS), which is often fatal and currently there are no effective treatment modalities.
Experimental Approach
We used mouse model of SEB‐mediated ARDS to test the efficacy of Δ9‐tetrahydrocannabinol (THC). These mice were monitored for lung inflammation, alterations in gut and lung microbiota and production of short‐chain fatty acids (SCFA). Gene dysregulation of lung epithelial cells was studied by transcriptome arrays. Fecal microbiota transplantation (FMT) was performed to confirm the role of microbiota in suppressing ARDS.
Key results
While SEB triggered ARDS and 100% mortality in mice, THC protected the mice from fatality effects. Pyrosequencing analysis revealed that THC caused significant and similar alterations in microbiota in the lungs and gut of mice exposed to SEB. THC significantly increased the abundance of beneficial bacterial species, Ruminococcus gnavus, but decreased pathogenic microbiota, Akkermansia muciniphila. FMT confirmed that THC‐mediated reversal of microbial dysbiosis played crucial role in attenuation of SEB‐mediated ARDS. THC treatment also led to increase in SCFA, of which propionic acid was found to inhibit the inflammatory response. Transcriptome array showed that THC up‐regulated several genes like lysozyme‐1&2, β‐defensin‐2, claudin, zonula‐1, occludin‐1, Mucin2 and Muc5b while downregulating β‐defensin‐1.
Conclusions
Current study demonstrates for the first time that THC attenuates SEB‐mediated ARDS and toxicity by altering the microbiota in the lungs and the gut as well as promoting anti‐microbial and anti‐inflammatory pathways.”
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7436585/
https://bpspubs.onlinelibrary.wiley.com/doi/10.1111/bph.15226
“Acute Respiratory Distress Syndrome (ARDS) causes up to 40% mortality in humans and is difficult to treat. ARDS is also one of the major triggers of mortality associated with coronavirus-induced disease (COVID-19). We used a mouse model of ARDS induced by Staphylococcal enterotoxin B (SEB), which triggers 100% mortality, to investigate the mechanisms through which Δ9-tetrahydrocannabinol (THC) attenuates ARDS.
“In the present work, Cannabis sativa L. cv Futura 75 inflorescences, cultivated in the Abruzzo territory, were characterized for their volatile fraction through SPME-GC-MS. In addition, the essential oil extracted from these inflorescences was investigated for the antioxidant potentialities and for the terpenic profile.
“Methicillin-resistant Staphylococcus aureus (MRSA) has proven to be an imminent threat to public health, intensifying the need for novel therapeutics.
“Acute Respiratory Distress Syndrome (ARDS) is a life-threatening complication that can ensue following Staphylococcus aureus infection. The enterotoxin produced by these bacteria (SEB) acts as a superantigen thereby activating a large proportion of T cells leading to cytokine storm and severe lung injury.
“The emergence of multi-drug resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) causes a major threat to public health due to its limited therapeutic options.
“The growing concern on the antibiotic resistance spreading among bacteria has stimulated the search for valuable alternatives from plant sources.
“The