Showing posts with label Folinic acid. Show all posts
Showing posts with label Folinic acid. Show all posts

Thursday, 8 December 2016

Nitrosative Stress, Nitric Oxide and Peroxynitrite

In this example of Brain Injury, developing oligodendrocytes are injured and killed by substances released from activated microglia, including nitric oxide and superoxide, which form peroxynitrite. Peroxynitrite has been found to kill these cells through the activation of the 12-lipoxygenase pathway for metabolizing arachidonic acid. Mitochondria may be involved in this pathway as a source of reactive oxygen species.

Much has been written in this blog about oxidative stress, which has now been extremely well researched in autism and more generally. Let’s recap oxidative stress.

The most knowledgeable researcher in this area is Abha Chauhan.  Based on her research and that of others we now know a great deal.  Recall that the body’s key antioxidant is called glutathione (GSH) and when it neutralizes a free radical GSH is converted to its oxidized form, glutathione disulfide (GSSG).  A good measure of oxidative stress is the ratio of  GSH/GSSG.

·        Autism is associated with deficits in glutathione antioxidant defence in selective regions of the brain.

·        In the cerebellum and temporal cortex from subjects with autism, GSH levels are significantly decreased by 34.2 and 44.6 %, with a concomitant increase in the levels of GSSG

·        There is also a significant decrease in the levels of total GSH (tGSH) by 32.9 % in the cerebellum, and by 43.1 % in the temporal cortex of subjects with autism.

·        In contrast, there was no significant change in GSH, GSSG and tGSH levels in the frontal, parietal and occipital cortices in autism

·        The redox ratio of GSH to GSSG was also significantly decreased by 52.8 % in the cerebellum and by 60.8 % in the temporal cortex of subjects with autism, suggesting glutathione redox imbalance in the brain of individuals with autism.

·        Disturbances in brain glutathione homeostasis may contribute to oxidative stress, immune dysfunction and apoptosis, particularly in the cerebellum and temporal lobe, and may lead to neurodevelopmental abnormalities in autism.

·        The activity of glutathione cysteine ligase (GCL), an enzyme for glutathione synthesis is impaired in autism.

·        The protein expression of its modulatory subunit GCLM was decreased in autism.

·        The activities of glutathione peroxidase (GPx) and glutathione S-transferase were decreased in autism.

For those interested, GPx is a family of enzymes that catalyze the reaction that converts GSH to GCCG.  So in order to soak up those free radicals you need both GSH and GPx.

Glutathione cysteine ligase (GCL) is a key enzyme needed to make the antioxidant GSH.  Dysregulation of GCL enzymatic function and activity is known to be involved in many human diseases, such as diabetes, Parkinson's disease, Alzheimer’s disease, COPD, HIV/AIDS, cancer and autism.  Without sufficient GCL your body cannot make enough glutathione (GSH).

I did have some conversation with Abha Chauhan a few years ago when I found that NAC (N-acetyl cysteine), a known precursor to GSH, really does have a positive behavioral impact in autism.  She is clearly very nice, but not the type to make the leap to translating her science into therapy.

As I have shown there are many other treatable aspects of oxidative stress.

The chart below is my annotated version of the original by Professor Helmut Sies, the German “Redox Pioneer”.  He has published 500 scientific papers.

Nitrosative Stress

Finally to nitrogen.

Nitrogen is the most common pure element in the earth, making up 78.1% of the entire volume of the atmosphere.  Although nitrogen is non-toxic, when released into an enclosed space it can displace oxygen, and therefore presents an asphyxiation hazard. 

Nitrogen is an anesthetic agent. Nitrous oxide (N2O) is commonly known as laughing gas.  It is used in medicine for its unaesthetic and analgesic effects

It is also used as an oxidizer in rocket propellants, and in motor racing to increase the power output of engines, like Mad Max.

In humans we are dealing with Nitric Oxide (NO) and when things go wrong with peroxynitrite and then other Reactive nitrogen species (RNS).  In simple terms Reactive nitrogen species (RNS), like Reactive oxygen species (ROS) are bad news.

Nitric Oxide (NO) itself does lots of good things in your body.  Too much may not be good, but a little more can actually do you good.  NO is a potent vasodilator.

For over 130 years, nitroglycerin has been used to treat heart conditions, such as angina and chronic heart failure.  Nitroglycerin produces nitric oxide (NO). In hospital most patients will receive nitroglycerin during and after a heart attack, people at risk of a heart attack often carry nitroglycerin with them.

If you want to lower your blood pressure or an athlete wanting to legally improve exercise endurance you can increase Nitric Oxide (NO) via diet.  One easy way is to drink beetroot juice, as is common in endurance cycling.  In people with peroxynitrite-derived radicals this may be unwise, because they may have too much NO.


The starting point for the production of those unhelpful Reactive Nitrogen Species (RNS) is this chemical reaction

NO (nitric oxide) + O2· (superoxide) → ONOO (peroxynitrite)

NO production is affected by the enzyme nitric oxide synthase 2 (NOS2).

Superoxide production is catalyzed by NADPH oxidase.

Superoxide also produces Reactive Oxygen Species (ROS).

NADPH oxidase is implicated in many diseases including schizophrenia and autism.

NADPH oxidase 4 (Nox4) activity decreases mitochondrial function (chain complex I).

Activated microglia (as found in autism) produce both nitric oxide and superoxide and are therefore a source of peroxynitrite.

This has started to get rather complicated. So those interested in NADPH should refer to the literature.

Peroxynitrite can directly react with various biological targets and components of the cell including lipids, thiols, amino acid residues, DNA bases, and low-molecular weight antioxidants.

Additionally peroxynitrite can react with other molecules to form additional types of RNS including nitrogen dioxide (·NO2) and dinitrogen trioxide (N2O3) as well as other types of chemically reactive free radicals.

Nitric Oxide and Peroxynitrite in Health and Disease

I have referred on this blog to Abha Chauhan’s mammoth book on oxidative stress in autism on several occasions.  A work of similar quality but this time on Nitric Oxide and Peroxynitrite, is the paper below, by Hungarian Pal Pacher, who works at the US National Institute of Health’s Section on Oxidative Stress Tissue Injury.  He looks like a citation generating machine.

You could spend a long time reading this paper, but in summary peroxynitrite and its derived products have a negative effect on a very wide range of conditions including all the common neurological conditions, inflammatory diseases and again diabetes.  The answer would be peroxynitrite scavengers.

The discovery that mammalian cells have the ability to synthesize the free radical nitric oxide (NO) has stimulated an extraordinary impetus for scientific research in all the fields of biology and medicine. Since its early description as an endothelial-derived relaxing factor, NO has emerged as a fundamental signaling device regulating virtually every critical cellular function, as well as a potent mediator of cellular damage in a wide range of conditions. Recent evidence indicates that most of the cytotoxicity attributed to NO is rather due to peroxynitrite, produced from the diffusion-controlled reaction between NO and another free radical, the superoxide anion. Peroxynitrite interacts with lipids, DNA, and proteins via direct oxidative reactions or via indirect, radical-mediated mechanisms. These reactions trigger cellular responses ranging from subtle modulations of cell signaling to overwhelming oxidative injury, committing cells to necrosis or apoptosis. In vivo, peroxynitrite generation represents a crucial pathogenic mechanism in conditions such as stroke, myocardial infarction, chronic heart failure, diabetes, circulatory shock, chronic inflammatory diseases, cancer, and neurodegenerative disorders. Hence, novel pharmacological strategies aimed at removing peroxynitrite might represent powerful therapeutic tools in the future. Evidence supporting these novel roles of NO and peroxynitrite is presented in detail in this review.

Some excerpts:-

·        The different events set in motion by the initial generation of peroxynitrite indicate that potent peroxynitrite decomposition catalysts and PARP inhibitors might represent useful therapeutic agents for debilitating chronic inflammatory diseases

·        In summary, available evidence indicates that NO plays dichotomous roles (promotion vs. suppression) in tumor initiation and progression. The activation of angiogenesis and the induction of DNA mutations represent key aspects of the procarcinogenic effects of NO. Peroxynitrite is emerging as a major NO-derived species responsible for DNA damage, mainly through guanine modifications and the inhibition of DNA repair enzymes. In chronic inflammatory states, the identification of 8-nitroguanine in tissues indicates that nitrative DNA damage consecutive to overproduction of NO and peroxynitrite may represent an essential link between inflammation and carcinogenesis.

·        In summary, the different studies listed above indicate that small amounts of NO produced by eNOS in the vasculature during the early phase of brain ischemia are essential to limit the extent of cerebral damage, whereas higher concentrations of NO, generated initially by nNOS and later by iNOS, exert essentially neurotoxic effects in the ischemic brain. Evidence that such toxicity depends, in large part, on the rapid reaction of NO with locally produced superoxide to generate peroxynitrite will be now exposed

·        NO is produced by all brain cells including neurons, endothelial cells, and glial cells (astrocytes, oligodendrocytes, and microglia) by Ca2+/calmodulin-dependent NOS isoforms. Physiologically NOS in neurons (nNOS, type I NOS) and endothelial cells (eNOS, type III NOS) produce nanomolar amounts of NO for short periods in response to transient increases in intracellular Ca2+, which is essential for the control of cerebral blood flow and neurotransmission and is involved in synaptic plasticity, modulation of neuroendocrine functions, memory formation, and behavioral activity (491, 890, 1229). The brain produces more NO for signal transduction than the rest of the body combined, and its synthesis is induced by excitatory stimuli. Consequently, NO plays an important role in amplifying toxicity in the CNS. Indeed, under various pathological conditions associated with inflammation (e.g., neurodegenerative disorders and cerebral ischemia), large amounts of NO are produced in the brain as a result of the induced expression of iNOS (type II NOS) in glial cells, phagocytes, and vascular cells, which can exert various deleterious roles (39, 491, 890). Thus NO may be a double-edged sword, exerting protective effects by modulating numerous physiological processes and complex immunological functions in the CNS on one hand and on the other hand mediating tissue damage (446, 491, 890). The detailed discussion of the role of NO in the pathophysiology of various neurodegenerative disorders including Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS), just mentioning a few, is the subject of numerous excellent recent overviews (77, 145, 194, 219, 491, 890, 1003, 1205, 1433) and beyond the scope of this paper. Here we cover only the role of peroxynitrite and protein nitration, which are likely responsible for most deleterious effects of NO in neurodegenerative disorders.

·        Peroxynitrite formation has been implicated in Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, MS, ALS, and traumatic brain injury (reviewed in Refs. 194, 608, 1119, 1284). Nitrotyrosine immunoreactivity has been found in early stages of all of these diseases in human autopsy samples as well as in experimental animal models. Increased nitrite, nitrate, and free nitrotyrosine has been found to be present in the cerebral spinal fluid (CSF) and proposed to be useful marker of neurodegeneration (168; reviewed in Refs. 608, 1119, 1284). Once formed in the diseased brain, peroxynitrite may exert its toxic effects through multiple mechanisms, including lipid peroxidation, mitochondrial damage, protein nitration and oxidation, depletion of antioxidant reserves (especially glutathione), activation or inhibition of various signaling pathways, and DNA damage followed by the activation of the nuclear enzyme PARP (608, 1119, 1284).

·        Uric acid has proven to be a useful inhibitor of tyrosine nitration (although it is not a direct peroxynitrite scavenger) (1271) and has been shown to protect the blood-brain barrier and largely prevent the entry of inflammatory cells into the CNS (566, 567). Additionaly, it also prevented CNS injury after inflammatory cells have already migrated into the CNS (1141). Urate has also proven beneficial in reducing the morbidity associated with viral infections (710, 1141). Interestingly, in humans there is an inverse correlation between affliction with gout and MS (710, 1195). Numerous studies have reported lower levels of uric acid in MS patients favoring the view that reduced uric acid in MS is secondary to its “peroxynitrite scavenging” activity during inflammatory disease, rather than a primary deficiency (reviewed in Ref. 694). These studies have also suggested that serum uric acid levels could be used as biomarkers for monitoring disease activity in MS


·        Recent evidence suggests that mitochondrial complex I inhibition may be the central cause of sporadic PD and that derangements in complex I lead to α-synuclein aggregation, which contributes to the demise of dopamine neurons (293). Accumulation and aggregation of α-synuclein may further facilitate the death of dopamine neurons through impairments in protein handling and detoxification (293). As already mentioned above, both mitochondrial complex I and synuclein can be targets for peroxynitrite-induced protein nitration

·        The significance of this intricate interplay may have important ramifications not only for ALS but also for PD and AD (6, 58, 1102). Reactive astrocytes are common hallmark of neurodegeneration, and these results suggest that peroxynitrite may play an important role in promoting this phenotype as well as causing the degeneration of neurons. In ALS, the transformation of astrocytes into a reactive phenotype may explain why ALS is progressive, causing the relentless death of neighboring motor neurons. Interfering in such a cascade to stop the progressive death of motor neurons would not necessarily cure ALS but may keep it from being a death sentence.

·        There is accumulating evidence suggesting that increased oxidative stress and excessive production of NO might contribute to the development of HD by damaging neighboring neurons (reviewed in Refs. 63, 163). Accordingly, increased iNOS expression was observed in neuronal, glial, and vascular cells from brains of HD patients and mouse models of disease (206, 491). Similarly, numerous studies have demonstrated increased 3-NT formation in brain tissues (neurons, glia, and/or vasculature) of mice transgenic for the HD mutation, rats injected into the striatum with quinolinic acid (rat model of HD), and HD patients (300302, 427, 1022, 1023, 1096, 1117). Importantly, both NOS inhibitors and peroxynitrite scavengers decreased neuronal damage, improved disease progression, and also decreased brain 3-NT content in experimental models (301, 1022, 1117). These results suggest that peroxynitrite might be an important mediator of oxidative damage associated with HD.

·        The pathogenetic role of peroxynitrite in TBI is supported by evidence demonstrating increased brain 3-NT levels following TBI in experimental mouse and rat models (9294, 423, 507, 508, 898, 1171, 1360), and by the beneficial effects of NOS inhibitor and peroxynitrite scavengers in reducing neuronal injury and improving neurological recovery following injury (423, 508, 898).Collectively, multiple lines of evidence discussed above provide strong support for the important role of peroxynitrite formation and/or protein nitration in neurodegenerative disorders and suggest that the neutralization of this reactive species may offer significant therapeutic benefits in patients suffering from these devastating diseases.

·        Collectively, the evidence reviewed above support the view that peroxyntrite-induced damage plays an important role in numerous interconnected aspects of the pathogenesis of diabetes and diabetic complications. Neutralization of RNS or inhibition of downstream effector pathways including PARP activation may represent a promising strategy for the prevention or reversal of diabetic complications.

·        In conclusion, multiple lines of evidence discussed above and listed in Table 4 suggest that peroxynitrite plays an important role in various forms of cardiovascular dysfunction and injury; pharmacological neutralization of this reactive oxidant or targeting the downstream effector pathways may represent a promising strategy to treat various cardiovascular disorders.

·        In summary, circulatory shock is a leading cause of death in intensive care units. Considerable improvement in our understanding of the molecular and cellular mechanisms of shock over the past 20 years makes it now a reasonable expectation that novel, efficient mechanism-based therapies will emerge in the near future. Considerable evidence now exists that overproduction of NO and superoxide, triggering the generation of large amounts of peroxynitrite, is a central aspect of shock pathophysiology. In addition to direct cytotoxic effects such as the peroxidation of lipids, proteins, and DNA, peroxynitrite also occupies a critical position in a positive feedback loop of inflammatory injury, by (directly or indirectly, via PARP activation) activating proinflammatory signaling and by triggering the recruitment of phagocytes within injured tissues, leading to further NO, superoxide, and peroxynitrite production, which will progressively amplify the initial inflammatory reactions (see sect. VID, Fig. 14). These various observations support the view that future strategies reducing peroxynitrite or its precursors might have a considerable therapeutic impact in clinical circulatory shock.

Peroxynitrite Scavengers

We have already covered two substances in this blog that are potential Peroxynitrite Scavengers:-

Calcium Folinate

This is Roger’s magic pill to treat his Cerebral Folate Deficiency, but it may have application far beyond this, likely rare, condition, for those that tolerate it.

Tetrahydrofolic acid, or tetrahydrofolate, is a folic acid derivative. It has the potential to quench those peroxynitrite-derived radicals.

The presumed protective effect of folic acid on the pathogenesis of cardiovascular, hematological and neurological diseases and cancer has been associated with the antioxidant activity of folic acid. Peroxynitrite (PON) scavenging activity and inhibition of lipid peroxidation (LPO) of the physiological forms of folate and of structurally related compounds were tested. It was found that the fully reduced forms of folate, i.e. tetrahydrofolate (THF) and 5-methyltetrahydrofolate (5-MTHF), had the most prominent antioxidant activity. It appeared that their protection against LPO is less pronounced than their PON scavenging activity. The antioxidant activity of these forms of folic acid resides in the pterin core, the antioxidant pharmacophore is 4-hydroxy-2,5,6-triaminopyrimidine. It is suggested that an electron donating effect of the 5-amino group is of major importance for the antioxidant activity of 4-hydroxy-2,5,6-triaminopyrimidine. A similar electron donating effect is probably important for the antioxidant activity of THF and 5-MTHF.

Uric Acid

Uric acid has proven to be a useful inhibitor of tyrosine nitration.  It was thought to be a scavenger of peroxynitrite, but our clever Pal from Hungary tells thatit is not a direct peroxynitrite scavenger ….Numerous studies have reported lower levels of uric acid in MS patients favoring the view that reduced uric acid in MS is secondary to its “peroxynitrite scavenging” activity during inflammatory disease, rather than a primary deficiency”.

An old paper:-

Uric acid, the naturally occurring product of purine metabolism, is a strong peroxynitrite scavenger, as demonstrated by the capacity to bind peroxynitrite but not nitric oxide (NO) produced by lipopolysaccharide-stimulated cells of a mouse monocyte line. In this study, we used uric acid to treat experimental allergic encephalomyelitis (EAE) in the PLSJL strain of mice, which develop a chronic form of the disease with remissions and exacerbations. Uric acid administration was found to have strong therapeutic effects in a dose-dependent fashion. A regimen of four daily doses of 500 mg/kg uric acid was required to promote long-term survival regardless of whether treatment was initiated before or after the clinical symptoms of EAE had appeared. The requirement for multiple doses is likely to be caused by the rapid clearance of uric acid in mice which, unlike humans, metabolize uric acid a step further to allantoin. Uric acid treatment also was found to diminish clinical signs of a disease resembling EAE in interferon-γ receptor knockout mice. A possible association between multiple sclerosis (MS), the disease on which EAE is modeled, and uric acid is supported by the finding that patients with MS have significantly lower levels of serum uric acid than controls. In addition, statistical evaluation of more than 20 million patient records for the incidence of MS and gout (hyperuricemic) revealed that the two diseases are almost mutually exclusive, raising the possibility that hyperuricemia may protect against MS.

Here we have a paper with the link to Tetrahydrobiopterin (BH4,), also known as sapropterin, covered in an old post:-

Interactions of peroxynitrite with uric acid in the presence of ascorbate and thiols: Implications for uncoupling endothelial nitric oxide synthase

It has been suggested that uric acid acts as a peroxynitrite scavenger although it may also stimulate lipid peroxidation. To gain insight into how uric acid may act as an antioxidant, we used electron spin resonance to study the reaction of uric acid and plasma antioxidants with ONOO-. Peroxynitrite reacted with typical plasma concentrations of urate 16-fold faster than with ascorbate and 3-fold faster than cysteine. Xanthine but not other purine-analogs also reacted with peroxynitrite. The reaction between ONOO- and urate produced a carbon-centered free radical, which was inhibited by either ascorbate or cysteine. Moreover, scavenging of ONOO- by urate was significantly increased in the presence of ascorbate and cysteine. An important effect of ONOO- is oxidation of tetrahydrobiopterin, leading to uncoupling of nitric oxide synthase. The protection of eNOS function by urate, ascorbate and thiols in ONOO(-)-treated bovine aortic endothelial cells (BAECs) was, therefore, investigated by measuring superoxide and NO using the spin probe 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine (CMH) and the NO-spin trap Fe[DETC]2. Peroxynitrite increased superoxide and decreased NO production by eNOS indicating eNOS uncoupling. Urate partially prevented this effect of ONOO- while treatment of BAECs with the combination of either urate with ascorbate or urate with cysteine completely prevented eNOS uncoupling caused by ONOO-. We conclude that the reducing and acidic properties of urate are important in effective scavenging of peroxynitrite and that cysteine and ascorbate markedly augment urate's antioxidant effect by reducing urate-derived radicals.

Xanthine oxidase (XO, sometimes 'XAO') is a form of xanthine oxidoreductase, a type of enzyme that generates reactive oxygen species.[2] These enzymes catalyze the oxidation of hypoxanthine to xanthine and can further catalyze the oxidation of xanthine to uric acid. These enzymes play an important role in the catabolism of purines in some species, including humans.

Because xanthine oxidase is a metabolic pathway for uric acid formation, the xanthine oxidase inhibitor allopurinol is used in the treatment of gout.

Inhibition of xanthine oxidase has been proposed as a mechanism for improving cardiovascular health.  A study found that patients with chronic obstructive pulmonary disease (COPD) had a decrease in oxidative stress, including glutathione oxidation and lipid peroxidation, when xanthine oxidase was inhibited using allopurinol.

Reactive nitrogen species, such as peroxynitrite that xanthine oxidase can form, have been found to react with DNA, proteins, and cells, causing cellular damage or even toxicity. Reactive nitrogen signaling, coupled with reactive oxygen species, have been found to be a central part of myocardial and vascular function, explaining why xanthine oxidase is being researched for links to cardiovascular health.

We also should recall that abnormalities are common in autism.

So perhaps allopurinol for those with too much uric acid?  Perhaps this is a good marker for peroxynitrites ?


As is often the case there some contradiction in the science.  Is NO good for you or not?  Are both high and low uric acid actually indicating the same biological problem.

It looks like the research into very expensive BH4 therapy might be better directed into peroxynitrite scavengers.

I think we have found the reason why so many people with autism respond to Leucovorin (calcium folinate) and, unlike in our friend Roger, it may not be because of cerebral folate deficiency.

It looks like many other chronic conditions from diabetes to COPD to schizophrenia might also benefit from  calcium folinate.

Before I forget, in the Helmut Sies oxidative stress graphic I did highlight selenium.  The GPx enzymes contain selenium and if there is selenium deficiency the body's key antioxidant mechanism will be compromised. According to Abha Chauhan's book,  "Likewise, levels of exogenous antioxidants were also found to be reduced in autism, including vitamin C, vitamin E, and vitamin A in plasma, and zinc and selenium in erythrocytes (James et al., 2004)".  This might suggest adding a little extra selenium.

I think Allopurinol is worth a look for some autism.  Allopurinol does indeed reduce reactive nitrogen species in COPD (severe asthma), as suggested above.

“These results suggest that oral administration of the xanthine oxidase inhibitor allopurinol reduces airway reactive nitrogen species production in chronic obstructive pulmonary disease subjects. This intervention may be useful in the future management of chronic "

Thursday, 20 October 2016

Clinical Trial of Mega-dose Folinic Acid in Autism

The common form of Leucovorin Calcium is for injection, but it exists in 
tablet form. Maybe another opportunity for intra-nasal delivery?

As pointed out by Tyler, Richard Frye has published his trial on the effect of mega-dose folinic acid in children with autism and language impairment.

FRAA (folate receptor-αautoantibody) status was predictive of response to treatment.  This means that people who are FRAA positive are likely to really benefit from folinic acid treatment.

There are different types of folinic acid.  Dr Frye uses Calcium Leucovorin (Calcium Folinate), which is used in chemotherapy.  It is given by intramuscular injection or orally.

Dr Frye uses the oral form.

Folinic acid should be distinguished from folic acid (vitamin B9). However, folinic acid is a vitamer for folic acid, and has the full vitamin activity of this vitamin.

The dose is huge by normal standards of vitamin B9.  It was 2mg/kg per day (maximum 50mg per day) in two equally divided doses with half of the target dose given during the first 2 weeks. 

Two folate-related biomarkers were investigated. FRAA titers, both blocking and binding, were analyzed. Plasma free reduced-to-oxidized glutathione redox ratio was determined. Folate-related vitamins and minerals were measured. Serum total folate and vitamin B12 were measured 

Of 93 children with ASD, 60% and 44% were positive for blocking and binding FRAAs, respectively.

We sought to determine whether high-dose folinic acid improves verbal communication in children with non-syndromic autism spectrum disorder (ASD) and language impairment in a double-blind placebo control setting. Forty-eight children (mean age 7 years 4 months; 82% male) with ASD and language impairment were randomized to receive 12 weeks of high-dose folinic acid (2mgkg−1 per day, maximum 50mg per day; n=23) or placebo (n=25). Children were subtyped by glutathione and folate receptor-αautoantibody (FRAA) status. Improvement in verbal communication, as measured by a ability-appropriate standardized instrument, was significantly greater in participants receiving folinic acid as compared with those receiving placebo, resulting in an effect of 5.7 (1.0,10.4) standardized points with a medium-to-large effect size (Cohen’s d=0.70). FRAA status was predictive of response to treatment. For FRAA-positive participants, improvement in verbal communication was significantly greater in those receiving folinic acid as compared with those receiving placebo, resulting in an effect of 7.3 (1.4,13.2) standardized points with a large effect size (Cohen’s d=0.91), indicating that folinic acid treatment may be more efficacious in children with ASD who are FRAA positive. Improvements in subscales of the Vineland Adaptive Behavior Scale, the Aberrant Behavior Checklist, the Autism Symptom Questionnaire and the Behavioral Assessment System for Children were significantly greater in the folinic acid group as compared with the placebo group. There was no significant difference in adverse effects between treatment groups. Thus, in this small trial of children with non-syndromic ASD and language impairment, treatment with high-dose folinic acid for 12 weeks resulted in improvement in verbal communication as compared with placebo, particularly in those participants who were positive for FRAAs.

Separate analyses were conducted for each biomarker of folate metabolism (Table 2A). In general, improvement in verbal communication was significantly greater in participants on folinic acid as compared with those on placebo for participants with abnormal folate metabolism (i.e., FRAA positive, low glutathione redox ratio). For participants with biomarkers indicating more normal folate metabolism (i.e., FRAA negative, high glutathione redox ratio) improvement in verbal communication was not significantly different between groups.

This study suggests that FRAAs predict response to high-dose folinic acid treatment. This is consistent with the notion that children with ASD and FRAAs may represent a distinct subgroup.61 Other factors such as genetic polymorphisms in folate-related genes or mitochondrial dysfunction may be important in determining treatment response but were not examined in this study. When methylcobalamin was combined with folinic acid, improvement in communication as well as glutathione redox status was found.48 Indeed, future studies will be needed to define factors that predict response to treatment, investigate optimal dosing and help understand whether other compounds could work synergistically with folinic acid.


This study, and previous ones, suggest that > 50% of people tested have what Frye is calling positive Folate Receptor Antibody Status.  This combined with oxidative stress, as measured by low glutathione redox ratio, looks a like a good predictor of who will benefit from Calcium Folinate.

Clearly using tablets, as opposed to the usual injections, means that less of the folinic acid actually reaches the brain.  As was discussed in an earlier post, there are other forms of folate, like Metafolin, that are OTC.

Can Metafolin perform the same function as  Calcium Leucovorin?

It would be useful to know how much Metafolin = 2mg/kg of Calcium Leucovorin.  

The only way to find out would be to ask someone taking Calcium Leucovorin.

Metafolin® is a proprietary ingredient directly usable by the human organism, involved in lowering homocysteine blood levels, and the only form of folate able to cross the blood-brain barrier. In addition, Metafolin® does not mask a vitamin B12-deficiency and presents no risk of an accumulation of unmodified folic acid in the body.”

I suppose readers will now want to measure Folate Receptor Antibody (FRA) status and look for Calcium Leucovorin.  Our regular reader Roger may want to give his insights; perhaps he wants to see if Metafolin can do the job of Calcium Leucovorin?

Any side effects, Roger, after long term use of Calcium Leucovorin?

Friday, 8 April 2016

Mirtazapine and Folate for Idiopathic Schizophrenia, but for which Autism?

 China, where things tend to be big, even their clinical trials

A short while ago we looked at the possible mechanisms behind a reader’s successful experience in use of Mirtazapine (Remeron) in autism, then being prescribed to increase appetite.

Mirtazapine is a tricyclic antidepressant, meaning it is very closely related to first generation antihistamines, but it has numerous other effects;  more of that later.

Folate is vitamin B9.  Folic acid is synthetically produced, and used in fortified foods and supplements on the theory that it is converted into folate, which may not be the case.

It appears that in both schizophrenia and autism there is a family of possible folate dysfunctions that range from minor to severe.  The mild dysfunction responds to a small supplement of folate, while the severe dysfunction requires a much larger supplement of folate.

Roger, another reader of this blog has the more severe dysfunction called Cerebral Folate Deficiency (CFD) and this condition is best studied by Vincent Ramaekers  (Department of Pediatric Neurology and Center of Autism, University Hospital Liege) and Richard Frye at the Arkansas Children’s Hospital.

Cerebral folate deficiency as diagnosed by Ramaekers/Frye is extremely rare.

In a previous post we looked at Biotin (vitamin B7) and we saw that while biotin/biotinidase deficiency is technically extremely rare, a partial deficiency seems to exist in about 5% of people with autism.  

Both severe biotin/biotinidase deficiency and partial biotin/biotinidase deficiency responds well to high dose biotin supplementation.

Without going into the details of Folate Receptor Autoantibodies (FRAs), it is clear that Ramaekers has found the same condition in both Schizophrenia and Autism.

The milder folate dysfunction is very well known in schizophrenia.

The Chinese Trial

On the basis that bigger is better, a clinical trial is underway in China on 330 subjects with Schizophrenia to measure the benefit of Mirtazapine and/or folate as an add-on therapy.

I was quite surprised to come across this trial.

Today’s Post

Today’s post will look at the known effects of Mirtazapine and folate in schizophrenia and also the role folate plays in human biology.

There are lab tests that you could make to check for Folate dysfunction, just as there are for Biotin dysfunction. 

The standard therapy for Cerebral Folate Deficiency is the prescription drug leucovorin, normally used in cancer therapy.  There is also a supplement called Metafolin (Levomefolate calcium) that should have a very similar, if not identical, effect. Metafolin is produced by Merck and sold to supplement companies on the basis that it is only sold in low doses.  Metafolin appears more than your average “supplement”.

Another producer of Levomefolate calcium, is Pamlab; they sell it as a treatment for memory loss and peripheral neuropathy.  Pamlab was purchased by Nestlé Health Science in 2013; the Swiss tend to know what they are doing.


Schizophrenia overlaps significantly with autism in terms of its genetic origin.
Interestingly, people with schizophrenia may have a high rate of irritable bowel syndrome, but they often do not mention it unless specifically asked.

To better understand the clinical trials you need to know that the schizophrenia is a spectrum like autism with three main problem areas:-

Positive symptoms
These are symptoms that most individuals do not normally experience but are present in people with schizophrenia. They can include delusions, disordered thoughts and speech, and tactile, auditory, visual, olfactory and gustatory hallucinations, typically regarded as manifestations of psychosis. Hallucinations are also typically related to the content of the delusional theme. Positive symptoms generally respond well to medication.

Negative symptoms
These are deficits of normal emotional responses or of other thought processes, and are less responsive to medication. They commonly include flat expressions or little emotion, poverty of speech, inability to experience pleasure,lack of desire to form relationships, and lack of motivation. Negative symptoms appear to contribute more to poor quality of life, functional ability, and the burden on others than do positive symptoms. People with greater negative symptoms often have a history of poor adjustment before the onset of illness, and response to medication is often limited.


Cognitive dysfunction

The extent of the cognitive deficits an individual experiences is a predictor of how functional an individual will be, the quality of occupational performance, and how successful the individual will be in maintaining treatment.  The presence and degree of cognitive dysfunction in individuals with schizophrenia has been reported to be a better indicator of functionality than the presentation of positive or negative symptoms

Effective psychiatric drugs only exist for the positive symptoms, they do not exist for the negative symptoms or the cognitive dysfunction.

Folate Deficiency in Schizophrenia

Folate treatment in schizophrenia is linked to improvement in the negative symptoms that are normally untreatable.

Studies are mixed, but subgroups clearly exist in schizophrenia where folate supplementation improved well-being.

The rare severe dysfunction which is Cerebral Folate Deficiency is shown to exist in schizophrenia. 

Folate and vitamin B12 supplementation reduces disabling schizophrenia symptoms in patients with specific gene variants

Participants were all taking antipsychotic medications – which have been shown to alleviate positive symptoms, such as hallucinations and delusions, but not negative symptoms – and were randomized to receive daily doses of either folate and vitamin B12 or a placebo for 16 weeks. Every two weeks their medical and psychiatric status was evaluated, using standard symptom assessment tools along with measurements of blood levels of folate and homocysteine, an amino acid that tends to rise when folate levels drop. Nutritional information was compiled to account for differences in dietary intake of the nutrients. Participants' blood samples were analyzed to determine the variants they carried of MTHFR and three other folate-pathway genes previously associated with the severity of negative symptoms of schizophrenia. 

Among all 140 participants in the study protocol, those receiving folate and vitamin B12 showed improvement in negative symptoms, but the degree of improvement was not statistically significant compared with the placebo group. But when the analysis accounted for the variants in the genes of interest, intake of the two nutrients did provide significant improvement in negative symptoms, chiefly reflecting the effects of specific variants in MTHFR and in a gene called FOLH1. Variants in the other two genes studied did not appear to have an effect on treatment outcome.


Folate and vitamin B12 status in schizophrenic patients

This study showed that folate deficiency is common in schizophrenic patients; therefore, it is important to pay attention to folate levels in these patients.

Folinic acid treatment for schizophrenia associated with folate receptor autoantibodies

The Role of Folate/vitamin B9 in Human Biology

Vitamin B9 is essential for numerous bodily functions. Humans cannot synthesize folates de novo; therefore, folic acid has to be supplied through the diet to meet their daily requirements. The human body needs folate to synthesize DNA, repair DNA, and methylate DNA as well as to act as a cofactor in certain biological reactions.

Folic acid is synthetically produced, and used in fortified foods and supplements on the theory that it is converted into folate.  To be used it must be converted to tetrahydrofolate (tetrahydrofolic acid) by dihydrofolate reductase (DHFR). Increasing evidence suggests that this process may be slow in humans.

Note betaine below, which is also used to treat Cerebral Folate Deficiency, along with NAC.

Folic Acid, Folinic Acid and Folate

The terminology is confusing; what we want is folate, but there are several ways to get it.  Folic acid does not appear to be a good way.  Folinic acid, Levomefolic acid and Levomefolate calcium look to be the most effective supplements.

Here is a brief summary from Wikipedia:_

Folinic acid  or leucovorin, generally administered as the calcium or sodium salt (calcium folinate, sodium folinate, leucovorin calcium, leucovorin sodium), is an adjuvant used in cancer chemotherapy involving the drug methotrexate. It is also used in synergistic combination with the chemotherapy agent 5-fluorouracil.

Folinic acid (also called 5-formyltetrahydrofolate) was first discovered in 1948 as citrovorum factor and occasionally is still called by that name. Folinic acid should be distinguished from folic acid (vitamin B9). However, folinic acid is a vitamer for folic acid, and has the full vitamin activity of this vitamin.

Levomefolic acid is the primary biologically active form of folic acid used at the cellular level for DNA reproduction, the cysteine cycle and the regulation of homocysteine. It is also the form found in circulation and transported across membranes into tissues and across the blood-brain barrier. In the cell, L-methylfolate is used in the methylation of homocysteine to form methionine and tetrahydrofolate (THF). THF is the immediate acceptor of one carbon units for the synthesis of thymidine-DNA, purines (RNA and DNA) and methionine. The un-methylated form, folic acid (vitamin B9), is a synthetic form of folate, and must undergo enzymatic reduction by methylenetetrahydrofolate reductase (MTHFR) to become biologically active.

It is synthesized in the absorptive cells of the small intestine from polyglutamylated dietary folate. It is a methylated derivative of tetrahydrofolate. Levomefolic acid is generated by MTHFR from 5,10-methylenetetrahydrofolate (MTHF) and used to recycle homocysteine back to methionine by 5-methyltetrahydrofolate-homocysteine methyltransferase(MTR) also known as methionine synthase (MS).
Levomefolic acid (and folic acid in turn) has been proposed for treatment of cardiovascular disease and advanced cancers such as breast and colorectal cancers. It bypasses several metabolic steps in the body and better binds thymidylate synthase with fDump, a metabolite of the drug fluorouracil.

Levomefolate calcium, a calcium salt of levomefolic acid, is sold under the brand names Metafolin (a registered trademark of Merck KGaA) and Deplin (trademark of Pamlab, LLC). Methyl folate can be bought at online stores or in some chemists though without a prescription.

A good choice seems to be Metafolin, like in this product:-

Folate and Autism

We know from Roger and Frye/Ramaekers that the rare condition condition Cerebral folate deficiency (CFD) exists in autism, but what about the more widespread milder dysfunction like that found in schizophrenia?

As usual the level of knowledge in autism is less than that in schizophrenia.  The paper below concludes that when it comes to autism, not much is known.

Folic acid and autism: What do we know?


Autism spectrum disorders (ASD) consist in a range of neurodevelopmental conditions that share common features with autism, such as impairments in communication and social interaction, repetitive behaviors, stereotypies, and a limited repertoire of interests and activities. Some studies have reported that folic acid supplementation could be associated with a higher incidence of autism, and therefore, we aimed to conduct a systematic review of studies involving relationships between this molecule and ASD. The MEDLINE database was searched for studies written in English which evaluated the relationship between autism and folate. The initial search yielded 60 potentially relevant articles, of which 11 met the inclusion criteria. The agreement between reviewers was κ = 0.808. The articles included in the present study addressed topics related to the prescription of vitamins, the association between folic acid intake/supplementation during pregnancy and the incidence of autism, food intake, and/or nutrient supplementation in children/adolescents with autism, the evaluation of serum nutrient levels, and nutritional interventions targeting ASD. Regarding our main issue, namely the effect of folic acid supplementation, especially in pregnancy, the few and contradictory studies present inconsistent conclusions. Epidemiological associations are not reproduced in most of the other types of studies. Although some studies have reported lower folate levels in patients with ASD, the effects of folate-enhancing interventions on the clinical symptoms have yet to be confirmed.

Given the anecdotal evidence, including from our reader Seth, and the close biological relationship between autism and schizophrenia it seems pretty clear that a sub-group of people with autism do have a folate dysfunction that should respond to supplementation.  

How big this subgroup is remains to be seen.  For biotin it is about 5%, for vitamin B12 it about 10%.  Given it is known that MTHFR mutations are very common in autism, for example 23% were found to have the homozygous mutation 677CT allele (see the study below), it is very likely to be a sizeable group.  MTHFR is only one of the genes that could cause a folate problem.

A trial of metafolin could be a rewarding experience for some.

Back to the second half of that big Chinese Trial - Mirtazapine

There is a wealth of research that looks into the benefit of Mirtazapine in schizophrenia.  I choose to highlight a study from Finland because it is extremely comprehensive.

It has been reported earlier, from another part of this study, that clear-cut differences in all PANSS subscales and a large effect size of 1,00 (CI95% 0,23-1,67) on the PANSS total scores resulted from mirtazapine treatment when compared with a placebo in both within group and between group analyses during the double-blind phase (Joffe et al. 2009). In the open label phase, patients who switched to mirtazapine treatment demonstrated a clinical improvement in the same manner as their mirtazapine-treated counterparts in the double-blind phase. Prolonged treatment with mirtazapine led to more prominent improvements in clinical parameters than short-term treatment. A trend towards improvement was seen in all measured parameters, therefore providing more evidence of mirtazapine’s beneficial effect on schizophrenia symptoms.

The actual mechanism for a potential neurocognitive enhancing effect of mirtazapine in schizophrenia remains unknown, but it may be elucidated from its receptor binding profile. Like most SGAs, mirtazapine could also increase prefrontal dopaminergic and noradrenergic activity via 5-HT2A or 5-HT2C receptor blockade, as demonstrated in animal models (Liegeois et al. 2002; Meneses 2007; Zhang et al. 2000), and thus improve neurocognitive performance. Secondly, 5-HT3 receptor modulation by mirtazapine could also improve neurocognition (Akhondzadeh et al. 2009), presumably through increased release of acetylcholine (Ramirez et al. 1996). Thirdly, mirtazapine might improve neurocognition as a result of the indirect agonism of 5-HT1A receptors (Sumiyoshi et al. 2007). Moreover, mirtazapine is a more potent alpha-2 receptor antagonist than clozapine, which may explain its additional neurocognition-enhancing effect, even if it is added to clozapine (as in the study reported by Delle Chiae et al. 2007). The alpha-2 receptors remain an important target for neurocognitive research and its down-regulation may enhance neurocognition through a noradrenaline-mediated modulation of response to environmental stimuli (Friedman et al. 2004). Furthermore, alpha-2 receptor antagonism seems to boost hippocampal neurogenesis (Rizk et al. 2006). Also, mirtazapine may actually boost levels of brain-derived neurotrophic factor (BDNF) Rogoz et al. 2005), which is a major mediator of neurogenesis 62 and neuroplasticity. Correspondingly, those who suffer from schizophrenia often have abnormally low BDNF serum levels (Rizos et al. 2008).

During the 6-week extension phase, patients who had previously received six weeks of mirtazapine and those on placebo both showed significant improvement on several neurocognitive tests. Twelve-week mirtazapine treatment demonstrated better neurocognitive outcome than just six weeks of mirtazapine treatment, as evaluated by Stroop Dots time and TMT-B, number of mistakes, which are associated with general improvement in mental speed/attention control and executive functions. Twelve-week mirtazapine add-on to antipsychotic treatment indicated additional neurocognitive improvements of just six weeks, which demonstrates a progressive therapeutic effect.

In earlier posts on Mirtazapine/Remeron I raised various possible modes of action and other readers added their further ideas.

The table below lists some of the possible modes of action.  I declare a bias towards the importance of histamine, but clearly many more things are involved.

Mirtazapine has been trialed for a vast range of conditions:

A Review of Therapeutic Uses of Mirtazapine in Psychiatric and Medical Conditions

Mirtazapine is an effective antidepressant with unique mechanisms of action. It is characterized by a relatively rapid onset of action, high response and remission rates, a favorable side-effect profile, and several unique therapeutic benefits over other antidepressants. Mirtazapine has also shown promise in treating some medical disorders, including neurologic conditions, and ameliorating some of the associated debilitating symptoms of weight loss, insomnia, and postoperative nausea and vomiting.

And even Fibromyalgia, which I did suggest was the “almost autism” for females:-

In a 6-week open-label trial of mirtazapine, 54% of the 26 fibromyalgia patients who completed the study demonstrated a clinically significant reduction in pain intensity and in mean weekly dosage of acetaminophen. Additionally, there was a significant improvement in sleep quality and somatic symptoms, including cold extremities, dry mouth, sweating, dizziness, and headache. Of note, the magnitude of reduction in major fibromyalgia symptoms was significantly correlated with the magnitude of reduction in depression

Mirtazapine in Autism

In the new trial of Mirtazapine in autism they have chosen to focus on anxiety.  That looks odd to me given the very wide scope of benefits seen in schizophrenia and the feedback of our reader who asked why Remeron was working wonders with his child.

As is often the case, this trial at Massachusetts General Hospital uses doses that are extremely high.  Given the numerous effects of this drug it is highly likely that the effect may be completely different at higher/lower doses.

This study will determine the effectiveness of mirtazapine in reducing anxiety in children with autistic disorder, Asperger's disorder and Pervasive Developmental Disorder.

The starting dose for subjects is 7.5 mg daily. The maximum daily dose will be 45 mg.

I am very much in agreement with the readers of this blog using Mirtazapine at a lower dose.

As the schizophrenia trial showed, the effect grows over time, so better to try a low dose of 5mg for two months than race up to 45mg.