Let’s be Serious about the Data - Flavonoids, Cytokines & Autism

You may be wondering why, with so many research papers written about autism, so little progress has been made.  It is a very complex task, but nobody is coordinating it.

How do you find a Boeing 777 missing somewhere in Asia?  Another daunting challenge, but with the right people and resources it can be done.  With the wrong people, it will prove to be impossible.

Ashwood et al have documented the level of various inflammatory markers in autism.  Very helpfully, they created three groups: typical children, children with non-regressive autism, and children with regressive autism.

Elevated plasma cytokines in autism spectrum disorders provide evidence of immune dysfunction and are associated with impaired behavioral outcome

Table 2, on the third page, tells us what we need to know.  Certain cytokine levels are markedly elevated in regressive autism, including IL-6 and TNF-alpha.  Furthermore, the difference between the two types of autism is dramatic; rather implying the existence of two distinct conditions.

 

So now, I move on to what could have been an amazingly helpful study, had they spent 1% more time on it and collected some blood samples and split the kids into regressive and non-regressive groups.

Last year in Athens, a study was done using Theoharides’ mix of luteolin and quercetin flavonoids to look at the effect of mast cell stabilization on behaviour in autism.  From recent posts, you will recall that these flavonoids reduce the level of inflammatory cytokines, histamine and nerve growth factor, by stabilizing so called mast cells.  In effect, the study was looking at the impact of inhibiting certain cytokines on behaviour in autism.

An Open-Label Pilot Study of a Formulation Containing the Anti-Inflammatory Flavonoid Luteolin and Its Effects on Behavior in Children With Autism Spectrum Disorders

This sounds great and just what I wanted to find.  Get 40 kids with ASD measure their level of these cytokines/histamine and assess their behaviour.  Give them the cytokine inhibitor/mast cell stabilizer for six months, measure the levels in their blood and assess the behaviour again.

Sadly, they did not bother to take the before and after blood samples and send them downstairs to the hospital’s laboratory.

So we have a paper that took years of planning that tells us that the flavonoids do seem to help; but we do not know exactly why and we cannot correlate improvement in behaviour with change in cytokine levels.

What a pity.  

  

Palmitoylethanolamide (PEA) vs flavonoids Luteolin, Quercetin and Rutin in Autism, Allergies and Arthritis

You might be wondering the relevance of arthritis to an autism blog. Rheumatoid arthritis is an inflammatory condition in which the body's own immune system starts to attack body tissues.  It is often co-morbid with inflammatory bowel disease (including Crohn's disease and ulcerative colitis).  IBD is comorbid with autism.  The study below shows how many autoimmune diseases, including arthritis are connected with autism. 

Association of Family History of Autoimmune Diseases and Autism Spectrum Disorders

RESULTS: A total of 3325 children were diagnosed with ASDs, of which 1089 had an infantile autism diagnosis. Increased risk of ASDs was observed for children with a maternal history of rheumatoid arthritis and celiac disease. Also, increased risk of infantile autism was observed for children with a family history of type 1 diabetes.

CONCLUSIONS: Associations regarding family history of type 1 diabetes and infantile autism and maternal history of rheumatoid arthritis and ASDs were confirmed from previous studies. A significant association between maternal history of celiac disease and ASDs was observed for the first time. The observed associations between familial autoimmunity and ASDs/infantile autism are probably attributable to a combination of a common genetic background and a possible prenatal antibody exposure or alteration in fetal environment during pregnancy.

Note that in an earlier post on the vagus nerve, we saw how an implanted vagus nerve stimulator could reduce the inflammation in arthritis.  This is being developed as an alternative to the extremely expensive new drugs for arthritis that target IL-6 and TNF.

In earlier posts on Mast Cells we heard all about Dr Theoharides from Tufts University who is big on using naturally occurring flavonoids to stabilize mast cells and so treat all kinds of allergic reactions as in mastocytosis and in some types of autism.  See below for a reminder of the roll mast cells play in allergies:-

 

Source: Wikipedia

 

Luteolin is Theoharides’ favourite flavonoid because it is the most the most lipophilic and therefore more likely to enter the brain.  Mast cells are all over the body, including the brain.  In autism, he clearly is focused on the mast cells in the brain, but perhaps the mast cells elsewhere are equally problematic.  Indeed, perhaps the mast cells outside the brain are far more important, just because there are far more of them and the inflammatory mediators released by them will travel throughout the entire body.

 

The other two flavonoids know to effect mast cells and inflammation are Rutin and Quercetin. 

Arthritis Luteolin and Palmitoylethanolamide

I was quite surprised to find that research had been carried out on the anti-inflammatory effect of both Luteolin and Palmitoylethanolamide (PEA).  PEA is the substance I have been researching recently, it is not a flavonoid, but it is naturally occurring within the body and has some very interesting properties.

One of the inflammatory markers that is raised in autism is called IL-6.  The research was on arthritis in mice, but it did measure the effect of Luteolin and PEA on IL-6.  The result was interesting:-

 

PEA had the greater effect, but in combination with Luteolin the result improved further. 

Palmitoylethanolamide and luteolin ameliorate development of arthritis caused by injection of collagentype II in mice

This gives yet more reason to look into PEA for autism, but not to forget Luteolin.

The problem with Luteolin and Theoharides’ formulation called Neuroprotek is that it is really expensive in the suggested dosage.

 

What about Quercetin?

Quercetin is relatively cheap.

Unfortunately there is no direct comparison of Luteolin vs Quercetin in arthritis, but there is plenty of research showing that Quercetin is highly beneficial in arthritis. 

Therapeutic and preventive properties of quercetin in experimental arthritis correlate with decreased macrophage inflammatory mediators 

Abstract

Pentahydroxyflavone dihydrate, quercetin (QU) is one of common flavonols biosynthesized by plants and has been suggested to modulate inflammatory responses in various models. In the present study, we investigated in vivo effects of oral or intra-cutaneous QU in chronic rat adjuvant-induced arthritis (AA). Growth delay and arthritic scores were evaluated daily after AA induction in Lewis rats. Oral administration of QU (5 x 160 mg/kg) to arthritic rats resulted in a clear decrease of clinical signs compared to untreated controls. Intra-cutaneous injections of lower doses (5 x 60 mg/kg) of QU gave similar anti-arthritic effects, while 5 x 30 mg/kg concentrations were inefficient in this respect. Finally, injection of relatively low QU doses (5 x 30 mg/kg) prior to AA induction significantly reduced arthritis signs. As QU was suggested to inhibit macrophage-derived cytokines and nitric oxide (NO), we then analyzed macrophage response ex vivo. Anti-arthritic effects of QU correlated with significant decrease of inflammatory mediators produced by peritoneal macrophages, ex vivo and in vitro. These data indicate that QU is a potential anti-inflammatory therapeutic and preventive agent targeting the inflammatory response of macrophages. 

Here is a great paper summarizing the many and varied benefits of quercetin:-

QUERCETIN: A VERSATILE FLAVONOID

An interesting point with all flavonoids is their bioavailability.  This means what proportion that you eat is actually absorbed.

Quercetin is present in apples, but the largest amount is in the peel and is highest in red apples.   Quercetin is found is lesser amounts in red wine, but it appears the bioavailability is much higher because of the alcohol.  So grape juice would not help much. 


Applications of Quercetin

Asthma

Quercetin is an effective bronchodilator and helps reduce the release of histamine and other allergic or inflammatory chemicals in the body.

Quercetin has demonstrated significant anti-inflammatory activity because of direct inhibition of several initial processes of inflammation.

Cancer

Laboratory studies have investigated Quercetin's potential for use in anti-cancer applications. The American Cancer Society says while quercetin "has been promoted as being effective against a wide variety of diseases, including cancer," and "some early lab results appear promising, as of yet there is no reliable clinical evidence that quercetin can prevent or treat cancer in humans."

Eczema

Serum IgE levels are highly elevated in eczema patients, and virtually all eczema patients are positive for allergy testing. Excessive histamine release can be minimized by the use of antioxidants. Quercetin has been shown to be effective in reducing IgE levels in rodent models.

Inflammation

Several laboratory studies show quercetin may have anti-inflammatory properties, and it is being investigated for a wide range of potential health benefits.

Quercetin has been reported to be of use in alleviating symptoms of pollinosis. An enzymatically modified derivative was found to alleviate ocular but not nasal symptoms of pollinosis.

Studies done in test tubes have shown quercetin may prevent immune cells from releasing histamines which might influence symptoms of allergies.

A study with rats showed that quercetin effectively reduced immediate-release niacin (vitamin B₃) flush, in part by means of reducing prostaglandin D2 production. A pilot clinical study of four humans gave preliminary data supporting this.

Fibromyalgia

Quercetin may be effective in the treatment of fibromyalgia because of its potential anti-inflammatory or mast cell inhibitory properties shown in laboratory studies

Monoamine-oxidase inhibitor

Possibly an active component of heather, quercetin was suspected from a bioassay test on crude extracts to selectively inhibit monoamine oxidase, possibly indicating pharmacological properties.

Prostatitis

Quercetin has been found to provide significant symptomatic improvement in most men with chronic prostatitis, a condition also known as male chronic pelvic pain syndrome.

Luteolin

Luteolin is known to stabilize mast cells.  It has been studied in several preliminary in vitro scientific investigations. Proposed activities include antioxidant activity (i.e. scavenging of free radicals), promotion of carbohydrate metabolism, and immune system modulation. Other in vitro studies suggest luteolin has anti-inflammatory activity, and that it acts as a monoamine transporter activator, a phosphodiesterase inhibitor, and an interleukin 6 inhibitor. In vivo studies show luteolin affects xylazine/ketamine-induced anesthesia in mice. In vitro and in vivo experiments also suggest luteolin may inhibit the development of skin cancer.

In autism the ability to stabilize mast cells and inhibit IL-6 is very useful.

 

Luteolin reduces IL-6 production in microglia by inhibiting JNK phosphorylation and activation of AP-1

Luteolin, a flavonoid found in high concentrations in celery and green pepper, has been shown to reduce production of proinflammatory mediators in LPS-stimulated macrophages, fibroblasts, and intestinal epithelial cells. Because excessive production of proinflammatory cytokines by activated brain microglia can cause behavioral pathology and neurodegeneration, we sought to determine whether luteolin also regulates microglial cell production of a prototypic inflammatory cytokine, IL-6. Pretreatment of primary murine microlgia and BV-2 microglial cells with luteolin inhibited LPS-stimulated IL-6 production at both the mRNA and protein levels. To determine how luteolin inhibited IL-6 production in microglia, EMSAs were performed to establish the effects of luteolin on LPS-induced binding of transcription factors to the NF-κB and activator protein-1 (AP-1) sites on the IL-6 promoter. Whereas luteolin had no effect on the LPS-induced increase in NF-κB DNA binding activity, it markedly reduced AP-1 transcription factor binding activity. Consistent with this finding, luteolin did not inhibit LPS-induced degradation of IκB-α but inhibited JNK phosphorylation. To determine whether luteolin might have similar effects in vivo, mice were provided drinking water supplemented with luteolin for 21 days and then they were injected i.p. with LPS. Luteolin consumption reduced LPS-induced IL-6 in plasma 4 h after injection. Furthermore, luteolin decreased the induction of IL-6 mRNA by LPS in hippocampus but not in the cortex or cerebellum. Taken together, these data suggest luteolin inhibits LPS-induced IL-6 production in the brain by inhibiting the JNK signaling pathway and activation of AP-1 in microglia. Thus, luteolin may be useful for mitigating neuroinflammation.

Health effects of Rutin

While a body of evidence for the effects of rutin and quercetin is available in mice, rats, hamsters, and rabbits, as well as in vitro studies, no clinical studies directly demonstrate significant, positive effects of rutin as dietary supplement in humans.

• Rutin inhibits platelet aggregation, as well as decreases capillary permeability, making the blood thinner and improving circulation.^]
• Rutin shows anti-inflammatory activity in some animal and in vitro models^]
• Rutin inhibits aldose reductase activity.
• Recent studies show rutin could help prevent blood clots, so could be used to treat patients at risk of heart attacks and strokes.
• Some evidence also shows rutin can be used to treat hemorrhoids, varicosis, and microangiopathy.
• Rutin increases thyroid iodide uptake in rats without raising serum T3 or T4.
• Rutin is also an antioxidant, compared to quercetin, acacetin, morin, hispidulin, hesperidin, and naringin, it was found to be the strongest. However, in other trials, the effects of rutin were lower or negligible compared to those of quercetin.

 

Vox Populi (from Amazon.com reviews)

Rutin   

Few comments

-    “This works wonders for hemorrhoids”

 

Quercetin

Hundreds of positive comments for: Nasal allergy, eczema, sinusitis, prostatitis, joint pain etc.

“Lifesaver for allergies”

“This really helps and works like Sudafed” 

Luteolin / Neuroprotek (main ingredient is Luteolin)

Few comments mainly:  mastocytosis, allergies, eczema, autism

Works for some people with autism and not for others:

“My son with autism stopped his aggressive behaviour in a day”

“Works for my fibromyalgia”

 

Conclusion

I do have a couple of jars of Neuroprotek, which I was going to try on Monty, aged 10 with ASD, when the pollen season returns in the summer.  Using it all year round would not be cheap and might have little effect.  I find Quercetin very interesting and worthy of investigation; but PEA remains my current favourite.

It does come down to the question of which mast cells de-granulating cause the problem in autism.  In some people it could be the ones in their digestive tract and in others the ones in their eyes and nose.  The ones in the brain may or may not be relevant; these are the ones Theoharides seems to focus on.

PEA, Quercetin and Luteolin seem to have many benefits unrelated to mast cells.  Since they cannot be patented, there is no incentive for Big Pharma to invest in developing their potential.  So even if they did had some remarkable property, like in cancer therapy, we would likely never find out.

If I was a mouse with arthritis, I would add PEA and Quercetin (or Luteolin) to my weekly shop.  Anyone who is a big user of H1 antihistamines should find Quercetin helpful.