Showing posts with label Fragile X. Show all posts
Showing posts with label Fragile X. Show all posts

Tuesday, 6 November 2018

When is an SSRI not an SSRI? Low dose SSRIs as Selective Brain Steroidogenic Stimulants (SBSSs) via Allopregnanolone modifying GABAa receptors and neonatal KCC2 expression

Today’s post might seem to have a very complicated tittle, but to regular readers it is really just another take on what we have seen time and time again.
Today we see how another steroid imbalance in autism – low levels of allopregnenolone in this case – affects the neurotransmitter GABA and indeed the chloride transporter KCC2.

Putting Prozac/Zoloft to a better use?

I did report previously on a trial in adults with autism where pregnenolone was used.

Recall that disturbed hormonal homeostasis is a key feature of autism. What matters is the level of each hormone inside the brain (i.e. centrally), not in your blood. The only way to get a reliable idea of what is going on would be to take a sample of spinal fluid.

Today we look at boosting allopregnenolone not with a steroid hormone, but with a 1/10th dose of Prozac (Fluoxetine) or indeed Zoloft (Sertraline). Prozac is a selective serotonin reuptake inhibitor (SSRI) when given at the usual dose of 20-80mg, but at 2.5mg it does not function as an SSRI.
At regular doses selective serotonin reuptake inhibitors (SSRI) drugs like Prozac are well known to cause problems, as do benzodiazepines like Clonazepam.
Thanks to Professor Catterall we saw in earlier posts how tiny doses of Clonazepam have an effect on one particular sub-unit of GABAA receptors. By fine tuning the response of this receptor we saw how a cognitive improvement can be achieved, in some people. The dose is so low there appear to be no long term side effects. At least one other professor of medicine, I am in contact with, has been treating his son with autism with low dose clonazepam for years.
Many adults and children with autism are prescribed Prozac for anxiety. Even Temple Grandin has said she takes Prozac.
At low, non-serotonergic doses, some drugs like Prozac show a different mode of action, they potently, positively, and allosterically modulate GABA action at GABAA receptors. These drugs achieve this by increasing the amount of the steroid hormone allopregnanolone.
Neurosteroid biosynthesis down‐regulation and changes in GABAA receptor subunit composition are a feature of several neurological conditions, including some autism.
Stimulating allopregnenalone biosynthesis will have multiple effects including on TSPO and endocannabinoid receptors.

Brain principal glutamatergic neurons synthesize 3α-hydroxy-5α-pregnan-20-one (Allo), a neurosteroid that potently, positively, and allosterically modulates GABA action at GABAA receptors. Cerebrospinal fluid (CSF) Allo levels are decreased in patients with posttraumatic stress disorder (PTSD) and major depression. This decrease is corrected by fluoxetine in doses that improve depressive symptoms. Emotional-like behavioral dysfunctions (aggression, fear, and anxiety) associated with a decrease of cortico-limbic Allo content can be induced in mice by social isolation. In socially isolated mice, fluoxetine and analogs stereospecifically normalize the decrease of Allo biosynthesis and improve behavioral dysfunctions by a mechanism independent from 5-HT reuptake inhibition. Thus, fluoxetine and related congeners facilitate GABAA receptor neurotransmission and effectively ameliorate emotional and anxiety disorders and depression by acting as selective brain steroidogenic stimulants (SBSSs).                               
When the results of these in vitro studies are compared to those of our in vivo studies, it becomes evident that in mice the doses of fluoxetine and norfluoxetine that cause a rapid increase in brain Allo levels do not exceed brain concentrations in the low nanomolar range, whereas the fluoxetine concentrations that directly activate 3a-HSD in vitro are in the micromolar range. Moreover, the high potency and stereospecificity of fluoxetine and norfluoxetine in decreasing aggressive behavior and normalizing brain Allo content during social isolation (see Table 1, and Figure 3) support the notion that these compounds facilitate the action of 5a-R type I or 3a-HSD by an unidentified indirect mechanism, which is most probably perturbed by protracted social isolation.

Thus, these drugs, which were originally termed ‘SSRI’ antidepressants, may be beneficial in psychiatric disorders because in doses that are inactive on 5-HT reuptake mechanisms, they increase the bioavailability of neuroactive GABAergic steroids. On the basis of these considerations, we now propose that the term ‘SSRIs’ should be changed to the more appropriate term ‘selective brain steroidogenic stimulants’ (SBSSs), which more accurately defines the pharmacological mechanisms expressed by fluoxetine and its congeners.


The pharmacology of the S stereoisomers of fluoxetine and norfluoxetine appears to be prototypic for molecules that possess specific neurosteroidogenic activity. The doses of S-fluoxetine and S-norfluoxetine required to normalize brain Allo content downregulation, pentobarbital action, aggressiveness, and anxiety in socially isolated mice are between 10-fold to 50-fold lower than those required to induce SSRI activity. However, the precise mechanisms of action by which S-fluoxetine and S-norfluoxetine increase neurosteroids remain to be investigated.

Derivatives of S-fluoxetine and S-norfluoxetine, acting with high potency and specificity on brain neurosteroid expression at doses devoid of significant action on brain 5-HT reuptake mechanisms, may represent a new class of pharmacological tools important for the management of anxiety, related mood disorders, dysphoria, fear, and impulsive aggression.

On the basis of these data, new drugs devoid of SSRI activity but that are potent neurosteroidogenic agents should be developed for the treatment of psychiatric disorders that result from the downregulation of neurosteroid expression, including major depression, and in the prevention of PTSD.

France often gets very negative comments about how it treats people with autism, but in the case studies below it looks like some innovative work is going on in some of their day hospitals, where boys and girls with severe autism are sent to pass their time. 

The system in England has recently been highlighted as being pretty appalling, where over 2,000 people with autism are currently detained in Assessment and Treatment Units (ATUs), privately run secure residential "hospitals", at great cost paid for by the State. Those inside might enter with the approval of their family to stay for 3 weeks for respite care, but end up being detained for 3 years, or even longer. The State assumes their guardianship and the individual and parents are powerless. The individuals are kept in prison-like conditions and not surprisingly get worse not better, the worse they get, the harder it is ever to be released. Hard to believe this is still happening.  If you live in England, best not to hand your child over to the State. Someone has even written a book about escaping from such a unit. This is no better than the old State Hospitals in the US, that finally were closed down in the 1970s, that warehoused mentally disabled people, until their premature death.

Autism Spectrum Disorder (ASD) is defined by the copresence of two core symptoms: alteration in social communication and repetitive behaviors and/or restricted interests. In ASD children and adults, irritability, self-injurious behavior (SIB), and Attention Deficit and Hyperactivity Disorders- (ADHD-) like symptoms are regularly observed. In these situations, pharmacological treatments are sometimes used. Selective Serotonin Reuptake Inhibitors- (SSRI-) based treatments have been the subject of several publications: case reports and controlled studies, both of which demonstrate efficacy on the symptoms mentioned above, even if no consensus has been reached concerning their usage. In this article four clinical cases of children diagnosed with ASD and who also present ADHD-like symptoms and/or SIB and/or other heteroaggressive behaviors or irritability and impulsivity treated with low doses of fluoxetine are presented.
Case 1 
An 8-year-old girl (19 kg) had an ASD diagnosis according to the DSM-5 and ADI-R criteria based on information provided by parents. She also had significant mental retardation, with severe SIB (banging her head against objects and biting her hands), forcing her entourage to maintain a daily and permanent physical restraint. She spends most of her time in a day hospital. She received the following pharmacological treatment: risperidone 2 mg/d and cyamemazine 80 mg/d without modifications to her SIB and at the price of a major slowing down and a manifestation of a tendency toward blunting. The CGI severity of illness score was at five (markedly ill). We decreased and stopped risperidone and started valproic acid. After four weeks of valproic acid 400 mg/d in combination with cyamemazine (60 mg/day), SIBs did not improve. Then, we added fluoxetine 2.5 mg/d and increased it after one week to 5 mg/d and to 10 mg/d in the third week. After one week, the CGI improvement scale (CGI-I) was at two; after three weeks, it lowered to 1 (very much improved). We also observed a significant decrease in anxiety as well as the disappearance of SIB (disappearance of the behavior consisting of the banging and rubbing her head against objects). However, it should be noted that the entourage kept the bandages on her hands because she continued to bite them, even if she did it with less intensity than before. There were no side effects. After three months of fluoxetine, her clinical state remains stable.

Case 2 
A 12-year-old boy (70 kg), with DSM-5 criteria for an ASD and ADI-R confirming this diagnosis, exhibited extreme irritability, violence, and impulsiveness as well as SIB (he had thrown seven television sets out of the window). The CGI severity illness scoring was at six (severely ill). In the day hospital where he spent most of his time, it was difficult for staff to manage his impulsivity and unpredictability. His treatment included risperidone 4 mg/d as well as loxapine 80 mg/d. Despite this pharmacological treatment, episodes of aggression and SIBs continued. This treatment induced a significant weight gain (8 kg in 5 months). Treatment with fluoxetine 2.5mg/d was introduced and increased to5mg/d after one week and to 10 mg/d at the beginning of the third week. After one week, there was a CGI-I score of three, which decreased to two after two weeks of treatment and to one after three weeks. Such a positive clinical response allowed for a reduction in risperidone to 2mg/d and in loxapine to 60 mg/d. The treatment was tolerated well by the patient, and he began to lose weight (4 kg). After two months off luoxetine, his clinical state remains stable.

Case 3
 A 6-year-old male child (30 kg) with DSM-5 criteria and ADI-R for an ASD exhibited problems of SIB and repetitive behaviors (washing his hands for more than 30 minutes at least two to three times per day), severe irritability, frequent crying, social withdrawal, and inappropriate speech. Treatment with risperidone 2mg/d had improved irritability and partially the SIB, but it had also produced significant weight gain (four kg in three months). A decrease in the risperidone dosage seemed necessary. Treatment with fluoxetine2.5mg/d was begun, which quickly led to a reduction in inappropriate behavior (for example, impulsive crawling on the ground in the classroom). After one week, the CGI-I scoring was at two. The dosage was gradually increased to 5 mg/d the second week and to 7.5mg/d the third week. The repetitive behaviors gradually subsided. After three weeks the CGI-I score was at one, and it remained stable for nine weeks. The risperidone dosage could be decreased to 0,5 mg/day and the patient’s weight remained the same.
Case 4 
A 12-year-old boy (62kg) withDSM-5 and ADI-R criteria for a severe case of ASD, including severe ADHD-like symptoms, often required physical restraint and did not improve despite a long-term treatment of risperidone 3 mg/d as well as melaton in 4mg at bedtime. The CGI severity illness scoring was at 6 (severely ill). The behavioral pattern included irritability, marked agitation, crying, severe hyperactivity, and other behaviors typical of this disorder. He was also anxious, rendering the situation at his day hospital where he spent most of his time all the more difficult. A prescription of fluoxetine 2.5mg/d was initiated with an immediate and complete improvement of ADHD-like symptoms:CGI-I at one week of treatment was at a one, making this case the most remarkable of the four presented here. Treatment with fluoxetine was continued with a dosage increase up to 5 mg/d to allow for a decrease in the risperidone dose to 1 mg/d. CGI-I score remained stable at one for the duration of the nine weeks.

Our reader Mira, whose son has FXS, recently referred to Dr Hagerman’s trial of low dose Sertaline/Zoloft in Fragile X. GABAA malfunction appears to be a feature of Fragile X, but it is not necessarily the identical malfunction to those with idiopathic autism who respond to bumetanide.


Observational studies and anecdotal reports suggest sertraline, a selective serotonin reuptake inhibitor (SSRI), may improve language development in young children with fragile X syndrome (FXS). We evaluated the efficacy of six months of treatment with low-dose sertraline in a randomized, double-blind, placebo-controlled trial in 52 children with FXS ages 2–6 years.


Eighty-one subjects were screened for eligibility and 57 were randomized to sertraline (27) or placebo (30). Two subjects from the sertraline arm and three from the placebo arm discontinued. Intent-to-treat analysis showed no difference from placebo on the primary outcomes: the Mullen Scales of Early Learning (MSEL) expressive language age equivalent and Clinical Global Impression-Improvement (CGI-I). However, analyses of secondary measures showed significant improvements, particularly in motor and visual perceptual abilities and social participation. Sertraline was well tolerated, with no difference in side effects between sertraline and placebo groups. No serious adverse events occurred.


This randomized controlled trial of six-months of sertraline treatment showed no primary benefit with respect to early expressive language development and global clinical improvement. However, in secondary, exploratory analyses there were significant improvements seen on motor and visual perceptual subtests, the Cognitive T score sum on the MSEL, and on one measure of Social Participation on the Sensory Processing Measure–Preschool. Further, post hoc analysis found significant improvement in early expressive language development as measured by the MSEL among children with ASD on sertraline. Treatment appears safe for this 6-month period in young children with FXS, but we do not know the long-term side effects of this treatment. These results warrant further studies of sertraline in young children with FXS using refined outcome measures, as well as longer term follow-up studies to address long-term side effects of low-dose sertraline in early childhood.

Neurosteroid biosynthesis down‐regulation and changes in GABAA receptor subunit composition: a biomarker axis in stress‐induced cognitive and emotional impairment

By rapidly modulating neuronal excitability, neurosteroids regulate physiological processes, such as responses to stress and development. Excessive stress affects their biosynthesis and causes an imbalance in cognition and emotions. The progesterone derivative, allopregnanolone (Allo) enhances extrasynaptic and postsynaptic inhibition by directly binding at GABAA receptors, and thus, positively and allosterically modulates the function of GABA. Allo levels are decreased in stress-induced psychiatric disorders, including depression and post-traumatic stress disorder (PTSD), and elevating Allo levels may be a valid therapeutic approach to counteract behavioural dysfunction. While benzodiazepines are inefficient, selective serotonin reuptake inhibitors (SSRIs) represent the first choice treatment for depression and PTSD. Their mechanisms to improve behaviour in preclinical studies include neurosteroidogenic effects at low non-serotonergic doses. Unfortunately, half of PTSD and depressed patients are resistant to current prescribed 'high' dosage of these drugs that engage serotonergic mechanisms. Unveiling novel biomarkers to develop more efficient treatment strategies is in high demand. Stress-induced down-regulation of neurosteroid biosynthesis and changes in GABAA receptor subunit expression offer a putative biomarker axis to develop new PTSD treatments. The advantage of stimulating Allo biosynthesis relies on the variety of neurosteroidogenic receptors to be targeted, including TSPO and endocannabinoid receptors. Furthermore, stress favours a GABAA receptor subunit composition with higher sensitivity for Allo. The use of synthetic analogues of Allo is a valuable alternative. Pregnenolone or drugs that stimulate its levels increase Allo but also sulphated steroids, including pregnanolone sulphate which, by inhibiting NMDA tonic neurotransmission, provides neuroprotection and cognitive benefits. In this review, we describe current knowledge on the effects of stress on neurosteroid biosynthesis and GABAA receptor neurotransmission and summarize available pharmacological strategies that by enhancing neurosteroidogenesis are relevant for the treatment of SSRI-resistant patients. Linked Articles This article is part of a themed section on Pharmacology of Cognition: a Panacea for Neuropsychiatric Disease? To view the other articles in this section visit

Too little allopregnanalone can induce autism.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with core symptoms of social impairments and restrictive repetitive behaviors. Recent evidence has implicated a dysfunction in the GABAergic system in the pathophysiology of ASD. We investigated the role of endogenous allopregnanolone (ALLO), a neurosteroidal positive allosteric modulator of GABAA receptors, in the regulation of ASD-like behavior in male mice using SKF105111 (SKF), an inhibitor of type I and type II 5α-reductase, a rate-limiting enzyme of ALLO biosynthesis. SKF impaired sociability-related performance, as analyzed by three different tests; i.e., the 3-chamber test and social interaction in the open field and resident-intruder tests, without affecting olfactory function elucidated by the buried food test. SKF also induced repetitive grooming behavior without affecting anxiety-like behavior. SKF had no effect on short-term spatial working memory or long-term fear memory, but enhanced latent learning ability in male mice. SKF-induced ASD-like behavior in male mice was abolished by the systemic administration of ALLO (1mg/kg, i.p.) and methylphenidate (MPH: 2.5mg/kg, i.p.), a dopamine transporter inhibitor. The effects of SKF on brain ALLO contents in male mice were reversed by ALLO, but not MPH. On the other hand, SKF failed to induce ASD-like behavior or a decline in brain ALLO contents in female mice. These results suggest that ALLO regulates episodes of ASD-like behavior by positively modulating the function of GABAA receptors linked to the dopaminergic system. Moreover, a sex-dependently induced decrease in brain ALLO contents may provide an animal model to study the main features of ASD.

Some steroids, whose levels are raised in autism (allopregnanolone, androsterone, pregnenolone, dehydroepiandrosterone and their sulfate conjugates) are neuroactive and modulate GABA, glutamate, and opioid neurotransmission, affecting brain development and functioning. These steroids may contribute to autism pathobiology and symptoms such as elevated anxiety, sleep disturbances, sensory deficits, and stereotypies among others.

Tuning the Brain
I did write a post a while back to show the effect of tuning GABAa receptors.

The effect of allopregnanolone of KCC2 expression and hence the level of chloride within neurons.

Neonatal allopregnanolone or finasteride administration modifies hippocampal K(+) Cl(-) co-transporter expression during early development in male rats.


The maintenance of levels of endogenous neurosteroids (NS) across early postnatal development of the brain, particularly to the hippocampus, is crucial for their maturation. Allopregnanolone (Allop) is a NS that exerts its effect mainly through the modulation of the GABAA receptor (GABAAR). During early development, GABA, acting through GABAAR, that predominantly produces depolarization shifts to hyperpolarization in mature neurons, around the second postnatal week in rats. Several factors contribute to this change including the progressive increase of the neuron-specific K(+)/Cl(-) co-transporter 2 (KCC2) (a chloride exporter) levels. Thus, we aimed to analyze whether a different profile of NS levels during development is critical and can alter this natural progression of KCC2 stages. We administrated sustained Allop (20mg/kg) or Finasteride (5α-reductase inhibitor, 50mg/kg) from the 5th postnatal day (PD5) to PD9 and assessed changes in the hippocampal expression of KCC2 at transcript and protein levels as well as its active phosphorylated state in male rats. Taken together data indicated that manipulation of NS levels during early development influence KCC2 levels and point out the importance of neonatal NS levels for the hippocampal development.                                                                                                                           

Add very low dose Prozac to the long list of possible SIB therapies, more practical than electroconvulsive therapy (ECT), that is for sure!

This post was long waiting in my “to-complete” pile. I thought it would be a short one, but it kept growing.  It does draw together several interesting issues and shows there is a pattern developing in all these blog posts.
The majority of psychiatric drugs have such severe drawbacks that the great majority of children are better off without them.  However, there are many existing drugs that have little known neurological effects that can be highly beneficial and are known to be safe to use long term.
Psychiatric drugs that can be repurposed at lower dosages for different purposes may indeed be free of the major drawbacks encountered at higher doses.
It looks like humans with Fragile X Syndrome (FXS) are leading the way with low dose SSRI therapy to modulate GABA.  It would seem highly plausible that other idiopathic autism might also benefit and the French case studies in this post are examples of those who did benefit.
I think this is another example of fine-tuning the brain to optimize its functioning. It probably will not produce miracles, but the science shows that allopregnenalone can be tuned to vary mood in humans.  Low levels of allopregnenalone can produce autistic-like behaviours in mouse models.
The effect of allopregnenalone on KCC2 expression may only be present in tiny babies, if it continues into childhood that would be another reason to consider it as a target for modulation.  If that were the case, then Finasteride the cheap generic drug for prostate enlargement, should be investigated.
As is always the case in autism, both extremes are likely to exist; some people will likely benefit from low dose SSRIs but it will make some others worse (anxiety, SIB etc). If you start with elevated allopregnenalone, you would want less, not more.
Repurposing existing drugs has huge unrealized potential.
The OTC antihistamine Clemastine, which I highlighted in an earlier post as being a Positive Allosteric Modulator (PAM) of P2X7, and so helps remyelination, is yet another example of repurposing a safe drug.  Reportedly, it has this effect even below the regular dosage for allergy; at the high dosage usage in MS trials it will send you to sleep and risk some other side effects. As MS is not a singular condition, it seems that some people respond much more so than others. It also seems to have a benefit is some psychiatric disorders; not bad for a cheap OTC antihistamine.

Wednesday, 24 October 2018

Choose your Statin with Care in FXS, NF1 and idiopathic Autism

There are several old posts in this blog about the potential to treat some autism using statins; this has nothing to do with their ability to lower cholesterol. 

Statins are broadly anti-inflammatory but certain statins do some other particularly clever things. This led me to use Atorvastatin and Fragile-X researchers to use Lovastatin.

Fragile X is suggested by an elongated face and big/protruding ears; 
other features include MR/ID and autism.

I was recently forwarded a Scottish study showing why Simvastatin does not work in Fragile X syndrome, but Lovastatin does.
Fragile X mental retardation protein (FMR1) acts to regulate translation of specific mRNAs through its binding of eIF4E (see chart below). In people with Fragile X, they lack the FMR1 protein. Boys are worse affected than girls, because females have a second X chromosome and so a "spare" copy of the gene.

         Simvastatin does not reduce ERK1/2 or mTORC1 activation in the Fmr1-/y hippocampus.

So  ? = Does NOT inhibit

The researchers in Scotland did not test Atorvastatin in their Fragile X study.
The key is to reduce Ras. In the above graphic it questions does Simvastatin inhibit RAS and Rheb.

RASopathies have been covered in this blog. Too much of the Ras protein is a common feature of much ID/MR. Investigating RAS took me to PAK1 inhibitors and the experimental drug FRAX486. This drug was actually developed to treat Fragile X; it is now owned by Roche. At least one person is using FRAX486 to treat autism.
You might wonder why the researchers do not just try Lovastatin in humans with Fragile X.  Unfortunately, Lovastatin was never approved as a drug in Scotland, or indeed many other countries.  Some researchers just assumed they could substitute Simvastatin, which on paper looks a very similar drug and one that crosses the blood brain barrier better than Lovastatin.

The cholesterol-lowering drug lovastatin corrects neurological phenotypes in animal models of fragile X syndrome (FX), a commonly identified genetic cause of autism and intellectual disability. The therapeutic efficacy of lovastatin is being tested in clinical trials for FX, however the structurally similar drug simvastatin has been proposed as an alternative due to an increased potency and brain penetrance. Here, we perform a side-by-side comparison of the effects of lovastatin and simvastatin treatment on two core phenotypes in the Fmr1-/y mouse model. We find that while lovastatin normalizes excessive hippocampal protein synthesis and reduces audiogenic seizures (AGS) in the Fmr1-/y mouse, simvastatin does not correct either phenotype. These results caution against the assumption that simvastatin is a valid alternative to lovastatin for the treatment of FX.  

Although we propose the beneficial effect of lovastatin stems from the inhibition of ERK1/2-driven protein synthesis, it is important to note that statins are capable of affecting several biochemical pathways. Beyond the canonical impact on cholesterol biosynthesis, statins also decrease isoprenoid intermediates including farnesyl and geranylgeranyl pyrophosphates that regulate membrane association for many proteins including the small GTPases Ras, Rho and Rac [18, 46, 48, 49]. The increase in protein synthesis seen with simvastatin could be linked to altered posttranslational modification of these or other proteins. Indeed, although we see no change in mTORC1-p70S6K signaling, other studies have shown an activation of the PI3 kinase pathway that could be contributing to this effect [32]. However, our comparison of lovastatin and simvastatin shows that there is a clear difference in the correction of pathology in the Fmr1-/y model, suggesting that the impact on ERK1/2 is an important factor in terms of pharmacological treatment for FX.  There are many reasons why statins would be an attractive option for treating neurodevelopmental disorders such as FX. They are widely prescribed worldwide for the treatment of hypercholesterolemia and coronary heart disease [50], and safely used for longterm treatment in children and adults [46]. However, our study suggests that care should be taken when considering which statin should be trialed for the treatment of FX and other disorders of excess Ras. Although the effect of different statins on cholesterol synthesis has been well documented, the differential impact on Ras-ERK1/2 signaling is not well established. We show here that, contrary to lovastatin, simvastatin fails to inhibit the RasERK1/2 pathway in the Fmr1-/y hippocampus, exacerbates the already elevated protein synthesis phenotype, and does not correct the AGS phenotype. These results are significant for considering future clinical trials with lovastatin or simvastatin for FX or other disorders of excess Ras. Indeed, clinical trials using simvastatin for the treatment of NF1 have shown little promise, while trials with lovastatin show an improvement in cognitive deficits [28-30]. We suggest that simvastatin could be similarly ineffective in FX and may not be a suitable substitute for lovastatin in further clinical trials.

If you are treating Fragile X, best to start with Lovastatin and see if it helps.  In theory it might also help NF1 (Neurofibromatosis Type 1).

It looks to me that Atorvastatin also inhibits the relevant pathway and does much more besides that (PTEN, BCL2 etc)

What is Roche doing with FRAX486?

Wednesday, 3 October 2018

Ketones and Autism Part 6 - Capric Acid (C10) for Mitochondrial Disease, in Particular Complex 1, plus more on Metformin

Capric Acid (C10) is so named because it smells like a goat (Goat in Latin = Caper)
Photographer: Armin Kübelbeck, CC-BY-SA, Wikimedia Commons

Rather than Goaty acid, C10 is called Capric acid, or indeed Decanoic acid (after its 10 carbon atoms). Today’s post is indirectly again about ketones, because if you eat a Ketogenic Diet (KD) you are likely to consume a fair amount of Capric acid (C10).
I have written a lot in this blog about mitochondria, even though I do not think my son has mitochondrial dysfunction. Clearly many people with autism do have a lack of one or more of the critical mitochondrial enzyme complexes that allow glucose to be converted to ATP (usable energy), by the clever process OXPHOS (Oxidative phosphorylation).

The “rate limiting” enzyme is usually Complex 1, meaning that is the one it is most important not to be short of.
Another favourite, but obscure, subject of this blog is PPAR gamma.

Peroxisome proliferator-activated receptors (PPARs) are a group of proteins that function as transcription factors regulating the expression of certain genes. Transcription factors are particularly important because they trigger numerous effects.
PPAR gamma plays a key role in fat storage and glucose metabolism, but has other functions. 

Activation of PPAR-gamma by Capric acid (C10) has been shown to increase the number of mitochondria, increase the mitochondrial enzyme citrate synthase, increase complex I activity in mitochondria, and increase activity of the antioxidant enzyme catalase. 
So, if you have autism and impaired mitochondrial function, C10 may well give a benefit because it can increase the peak power available to your brain.

The Ketogenic diet (KD) is an effective treatment with regards to treating pharmaco-resistant epilepsy. However, there are difficulties around compliance and tolerability. Consequently, there is a need for refined/simpler formulations that could replicate the efficacy of the KD. One of the proposed hypotheses is that the KD increases cellular mitochondrial content which results in elevation of the seizure threshold. Here, we have focussed on the medium-chain triglyceride form of the diet and the observation that plasma octanoic acid (C8) and decanoic acid (C10) levels are elevated in patients on the medium-chain triglyceride KD. Using a neuronal cell line (SH-SY5Y), we demonstrated that 250-μM C10, but not C8, caused, over a 6-day period, a marked increase in the mitochondrial enzyme, citrate synthase along with complex I activity and catalase activity. Increased mitochondrial number was also indicated by electron microscopy. C10 is a reported peroxisome proliferator activator receptor γ agonist, and the use of a peroxisome proliferator activator receptor γ antagonist was shown to prevent the C10-mediated increase in mitochondrial content and catalase. C10 may mimic the mitochondrial proliferation associated with the KD and raises the possibility that formulations based on this fatty acid could replace a more complex diet. We propose that decanoic acid (C10) results in increased mitochondrial number. Our data suggest that this may occur via the activation of the PPARγ receptor and its target genes involved in mitochondrial biogenesis. This finding could be of significant benefit to epilepsy patients who are currently on a strict ketogenic diet. Evidence that C10 on its own can modulate mitochondrial number raises the possibility that a simplified and less stringent C10-based diet could be developed.

Capric Acid (C10) as a PPARγ agonist

As shown in the above study the mechanism by which C10 benefits the mitochondria is via PPARγ agonism.

Here is another study confirming that C10 is indeed a PPARγ agonist.

Background: Mechanism of action of medium chain fatty acid remains unknown.

Results: Our results show that decanoic acid (C10) binds and activates PPARγ.

Conclusion: Decanoic acid acts as a modulator of PPARγ and reduces blood glucose levels with no weight gain.

Significance: This study could lead to design of better type 2 diabetes drugs.

Other PPARγ agonists
PPARγ agonists have been covered previously in this blog and we know that glitazones, a class of drugs for diabetes, do improve some types of autism. Glitazones are PPARγ agonists.

Metformin, a very widely used drug for type 2 diabetes, works differently to Glitazones, but I did suggest a while back it should help some types of autism. Last year it was indeed found to be beneficial in Fragile X.

 "Basically, it's something like a wonder drug," Sonenberg said.
The study suggests that metformin might also be used to treat other autism spectrum disorders, said Ilse Gantois, a research associate in Sonenberg's lab at McGill.
"We mostly looked at the autistic form of behaviour in the Fragile X mouse model," explained Gantois, who is co-lead author with McGill researchers Arkady Khoutorsky and Jelena Popic. "We want to start testing other mouse models to see if the drug could also have benefits for other types of autism."

Metformin is very cheap and has been used in humans for 60 years. It is another example of re-purposing a drug from Grandpa’s medicine cabinet to treat Grandson’s autism. 

Metformin has been trialled to combat obesity in idiopathic autism caused by antipsychotics. It did help with weight gain, but no comments were made about behavioural improvements, but then those studied were on antipsychotic drugs, which might mask such effects. 
Glitazone-type drugs appear more problematic than Metformin.

There are natural PPAR gamma agonists and they are often used to lower cholesterol, lower blood sugar and improve insulin sensitivity.
Sytrinol, a product containing flavanols tangeretin and nobiletin does indeed have a positive effect on some people’s autism, but for most people (but not all) the effect is lost after a few days.

Our doctor reader Maja, did suggest combining it with a PPARα agonist to see if the effect might be maintained.
This combination has indeed been researched for type 2 diabetes.               

The effect of dual PPAR alpha/gamma stimulation with combination of rosiglitazone and fenofibrate on metabolic parameters in type 2 diabetic patients.

There actually is another natural substance that is an agonist of both PPARγ and PPARα, Berberine, the alkaloid long used in Chinese medicine.
In the research it is suggested that BRB localizes in mitochondria, inhibits respiratory electron chain and activates AMPK”, which is not what you would want. But this may not be correct.

People who like supplements might want to follow up on Berberine.
Berberine is used by many people with diabetes and a few with autism, for all kinds of reasons, from mercury to GI problems.

Berberine is a potent agonist of peroxisome proliferator activated receptor alpha.

Although berberine has hypolipidemic effects with a high affinity to nuclear proteins, the underlying molecular mechanism for this effect remains unclear. Here, we determine whether berberine is an agonist of peroxisome proliferator-activated receptor alpha (PPARalpha), with a lipid-lowering effect. The cell-based reporter gene analysis showed that berberine selectively activates PPARalpha (EC50 =0.58 mM, Emax =102.4). The radioligand binding assay shows that berberine binds directly to the ligand-binding domain of PPARalpha (Ki=0.73 mM) with similar affinity to fenofibrate. The mRNA and protein levels of CPT-Ialpha gene from HepG2 cells and hyperlipidemic rat liver are remarkably up-regulated by berberine, and this effect can be blocked by MK886, a non-competitive antagonist of PPARalpha. A comparison assay in which berberine and fenofibrate were used to treat hyperlipidaemic rats for three months shows that these drugs produce similar lipid-lowering effects, except that berberine increases high-density lipoprotein cholesterol more effectively than fenofibrate. These findings provide the first evidence that berberine is a potent agonist of PPARalpha and seems to be superior to fenofibrate for treating hyperlipidemia.


Sources of Capric Acid (C10)
Goat milk is a good source of capric acid.
Capric acid is 8-10% of coconut oil and 4% of palm kernel oil

Capric acid is a large component (about 40%) of the less expensive MCT oil supplements.

1.2. Fatty acid composition in goat milk fat Average goat milk fat differs in contents of its fatty acids significantly from average cow milk fat, being much higher in butyric (C4:0), caproic (C6:0), caprylic (C8:0), capric (C10:0), lauric (C12:0), myristic (C14:0), palmitic (C16:0), linoleic (C18:2), but lower in stearic (C18:0), and oleic acid (C18:1) (Table 1). Three of the medium chain fatty acids (caproic, caprylic, and capric) have actually been named after goats, due to their predominance in goat milk. They contribute to 15% of the total fatty acid content in goat milk in comparison to 5% in cow milk (Haenlein, 1993). The presence of relatively high levels of medium chain fatty acids (C6:0 to C10:0) in goat milk fat could be responsible for its inferior flavour (Skjevdal, 1979). 

If someone responds well to coconut oil or cheaper MCT oil the reason may have more to do with PPAR gamma and improved mitochondrial function than anything to do with ketones and what they do.
Cheaper MCT oils are mainly a mixture of C8 and C10. To maximize the production of the ketone BHB you really want just C8, but if what you really need is a PPAR gamma agonist, to perk up your mitochondria, it is the C10 you need.
You may indeed benefit from both ketones and agonizing PPAR gamma, in which case you either follow the Ketogenic Diet, or supplement BHB, C8 and C10.
I think this explains why some people with autism reportedly respond well to teaspoon-sized doses of cheaper MCT oil or small amounts of coconut oil.
If you have Complex 1 mitochondrial dysfunction then a dose of Capric acid (C10) is likely to help.
Berberine may, or may not be, as effective as C10. I doubt we will ever know. I think C10 is the better option. 
I wonder when the Canadian researchers will publish their results showing whether Metformin is beneficial beyond Fragile X syndrome. They do not really know why it helps, but that is a repeating theme in medicine.  It is a cheap safe drug, so it would be a pity to waste time finding out if it could be repurposed for some autism.

Thursday, 13 September 2018

Ginseng, as a GABAb Antagonist, as an "Add-on Therapy" for some Autism? Also Homotaurine and Acamprosate

Rather like negotiating with North Korea, today’s post does rather meander. It does in the end up with some interesting options for some people. 

Korea - the centre of Ginseng research
This post was prompted by research highlighted by our reader Ling, which suggested that bumetanide responders (i.e. people with high intracellular chloride) might benefit from a GABAB antagonist. 
There has been quite a lot of coverage in this blog about agonists of GABAB receptors, like Baclofen and Arbaclofen. Some people with an autism diagnosis do indeed seem to benefit, ranging from some with Fragile-X to others with Asperger’s. Russian-developed GABAB agonists like Phenibut and Pantogam are widely used by adults self-treating their behavioural/emotional disturbances.
Some Aspies have commented in this blog that far from helping, Baclofen made them feel worse; perhaps the opposite therapy might help? (the Goldilocks scenario, from the previous post) 
The paper below shows how a GABAB antagonist (the opposite of Baclofen) might benefit some with autism.

GABAB receptors are G-protein-coupled receptors that mediate inhibitory synaptic actions through a series of downstream target proteins. It is increasingly appreciated that the GABAB receptor forms part of larger signaling complexes, which enable the receptor to mediate multiple different effects within neurons. Here we report that GABAB receptors can physically associate with the potassium-chloride cotransporter protein, KCC2, which sets the driving force for the chloride-permeable ionotropic GABAA receptor in mature neurons. Using biochemical, molecular, and functional studies in rodent hippocampus, we show that activation of GABAB receptors results in a decrease in KCC2 function, which is associated with a reduction in the protein at the cell surface. These findings reveal a novel "crosstalk" between the GABA receptor systems, which can be recruited under conditions of high GABA release and which could be important for the regulation of inhibitory synaptic transmission.

SIGNIFICANCE STATEMENT Synaptic inhibition in the brain is mediated by ionotropic GABAA receptors (GABAARs) and metabotropic GABAB receptors (GABABRs). To fully appreciate the function and regulation of these neurotransmitter receptors, we must understand their interactions with other proteins. We describe a novel association between the GABABR and the potassium-chloride cotransporter protein, KCC2. This association is significant because KCC2 sets the intracellular chloride concentration found in mature neurons and thereby establishes the driving force for the chloride-permeable GABAAR. We demonstrate that GABABR activation can regulate KCC2 at the cell surface in a manner that alters intracellular chloride and the reversal potential for the GABAAR. Our data therefore support an additional mechanism by which GABABRs are able to modulate fast synaptic inhibition.

In bumetanide-responsive autism, neurons remain immature because the “GABA switch“ never flipped and so NKCC1 is overexpressed and KCC2 is underexpressed, chloride levels remain high and the neurotransmitter GABA works backwards (excitatory, rather than inhibitory).
Bumetanide partially counters the over-abundance of NKCC1 transporters that carry chloride into neurons, but is a partial solution.
The above research suggests that blocking GABAB receptors might increase the flow of chloride ions exiting through KCC2.
All very complicated sounding, but in effect it means that a GABAB antagonist might boost the effect of bumetanide.

Which GABAB antagonist?
This was Ling’s question.
Saclofen is a competitive antagonist for the GABAB receptor. This drug is an analogue of the GABAB agonist baclofen.
Phaclofen/phosphonobaclofen, is a selective antagonist for the GABAB receptor.
Since these “–aclofens” are not accessible we are left with a choice of homotaurine (developed to treat Alzheimer’s) or Ginsenosides from Korean/Panax ginseng.
Both homotaurine and Ginsenosides have various other effects beyond GABAB.
Since Ling is in Scandinavia, homotaurine is an option. It seems to be banned in the US, though it is approved in Canada and sold in Europe.
Ginseng is very widely used, indeed it is the most widely consumed herbal nutritional product in the world, with sales of $400 million in 2012.
I was surprised that there actually is research in both humans and animal models using Ginseng in autism and indeed ADHD.
N-Acetyl homotaurine,  a derivative of homotaurine, is a registered drug called Acamprostate. It is used to treat alcohol dependence. It affects both NMDA and GABA receptors. Acamprostate has been shown to benefit Fragile-X, as has bumetanide. A drug that affects GABAB will inevitably also affect NMDA receptors.
This was covered in this post from 2015.

which highlighted this paper:

Homotaurine has been reported as a GABA antagonist as well as a GABA agonist. In vitro studies have found that homotaurine is a GABAA partial agonist as well as a GABAB receptor partial agonist with low efficacy, becoming an antagonist and a displacing full agonist of GABA or baclofen at this receptor.[15] In a study in rats, homotaurine reversed the catatonia induced by baclofen (the prototypical GABAB agonist),[16] and was able to produce analgesia via the GABAB receptor, an effect that was abolished when CGP 35348, a GABAB receptor antagonist was applied.[17][18] 
One study suggests Homotaurine increases dopamine levels.[19]

One study in rats showed that homotaurine suppressed ethanol-stimulated dopamine release, as well as ethanol intake and preference in rats in a way similar to the N-acetyl derivative of homotaurine, acamprosate.[20] Acamprosate was approved by the FDA in 2004 to treat alcohol dependence.[3]

Fragile X syndrome (FXS) is an inherited form of developmental disability and a single gene cause of autism. As a disorder with increasingly understood pathophysiology, FXS is a model form of developmental disability for targeted drug development efforts. Preclinical animal model findings have focused targeted drug treatment development in FXS on an imbalance between excessive glutamate and deficient gamma-aminobutyric acid (GABA) neurotransmission.
Acamprosate was generally safe and well tolerated and was associated with a significant improvement in social behavior and a reduction in inattention/hyperactivity. The increase in BDNF that occurred with treatment may be a useful pharmacodynamic marker in future acamprosate studies. Given these findings, a double-blind, placebo-controlled study of acamprosate in youth with FXS is warranted.

Back to Ginseng
Autism spectrum disorder (ASD) is heterogeneous neurodevelopmental disorders that primarily display social and communication impairments and restricted/repetitive behaviors. ASD prevalence has increased in recent years, yet very limited therapeutic targets and treatments are available to counteract the incapacitating disorder. Korean Red Ginseng (KRG) is a popular herbal plant in South Korea known for its wide range of therapeutic effects and nutritional benefits and has recently been gaining great scientific attention, particularly for its positive effects in the central nervous system.


Thus, in this study, we investigated the therapeutic potential of KRG in alleviating the neurobehavioral deficits found in the valproic acid (VPA)-exposed mice models of ASD.


Starting at 21 days old, VPA-exposed mice were given daily oral administrations of KRG solution (100 or 200 mg/kg) until the termination of all experiments. From P28, mice behaviors were assessed in terms of social interaction capacity, locomotor activity, repetitive behaviors, short-term spatial working memory, motor coordination, and seizure susceptibility.


VPA-exposed mice showed sociability and social novelty preference deficits, hyperactivity, increased repetitive behavior, impaired spatial working memory, slightly affected motor coordination, and high seizure susceptibility. Remarkably, long-term KRG treatment in both dosages normalized all the ASD-related behaviors in VPA-exposed mice, except motor coordination ability.


As a food and herbal supplement with various known benefits, KRG demonstrated its therapeutic potential in rescuing abnormal behaviors related to autism caused by prenatal environmental exposure to VPA.

In the trial below the dose appears very low at 250mg. In the more encouraging study in ADHD the dose was 1000mg twice a day.

Autism is a pervasive developmental disorder, with impairments in reciprocal social interaction and verbal and nonverbal communication. There is often the need of psychopharmacological intervention in addition to psychobehavioral therapies, but benefits are limited by adverse side effects. For that reason, Panax ginseng, which is comparable with Piracetam, a substance effective in the treatment of autism, was investigated for possible improvement of autistic symptoms. There was some improvement, which suggests some benefits of Panax ginseng, at least as an add-on therapy.
Three male outpatients (age range 18.4–22.2 years; mean=21.3 years; SD =4.1 years) meeting ICD-10 criteria for autistic disorder participated in our observation. IQs ranged from 54 to 82 (68 +/− 14), which were obtained from the Wechsler Intelligence Scale. At least two child and adolescent psychiatrists independently diagnosed the subjects for autistic disorder. All subjects had no additional medical or neurological illnesses. They had been treated with either methylphenidate, or neuroleptics before entry into the study, without any positive effect (nonresponder). One patient’s language consisted of monosyllabic utterances, second patient’s language consisted of single words(10-word vocabulary),and the third patient spoke in sentences. Parents and mentors’ (i.e., the person who takes care of the patient in daily life, and supports the patient’s educational efforts) rated instruments included weekly ratings by means of the Aberrant Behavior and Symptom Checklist. Clinician ratings consisted of the Global Assessment Scale, Psychiatric Rating Scale (CPRS), and Clinical Global Improvement. Panax ginseng (oral administration of tablets containing 250-mg alcoholic Panax ginseng berry extract, pure encapsulations) was administered for 4 weeks (dosage: 250 mg daily). Patients were free of medication for at least 4 weeks before the beginning of the study. During that time, there were no changes in the symptoms of the patients. Subjects continued to receive educational and behavioral interventions, which were not altered substantially in any of the patients during their participation in the study. The means of parent and mentor ratings were averaged over the 4-week treatment period. Clinician and mentor ratings were made at the beginning of the treatment period and then weekly up to the end of the treatment. Ratings were compared by paired t-test.

Panax ginseng slightly improved the ratings on the ABC factors: irritability (before treatment, 13.2 +/− 5.9; after treatment, 11.3 +/− 6.2; p =.41), hyperactivity (before treatment, 20.6+/−12.4;     after,18.4+/− 9.4; p = .33), inadequate eye contact (before treatment, 8.6 +/− 5.4; after, 7.5 +/− 3.2; p .35), and inappropriate speech (before treatment, 6.1+/−2.2;after, 4.3 +/− 3.6; p = .41). The symptom checklist scores revealed a slight increase in drowsiness (before treatment, 1.6 +/− 2.2; after, 2.9+/−4.2; p =.31) and decreased activity (before treatment, 2.5 +/− 3.3; after, 4.4 +/− 3.1; p = 0.40). None of the clinician ratings showed significant improvement. This may result from different impressions of clinical visits and daily life observations of caregivers. Panax ginseng has some moderate sedative effect with effects especially on daily life, a fact that also makes it effective in the treatment of attention deficit/hyperactive disorders. None of the subjects appeared to have headaches or stomach aches, although report of such side effects was limited by the expressive language and social skills of these subjects. Medication was continued after the observation period. We did not see any significant changes in symptoms.

Although this was a very small study (n = 3), which revealed very modest therapeutic effect of Panax ginseng in the management of autistic patients in some of the subjects (which might be due to the small sample size), it may be mentioned that its role in the management of these symptoms in patients with autistic disorder may be limited, especially because of its risk for estrogen-associated problems in females (Papapetropoulos, 07). Since there does not seem to be any significant improvement caused by Panaxginseng, its effect as an add-on therapy remains completely open and requires further investigation. Before knowing its efficacy for adults, Panax ginseng should not be recommended for treating children suffering from autism.

Ginseng for ADHD? 

Objective: There is evidence that Korean red ginseng (KRG) can reduce the production of the adrenal corticosteroids, cortisol, and dehydroepiandrosterone (DHEA), and thus may be a viable treatment for attention-deficit/hyperactivity disorder (ADHD). The present randomized double-blind placebo-controlled clinical trial tested the effect of KRG on children with ADHD symptoms.
Methods: Subjects 6–15 years, who satisfied the inclusion criteria and had ADHD symptoms, were randomized into a KRG group (n=33) or a control group (n=37). The KRG group received one pouch of KRG (1g KRG extract/pouch) twice a day, and the control group received one pouch of placebo twice a day. At the 8 week point, the primary outcomes were the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for inattention and hyperactivity scale scores, which were measured at baseline and 8 weeks after starting treatment. Secondary outcomes were quantitative electroencephalography theta/beta ratio (QEEG TBR) (measured at baseline and week 8) and salivary cortisol and DHEA levels (measured at baseline and at 4 and 8 weeks).
Results: The baseline characteristics of the KRG and control groups were not statistically different. The mean ages of the KRG and control groups were 10.94±2.26 and 10.86±2.41, respectively. The KRG group had significantly decreased inattention/hyperactivity scores compared with the control group at week 8 (least squared means of the differences in inattention adjusted for baseline scores: −2.25 vs. −1.24, p=0.048; hyperactivity: −1.53 vs. −0.61, p=0.047). The KRG group had significantly decreased QEEG TBR compared with the control group (least squared means of the differences: −0.94 vs. −0.14, p=0.001). However, neither the KRG group nor the control group exhibited significant differences in salivary cortisol or DHEA levels at week 8 compared with the baseline levels. No serious adverse events were reported in either group.
Conclusions: These results suggest that KRG extract may be an effective and safe alternative treatment for children with inattention and hyperactivity/ impulsivity symptoms. Further studies to investigate the efficacy and safety of KRG are warranted. 
Although medications to treat psychiatric disorders for children and adolescents have been widely researched and several are on the market, natural products may also be effective in these patients while inducing fewer significant adverse effects. The present randomized controlled trial was performed to assess whether KRG, a well-known traditional medicine plant that is used particularly frequently in Eastern Asia, can improve the adrenal function and inattention/hyperactivity symptoms of chronically stressed children with ADHD symptoms. KRG extract significantly improved the inattention and hyperactivity of the subjects and had a good safety profile. However, the KRG extract did not have significant effects on cortisol or DHEA levels

Clinical Significance
To our knowledge, this is the first randomized controlled trial to investigate the efficacy and safety of Korean red ginseng extract for children with ADHD. The stimulant medications for ADHD have demonstrated not only clinical efficacy, but also significant adverse events such as poor growth, tics, and psychosis. Although KRG extract did not affect the salivary cortisol or DHEA, it significantly improved ADHD symptoms and QEEG TBR. And the safety profile of KRG extract was good. The results imply that KRG extract is a possible effective alternative medication for ADHD children.


A combination herbal product containing American ginseng extract, Panax quinquefolium, (200 mg) and Ginkgo biloba extract (50 mg) (AD-FX; CV Technologies, Edmonton, Alta.) was tested for its ability to improve the symptoms of attention-deficit hyperactivity disorder (ADHD). 


Open study. 


36 children ranging in age from 3 to 17 years who fit the diagnostic criteria for ADHD. 


AD-FX capsules were taken twice a day on an empty stomach for 4 weeks. Patients were instructed not to change any other medications during the study. 


At the beginning of the study, after 2 weeks, and then at the end of the 4-week trial, parents completed the Conners' Parent Rating Scale--revised, long version, a questionnaire that assesses a broad range of problem behaviours (and was used as an indication of ADHD symptom severity). 


After 2 weeks of treatment, the proportion of the subjects exhibiting improvement (i.e., decrease in T-score of at least 5 points) ranged from 31% for the anxious-shy attribute to 67% for the psychosomatic attribute. After 4 weeks of treatment, the proportion of subjects exhibiting improvement ranged from 44% for the social problems attribute to 74% for the Conners' ADHD index and the DSM-IV hyperactive-impulsive attribute. Five (14%) of 36 subjects reported adverse events, only 2 of which were considered related to the study medication. 


These preliminary results suggest AD-FX treatment may improve symptoms of ADHD and should encourage further research on the use of ginseng and Ginkgo biloba extracts to treat ADHD symptoms.

Interactions of ginsenosides with ligand-bindings of GABA(A) and GABA(B) receptors.


1. Total saponin fraction decreased the affinity of specific [3H]muscimol binding without changes in Bmax. Ginsenoside Rb1 Rb2, Rc, Re, Rf and Rg1 inhibited the specific [3H]muscimol binding to the high-affinity site. 2. Total saponin fraction increased the affinity of specific [3H]flunitrazepam binding. Ginsenoside Re and Rf enhanced specific [3H]flunitrazepam binding.

3. Total saponin fraction decreased the affinity of specific [35S]TBPS binding without changes in Bmax. Ginsenosides did not affect specific or non-specific [35S]TBPS binding.
4. Total saponin fraction decreased the affinity of specific [3H]baclofen binding without changes in Bmax. Ginsenoside Rc inhibited specific [3H]baclofen binding.

very detailed paper

Also (Ling) note that there is an effect on ERbeta

A ginseng-derived oestrogen receptor beta (ERbeta) agonist, Rb1 ginsenoside, attenuates capillary morphogenesis.

 Ginseng extracts contain a variety of active ingredients and have been shown to promote or inhibit angiogenesis, depending on the presence of different ginsenosides that exert opposing effects on blood vessel growth. Leung et al. in this issue of the British Journal of Pharmacology report that Rb1, a ginsenoside that constitutes only 0.37–0.5% of ginseng extracts (depending on manufacturing and processing methods), blocks tube-like network formation by endothelial cells in vitro. At the molecular level, Rb1 binds to the oestrogen receptors and stimulates the transcription of pigment epithelium-derived factor that, in turn, inhibits matrix-driven capillary morphogenesis.

Ginseng, the root of Panax ginseng and related species, has been a key component of traditional medicine in the Far East for over a thousand years. The genus name Panax means ‘cure all' in Greek; it, thus, comes as no surprise that ginseng has been described as beneficial in many different ailments (Huang, 1999; Kiefer and Pantuso, 2003; Ng, 2006). Perhaps the most studied biological actions of ginseng extracts and constituents are those relating to its inhibitory effects on solid tumour growth (Yun, 2001). The main active ingredients in ginseng-based herbal preparations are thought to be the ginsenosides, comprising 3–6% of ginseng extracts (Huang, 1999). 

Reviewed here is the existing evidence for the effects of ginseng extracts and isolated ginsenosides relevant to cognition in humans. Clinical studies in healthy volunteers and in patients with neurological disease or deficit, evidence from preclinical models of cognition, and pharmacokinetic data are considered. Conditions under which disease modification may indirectly benefit cognition but may not translate to cognitive benefits in healthy subjects are discussed. The number of chronic studies of ginseng effects in healthy individuals is limited, and the results from acute studies are inconsistent, making overall assessment of ginseng's efficacy as a cognitive enhancer premature. However, mechanistic results are encouraging; in particular, the ginsenosides Rg3 , Rh1 , Rh2 , Rb1 , Rd, Rg2 , and Rb3 , along with the aglycones protopanaxadiol and protopanaxatriol, warrant further attention. Compound K has a promising pharmacokinetic profile and can affect neurotransmission and neuroprotection. Properly conducted trials using standardized tests in healthy individuals reflecting the target population for ginseng supplementation are required to address inconsistencies in results from acute studies. The evidence summarized here suggests ginseng has potential, but unproven, benefits on cognition.

Ginseng is the most widely consumed herbal nutritional product in the world. According to the most recent data available, ginseng had a total world export value in 2010 of over US$350 million, which was expected to rise to more than US$400 million in 2012

The survey had 54 respondents and 4 (8.5%) used Ginseng.

There is a long list of substances shown to have a benefit in some autism. Today we can add the Asian type of Ginseng and also Acamprosate (at least for Fragile-X).
It would be interesting to see the effect of Phaclofen and Saclofen which may be more selective for GABAB receptors.
Ginseng has so many effects there is no way to know which is the one that benefited autism and ADHD in today’s highlighted posts.
We also have the problem with natural substances that there is natural variation and that supplement companies are known to cheat with ingredients. Ginseng roots are not cheap and apparently ginseng is known to get adulterated.  Drug companies are usually much more reliable.
If anyone tries out homotaurine or ginseng, let us all know the result.
Homotaurine was originally developed as an Alzheimer’s drug, but did not work well enough, its developer then tried to sell it as a supplement called Vivimind, but it was rejected by the FDA. It is sold in Canada and Europe. 
For our Aspie readers, here is a link for them:-