Vitamin A (retinol) Is Endotoxin (LPS / TLR4) Antagonist

Discussion in 'Scientific Studies' started by haidut, Aug 3, 2016.

  1. haidut

    haidut Member

    Joined:
    Mar 18, 2013
    Messages:
    16,446
    Gender:
    Male
    Location:
    USA / Europe
    Another one in the series of endotoxin antagonism featuring so far vitamins D and B2.
    Vitamin B2 (riboflavin) Is Endotoxin Antagonist
    Vitamin B2 Remarkably Effective Against Endotoxin, Sepsis, And Other Bacterial Infections
    Vitamin D Is Endotoxin (LPS / TLR4) Antagonist, May Treat LPS-linked Conditions

    This study used plain retinol, which can easily be mimicked by supplementation with retinyl esters like acetate and palmitate, with the acetate ester having higher retinol equivalency and this allowing lower dose to achieve the same effects.

    Retinol suppresses the activation of Toll-like receptors in MyD88- and STAT1-independent manners. - PubMed - NCBI
    "...However, it has not been fully elucidated how retinol regulates TLR activation in macrophages. Therefore, we investigated the effect of retinol on the activation of TLRs and downstream signaling pathways in macrophages. We found that retinol attenuated TLR2-, TLR3-, and TLR4-mediated production of cytokines and chemokines in macrophages. The inhibitory effects of retinol on TLR activation were still observed in MyD88- or signal transducer and activator of transcription 1 (STAT1)- deficient macrophages, suggesting that MyD88 and STAT1 are dispensable for anti-inflammatory activity of retinol in macrophages. Our study provides new insight in understanding the role of retinol in regulation of immune responses mediated through the inhibition of TLR activation in macrophages."
     
  2. raypeatclips

    raypeatclips Member

    Joined:
    Jul 8, 2016
    Messages:
    2,533
    Thank you for posting haidut. It seems the full article costs a fair amount of money to buy. Do you have an opinion on what amount of Vitamin A is needed?
     
  3. OP
    haidut

    haidut Member

    Joined:
    Mar 18, 2013
    Messages:
    16,446
    Gender:
    Male
    Location:
    USA / Europe
    The effective concentrations started at a level achievable with as little as 10,000 IU vitamin A.
     
  4. raypeatclips

    raypeatclips Member

    Joined:
    Jul 8, 2016
    Messages:
    2,533
    Excellent, thank you for the reply.
     
  5. Area-1255

    Area-1255 Member

    Joined:
    Jul 12, 2016
    Messages:
    131
    Gender:
    Male
    This type of research is what perks my eyes and ears and rats eyes and ears right up! :)
     
  6. artist

    artist Member

    Joined:
    May 31, 2015
    Messages:
    206
    This would explain my experiences with supplementing A
     
  7. Constatine

    Constatine Member

    Joined:
    Sep 28, 2016
    Messages:
    1,623
    Gender:
    Male
  8. OP
    haidut

    haidut Member

    Joined:
    Mar 18, 2013
    Messages:
    16,446
    Gender:
    Male
    Location:
    USA / Europe
    Great find, thanks. The IV dose of retinyl palmitate used in that study was high but probably worth it for people with acute endotoxin attack. The HED of oral ratinyl palmitate needed to replicate this study would be in the range 250,000 IU - 300,000 IU. It would probably be OK if used sporadically and with 400 IU vitamin E.
     
  9. Anders86

    Anders86 Member

    Joined:
    Feb 7, 2017
    Messages:
    175
    Gender:
    Male
    When attacking Endotoxin is oral route preferable to topical?
     
  10. docall18

    docall18 Member

    Joined:
    Dec 11, 2013
    Messages:
    295
    Gender:
    Male
    Location:
    LA
    Bump
     
  11. raypeatclips

    raypeatclips Member

    Joined:
    Jul 8, 2016
    Messages:
    2,533
    Interested in this too.
     
  12. Elephanto

    Elephanto Member

    Joined:
    May 21, 2015
    Messages:
    820
    Taking that much Vitamin A doesn't seem like a good idea, Peat has mentioned that more than 5000 iU inhibits thyroid function. With low gastric acid output from hypothyroidism/high serotonin as a main factor for pathogenic growth/endotoxin overload, who knows if the long-term effect on endotoxins wouldn't actually be a promoting one. You have posted many substances (coconut oil, B2, D) that would essentially have the same effect without this drawback. Also, before the research on systemic damage from overaccumulation of vitamin A in liver is proven false, caution should be used.
     
  13. OP
    haidut

    haidut Member

    Joined:
    Mar 18, 2013
    Messages:
    16,446
    Gender:
    Male
    Location:
    USA / Europe
    That's why I said "used sporadically and with vitamin E". Most of the toxicity of vitamin A has been shown to be completely preventable by adding E, but with even with adding E I would not use a dose of A that high for more than a few days in a row.
     
Loading...