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Showing posts with label Ibuprofen. Show all posts
Showing posts with label Ibuprofen. Show all posts

Tuesday 29 September 2015

Is Reductive Stress a common feature of Atypical Autism?







Lay summary:


·        Oxidative injury can be caused by both oxidative stress and the opposite, reductive stress. 

·        Both extremes of redox balance are known to cause cardiac injury

·        Both extremes of redox balance disrupt mitochondria

·        It appears that either extreme of redox balance may occur in autism.


Reductive stress is the opposite of oxidative stress and I am calling it “Atypical Autism” because all the research shows that the great majority of autism and indeed schizophrenia is associated with oxidative stress.


NAC and stereotypy/stimming

Most young children with classic autism exhibit stereotypy/stimming; this kind of obsessive, repetitive behavior can really get in the way of daily life.  You can use the principles of ABA to limit or redirect this behavior, but it turns out that there is a biological cause for it.

Taking NAC (N-acetylcysteine) increases the body’s production of GSH, its main antioxidant.  Once the intake in NAC is high enough to shift the balance between oxidants and antioxidants the stereotypy/stimming stops all by itself.  This does not mean that the child will still not enjoy repetition.

In some children it takes quite a lot of NAC before any effect is visible, one parent mentioned no effect until 1,800 mg a day.  In other people, the effect starts with the first 600mg and just keeps growing before plateauing around 3,000 mg a day.

This variation makes sense; it all depends just how out of balance the oxidants/antioxidants were at the outset.

If you have access to lab testing you would look at the ratio between GSH and GSSG. This would give you a good indication of your Redox balance.


NAC and Nrf-2 Activators making things worse

In a small number of cases NAC and Sulforaphane/broccoli (a Nrf-2 activator) actually makes things worse.  This does not mean more stereotypy/stimming; I think it quite likely that in those people, stereotypy/stimming are not a feature of their "autism",

Worsening autism can be an increase in anxiety.

Anxiety is often a feature of Asperger’s.

Anxiety is not an issue at all in many cases of classic autism.

NAC is itself an anti-oxidant as well as increasing GSH.  

Sulforaphane/broccoli activates Nrf-2 which in turn affects the genes that control the antioxidant response.  If this make things worse, it seems likely that there was no oxidative stress; either redox was in balance or they are already at the other extreme, reductive stress.


Some Science

The summary below is from the following paper




“Whenever a cell’s internal environment is perturbed by infections, disease, toxins or nutritional imbalance, mitochondria diverts electron flow away from itself, forming reactive oxygen species (ROS) and reactive nitrogen species (RNS), thus lowering oxygen consumption.

This “oxidative shielding” acts as a defense mechanism for either decreasing cellular uptake of toxic pathogens or chemicals from the environment, or to kill the cell by apoptosis and thus avoid the spreading to neighboring cells.

Therefore, ROS formation is a physiological response to stress.

The term “oxidative stress” has been used to define a state in which ROS and RNS reach excessive levels, either by excess production or insufficient removal. Being highly reactive molecules, the pathological consequence of ROS and RNS excess is damage to proteins, lipids and DNA. Consistent with the primary role of ROS and RNS formation, this oxidative stress damage may lead to physiological dysfunction, cell death, pathologies such as diabetes and cancer, and aging of the organism.”


But reductive stress also leads to ROS formation


Reductive Stress and Oxidants

Reductive stress can be just as bad as oxidative stress and, very surprisingly, can have exactly the same negative effect on mitochondria (see below)




Abstract

To investigate the effects of the predominant nonprotein thiol, glutathione (GSH), on redox homeostasis, we employed complementary pharmacological and genetic strategies to determine the consequences of both loss- and gain-of-function GSH content in vitro. We monitored the redox events in the cytosol and mitochondria using reduction-oxidation sensitive green fluorescent protein (roGFP) probes and the level of reduced/oxidized thioredoxins (Trxs). Either H2O2 or the Trx reductase inhibitor 1-chloro-2,4-dinitrobenzene (DNCB), in embryonic rat heart (H9c2) cells, evoked 8 or 50 mV more oxidizing glutathione redox potential, Ehc (GSSG/2GSH), respectively. In contrast, N-acetyl-l-cysteine (NAC) treatment in H9c2 cells, or overexpression of either the glutamate cysteine ligase (GCL) catalytic subunit (GCLC) or GCL modifier subunit (GCLM) in human embryonic kidney 293 T (HEK293T) cells, led to 3- to 4-fold increase of GSH and caused 7 or 12 mV more reducing Ehc, respectively. This condition paradoxically increased the level of mitochondrial oxidation, as demonstrated by redox shifts in mitochondrial roGFP and Trx2. Lastly, either NAC treatment (EC50 4 mM) or either GCLC or GCLM overexpression exhibited increased cytotoxicity and the susceptibility to the more reducing milieu was achieved at decreased levels of ROS. Taken together, our findings reveal a novel mechanism by which GSH-dependent reductive stress triggers mitochondrial oxidation and cytotoxicity.—Zhang, H., Limphong, P., Pieper, J., Liu, Q., Rodesch, C. K., Christians, E., Benjamin, I. J. Glutathione-dependent reductive stress triggers mitochondrial oxidation and cytotoxicity.


Reductive Stress in Disease





Both extremes of redox balance are known to cause cardiac injury, with mounting evidence revealing that the injury induced by both oxidative and reductive stress is oxidative in nature. During reductive stress, when electron acceptors are expected to be mostly reduced, some redox proteins can donate electrons to O2 instead, which increases reactive oxygen species (ROS) production.

However, the high level of reducing equivalents also concomitantly enhances ROS scavenging systems involving redox couples such as NADP/NADPH and GSH/GSSG. Here we have further explored, using isolated intact and permeabilized cardiac mitochondria and purified NADP-dependent enzymes, how reductive stress paradoxically increases net mitochondrial ROS production despite the concomitant enhancement of ROS scavenging systems.

We show that one of the latter components, thioredoxin reductase 2, is converted into a potent NADPH oxidase during reductive stress, due to limited availability of its natural electron acceptor, oxidized thioredoxin. This finding may explain in part how ROS production during reductive stress overwhelms ROS scavenging capability, generating the net mitochondrial ROS spillover causing oxidative injury.



Reductive stress: A new concept in Alzheimer’s disease



Reactive oxygen species play a physiological role in cell signaling and also a pathological role in diseases, when antioxidant defenses are overwhelmed causing oxidative stress. However, in this review we will focus on reductive stress that may be defined as a pathophysiological situation in which the cell becomes more reduced than in the normal, resting state. This may occur in hypoxia and also in several diseases in which a small but persistent generation of oxidants results in a hormetic overexpression of antioxidant enzymes that leads to a reduction in cell compartments. This is the case of Alzheimer’s disease. Individuals at high risk of Alzheimer’s (because they carry the ApoE4 allele) suffer reductive stress long before the onset of the disease and even before the occurrence of mild cognitive impairment. Reductive stress can also be found in animal models of Alzheimer’s disease (APP/PS1 transgenic mice), when their redox state is determined at a young age, i.e. before the onset of the disease. Later in their lives they develop oxidative stress. The importance of understanding the occurrence of reductive stress before any signs or symptoms of Alzheimer’s has theoretical and also practical importance as it may be a very early marker of the disease.








 Oxidative Shielding

I was surprised that one of the very few papers to mention Reductive Stress is by Robert Naviaux, a well-known autism researcher.  He is the one behind Antipurinergic Therapy and Suramin as a therapy.  I just promoted him to my Dean’s List.




Abstract
In this review I report evidence that the mainstream field of oxidative damage biology has been running fast in the wrong direction for more than 50 years. Reactive oxygen species (ROS) and chronic oxidative changes in membrane lipids and proteins found in many chronic diseases are not the result of accidental damage. Instead, these changes are the result of a highly evolved, stereotyped, and protein-catalyzed “oxidative shielding” response that all eukaryotes adopt when placed in a chemically or microbially hostile environment. The machinery of oxidative shielding evolved from pathways of innate immunity designed to protect the cell from attack and limit the spread of infection. Both oxidative and reductive stress trigger oxidative shielding. In the cases in which it has been studied explicitly, functional and metabolic defects occur in the cell before the increase in ROS and oxidative changes. ROS are the response to disease, not the cause. Therefore, it is not the oxidative changes that should be targeted for therapy, but rather the metabolic conditions that create them. This fresh perspective is relevant to diseases that range from autism, type 1 diabetes, type 2 diabetes, cancer, heart disease, schizophrenia, Parkinson's disease, and Alzheimer disease. Research efforts need to be redirected. Oxidative shielding is protective and is a misguided target for therapy. Identification of the causal chemistry and environmental factors that trigger innate immunity and metabolic memory that initiate and sustain oxidative shielding is paramount for human health

In his paper Naviaux is quite right, it is much better to treat the cause of the oxidative/reductive stress; right now I do not know how to do this.



Oxidants as a therapy?

Most people with autism should avoid oxidants.

They should avoid paracetamol/ acetaminophen/Tylenol, because it depletes the body’s main antioxidant, GSH.  This is the mechanism behind why, at very high doses, it can kill you.  If they put NAC inside Tylenol, people could not use it to kill themselves.

One surprising oxidant that some people use to “treat” autism is MMS a, toxic solution of 28% sodium chlorite.  Is this the reason why there is such a cult therapy for drinking “bleach” to “cure” autism?

The only reason I mention this is that one reader whose child responded negatively to NAC and Sulforaphane had responded very positively to three doses of MMS some years ago.

For people with autism, and apparent reductive stress, I certainly do not suggest drinking bleach, but a few days of paracetamol / acetaminophen, as if you had the flu, might tell you a lot.

For most people with autism, Ibuprofen is a much better choice of painkiller;  it does not deplete GSH.









Wednesday 6 May 2015

Tangeretin vs Ibuprofen, as PPARγ agonists for Autism. What about PPARγ for Epilepsy?




Summary of the therapeutic actions of PPARγ in diabetic nephropathy


I did write an earlier post about NSAIDs (Nonsteroidal anti-inflammatory drugs) like Ibuprofen, which I expected to have no effect on autism.

  


However, to my surprise, I found that certain types of autism “flare-up” do respond very well to Ibuprofen.  Based on the comments I received, it seems that many other people have the same experience.

NSAIDs work by inhibiting something called COX-2, but they also inhibit COX-1.  The side effects of NSAIDs come from their unwanted effect on COX-1.

NSAIDs are both pain relievers and, in high doses, anti-inflammatory.  Long term use of NSAIDs is not recommended, due to their (COX-1 related) side effects.


Observational Study

All I can say is that in Monty, aged 11 with ASD, and with his last four milk teeth wobbly but refusing to come out, the increase in the cytokine IL-6 that the body uses to signal the roots of the milk teeth to dissolve seems to account for some of his flare-ups.  I do not think it is anything to do with pain.

This is fully treatable with occasional use of Ibuprofen and then “extreme behaviours” are entirely avoided.


Sytrinol (Tangeretin) vs Ibuprofen

Since Ibuprofen, when given long term, has known problems, I looked for something else.

On my list of things to investigate has been “selective PPAR gamma agonists”, which is quite a mouthful.  The full name is even longer.  The nuclear transcription factor peroxisome proliferator activated receptor gamma (PPARy) regulates genes in anti-inflammatory, anti-oxidant and mitochondrial pathways.  All three of these pathways are affected in autism.

We already know that non-selective PPARy agonists, like pioglitazone, developed to treat type 2 diabetes, can be used to treat autism.  The problem is that being “non-selective” they can have nasty side effects, leading to Pioglitazone being withdrawn in some markets.
  

  
While looking for a “better” PPARγ agonist, I came across the flavonoid Tangeretin, which is commercially available in a formulation called Sytrinol.

An effective PPARγ agonist would have many measurable effects.  The literature is full of natural substances that may, to some degree, be PPARγ agonists, but you might have to consume them by the bucket load to have any effect.

The attraction of Sytrinol is that it does have a measurable effect in realistic doses.  Sytrinol is sold as a product to lower cholesterol.  Tangeretin is a PPARγ agonist and you would expect a PPARγ agonist to improve insulin sensitivity and also reduce cholesterol. There are clinical trials showing this effect of Sytrinol.


Sytrinol (Tangeretin) Experiment

The most measurable effect of using Sytrinol for six weeks is that we no longer need any Ibuprofen.  It is measurable, since I am no longer needing to buy Ibuprofen any more.

About three days a week Monty’s assistant would need to give him Ibuprofen at school.  This all stopped, even though occasional complaints about wobbly teeth continue.

Nobody markets  Sytrinol (Tangeretin) as a painkiller.

Note:- Sytrinol capsules contain a blend of 270mg PMF (polymethoxylated flavones, consisting largely of tangeretin and nobiletin) + 30mg tocotrienols. Nobiletin is closely related to tangeretin, while tocotrienols are members of the vitamin E family.  All three should be good for you.


Tangeretin and Ibuprofen are both PPARγ agonists

The explanation for all this may indeed be that Tangeretin and Ibuprofen are both PPARγ agonists.  Inhibiting COX-2 may have been irrelevant.


  
It may be that by regulating the anti-inflammatory genes, via  PPARγ, the Sytrinol has countered the “flare-up” caused by the spike in IL-6.

Anyway, in the earlier post we did see that research shows that dissolving milk teeth is signalled via increased IL-6 and we do know that increased IL-6, caused by allergies, can trigger worsening autism. 

So it does make sense, at least to me.

Regular uses of Sytrinol/Tangeretin looks a much safer bet than any NSAID.

If anyone tries it, particularly those who regularly use NSAIDs, let us all know.



PPARγ and Epilepsy

If you Google PPARγ and autism you will soon end up back at this blog.

For any sceptics, better to Google PPARγ and Epilepsy.  Epilepsy looks to be the natural progression of un-treated classic autism.  If this progression can be prevented, that should be big news.

Prevention is always better than a cure.  All kinds of conditions appear to be preventable, or at least you can minimize their incidence.  

Here are just the ones I have stumbled upon while researching autism:- Asthma  (Ketotifen), type 2 diabetes (Verapamil), prostate cancer (Lycopene) and many types of cancer (Sulforaphane).

There are of course types of epilepsy unconnected to autism, but epilepsy, seizures and electrical activity are highly comorbid with classic autism




Abstract

Approximately 30% of people with epilepsy do not achieve adequate seizure control with current anti-seizure drugs (ASDs). This medically refractory population has severe seizure phenotypes and is at greatest risk of sudden unexpected death in epilepsy (SUDEP). Therefore, there is an urgent need for detailed studies identifying new therapeutic targets with potential disease-modifying outcomes. Studies indicate that the refractory epileptic brain is chronically inflamed with persistent mitochondrial dysfunction. Recent evidence supports the hypothesis that both factors can increase the excitability of epileptic networks and exacerbate seizure frequency and severity in a pathological cycle. Thus, effective disease-modifying interventions will most likely interrupt this loop. The nuclear transcription factor peroxisome proliferator activated receptor gamma (PPARy) regulates genes in anti-inflammatory, anti-oxidant and mitochondrial pathways. Preliminary experiments in chronically epileptic mice indicate impressive anti-seizure efficacy. We hypothesize that (i) activation of brain PPARy in epileptic animals will have disease modifying effects that provide long-term benefits, and (ii) determining PPARy mechanisms will reveal additional therapeutic targets. Using a mouse model of developmental epilepsy, we propose to (1) elucidate the cellular, synaptic and network mechanisms by which PPARy activation restores normal excitability;(2) demonstrate the significant contribution of mitochondrial health in pathologic synaptic activity in epileptic brain;(3) demonstrate inflammatory regulation of PPARy in epileptic brain;and (4) determine whether PPARy activation extends the lifespan of severely epileptic animals. The proposed studies, spanning in vivo and in vitro systems using a combination of techniques in molecular biology, electrophysiology, microscopy, bioenergetics and pharmacology, will provide insight into the interplay of seizures, mitochondria, inflammation and homeostatic mechanisms. The results will have tremendous, immediate translational potential because PPARy agonists are currently used for clinical treatment of Type II Diabetes. PPARy is under investigation as treatment for a wide variety of other neurological diseases with cell death and inflammation as common denominators;therefore, the results of this proposal will have a broad impact.

Public Health Relevance

Approximately 30% of people with epilepsy do not achieve adequate seizure control with current anti-seizure drugs (ASDs). This medically refractory population has severe seizure phenotypes and is at greatest risk of sudden unexpected death in epilepsy (SUDEP). Therefore, there is an urgent need for detailed studies identifying new therapeutic targets with potential disease- modifying outcomes.




Activation of cerebral peroxisome proliferator-activated receptors gamma exerts neuroprotection by inhibiting oxidative stress following pilocarpine-induced status epilepticus.

Abstract

Status epilepticus (SE) can cause severe neuronal loss and oxidative damage. As peroxisome proliferator-activated receptor gamma (PPARgamma) agonists possess antioxidative activity, we hypothesize that rosiglitazone, a PPARgamma agonist, might protect the central nervous system (CNS) from oxidative damage in epileptic rats. Using a lithium-pilocarpine-induced SE model, we found that rosiglitazone significantly reduced hippocampal neuronal loss 1 week after SE, potently suppressed the production of reactive oxygen species (ROS) and lipid peroxidation. We also found that treatment with rosiglitazone enhanced antioxidative activity of superoxide dismutase (SOD) and glutathione hormone (GSH), together with decreased expression of heme oxygenase-1 (HO-1) in the hippocampus. The above effects of rosiglitazone can be blocked by co-treatment with PPARgamma antagonist T0070907. The current data suggest that rosiglitazone exerts a neuroprotective effect on oxidative stress-mediated neuronal damage followed by SE. Our data also support the idea that PPARgamma agonist might be a potential neuroprotective agent for epilepsy.




CONCLUSION:

The present study demonstrates the anticonvulsant effect of acute pioglitazone on PTZ-induced seizures in mice. This effect was reversed by PPAR-γ antagonist, and both a specific- and a non-specific nitric oxide synthase inhibitors, and augmented by nitric oxide precursor, L-arginine. These results support that the anticonvulsant effect of pioglitazone is mediated through PPAR-γ receptor-mediated pathway and also, at least partly, through the nitric oxide pathway.



Note that elsewhere in this blog I have already highlighted that PPAR alpha agonists also seem to have an effect against epilepsy.  For example in this research:-


          

I was originally interested in PPAR-alpha, because of its role in regulating mast cells.  It seems that PPARγ also affects mast cells.


  


PPARγ modulators – drugs vs neutraceuticals vs functional food

It does seem that many people with inflammatory diseases, epilepsy, autism and even people who are obese, might greatly benefit from selective PPARγ agonists.

The choice would be between drugs, “nutraceuticals” and functional (good) food.

The drugs have not yet arrived that are safe and selective.  The current Thiazolidinedione (TZD) class of drugs TZDs tend to increase fat mass as well as improving insulin sensitivity and glucose tolerance in both lab animals and humans.




Since its identification in the early 1990s, peroxisome-proliferator-activated receptor γ (PPARγ), a nuclear hormone receptor, has attracted tremendous scientific and clinical interest. The role of PPARγ in macronutrient metabolism has received particular attention, for three main reasons: first, it is the target of the thiazolidinediones (TZDs), a novel class of insulin sensitisers widely used to treat type 2 diabetes; second, it plays a central role in adipogenesis; and third, it appears to be primarily involved in regulating lipid metabolism with predominantly secondary effects on carbohydrate metabolism, a notion in keeping with the currently in vogue ‘lipocentric’ view of diabetes. This review summarises in vitro studies suggesting that PPARγ is a master regulator of adipogenesis, and then considers in vivo findings from use of PPARγ agonists, knockout studies in mice and analysis of human PPARγ mutations/polymorphisms.



As usual there are numerous “natural substances” that may also modulate PPAR-γ




A direct correlation between adequate nutrition and health is a universally accepted truth. The Western lifestyle, with a high intake of simple sugars, saturated fat, and physical inactivity, promotes pathologic conditions. The main adverse consequences range from cardiovascular disease, type 2 diabetes, and metabolic syndrome to several cancers. Dietary components influence tissue homeostasis in multiple ways and many different functional foods have been associated with various health benefits when consumed. Natural products are an important and promising source for drug discovery. Many anti-inflammatory natural products activate peroxisome proliferator-activated receptors (PPAR); therefore, compounds that activate or modulate PPAR-gamma (PPAR-γ) may help to fight all of these pathological conditions. Consequently, the discovery and optimization of novel PPAR-γ agonists and modulators that would display reduced side effects is of great interest. In this paper, we present some of the main naturally derived products studied that exert an influence on metabolism through the activation or modulation of PPAR-γ, and we also present PPAR-γ-related diseases that can be complementarily treated with nutraceutics from functional foods.



Conclusion

If you are one of those people successfully using NSAIDs, like Ibuprofen, to reduce autistic behaviors, you might well be in the group that would benefit from Sytrinol/Tangeretin.

If NSAIDs never help resolve your autism flare-ups, Sytrinol/Tangeretin may not help either.

Tangeretin does appear to have other effects, beyond not needing to use Ibuprofen.  It was found to be a potent antagonist at P2Y2 receptors.

Suramin is another potent P2Y2 antagonist and Suramin is showing a lot of promise in Robert Naviaux’s autism studies at the University of California at San Diego.  Suramin is not viewed as safe for regular use in humans.








Thursday 26 February 2015

Inflammation Leading to Cognitive Dysfunction


Today’s post highlights a paper with some very concise insights into how microglial cells become “activated” resulting in the “exaggerated inflammatory response” that many people with autism experience on a daily basis.  

This is very relevant to treatment, which is not usually the objective of much autism research.

I recall reading a comment from John’s Hopkins about neuroinflammation/activated microglia in autism; they commented that no known therapy currently exists and that, of course, common NSAIDs like ibuprofen will not be effective.  But NSAIDs are effective.

As we see in today’s paper, there a least 4 indirect cytokine-dependent pathways leading to the microglia, plus one direct one.
NSAIDs most definitely can reduce cytokine signaling and thus, indirectly, reduce microglial activation.

The ideal therapy would act directly at the microglia, and as Johns Hopkins pointed out, that does not yet exist with today's drugs.  If you read the research on various natural flavonoids you will see that “in vitro” there are known substances with anti-neuroinflammatory effects on microglial activation.  The recurring “problem” with such substances is low bioavailability and inability to cross the blood brain barrier.


Back to Today’s Paper

It was a conference paper at the 114th Abbott Nutrition Research Conference - Cognition and Nutrition



The paper is not about autism, it is about more general cognitive dysfunction.  It is from mainstream science (I checked).

It explains how inflammation anywhere in the body can be translated across the BBB (Blood Brain Barrier) to activate the microglia.  This of course allows you to think of ways to counter these mechanisms.

It also raises the issue of whether or not anti-inflammatory agents really need to cross the BBB.  While you might think that ability to cross the BBB is a perquisite to mitigate the activated microglia, this may not be the case.  Much can be achieved outside the BBB, and we should not rule out substances that cannot cross the BBB.

Very many known anti-inflammatory substances do not cross the BBB.   

  



extracts from the above paper ...








Example – Influenza and Cognition

Neurological and cognitive effects associated with influenza infection have been reported throughout history.

The simplest explanation for these neurocognitive effects is that influenza virus makes its way to the brain, where it is detected by neurons.

However, most influenza strains, including those responsible for pandemics, are considered non-neurotropic, neurological symptoms associated with influenza infection are not a result of direct viral invasion into the CNS.

Moreover, neurons do not have receptors to detect viruses (or other pathogens) directly.

Cells of the immune system do, however, as the immune system’s primary responsibility is to recognize infectious pathogens and contend with them. For example, sentinel immune cells such as monocytes and macrophages are equipped with toll-like receptors (TLR) that recognize unique molecules associated with groups of pathogens (i.e., pathogen-associated molecular patterns). Stimulation of TLRs that recognize viruses (TLR3 and TLR7) and bacteria (TLR4) on immune sentinel cells can have profound neurological and cognitive effects, suggesting the immune system conveys a message to the brain after detecting an infectious agent. This message is cytokine based.

Macrophages and monocytes produce inflammatory cytokines (e.g., interleukin [IL]-1β, IL-6, and tumor necrosis factor-α [TNF-α]) that facilitate communication between the periphery and brain.


Cytokine-dependent Pathways to the Brain

Several cytokine-dependent pathways that enable the peripheral immune system to transcend the blood-brain barrier have been dissected.

Inflammatory cytokines present in blood can be actively transported into the brain.
But there are also four indirect pathways:-

1.     Cytokines produced in the periphery need not enter the brain to elicit neurocognitive changes. This is because inflammatory stimuli in the periphery can induce microglial cells to produce a similar repertoire of inflammatory cytokines. Thus, brain microglia recapitulates the message from the peripheral immune system.

2.     in a second pathway, inflammatory cytokines in the periphery can bind receptors on blood-brain barrier endothelial cells and induce perivascular microglia or macrophages to express cytokines that are released into the brain

3.     In a third pathway, cytokines in the periphery convey a message to the brain via the vagus nerve. After immune challenge, dendritic cells and macrophages that are closely associated with the abdominal vagus have been shown to express IL-1β protein; IL-1 binding sites have been identified in several regions of the vagus as well. When activated by cytokines, the vagus can activate specific neural pathways that are involved in neurocognitive behavior. However, activation of the vagus also stimulates microglia in the brain to produce cytokines via the central adrenergic system 

4.     A fourth pathway provides a slower immune-to-brain signaling mechanism based on volume transmission.  In this method of immune-to-brain communication, production of IL-1β by the brain first occurs in the choroid plexus and circumventricular organs—brain areas devoid of an intact blood-brain barrier. The cytokines then slowly diffuse throughout the brain by volume transmission, along the way activating microglia, neurons, and neural pathways that induce sickness behavior and inhibit cognition.


Can Flavonoids Reduce Neuroinflammation and Inhibit Cognitive Aging?

Flavonoids are naturally occurring polyphenolic compounds present in plants. The major sources of flavonoids in the human diet include fruits, vegetables, tea, wine, and cocoa.  Significant evidence has emerged to indicate that consuming a diet rich in flavonoids may inhibit or reverse cognitive aging

Flavonoids may improve cognition in the aged through a number of physiological mechanisms, including scavenging of reactive oxygen and nitrogen species and interactions with intracellular signaling pathways. Through these physiological mechanisms, flavonoids also impart an anti-inflammatory effect that may improve cognition. This seems likely for the flavone luteolin, which is most prominent in parsley, celery, and green peppers.
Whereas luteolin inhibits several transcription factors that mediate inflammatory genes (e.g., nuclear factor kappa B [NF-κB]and activator protein 1 [AP-1]), it is a potent activator of nuclear factor erythroid 2-related factor 2 (Nrf2), which induces the expression of genes encoding antioxidant enzymes. A recent study of old healthy mice found improved learning and memory and reduced expression of inflammatory genes in the hippocampus when luteolin was included in the diet. Thus, dietary luteolin may improve cognitive function in the aged by reducing brain microglial cell activity.
Hence, the flavonoid luteolin is a naturally occurring immune modulator that may be effective in reducing inflammatory microglia in the senescent brain.

Conclusion
In light of the recent evidence suggesting microglial cells become dysregulated due to aging and cause neuroinflammation, which can disrupt neural structure and function, it is an interesting prospect to think dietary flavonoids and other bioactives can be used to constrain microglia. But how can flavonoids impart this anti-inflammatory effect? Although in vitro studies clearly indicate that several flavonoids can act directly on microglial cells to restrict the inflammatory response, results from in vivo studies thus far do not prove that dietary flavonoids access the brain to interact with microglia in a meaningful way. This is a complicated question to dissect because flavonoids reduce inflammation in the periphery and microglia seem to act like an “immunostat,” detecting and responding to signals emerging from immune-to-brain signaling pathways. Thus, whether dietary flavonoids enter the brain and impart an anti-inflammatory effect on microglia is an interesting question but one that is more theoretical than practical because what is most important is how the immunostat is adjusted, whether that is via a direct or indirect route. However, because flavonoids are detectable in the brain they most likely affect microglia both directly and by dampening immune-to-brain signaling.



Interesting Natural Substances

In no particular order, these are several very interesting flavonoids/carotenoids.  In the lab, they all do some remarkable things.

In humans, they also do some interesting things; how helpful they might be in autism remains to be seen.

Being “natural” does not mean they are good for you and have no side-effects.

Some of the following are very widely used and so you can establish if there are issues with long term use.  It also makes them accessible.


Quercetin (found in many fruits, numerous interesting effects)


and two Quercetin-related flavonoids:-

Kaempferol (widely used in traditional medicine)

Myricetin (has good and bad effects)



Lycopene  (from tomatoes, potent anti-cancer, does not cross the BBB)

  
Luteolin(in many vegetables, like broccoli) 

Apigenin (from chamomile, stimulates neurogenesis, PAM of GABAA, block NDMA receptors, antagonist of opioid receptors …)


Tangeretin (from tangerines, does cross the BBB, has potent effects in vitro)


Nobiletin (from tangerines)

Hesperidin (from tangerines)


Naringin (from Grapefruit, contraindicated with many prescription drugs)


Epicatechin/Catechin  (the chocolate/cocoa flavonoids, do cross the BBB, well researched)