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Showing posts with label H3. Show all posts
Showing posts with label H3. Show all posts

Monday 24 March 2014

Summertime Raging in Autism – H1 Anti-histamine Effect on Histamine Levels and IL-6



Last summer, I wrote a lot about autism getting much worse in that time of the year and how I found that common “24 hour” anti-histamine drugs seemed to have a magical effect; but one that lasted only 2-3 hours. There were only visible signs of a mild allergy, which could indeed easily be overlooked.

I did later receive a message from a reader who noticed his child’s ASD behaviours were greatly improved by Zrtec and his doctor agreed to prescribe this H1 antihistamine all year round.

Recently, I stumbled upon a blog, rich with many comments of parents of kids with severer types of autism.  Here I noted some parents referring to “summertime raging”, and I thought to myself, I know what they mean.  Fortunately, I found out how to make it go away.


Ant-histamine drugs

The two most common antihistamine drugs are Claritin (Loratadine), its active derivative Aerius (Desloratadine) and Zrtec (Ceterizine) and its active derivative Xyzal (levocetirizine).

The main action of an antihistamine is not actually to reduce the amount of histamine in your blood, rather it is to block the effect of histamine on the H1 receptors.

An H2 antihistamine blocks H2 receptors that are mainly in your intestines, and is used to reduce the amount of acid in the stomach.

This led me on a quest for substances that actually stop the increase in histamine, rather than just blocking some effects.  The only thing that does this is something that can stop so-called mast cells from degranulating and spilling their load of histamine, serotonin, nerve growth factor and cytokines, including IL-6, into the blood; from where, all except serotonin, are free to travel to the brain, across the blood brain barrier (BBB).  Serotonin cannot cross the BBB.

According to the mast cell specialist Theoharides, conventional drugs are not genuine mast cell stabilizers.  There are some partial ones, like Ketotifen, Cromalin, Rupatadine and Azelastine, but Theoharides thinks naturally occurring flavonoids like Luteolin and Quercetin work best.

Last summer in this blog I looked at newly discovered histamine receptors types H3 and H4 which are known to be present in the brain.


So how is it that Claritin and Zrtec can reduce autistic behaviours ?

I did note that both the above drugs did reduce summertime raging and also the Theoharides' research that showed they probably should not, since they are not mast cell stabilizers. 

Since my blog reader also found Zrtec helpful, so much so he gives it to his kid year round and it now seems summertime raging is not an unusual phenomenon in autism, I did some more checking.

In spite of what Theoharides tells us, it turns out that both Claritin and Zrtec do indeed reduce the amount of histamine in the blood.

Also, it turns out that not only is the pro-inflammatory cytokine IL-6 released from mast cells but it is also released from another type of cell, called the endothelial cell.

The endothelium is the thin layer of cells that lines the interior surface of blood vessels and lymphatic vessels, forming an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. The cells that form the endothelium are called endothelial cells. Endothelial cells in direct contact with blood are called vascular endothelial cells, whereas those in direct contact with lymph are known as lymphatic endothelial cells.

And what prompts endothelial cells to release IL-6? Histamine does.

Indeed we have studies showing how Claritin (loratadine) and  Zrtec (Ceterizine) reduce histamine and IL-6; it is the IL-6 from the endothelial cells.


"CONCLUSION:

These results demonstrate that both L and DCL are active to reduce the histamine-induced activation of EC. Interestingly, DCL seems to be effective at lesser concentrations especially to inhibit cytokine secretion."

The above study would suggest that Aerius (DCL) should be more effective than Claritin (L) its predecessor.



"Histamine is a major constituent of the mast cell. The effect of histamine on endothelial cells is primarily mediated through H1R

Collectively, our results suggest that mast cell-derived histamine and proteases play an important role in vascular inflammation and calcification in addition to their well-recognized participation in allergic diseases."

This study, and others like it, show how mast cell degranulation contributes to heart disease.  This would suggest that mast cell stabilizers have a much wider role in human health than is realized.  Another example of how a red apple a day (with the skin) may indeed help keep the doctor away and a glass of red wine will do the same.  Both are rich sources of the mast stabilizer Quercetin.  The alcohol increases the bio-availability.


"Conclusion

These results suggest that cetirizine exerts its beneficial effects on viral myocarditis by suppressing expression of pro-inflammatory cytokines, genes related to cardiac remodeling in the hearts of mice."


So how do Claritin and Zrtec reduce summertime/year round raging in autism?  Well it could be histamine or it could be IL-6, we cannot know for sure.  The science tells us that the brain has many H3 and H4 receptors, so they are possibly to be implicated.  Or, it may just be IL-6;  histamine’s involvement could be just provoking the endothelial cells to release more IL-6.


Conclusion

Claritin/Zrtec/Xyzal are relatively cheap, in theory they are long lasting drugs.  In Monty, aged 10 with ASD, they all work for summertime time raging, but not for long.  Adults should take one per 24 hours.  Monty would need one every 3 hours.

The, supposedly better, mast cell stabilizers like Ketotifen and Rupatadine take a few days before they have any effect at all.  Azelastin is available as a nasal spray and is supposed to be effective quickly as an allergy treatment.

My preferred mast cell stabilizing, IL-6 inhibiting, strategy is to combine PEA (palmitoylethanolamide) which is already naturally in your body, with the flavonoid quercetin, which is found in the skin of red apples and red grapes.  In theory, according to the research, this is both a potent combination and should be free of harmful side effects.

Very frequent doses of Claritin/Zrtec/Xyzal are not going to be good.


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