Garlic in Autism – Miscreant Microglia? ACE inhibition? or even Nitric Oxide?

Many people avoid garlic because it gives you bad breath, but if you eat enough of it, it can be a potent drug.

There is a substantial amount of research about garlic and general health - it is consistently positive. However, there is an odd resistance to tell people about it.  A good example is this quote from the website of the UK’s National Health Service.

“Studies using high concentrations of garlic extracts have been associated with improved blood circulation, healthier cholesterol levels and lower blood pressure, all of which reduce the risk of cardiovascular disease. However, current evidence does not support the use of garlic supplements to improve health.”

Which sounds like “garlic is really good for you, but don’t eat it”.

Garlic has numerous different modes of action that have a potential health benefit, the best known relate to your heart and circulation, but there are others. 

Garlic and Neurological Conditions with Activated Microglia

There is recent research showing positive effects on the activated microglia.  Activated microglia, the brain’s immune cells, is a feature of autism and other diseases, like Alzheimer’s.

Some people try and treat activated microglia in autism using therapies like:-

·        Minocycline

·        Ibudilast

Some researchers use garlic to try to minimize the damage caused by activated microglia.

They tend to use capsules that contain aged garlic.  It is important not to cook it and there is a difference between fresh garlic, aged garlic and steamed garlic. 

Table 1. Principal Organosulfur Compounds in Commercial Garlic Preparations
Product	Principal Organosulfur Compounds	Delivers allicin-derived compounds?
Fresh garlic cloves	Cysteine sulfoxides (Alliin) γ-glutamylcysteines	Yes, when chopped, crushed, or chewed raw. Minimal, when garlic cloves are cooked before crushing or chopping.
Powdered garlic (tablets)	Cysteine sulfoxides (Alliin) γ-glutamylcysteines	Varies greatly among commercial products. Enteric-coated tablets that pass the USP allicin release test are likely to provide the most.
Steam distilled garlic oil (capsules)	Diallyl disulfide Diallyl trisulfide Allyl methyl trisulfide	Yes
Garlic oil macerate (capsules)	Vinyldithiins Ajoene Diallyl trisulfide	Yes
Aged garlic extract™ (tablets or capsules)	S-Allylcysteine S-Allylmercaptocysteine S-1-Propenylcysteine	Minimal

  

Source: -http://lpi.oregonstate.edu/mic/food-beverages/garlic

  

Benefits Of Garlic Extract May Protect Brain From Inflammation, Diseases Like Alzheimer's

Now, a new study finds that one of these compounds, called FruArg, may protect the brain from age-related disease like dementia and Alzheimer’s.

As a carbohydrate derivative of garlic, there’s a relatively high concentration of FruArg in aged garlic extract (AGE), the authors wrote — AGE is typically sold as supplements. Looking at isolated FruArg’s impact on brain cells, researchers from the University of Missouri found it could protect brain cells from an overexcited immune response caused by environmental factors like pollution and smoking, as well as normal aging, brain injuries, and drinking lots of alcohol.

“Microglia are immune cells in the brain and spinal cord that are the first and main line of defense in the central nervous system,” said lead author Zezong Gu, an associate professor of pathology and anatomical sciences at the university’s School of Medicine. “Unlike other mature brain cells that seldom regenerate themselves, microglial cells respond to inflammation and environmental stresses by multiplying. By massing themselves and migrating toward an injury site, they are able to respond to inflammation and protect other brain cells from destruction.”

But microglia also tread a line between benefiting the body and harming it, protecting only to an extent. A byproduct of their function is nitric oxide, a free radical. And when a lot of microglia are produced, so are nitric oxide molecules, which can lead to oxidative stress and inflammation within the brain and nervous system. As we’ve all heard before, however, antioxidants fight oxidative stress, and in this case, that antioxidant compound is FruArg. 

For their study, Gu and his colleagues applied stress to a cell model of microglial cells and then added FruArg to them once nitric oxide concentrations rose. They found the microglial cells “adapted to the stress by reducing the amount of nitric oxide they produced.” What’s more, FruArg also promoted the production of antioxidants, which then went on to protect and heal other brain cells. “This helps us understand how garlic benefits the brain by making it more resilient to the stress and inflammation associated with neurological diseases and aging,” Gu said. 

Full study:- 

Proteomic analysis of the effects of aged garlic extract and its FruArg component on lipopolysaccharide-induced neuroinflammatory response in microglial cells.

Collectively, these results suggest that AGE and FruArg attenuate neuroinflammatory responses and promote resilience in LPS-activated BV-2 cells by suppressing NO production and by regulating expression of multiple protein targets associated with oxidative stress. 

Effects of aged garlic (AGE) extract and FruArg on gene expression and signaling pathways in lipopolysaccharide-activated microglial cells 

These effects could be modulated by treatment with both AGE and FruArg. These findings suggests that AGE and FruArg are capable of alleviating oxidative stress and neuroinflammatory responses stimulated by LPS in BV-2 cells.

  

Evaluating the Anti-Neuroinflammatory Capacity of Raw and Steamed Garlic as Well as Five Organosulfur Compounds

Abstract

: The anti-neuroinflammatory capacities of raw and steamed garlic extracts as well as five organosulfur compounds (OSCs) were examined in lipopolysaccharide (LPS)-stimulated BV2 microglia. According to those results, steaming pretreatment blocked the formation of alliinase-catalyzed OSCs such as allicin and diallyl trisulfide (DATS) in crushed garlic. Raw garlic, but not steamed garlic, dose-dependently attenuated the production of LPS-induced nitric oxide (NO), interleukin-1β (IL-1β), tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein-1 (MCP-1). DATS and diallyl disulfide at 200 and 400 μM, respectively, displayed significant anti-neuroinflammatory activity. Meanwhile, even at 1 mM, diallyl sulfide, S-allyl cysteine and alliin did not display such activity. Inhibition of nuclear factor-κB activation was the mechanism underlying this protective effect of raw garlic and DATS. Analysis results indicated that the anti-neuroinflammatory capacity of raw garlic is due to the alliin-derived OSCs. Importantly, DATS is a highly promising therapeutic candidate for treating inflammation-related neurodegenerative diseases.

As expected, raw garlic extract inhibited NO, proinflammatory cytokine, and chemokine production by through suppression of NF-κB activation in LPS-activated BV2 microglia; it also had a potent anti-neuroinflammatory capacity. Additionally, steaming pretreatment abolished both the anti-neuroinflammatory capacity and alliin-derived OSCs formation of garlic simultaneously. In sum, this study demonstrates that alliinase catalysis and chemical transformation are essential for the formation of active OSCs, which are responsible for the anti-neuroinflammatory capacity of garlic. Based on above, it is suggested that consumers to crush or cut raw garlic before cooking in order to obtain more health benefits of garlic. As one of the most potent anti-neuroinflammatory components of garlic, DATS is highly promising for use as a dietary agent to prevent inflammation-related neurodegenerative disease. 

Garlic as an ACE inhibitor 

We saw in a recent post how too much angiotensin II is likely a problem in schizophrenia and some autism.  The biomarker of those affected would be high levels of IL-17a. 

Targeting Angiotensin in Schizophrenia and Some Autism

There are numerous references in the literature to garlic being an ACE inhibitor, which will reduce the level of angiotensin II and hence IL-17 and IL-17a. 

Garlic extract reduces serum angiotensin converting enzyme (ACE) activity in nondiabetic and streptozotocin-diabetic rats. 

Although garlic extract administration had no significant effect on serum glucose, it significantly strongly decreased the serum ACE activity. ACE activity was higher in diabetic than nondiabetic rats, but in diabetic animals treated with garlic extract, the elevation of ACE activity did not occur. These results suggest that garlic extract might have value as ACE inhibitor to prevent some vascular complications of diabetes mellitus.

So perhaps some people with autism, who respond to garlic are actually not feeling the microglia effect, but actually the angiotensin II reducing effect. 

Potent activation of nitric oxide synthase by garlic: a basis for its therapeutic applications. 

Activation of calcium-dependent nitric oxide synthase and the subsequent production of nitric oxide is probably the most novel mechanism yet claimed by which garlic can exert its therapeutic properties.

   

Conclusion  

Garlic has numerous health benefits and different types of processing lead to very different chemical compositions.  So it does depend how you take your garlic.

Does any type of garlic provide a benefit in any type of autism? 

For one reader fresh garlic is effective in treating autism, whereas aged garlic is not; this is not what she expected. This would of course suggest something about its mode of action. 

Perhaps some people are actually benefiting from a reduction in angiotensin II.  Or maybe it is production of nitric oxide?

There are actually other natural ACE inhibitors that you might be using by accident.

People trying to make tasty drinkable sulforaphane, using the Australian mixture of broccoli and pomegranate powders, are actually also making an ACE inhibitor.  

Effect of pomegranate juice on Angiotensin II-induced hypertension in diabetic wistarrats

The results suggest that the PJ extract could prevent the development of high blood pressure induced by Ang II in diabetic rats probably by combating the oxidative stress induced by diabetes and Ang II and by inhibiting ACE activity.

Pharmacological review on Natural ACE inhibitors 

All we can say is some people with autism respond to specific types of garlic, but nobody can be sure what the mode of action is; there are several possible credible explanations.  

Angiotensin II in the Brain & Therapeutic Considerations

In a previous post I suggested that another cheap generic drug (an ACE inhibitor) could potentially be repurposed to treat schizophrenia and some autism. The original idea was related more to modifying the immune/inflammatory response in the body, rather than the brain.  There is however plenty of research regarding Angiotensin within the brain and the numerous roles it plays.

Juggling - maximizing effects, while minimizing
drug interventions

You may recall in the earlier post that in both schizophrenia and autism there is elevated angiotensin II.

In the brain there are two types of angiotensin receptor, AT1 and AT2.  Their actions are opposing each other.

In many kinds of disease we would want to stimulate AT2, but inhibit AT1.

AT2 is thought to be important for cognitive function and is now a target for Alzheimer’s research.

Using an ACE inhibitor you reduce the amount of angiotensin II and so in effect inhibit both AT1 and AT2.

In theory angiotensin II should not cross the blood brain barrier (BBB), so we should be dealing with centrally produced (i.e. inside the brain) angiotensin II.  In practical terms it seems that people with high levels of angiotensin II may have a permeable BBB.

This is relevant because most ACE inhibitors do not cross the BBB, but the original ACE inhibitor called Captopril does cross the BBB.  So if a centrally acting ACE inhibitor were found to be required, it was discovered 40 years ago.

A therapy would ideally be targeted selectively at AT1 or AT2 receptors.  An AT1 blocker might treat for stress-induced disorders.  An experimental AT2 receptor agonist, called compound 21, is now available and is expected to reduce inflammation and oxidative stress.

Compound 21, a selective agonist of angiotensin AT2 receptors, prevents endothelial inflammation and leukocyte adhesion in vitro and in vivo.

Angiotensin II receptor AT1 antagonists are widely used drugs indicated for hypertension, diabetic nephropathy and congestive heart failure. They block effect of Angiotensin on AT1 and might be good in the brain.

We would like to increase the effect on AT2, we could do that with more Angiotensin II, but then we would make things worse with AT1.

                          Do nothing  ACE inhibitor    AT1 antagonist      AT2 agonist

Effect on AT1               none                            good                                     good                          none

Effect on AT2               none                            bad                                       none                          good

AT1 antagonists are widely available and seen as well tolerated.

AT1 antagonists appear to protect against Alzheimer’s.

The only AT2 agonist is an experimental drug called Compound 21.

The only ACE inhibitor that should affect AT2 in the brain is Captopril and so may be an unwise choice. It will reduce Angiotensin II in the brain and in the rest of the body.


Why were we interested in Angiotensin?

Targeting Angiotensin in Schizophrenia and Some Autism

In the original Angiotensin post in this blog we saw that in schizophrenia and some autism, that Angiotensin II is elevated.  We also saw that:-

·        Blocking angiotensin-converting enzyme (ACE) induces those potent regulatory T cells that are lacking in autism and modulates Th1 and Th17 mediated autoimmunity.  See my last post on Th1, Th2 and Th17. 

·        In addition, Angiotensin II affects the function of the NKCC1/2 chloride cotransporters that are dysfunctional in much autism and at least some schizophrenia.

·        It should also reduce any troubling high levels of leptin, which we saw in another post is an issue in most autism

So the idea was that many broadly anti-inflammatory effects of reducing Angiotensin II might be helpful in autism.

But what about inside the brain?

Angiotensin in the Brain

Here we do get to the science, but I will start with the conclusion. We actually want more effect from the Angiotensin AT2 receptor, which should give numerous benefits, but have no means of achieving this. What we can do is make sure we do not reduce AT2 activity, this means better to use and AT1 antagonist, rather than an ACE inhibitor.

The science supporting the use of an AT agonist follows:-

In the text you will see ARB and compound 21. Both are doing good things. The suggestion is that by doing all these good things there should be improved cognitive function; this has yet to be proved in human tests.

ARB = Angiotensin Receptor AT1 Blocker

Compound 21 = Angiotensin Receptor AT2 agonist

Roles of Brain Angiotensin II in Cognitive Function and Dementia

The brain renin-angiotensin system (RAS) has been highlighted as having a pathological role in stroke, dementia, and neurodegenerative disease. Particularly, in dementia, epidemiological studies indicate a preventive effect of RAS blockade on cognitive impairment in Alzheimer disease (AD). Moreover, basic experiments suggest a role of brain angiotensin II in neural injury, neuroinflammation, and cognitive function and that RAS blockade attenuates cognitive impairment in rodent dementia models of AD. Therefore, RAS regulation is expected to have therapeutic potential for AD. Here, we discuss the role of angiotensin II in cognitive impairment and AD. Angiotensin II binds to the type 2 receptor (AT₂) and works mainly by binding with the type 1 receptor (AT₁). AT₂ receptor signaling plays a role in protection against multiple-organ damage. A direct AT₂ receptor agonist is now available and is expected to reduce inflammation and oxidative stress and enhance cell differentiation. We and other groups reported that AT₂ receptor activation enhances neuronal differentiation and neurite outgrowth in the brain. Here, we also review the effect of the AT₂ receptor on cognitive function. RAS modulation may be a new therapeutic option for dementia including AD in the future.

Figure 1: Possible effect of angiotensin II on neurovascular unit. AT₂: angiotensin II type 2 receptor, AchR: acetylcholine receptor, BBB: blood brain barrier, and TGF-β: transforming growth factor β.

Figure 2: Effect of angiotensin II type 2 receptor signaling on cognitive function. AT₂: angiotensin II type 2 receptor, ATIP: AT₂ receptor-interacting protein, Id1: inhibitor of DNA binding protein 1, MMS2: methyl methanesulfonate-sensitive 2, NO: nitric oxide, SHP-1: Src homology 2 domain-containing protein-tyrosine phosphatase 1, and Ubc-13: ubiquitin conjugating enzyme 13.

Figure 3: Effect of angiotensin II on cognitive function. ACE: angiotensin converting enzyme inhibitor, AT₁: angiotensin II type 1 receptor, AT₂: angiotensin II type 2 receptor, and ARB: angiotensin II type 1 receptor blocker.

Continuous stimulation with angiotensin II may damage neurons via multiple cascades through AT₁ receptor stimulation. On the other hand, stimulation of the AT₂ receptor is expected to prevent neural damage and cognitive impairment (Figure 3). However, it is difficult to perform clinical intervention studies to confirm the results of animal studies because of the long-term progression of cognitive impairment. Moreover, in clinical practice, it is not possible to exclude the antihypertensive effect of RAS blockade on cognition in patients with hypertension. However, RAS modulation may be a new therapeutic option for dementia including AD in the future. Therefore, the hypothesis that RAS regulation affects future cognitive function should be confirmed with carefully designed clinical studies.

Which ARB (Angiotensin Receptor Blocker) for Autism?

Very many biological markers are disturbed in autism and many of them seem to be best ignored, you cannot “correct” them all.

However, there will be an underlying reason behind each one of them being disturbed.

As we saw in the recent post on metabolic syndrome, it is not uncommon to find a cascade of downstream problems that might seem to indicate a huge list of drugs.  A different approach is required, it is necessary to treat the underlying (upstream) problems and have a much shorter list of therapies.

We saw in the post on leptin that the elevated levels in autism are treatable, but is there any point?

We have a long list of other things that might be useful in autism and it would be nice to have a single therapy that might address many of them.

It appears that selecting the optimal ARB might give the opportunity to address numerous issues at once.

Telmisartan seems to have numerous potentially useful additional effects:

·        Acts as a PPAR gamma agonist, like the glitazone drugs shown effective in autism trials

·        Acts as a PPAR delta agonist, which should activate the impaired PPARδ  PGC-1α signaling pathway, and enhance mitochondrial biogenesis. This should help people with mitochondrial disease and should be evident by increased exercise endurance and, in theory, improved cognitive function.

·        Telmisartan regulates the Bcl-2 cancer gene, implicated in autism

BDNF-Akt-Bcl2 antiapoptotic signaling pathway is compromised in the brain of autistic subjects

While the effect in autism is complex, Telmisartan is already seen as a potent target for prevention and treatment in human prostate cancer

·        Telmisartan and other ARBs appear to give protection from Alzheimer’s Disease (suggested to be via its effect on PPAR gamma). Perhaps useful for young adults with Down Syndrome, where early onset Alzheimer’s is expected?

·       Telmisartan and other ARBs have a tendency to increase the level of potassium in blood. Up to 10% of people would experience mild hyperkalemia.  For people with autism taking bumetanide, this effect on potassium might actually be helpful. They would need to reduce their potassium supplementation, or might need none at all.

Telmisartan in clinical trials related to autism

As is repeatedly the case, schizophrenia research is again more advanced than autism research. A quick check showed this:-

Telmisartan Completed Phase 4 Trials for Schizoaffective Disorders / Schizophrenia Treatment

This is a 12-week, randomized, double-blinded, placebo-controlled trial of telmisartan 80 mg/day as an adjunctive to clozapine or olanzapine therapy, in 70 schizophrenia subjects to examine telmisartan's effect on glucose metabolism, weight, food intake, resting energy expenditure, and body composition. In addition, the study will examine insulin's effects on psychopathology and cognition.

Conclusion

We currently have no possibility of something like Compound 21, but Telmisartan looks very interesting and it would nice if those psychiatrists who have trialed it in schizophrenia would do the same in autism.  

It looks like the beneficial effects should come at a lower dose than that used to lower blood pressure. In the schizophrenia trial I think they used a higher dose (80mg) than necessary, I suppose they wanted to maximize their chance of success.  In order to minimize any possible negative effects, I would suggest the psychiatrists trial 20mg in youth with autism.

There will be a post on PPAR delta and mitochondrial disease, because there are at least two other ways to target mitochondrial disease in this way, if you do not like Telmisartan.  There is the cheap drug Bezafibrate and the supplement berberine.

Targeting Angiotensin in Schizophrenia and Some Autism

 A home run? Certainly worth further consideration.

Just when you thought we had run out of hormones to connect to autism and schizophrenia, today we have Angiotensin. 

Angiotensin is a hormone that causes vasoconstriction and a subsequent increase in blood pressure. It is part of the renin-angiotensin system, which is a major target for drugs (ACE inhibitors) that lower blood pressure. Angiotensin also stimulates the release of aldosterone, a hormone that promotes sodium retention which also drives blood pressure up.

Angiotensin I has no biological activity and exists solely as a precursor to angiotensin II.

Angiotensin I is converted to angiotensin II  by the enzyme angiotensin-converting enzyme (ACE).  ACE is a target for inactivation by ACE inhibitor drugs, which decrease the rate of Angiotensin II production.  

It turns out that Angiotensin has some other properties very relevant to schizophrenia, some autism and quite likely many other inflammatory conditions. 

Blocking angiotensin-converting enzyme (ACE) induces those potent regulatory T cells that are lacking in autism and modulates Th1 and Th17 mediated autoimmunity.  See my last post on Th1,Th2 and Th17. 

In addition, Angiotensin II affects the function of the NKCC1/2 chloride cotransporters that are dysfunctional in much autism and at least some schizophrenia.  

Drugs that reduce Angiotensin are very widely prescribed, so they are cheap and well understood. This means that yet another cheap generic has the potential to be repurposed to treat neurological disorders. 

As one paper puts it “modulation of the RAAS (renin-angiotensin-aldosterone system) with inexpensive, safe pharmaceuticals used by millions worldwide is an attractive therapeutic strategy for application to human autoimmune diseases.” 

No big profits then for big pharma. 

IL-17a 

We learnt all about the inflammatory cytokines IL-17 and IL-17a in a recent post. That post was about autism, but not surprisingly, elevated levels of IL-17a are a feature in big brother schizophrenia. Big brothers do tend to get more research attention.

In schizophrenia there is increased plasmatic Angiotensin Converting Enzyme (ACE) activity in patients compared to healthy controls, which is also associated to poor cognitive functioning. The ACE main product angiotensin II has known pro-inflammatory properties. 

So an ACE inhibitor looks an obvious choice for schizophrenia.  Very slowly research is indeed moving in that direction.

Angiotensin receptor blockers have even been proposed for bipolar disorder, autism’s other elder brother.

  

What about ACE and Autism? 

As we have got used to, kid bother autism has not had the same level of research attention as given to schizophrenia, but we do have this:- 

Genetic Variants of Angiotensin-Converting Enzyme Are Linked to Autism: A Case-Control Study

Autism is a disease of complex nature with a significant genetic component. The importance of renin-angiotensin system (RAS) elements in cognition and behavior besides the interaction of angiotensin II (Ang II), the main product of angiotensin-converting enzyme (ACE), with neurotransmitters in CNS, especially dopamine, proposes the involvement of RAS in autism. Since the genetic architecture of autism has remained elusive, here we postulated that genetic variations in RAS are associated with autism. 

Our data suggests the involvement of RAS genetic diversity in increasing the risk of autism.

   

Here is the supporting research:-  

Blocking angiotensin-converting enzyme induces potent regulatory T cells and modulates TH1- and TH17-mediated autoimmunity

The renin-angiotensin-aldosterone system (RAAS) is a major regulator of blood pressure. The octapeptide angiotensin II (AII) is proteolytically processed from the decapeptide AI by angiotensin-converting enzyme (ACE), and then acts via angiotensin type 1 and type 2 receptors (AT1R and AT2R). Inhibitors of ACE and antagonists of the AT1R are used in the treatment of hypertension, myocardial infarction, and stroke. We now show that the RAAS also plays a major role in autoimmunity, exemplified by multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Using proteomics, we observed that RAAS is up-regulated in brain lesions of MS. AT1R was induced in myelin-specific CD4⁺ T cells and monocytes during autoimmune neuroinflammation. Blocking AII production with ACE inhibitors or inhibiting AII signaling with AT1R blockers suppressed autoreactive TH1 and TH17 cells and promoted antigen-specific CD4+FoxP3+ regulatory T cells (Treg cells) with inhibition of the canonical NF-κB1 transcription factor complex and activation of the alternative NF-κB2 pathway. Treatment with ACE inhibitors induces abundant CD4+FoxP3+ T cells with sufficient potency to reverse paralytic EAE. Modulation of the RAAS with inexpensive, safe pharmaceuticals used by millions worldwide is an attractive therapeutic strategy for application to human autoimmune diseases.

  

Johns Hopkins Scientists Present Findings At The Society For Neuroscience Meeting - A Blood Pressure Hormone Implicated in Psychosis

In an effort to find a marker that predicts psychosis, postdoctoral researcher Lindsay Hayes, Ph.D., learned unexpectedly that mice and people with behavior disorders have abnormally low levels of a hormone system tied to blood pressure regulation and inflammation. In the cerebrospinal fluid of patients with first episode psychosis, she noticed abnormally low levels of the enzyme that makes the hormone angiotensin. To see if these results correlated to animals and could be studied in the lab, Hayes, who works in the laboratory of treated brain cells with angiotensin and inflammation activators in their mouse model for behavior disorders, then measured the output of proteins involved in inflammation. Compared to normal mice, the cells from the mouse with behavioral disorders released more inflammation protein when treated with low levels of angiotensin and less when treated with high levels. Next, she looked at gene expression levels of the angiotensin system components in the brain cells of the behavioral disorder mice. The gene expression levels for the receptor that detects angiotensin were abnormally low in a specific type of brain cell. Hayes says these specific cells in the behavior disorder mice seem to be less susceptible to angiotensin’s immunosuppressive properties, because they have less receptor to detect angiotensin than the same brain cells in normal mice. Hayes and Sawa plan to investigate whether targeting angiotensin could control inflammation and perhaps treat psychosis. 

Angiotensin converting enzyme activity is positively associated with IL-17a levels in patients with schizophrenia.

Abstract

Previous studies of our group showed increased plasmatic Angiotensin-I Converting Enzyme (ACE) activity in schizophrenia (SCZ) patients compared to healthy controls, which was also associated to poor cognitive functioning. The ACE main product angiotensin II (Ang-II) has pro-inflammatory properties. Activated immune-inflammatory responses in SCZ and their association with disease progression and cognitive impairments are also well-described. Therefore, we examined here the association of plasma ACE activity and inflammatory mediators in 33 SCZ patients and 92 healthy controls. Non-parametric correlations were used to investigate the association of the enzyme activity and the peripheral levels of immune inflammatory markers as interleukins, tumor necrosis factor (TNF-α), and interferon (IFN-γ). Although no significant correlations could be observed for ACE activity and measured cytokines levels in healthy controls, a significant positive correlation for ACE enzymatic activity and IL-17a levels was observed in SCZ patients. Correcting for gender did not change these results. Moreover, a significant association for ACE activity and IFN-γ levels was also observed. To our knowledge, this is the first study to show a significant association between higher ACE activity and the levels of cytokines, namely IL-17a and IFN-γ, in patients with SCZ. 

Cerebrospinal fluid angiotensin-converting enzyme (ACE) correlates with length of illness in schizophrenia. 

Abstract

The aim of the study was to evaluate a possible progression with time of cerebrospinal fluid (CSF) angiotensin-converting enzyme (ACE) levels in treated schizophrenia patients. CSF ACE was determined in duplicate by a sensitive inhibitor-binding assay (IBA) from morning CSF samples of 56 acute and chronic in-patients with schizophrenic psychoses diagnosed according to DSM-IV. CSF ACE correlated significantly with length of schizophrenic psychosis (r=0.39, p=0.003). There was also a positive significant correlation between CSF ACE and duration of current psychotic episode (r=0.39, p=0.003) as well as duration of current hospitalization (r=0.66, p<0 .001="" span=""> These significances were maintained even when patients who were not treated with antipsychotics at the time of sampling were excluded. The correlations also remained significant when controlling for current neuroleptic dose in chlorpromazine equivalents. Serum ACE did not correlate with any clinical variable. No significant correlations between serum or CSF ACE and age, diagnostic subgroup, gender, serum ACE, CSF to serum albumin ratios, or neuroleptic dose in chlorpromazine equivalents were detected. The elevation of CSF ACE seemed to be confined to a subgroup of chronic patients with few positive symptoms. Elevated CSF ACE may reflect an increased solubilization of ACE from cell membranes in the central nervous system or constitute an increased expression of the ACE gene in response to some stimuli. This may be a function of treatment or a result of the deteriorating schizophrenic process. 

Blocking angiotensin-converting enzyme induces potent regulatory T cells and modulates TH1- and TH17-mediated autoimmunity

The renin-angiotensin-aldosterone system (RAAS) is a major regulator of blood pressure. The octapeptide angiotensin II (AII) is proteolytically processed from the decapeptide AI by angiotensin-converting enzyme (ACE), and then acts via angiotensin type 1 and type 2 receptors (AT1R and AT2R). Inhibitors of ACE and antagonists of the AT1R are used in the treatment of hypertension, myocardial infarction, and stroke. We now show that the RAAS also plays a major role in autoimmunity, exemplified by multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Using proteomics, we observed that RAAS is up-regulated in brain lesions of MS. AT1R was induced in myelin-specific CD4⁺ T cells and monocytes during autoimmune neuroinflammation. Blocking AII production with ACE inhibitors or inhibiting AII signaling with AT1R blockers suppressed autoreactive TH1 and TH17 cells and promoted antigen-specific CD4+FoxP3+ regulatory T cells (Treg cells) with inhibition of the canonical NF-κB1 transcription factor complex and activation of the alternative NF-κB2 pathway. Treatment with ACE inhibitors induces abundant CD4+FoxP3+ T cells with sufficient potency to reverse paralytic EAE. Modulation of the RAAS with inexpensive, safe pharmaceuticals used by millions worldwide is an attractive therapeutic strategy for application to human autoimmune diseases.

P-358: Renin-angiotensin system alters NKCC-1 cotransport activity in healthy white but not black subjects:

African Americans have been shown to exhibit lower urinary potassium excretion when compared to Caucasians. Angiotensin II regulates both potassium handling by the kidney and the Na-K-2Cl (NKCC) cotransporter in vitro . However, little is known about the role of the reninangiotensin system (RAS) in human NKCC cotransport regulation in vivo. We hypothesized that regulation of RAS would induce concomitant alterations in NKCC activity in humans. The kidney and erythrocyte express NKCC-1 isoform. Therefore, we measured NKCC-1 activity in freshly isolated ex vivo red cells from 12 healthy blacks and 11 healthy whites in high (200 mmol/d) and low (10 mmol/d) salt balance, followed by a measure 24 h-post candesartan [16 mg] to block angiotensin II type I receptors on low salt diet. Baseline NKCC cotransport activity was significantly lower in Blacks when compared to Whites in balance on a typical high salt diet, and was reduced when the subjects were placed on a low salt diet in whites only. Administration of candesartan reversed the reduction seen with low salt diet in whites, where as in blacks there was no significant effect. These data suggest altered in vivo regulation of NKCC-1 via RAS in Blacks when compared to Whites, and provide a mechanism that may in part explain the altered potassium handling observed among otherwise healthy African Americans.

Conclusion

I think it is likely that some sub-types of autism would likely benefit from an ACE inhibitor. As a secondary benefit, it will also reduce any troubling high levels of leptin.

There are other ways to modulate Th1, Th2 and Th17, but if you have elevated Angiotensin Converting Enzyme (ACE), then an ACE inhibitor would appear the logical choice.

How about a clinical trial in adults with Asperger's?