Thread by @trikomes

#ScienceBreakdown: "Administration of THC Post-Staphylococcal Enterotoxin B Exposure Protects Mice From Acute Respiratory Distress Syndrome."

Full study here: frontiersin.org/articles/10.33…

Breakdown of the study in this thread.

#cannabis

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Acute Respiratory Distress Syndrome (ARDS) = deadly condition where lungs get super inflamed b/c immune system responds too strongly. This leads to lots of collateral damage to throughout the body.

Mortality rate in humans = 38.5%. No current drugs exist that help very much.

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ARDS can be induced by "super antigens," e.g. bacterial proteins like SEB that cause immune system to go haywire. If you expose mice to SEB, 100% die within ~one week.

Basic question: can death from ARDS be prevented by an immunosuppressive like THC?

en.wikipedia.org/wiki/Superanti…

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Why did scientists even think to look at THC and whether it impacts lung inflammation?

There's good evidence THC suppresses inflammation. Lots this anti-inflammatory effect probably comes from THC's activation of CB2 receptors in our immune system.

So what did they study?

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Basic groups of mice:

Naive = normal mice.

Veh = Mice given harmless "vehicle" (saline).

THC = Mice given THC. Another control to see if THC alone causes changes.

SEB+Veh: Mice given SEB, which induces ARDS.

SEB+THC: Mice given both SEB and THC.

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First they look at lung tissue in each group of mice. From bottom to top:

Naive, Veh, and THC groups look normal and do not differ across these control groups. This is what normal mouse lung tissue should look like.

Ok, what about SEB+Veh and SEB+THC groups?

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Lung tissue in SEB+Veh group is darker + more dense. This indicates lots of inflammation.

Lung tissue from SEB+THC mice looks way better. Not quite normal but way better than the SEB+Veh mice.

So lung tissue looks better, but what does mortality look like between groups?

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This is pretty insane. 100% of SEB+Veh mice that develop ARDS end up being put down b/c they get so sick.

100% of SEB+THC mice survive. These mice were exposed to THC when they were exposed to SEB, and given two more doses one and two days later.

All of them survive.

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Study goes into more detail. Basic idea is THC can reduce pro-inflammatory cytokines + increase anti-inflammatory cytokines.

Cytokines are important molecules for immune response. You may have heard of "cytokine storms" mentioned along w/ #COVID19.

en.wikipedia.org/wiki/Cytokine_…

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So, how much THC did they give mice? Three doses: 20mg/kg when exposed to the SEB super antigen, then two doses of 10 mg/kg.

Doing a little math and taking differences in drug metabolism into account, this is like a 150 lb. human taking ~178 mg THC, then two 89 mg doses.

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178 mg of THC would effect people very differently depending on tolerance levels. 178 mg would be a *very* large dose for most people. You would be very, very high. Probably all day.

I have friends who can handle 178 mg THC, but even then, that's a pretty big dose.

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So, does this mean we should all be taking THC if we have a respiratory infection like #COVID19? No!

First, this study was in mice. You always need to be cautious about extrapolating from mice to humans. It often does not work out. Follow @justsaysinmice to help see why.

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Second, immune system is a balancing act. Too little immune response is bad b/c infections run wild. Too much is bad b/c the body gets damaged.

Timing, dose and your own health quirks matter. Never a good idea to blindly take anything when you read about one study online.

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But this study did have some striking results, and was peer-reviewed and conducted by a serious group... unlike some other recent "science" that's been posted during the #COVID19 pandemic.

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Main result is a striking example of how cannabinoids like THC can have powerful anti-inflammatory effects. In this study, they suggest CB2 receptors have a lot to do with it. But THC also gets you high through CB1 receptors, which limits its clinical use in humans.

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Would be interesting to see if other drugs can act through CB2 to have this effect w/o the psychoactive effects of THC.

One candidate is the terpene caryophyllene. It iss anti-inflammatory through CB2 and is the only #cannabis terpene known to act on cannabinoid receptors.

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#Cannabis products high in caryophyllene + CBD but low in THC are interesting to think about.

Best example of a strain w/ a chemical profile in this direction that I can find on @Leafly is the "Lifter" strain, bred by @SethOregon (link below).

leafly.com/strains/lifter

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