PTSD susceptibility?

This 2021 rodent study investigated post-traumatic stress disorder (PTSD) susceptibility:

“PTSD is an incapacitating trauma-related disorder, with no reliable therapy. We show distinct DNA methylation profiles of PTSD susceptibility in the nucleus accumbens (NAc). Data analysis revealed overall hypomethylation of different genomic CpG sites in susceptible animals.

Is it possible to treat PTSD by targeting epigenetic processes? Such an approach might reverse genomic underpinning of PTSD and serve as a cure.

To test plausibility of such an approach, a reliable animal (rat) model with high construct validity is needed. Previously, we reported one such model, which uses predator-associated trauma, and cue reminders to evoke recurring trauma. This simulates clinical PTSD symptoms including re-experiencing, avoidance, and hyperarousal.

Individual PTSD-like (susceptible) behavior is analyzed, enabling identification of susceptible animals separately from those that are non-PTSD-like (resilient). This model captures salient features of this disorder in humans, in which only a fraction of trauma victims develop PTSD, while others are resilient.

experimental model

Sprague–Dawley rats were exposed to trauma and to three subsequent trauma-associated reminders. Freezing behavior was measured under conditions of:

  • Exploration;
  • Social interaction (with a companion); and
  • Hyperarousal.

Controls were exposed to identical conditions except for the traumatic event.

PTSD-like behavior of each animal was compared with baseline and with the population. Two unambiguous sub-populations were identified, resilient and susceptible.

After exposure to trauma and its reminders, susceptible animals showed an increase from baseline in freezing behavior, and over time in all three behavioral tests, as opposed to resilient and control groups.

DMRs

Differentially methylated sites in susceptible and resilient animals compared to control group.

Although we focused in this study on DNA methylation changes that associate with susceptibility, we also report unique changes in DNA methylation that occur in resilient animals. Inhibition of critical genes that are downregulated in susceptible animals convert resilient animals to become susceptible.”

https://www.researchgate.net/publication/353192082_Reduction_of_DNMT3a_and_RORA_in_the_nucleus_accumbens_plays_a_causal_role_in_post-traumatic_stress_disorder-like_behavior_reversal_by_combinatorial_epigenetic_therapy “Reduction of DNMT3a and RORA in the nucleus accumbens plays a causal role in post-traumatic stress disorder-like behavior: reversal by combinatorial epigenetic therapy” (registration required)


Rodents with the same genetics and environment displayed individual differences in their responses to traumatic events. Please provide evidence for that before venturing elsewhere.

Not sure why it took 3+ years for this study received in November 2017 to finally be published in July 2021. Sites other than https://doi.org/10.1038/s41380-021-01178-y are more transparent about their peer review and publication processes.

No causes for PTSD susceptibility were investigated. PTSD effects and symptoms aren’t causes, notwithstanding this study’s finding that:

“Our results support a causal role for the NAc as a critical brain region for expression of PTSD-like behaviors, and a role for programming genes by DNA methylation in the NAc in development of PTSD-like behaviors.”

Can’t say that I understand more about causes for PTSD susceptibility now than before I read this study. Researchers attaching significance to gene functional groups seemed like hypothesis-seeking efforts to overcome limited findings.

Will this study’s combination of a methyl donor with a Vitamin A metabolite address PTSD causes in humans? If it only temporarily alleviates symptoms, what lasting value will it have?


Several brain and body areas that store traumatic memories other than the nucleus accumbens were mentioned in The role of recall neurons in traumatic memories. A wide range of epigenetic memory storage vehicles is one reason why effective human therapies need to address each individual, their whole body, and their entire history.

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Osprey breakfast

Gut and brain health

This 2021 human review subject was interactions of gut health and disease with brain health and disease:

“Actions of microbial metabolites are key for appropriate gut-brain communication in humans. Among these metabolites, short-chain fatty acids (SCFAs), tryptophan, and bile acid metabolites / pathways show strong preclinical evidence for involvement in various aspects of brain function and behaviour.

Dietary fibres, proteins, and fats ingested by the host contain components which are metabolized by microbiota. SCFAs are produced from fermentation of fibres, and tryptophan-kynurenine (TRP-KYN) metabolites from dietary proteins. Primary bile acids derived from liver metabolism aid in lipid digestion, but can be deconjugated and bio-transformed into secondary bile acids.

1-s2.0-S0149763421001032-gr1

One of the greatest challenges with human microbiota studies is making inferences about composition of colonic microbiota from faeces. There are known differences between faecal and caecal microbiota composition in humans along with spatial variation across the gastrointestinal tract.

It is difficult to interpret microbiome-host associations without identifying the driving influence in such an interaction. Large cohort studies may require thousands of participants on order to reach 20 % explanatory power for a certain host-trait with specific microbiota-associated metrics (Shannon diversity, relative microbial abundance). Collection of metadata is important to allow for a better comparison between studies, and to identify differentially abundant microbes arising from confounding variables.”

https://www.sciencedirect.com/science/article/pii/S0149763421001032 “Mining Microbes for Mental Health: Determining the Role of Microbial Metabolic Pathways in Human Brain Health and Disease”


Don’t understand why these researchers handcuffed themselves by only using PubMed searches. For example, two papers were cited for:

“Conjugated and unconjugated bile acids, as well as taurine or glycine alone, are potential neuroactive ligands in humans.”

Compare scientific coverage of PubMed with Scopus:

  • 2017 paper: PubMed citations 39; Scopus citations 69.
  • 2019 paper: PubMed citations 69; Scopus citations 102.

Large numbers of papers intentionally missing from PubMed probably influenced this review’s findings, such as:

  1. “There are too few fibromyalgia and migraine microbiome-related studies to make definitive conclusions. However, one fibromyalgia study found altered microbial species associated with SCFA and tryptophan metabolism, as well as changes in serum levels of SCFAs. Similarly, the sole migraine-microbiota study reported an increased abundance of the kynurenine synthesis GBM (gut-brain module).
  2. Due to heterogeneity of stroke and vascular disease conditions, it is difficult to make substantial comparisons between studies. There is convincing evidence for involvement of specific microbial genera / species and a neurovascular condition in humans. However, taxa were linked to LPS biosynthesis rather than SCFA production.
  3. Several studies suggest lasting microbial changes in response to prenatal or postnatal stress, though these do not provide evidence for involvement of SCFA, tryptophan, or bile-acid modifying bacteria. Similar to stress, there are very few studies assessing impact of post-traumatic stress disorder on microbiota.”

These researchers took on a difficult task. Their study design could have been better.


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Wildlife

PXL_20210710_100826663

Take acetyl-L-carnitine for early-life trauma

This 2021 rodent study traumatized female mice during their last 20% of pregnancy, with effects that included:

  • Prenatally stressed pups raised by stressed mothers had normal cognitive function, but depressive-like behavior and social impairment;
  • Prenatally stressed pups raised by control mothers did not reverse behavioral deficits; and
  • Control pups raised by stressed mothers displayed prenatally stressed pups’ behavioral phenotypes.

Acetyl-L-carnitine (ALCAR) protected against and reversed depressive-like behavior induced by prenatal trauma:

alcar regime

ALCAR was supplemented in drinking water of s → S mice either from weaning to adulthood (3–8 weeks), or for one week in adulthood (7–8 weeks). ALCAR supplementation from weaning rendered s → S mice resistant to developing depressive-like behavior.

ALCAR supplementation for 1 week during adulthood rescued depressive-like behavior. One week after ALCAR cessation, however, the anti-depressant effect of ALCAR was diminished.

Intergenerational trauma induces social deficits and depressive-like behavior through divergent and convergent mechanisms of both in utero and early-life parenting environments:

  • We establish 2-HG [2-hydroxyglutaric acid, a hypoxia and mitochondrial dysfunction marker, and an epigenetic modifier] as an early predictive biomarker for trauma-induced behavioral deficits; and
  • Demonstrate that early pharmacological correction of mitochondria metabolism dysfunction by ALCAR can permanently reverse behavioral deficits.”

https://www.nature.com/articles/s42003-021-02255-2 “Intergenerational trauma transmission is associated with brain metabotranscriptome remodeling and mitochondrial dysfunction”


Previously curated studies cited were:

This study had an effusive endorsement of acetyl-L-carnitine in its Discussion section, ending with:

“This has the potential to change lives of millions of people who suffer from major depression or have risk of developing this disabling disorder, particularly those in which depression arose from prenatal traumatic stress.”

I take a gram daily. Don’t know about prenatal trauma, but I’m certain what happened during my early childhood.

I asked both these researchers and those of Reference 70 for their estimates of a human equivalent to “0.3% ALCAR in drinking water.” Will update with their replies.


PXL_20210704_095621886

The brainstem’s parabrachial nucleus

I often reread blog posts that you read. Yesterday, a reader clicked Treat your gut microbiota as one of your organs. On rereading, I saw that I didn’t properly reference the parabrachial nucleus as being part of the brainstem.

A “parabrachial nucleus” search led me to a discussion of two 2020 rodent studies:

“Nociceptive signals entering the brain via the spinothalamic pathway allow us to detect location and intensity of a painful sensation. But, at least as importantly, nociceptive inputs also reach other brain regions that give pain its emotional texture.

Key to that circuitry is the parabrachial nucleus (PBN), a tiny cluster of cells in the brainstem associated with homeostatic regulation of things like temperature and food intake, response to aversive stimuli, and perceptions of many kinds. Two new papers advance understanding of PBN’s role in pain:

  1. The PBN receives inhibitory inputs from GABAergic neurons in the central nucleus of the amygdala (CeA). Those inputs are diminished in chronic pain conditions, leading to PBN hyperactivity and increased pain perception. Disinhibition of the amygdalo-parabrachial pathway may be crucial to establishing chronic pain.
  2. The dorsal PBN is the first receiver of spinal nociceptive input. It transmits certain inputs to the ventral medial hypothalamus and lateral periaqueductal gray. Certain of its neurons transmit noxious inputs to the external lateral PBN, which then transmits those inputs to the CeA and bed nucleus of the stria terminalis. This is quite new, that nociceptive information the CeA receives has already been processed by the PBN. They measured many pain-related behaviors: place aversion, avoidance, and escape. That allowed them to dissect different pain-related behaviors in relation to distinct subnuclei of the PBN.

1Inline2

Chronic pain is manufactured by the brain. It’s not a one-way process driven by something coming up from the periphery. The brain is actively constructing a chronic pain state in part by this recurring circuit.

A role of the PBN is to sound an alarm when an organism is in danger, but its roles go further. It is a key homeostatic center, weighing short-term versus long-term survival. If you’re warm, fed, and comfortable, organisms can address long-term directives like procreation. When you’re unsafe, though, you need to put those things off and deal with the emergency.”

https://www.painresearchforum.org/news/147704-parabrachial-nucleus-takes-pain-limelight “The Parabrachial Nucleus Takes the Pain Limelight”

https://www.jneurosci.org/content/40/17/3424 “An Amygdalo-Parabrachial Pathway Regulates Pain Perception and Chronic Pain”

https://www.sciencedirect.com/science/article/pii/S089662732030221X “Divergent Neural Pathways Emanating from the Lateral Parabrachial Nucleus Mediate Distinct Components of the Pain Response”


Two dozen papers have since cited these two studies. One that caught my eye was a 2021 rodent study:

“Migraines cause significant disability and contribute heavily to healthcare costs. Irritation of the meninges’ outermost layer (the dura mater), and trigeminal ganglion activation contribute to migraine initiation.

Dura manipulation in humans during neurosurgery is often painful, and dura irritation is considered an initiating factor in migraine. In rodents, dura irritation models migraine-like symptoms.

Maladaptive changes in central pain-processing regions are also important in maintaining pain. The parabrachial complex (PB) receives diverse sensory information, including a direct input from the trigeminal ganglion.

PB-projecting trigeminal ganglion neurons project also to the dura. These neurons represent a direct pathway between the dura, a structure implicated in migraine, and PB, a key node in chronic pain and aversion.”

https://www.sciencedirect.com/science/article/pii/S2452073X21000015 “Parabrachial complex processes dura inputs through a direct trigeminal ganglion-to-parabrachial connection”


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Cow milk causes disease

This 2021 review followed up Epigenetic effects of cow’s milk and many papers since then:

“Epidemiological studies associate intake of cow milk with an increased risk of diseases, which are associated with overactivated mechanistic target of rapamycin complex 1 (mTORC1) signaling. Milk’s physiological function to maintain high mTORC1 signaling at the beginning of mammalian life turns into adverse health effects when this postnatal endocrine and epigenetic system is not discontinued as designated by physiological processing of the lactation genome.

Milk is a signaling interface between the maternal lactation genome and the infant’s cellular mTORC1 system that orchestrates growth, anabolism, metabolic, immunological, and neurological programming. Pasteurization combined with refrigeration exposed human milk consumers to bioactive milk exosome (MEX)-derived micro-ribonucleic acids (miRs), augmenting milk’s mTORC1 activity compared to boiled, ultra-heat-treated, or fermented milk.

milk-mediated mTORC1 signaling

Milk consumption activates five major pathways stimulating mTORC1 via:

  1. Growth factors, including growth hormone, insulin, and insulin-like growth factor 1;
  2. Amino acids, especially branched-chain amino acids;
  3. Milk fat-derived palmitic acid;
  4. Milk sugar lactose; and
  5. Epigenetic modifiers, especially MEX-derived miRs.

Understanding milk’s interaction with the central hub of metabolic regulation, mTORC1, will open new avenues for prevention of common diseases.”

https://www.mdpi.com/2218-273X/11/3/404/htm “Lifetime Impact of Cow’s Milk on Overactivation of mTORC1: From Fetal to Childhood Overgrowth, Acne, Diabetes, Cancers, and Neurodegeneration”


This reviewer is somewhat of a zealot. Still, he cited 555 references.

His genotype may tolerate lactose, but he didn’t argue for it:

“After breast feeding, mucosal expression of lactase, an intestinal enzyme hydrolyzing lactose into glucose and galactose, is downregulated in all mammals with the exception of Neolithic humans, who developed LCT [lactase gene] mutations allowing persistent lactase expression.

Lactose content of milk makes up around 2–8% by weight. Lactose hydrolysis provides glucose and galactose, which both activate mTORC1:

  • During glucose abundance and glycolysis, sufficient cellular energy is produced in the form of ATP, which suppresses AMPK activity. Aldolase operates as a sensor for glucose availability that directly links glucose shortage to activation of AMPK.
  • Galactose via induction of oxidative stress activates mTORC1. Galactose-induced overactivation of mTORC1 promotes senescence of neural stem cells and aging of mesenchymal stem cells.

Lactobacilli used in food and dairy fermentation increase NRF2 activation, resulting in NRF2-induced sestrin expression, which attenuates mTORC1 activation.”

Basal cognition

To follow up Electroceuticals, a 2021 article by Dr. Michael Levin:

“A key philosophical idea, borrowed from computer science, is substrate independence. Components of a living system can carry out appropriate, clearly specified cognitive functions.

Cognitive processes in embryogenesis and regeneration:

rstb20200458f01

    • (a) An egg will reliably give rise to a species-specific anatomical outcome.
    • (b) This process is usually described as a feed-forward system where activity of gene-regulatory networks (GRNs) within cells results in expression of effector proteins that, via structural properties of proteins and physical forces, will result in the emergence of complex shape. This class of models (bottom-up process driven by self-organization and parallel activity of large numbers of local agents) is difficult to apply to several biological phenomena. Regulative development can alter subsequent steps to reach the correct anatomical goal state despite drastic deviations of the starting state.
    • (c) For example, mammalian embryos can be divided in half, giving rise to perfectly normal monozygotic twins, each of which has regenerated the missing cell mass.
    • (d) Mammalian embryos can also be combined, giving rise to a normal embryo in which no parts are duplicated.
    • (e) Such capabilities suggest that pattern control is fundamentally a homeostatic process—a closed-loop system using feedback to minimize error (distance) between a current shape and a target morphology. Although these kinds of decision-making models are commonplace in engineering, they are only recently beginning to be employed in biology. This kind of pattern-homeostatic process must store a setpoint that serves as a stop condition; however, as with most types of memory, it can be specifically modified by experience.
    • (f) In the phenomenon of trophic memory, damage created at a specific point on the branched structure of deer antlers is recalled as ectopic branch points in subsequent years’ antler regeneration. This reveals ability of cells at the scalp to remember spatial location of specific damage events and alter cell behaviour to adjust the resulting pattern appropriately—a pattern memory that stretches across months of time and considerable spatial distance and is able to modify low-level (cellular) growth rules to construct a pre-determined stored pattern that differs from genome-default for this species.
    • (g) A similar capability was recently shown in a molecularly tractable model system, in which genetically normal planarian flatworms were bioelectrically reprogrammed to regenerate two-headed animals when cut in subsequent rounds of asexual reproduction in plain water.
    • (h) The decision making revealed by cells, tissues and organs in these examples of dynamic remodelling toward specific target states could be implemented by cybernetic processes at various positions along a scale of proto-cognitive complexity.

A challenge for the field of basal cognition is to reveal gradualism of cellular properties underwriting this critical biological function to leverage an understanding of clear phase transitions observed in cognitive capacities. The origin and development of nervous systems is so far the most dramatic example.”

https://royalsocietypublishing.org/doi/10.1098/rstb.2020.0458 “Uncovering cognitive similarities and differences, conservation and innovation”


Why aren’t more resources being directed toward these research efforts? Glad to see that at least one co-founder of Microsoft, Paul Allen, posthumously used his billions to sponsor science for human good.

Eat broccoli sprouts for your hearing

Two 2021 papers, both of which I found by each citing a 2009 Molecular mechanisms underlying cochlear degeneration in the tubby mouse and the therapeutic effect of sulforaphane (not freely available). First was a review:

“Hair cell damage and loss mediated by oxidative stress are important causes of hearing loss. Sensorineural hearing loss is the most common type of hearing loss, including noise induced hearing loss (NIHL), age-related hearing loss (ARHL), and ototoxic hearing loss.

Nrf2 reduces cell damage caused by oxidative stress, and maintains the dynamic balance of systematic redox by inducing and regulating expression of various antioxidant factors. This review summarizes correlation studies of Nrf2 in hearing loss, providing ideas for prevention and treatment of hearing loss with Nrf2 as the target.

fphar-12-620921-g002

There is positive feedback between p62-mediated autophagy and Nrf2. p62 promotes accumulation of Nrf2 and nuclear translocation. Concurrently, increased Nrf2 promotes p62 expression.

How Nrf2 regulates ROS changes in hair cells, and the upstream and downstream regulatory network of Nrf2 in hair cells, are still not fully understood. Studies on early prevention and treatment of hearing loss through the Keap1-Nrf2-ARE [antioxidant response element] signaling axis are still at the exploratory stage.”

https://www.frontiersin.org/articles/10.3389/fphar.2021.620921/full “The Role of Nrf2 in Hearing Loss”


Second paper was a rodent study:

“We examined oxidative stress and antioxidant response of the p62-Keap1-Nrf2 pathway in cochleae during age-related hearing loss (ARHL) and noise-induced hearing loss (NIHL). We elucidated the function of full-length and variant p62/Sqstm1 (referred to here as p62) in regulation of Nrf2 activation.

Cochlear damage was assessed by analyzing auditory brainstem response (ABR) and by counting hair cells (HCs). Malondialdehyde (MDA, a lipid peroxidation product) levels were measured in young and old mice to determine whether oxidative stress contributed to ARHL.

auditory brainstem response

  • (A) Audiometric threshold (dB) determined from click and pure tone evoked ABRs. Thresholds were each significantly different (P < 0.001) between young mice and old mice.
  • (B) HC loss percentage in basal cochlear turns. Significant differences (P < 0.001) were observed between young and old mice.
  • (C) MDA levels in the cochleae of old mice were significantly higher (P = 0.034) than those of young mice.

ROS accumulation is closely related to ARHL and NIHL. The inability of ROS accumulation to activate the Nrf2 antioxidant stress pathway under physiological conditions may be related to alternative splicing of p62 mRNA in cochleae.

However, the agonist of the Nrf2 pathway enhanced Nrf2 nuclear translocation. This suggests a mechanism in which the antioxidant pathway was difficult to be activated in the context of accumulation of ROS.”

https://www.researchsquare.com/article/rs-535219/v1 “New Target of Oxidative Stress Regulation in Cochleae:Alternative Splicing of the p62/Sqstm1 gene”


The study’s two-month-old mice were equivalent to a 20-year-old human. Its 13-to-14-month-old mice were equivalent to humans in their 60s to 70s.

I expected preconditioning to be mentioned in both papers. Maybe these researchers thought it was too obvious and didn’t need to be stated that:

  • Repeated use of a Nrf2 activator produces transient mild stress;
  • Which elicits a stronger response; and
  • Preconditions cells for future stress?

Sulforaphane in the Goldilocks zone and its cited papers exhaustively emphasized preconditioning’s importance. The main thing I’m trying to do with isothiocyanates is to send a weak pro-inflammatory signal to my endogenous ARE system to exercise natural defenses.

Twice-daily drills make me more proficient at responding to actual emergencies. Post-drill, my body recycles material to be ready to respond the next time.

I do the same thing once a day with β-glucan 1,3/1,6 to train my innate immune system. Microphages in my gut are the first responders. Like the very reactive isothiocyanates, I don’t take anything with, or an hour before or after β-glucan 1,3/1,6.

Why tolerate “the antioxidant pathway was difficult to be activated in the context of accumulation of ROS” when a sulforaphane “agonist of the Nrf2 pathway enhanced Nrf2 nuclear translocation”? For all we know, diminished natural defenses and hearing loss may exist to turn old mammals into prey.

Continued in Part 2.

Eat oats and regain cognitive normalcy

This 2020 rodent study investigated effects of different diets:

“The present study aimed to evaluate effects of β-glucan on the microbiota gut-brain axis and cognitive function in an obese mouse model induced by a high-fat and fiber-deficient diet (HFFD). After long-term supplementation for 15 weeks, β-glucan prevented HFFD-induced cognitive impairment, assessed behaviorally by object location, novel object recognition, and nesting building tests:

  • Long-term β-glucan supplementation suppressed microglia activation and inflammation in hippocampus of HFFD-fed mice;
  • β-glucan attenuated deleterious engulfment of synapses by activation of microglia seen in HFFD mice;
  • β-glucan significantly prevented upregulation of TNF-α, IL-1β, and IL-6 mRNA expression in hippocampus; and
  • A broad-spectrum antibiotic intervention abrogated β-glucan-induced improvement in cognitive function, highlighting the essential role of gut microbiota to mediate cognitive function and behavior.

We found that short-term β-glucan supplementation did not change cognitive behavior in HFFD fed mice. HFFD feeding for 7 days dramatically changed gut microbial profile, with β-glucan-fed mice clustered apart from HFFD-fed mice sample, suggesting:

  • Quick changes in gut microbiota are induced by short-term β-glucan consumption and
  • Possible causality of gut microbiota profile on cognition.

7% β-glucan 7% nondigestible fiber

β-glucan supplementation increased place discrimination ratio in object location test compared with HFFD mice; however, there was no significant difference in total exploration time with objects during test phases between the two groups. Higher place discrimination index in β-glucan supplementation group was not due to better general performance, but increased recognition memory.

Results provide consistent evidence linking increased β-glucan intake to improved:

  • Gut microbiota profile;
  • Intestinal barrier function;
  • Reduced endotoxemia; and
  • Enhanced cognitive function via more optimized synaptic and signaling pathways in critical brain areas.

It is speculative that β-glucan improvement of gut microbiota composition, but not necessarily diversity per se, may be most critical for improved cognition. Enhanced consumption of β-glucan-rich foods is an easily implementable nutritional strategy to attenuate diet-induced cognitive decline.

https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-020-00920-y “β-glucan attenuates cognitive impairment via the gut-brain axis in diet-induced obese mice”


This study did well by elaborating It’s the fiber, not the fat and Eat oats to prevent diabetes related findings. How many humans eat themselves into essentially the same situation as this HFFD group with no gut-microbiota-friendly dietary fiber?

Experiments were with β-glucan 1,3/1,4 found in oats. β-glucan 1,3/1,6 has separate effects, especially on innate immunity.

It’s a coin toss on whether observed cognitive improvement was due to 7% β-glucan soluble fiber, 7% indigestible fiber, or both. I do both, beginning with Avena nuda oats for breakfast.

Astaxanthin bioavailability

By request, research on astaxanthin bioavailability. I used a “astaxanthin” “bioavailability” “quinone reductase” 2021 search term, and read citing papers.

“The bioaccessibility, bioavailability, and antioxidative activities of three astaxanthin geometric isomers were investigated using an in vitro digestion model.

  • 13Z-Astaxanthin showed higher bioaccessibility than 9Z- and all-E-astaxanthins during in vitro digestion, and
  • 9Z-astaxanthin exhibited higher transport efficiency than all-E- and 13Z-astaxanthins.

These might explain why 13Z- and 9Z-astaxanthins are found at higher concentrations in human plasma than all-E-astaxanthin.

9Z- and 13Z- astaxanthins exhibited a higher protective effect than all-E-astaxanthin against oxidative stress.”

https://pubs.acs.org/doi/10.1021/acs.jafc.7b04254 “Bioaccessibility, Cellular Uptake, and Transport of Astaxanthin Isomers and their Antioxidative Effects in Human Intestinal Epithelial Caco-2 Cells” (2017, not freely available)


jf1c00087_0005

“Astaxanthin with a high proportion of Z-isomer (especially rich in 9Z- and 13Z-isomers) was prepared from (all-E)-astaxanthin by thermal treatment and solid–liquid separation. Z-isomer-rich astaxanthin diet resulted in higher levels of astaxanthin in blood and many tissues (in particular, skin, lung, prostate, and eye) compared to all-E-isomer-rich diet.

Z-isomer-rich diet enhanced the level of 13Z-isomer in blood and tissues rather than that of 9Z-isomer. (13Z)-astaxanthin would have higher bioavailability and tissue accumulation than other isomers.”

https://pubs.acs.org/doi/10.1021/acs.jafc.1c00087Z-Isomers of Astaxanthin Exhibit Greater Bioavailability and Tissue Accumulation Efficiency than the All-E-Isomer” (2021, not freely available)


“Astaxanthin is highly susceptible to light, oxygen, and heat stress degradation. In addition, poor water solubility and bioavailability limit its efficacy in vivo. Investigating novel astaxanthin delivery systems is necessary in order to solve these drawbacks.”

https://www.mdpi.com/1420-3049/24/14/2640/htm “The Neuroprotective Effects of Astaxanthin: Therapeutic Targets and Clinical Perspective” (2019)


“Astaxanthin Z-isomers potentially have greater bioavailability and biological activity than (all-E)-astaxanthin. However, stability of Z-isomers is lower than all-E-isomer, which is a serious problem affecting its practical use.

In this study, we investigated impacts of different suspension media (oils and fats) and additives on astaxanthin isomer stability.

  • Z-isomers of astaxanthin isomerized to all-E-isomer during storage.
  • When soybean and sunflower oils were used as the suspension medium, astaxanthin isomers were hardly degraded. However the total Z-isomer ratio decreased from ~80% to ~50% during 6-week storage at 30 °C.
  • (9Z)-astaxanthin showed higher stability than 13Z- and 15Z-isomers.”

https://www.sciencedirect.com/science/article/abs/pii/S0308814621003770 “Evaluation and improvement of storage stability of astaxanthin isomers in oils and fats” (2021, not freely available)


I looked for but didn’t find a graph similar to this one that comparatively plotted astaxanthin:

OMCL2019-2716870.006

I also didn’t find recent human studies.

It seems that a special delivery system is required for taking astaxanthin as a supplement. It would require investigating manufacturers’ claims about isomer content and stability.

Eating colorful seafood is another way to get astaxanthin. Don’t know about eating raw or dried algae.

Ride the waves of gene expression with betaine

This 2021 cell study investigated a dietary supplement’s role in preventing nerve disease:

“A loss of epigenetic control has been implicated in development of neurodegenerative diseases. Previous studies have implicated aberrant DNA and histone methylation in multiple sclerosis (MS) disease pathogenesis.

We have previously reported that methyl donor betaine is depleted in MS and is linked to changes in histone H3 trimethylation (H3K4me3) in neurons. We have also shown that betaine increases histone methyltransferase activity by activating chromatin bound betaine homocysteine S-methyltransferase (BHMT).

A hallmark of MS is the death of oligodendrocytes, the cells responsible for wrapping axons in myelin in the central nervous system and maintaining a healthy sheath. In demyelinating diseases like MS, oligodendrocyte progenitor cells (OPCs) fail to differentiate and make more myelin, resulting in sclerotic lesions.

Promoting differentiation of OPCs and generation of myelin is of great interest as a novel MS therapy. Waves of gene regulation (repression and activation) need to occur to promote myelination.

This BHMT-betaine methylation pathway ensures availability of S-adenosylmethionine (SAM) for a variety of DNA and histone methylation processes. OPC survival and differentiation are dependent upon DNA and histone methylation, and both processes require SAM.

journal.pone.0250486.g001

BHMT uses betaine to remethylate homocysteine to methionine. Betaine can be taken in through the diet or synthesized through the oxidation of choline in mitochondria.

We demonstrated that oligodendrocyte gene expression can be modulated by betaine supplementation through the BHMT-betaine methylation pathway. Our study suggests that dietary betaine supplementation may prove to be a therapeutic agent for MS and other demyelinating disorders.”

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0250486 “The BHMT-betaine methylation pathway epigenetically modulates oligodendrocyte maturation”


I started taking betaine 16 years ago. Didn’t know of these effects until reading this study.

Treating psychopathological symptoms will somehow resolve causes? had more on betaine (aka trimethyl glycine). Current dose is 1.5 grams twice daily.

Are rodent models of human neurodegenerative diseases realistic?

This 2020 stem cell review argued against rodent models of human neurodegenerative diseases:

“Neuronal loss is not caused solely by intrinsic degenerative processes but rather via impaired interactions with surrounding glia and other brain cells. Dysfunctional astrocytes do not provide sufficient nutrients and antioxidants to neurons, while dysfunctional microglia cannot efficiently clear pathogens and cell debris from extracellular space, resulting in chronic inflammatory processes in the brain.

Human glia, especially astrocytes, differ significantly in morphology and function from their mouse counterparts. Recent advances in stem cell technology make it possible to reprogram human patients’ somatic cells to induced pluripotent stem cells (iPSC) and differentiate them further into patient‐specific glia and neurons, thus providing a source of human brain cells.

stem3309-fig-0002-m

Astrocytes do not efficiently utilize energy resources and cannot provide adequate metabolic support to neurons. A coculture of healthy human neurons with diseased astrocytes impaired neuronal calcium responses to glutamate and γ‐aminobutyric acid (GABA) as compared to coculture with healthy human astrocytes.

Treatment with sulforaphane:

  • Normalized basal level glycolysis;
  • Decreased basal level Aβ42 secretion; as well as
  • Ameliorated inflammatory response to pro‐inflammatory cytokines TNF-α and IL1-β in PSEN1 mutant iPSC astrocytes.

It is essential to make sure that what we see in the dish is the real patient‐specific phenotype. Transplantation of human brain organoids containing microglia into mice could provide a novel tool for drug screening in vivo.”

https://stemcellsjournals.onlinelibrary.wiley.com/doi/full/10.1002/stem.3309 “Metabolic and immune dysfunction of glia in neurodegenerative disorders: Focus on iPSC models”


This review’s thesis seems plausible. However, one problem with in vitro stem cell studies is that they often don’t have a control group.

Red cabbage pigments and the brain

This 2020 sheep study measured red cabbage anthocyanin concentrations:

“Study aim was to determine whether strongly bioactive hydrophilic red cabbage anthocyanins cross the blood-cerebrospinal fluid barrier (blood-CSF barrier) and whether there is a selectivity of this barrier towards these compounds.

The blood-CSF barrier, apart from the vascular blood-brain barrier, is the second important barrier. Despite very tight connections between endothelial cells of blood vessels of the choroid plexus, blood-CSF barrier allows selective passing of substances from blood to CSF, which is considered as a medium actively involved in transport of information to nerve cells.

Uncharged, lipophilic, and small-sized substances (≤ 600 Da) can cross the brain barriers without major obstacles thanks to diffusion. The rate of these substances’ penetration into brain tissue is directly proportional to their lipid solubility, and inversely proportional to particle size. Hydrophilic substances require special carriers.

The average percentage level of native anthocyanins over the whole experiment was almost 39.5%, while their metabolites constituted just over 60.5%. However, the proportion of native forms vs. metabolites did not develop identically:

  1. Early term (0.5-4 hrs) was distinguished by native derivatives (> 76%).
  2. Second period (4.5 h) had a similar contribution of native anthocyanins (49.85%) and their metabolites (50.15%).
  3. Third interval (5.0-10 h) more than 87% of anthocyanins were metabolites.

For comparison, a human experiment showed only one period with maximum blood plasma anthocyanins concentration (2 h) after red cabbage consumption.

Only one of 17 native anthocyanins found in blood plasma was detected in CSF. Eleven of 17 metabolites found in blood were identified in CSF.

sheep csf cyanins

Due to their hydrophilic nature and considerable size (≥ 611 Da), there seems to be no possibility to use diffusion for permeation of red cabbage anthocyanins through the blood-CSF barrier. These pigments may pass through this barrier only by the use of special carriers. Other mechanisms of anthocyanins permeation through blood-CSF barrier cannot be eliminated.

Two maximal values of total anthocyanins concentration appeared in both blood and CSF. When the pool of cyanidin compounds available in blood became depleted, the decline of total anthocyanin concentration in CSF was also noted.

Nonacylated cyanidin derivatives penetrated the blood-CSF barrier, but acylated cyanidin derivatives did not. A significantly higher proportion of cyanidin sulfate forms in CSF (31%) compared to blood plasma (9%).

Further targeted studies are needed to determine which paths of permeation via blood-CSF barrier are actually responsible for anthocyanins passing, as well as what mechanisms are present during these processes. In addition, it is worth remembering that low molecular weight compounds formed mainly by colonic microbiota are very important metabolites of anthocyanins, and could be relevant in the context of permeation through brain barriers.”

https://pubs.acs.org/doi/10.1021/acs.jafc.0c03170 “The Blood–Cerebrospinal Fluid Barrier Is Selective for Red Cabbage Anthocyanins and Their Metabolites” (not freely available)


Don’t understand why this study hasn’t been cited even once. These researchers’ methods could be performed with broccoli and other red cabbage compounds.

Every hand’s a winner, and every hand’s a loser

Another great blog post Know When To Fold ‘Em by Dr. Paul Clayton:

“Newly formed proteins entering the endoplasmic reticulum must be correctly folded to achieve their final form and function. This is a complex procedure with a failure rate of over 80%.

When metabolism is sufficiently skewed, accuracy of protein folding in the endoplasmic reticulum falls below an already low baseline of 20%. Accumulation of misfolded or unfolded proteins in the endoplasmic reticulum then triggers stress.

Integrated Stress Response (ISR) is something that cells do when they are affected by major stressors:

  • ISR turns down global protein synthesis, which is designed to kill virally infected or cancerous cells. If it kills the cancer cell or virally infected cell, that is the end of it.
  • If the stressor is in the heat / hypoxia / nutrient group, however, ISR effectively puts a cell into dark mode until hard times are over. Once the stressor has passed, a cell can then start to recover and return to homeostatic health.
  • But if the stressor is sustained, a low-grade ISR continues to smolder away, causing long-term impairment locally and ultimately systemically. Accumulation of misfolded or unfolded proteins activates ISR, leading to a down-regulation of protein synthesis, and increasing protein folding and degradation of unfolded proteins.

This is analogous to inflammation. Acute inflammatory responses to a pathogen or to tissue damage are entirely adaptive, and essential. Chronic inflammation, on the other hand, causes local and eventually systemic damage if left unchecked for long enough.”


A 2020 rodent study was cited for “reversing age-related cognitive decline”:

“This suggests that the aged brain has not permanently lost cognitive capacities. Rather, cognitive resources are still there, but have been somehow blocked, trapped by a vicious cycle of cellular stress.

Our work with ISR inhibition demonstrates a way to break that cycle, and restore cognitive abilities that had become walled off over time.

stress response inhibitor effects

If these findings in mice translate into human physiology, they offer hope and a tangible strategy to sustain cognitive ability as we age.”

https://elifesciences.org/articles/62048 “Small molecule cognitive enhancer reverses age-related memory decline in mice”


I’m curious as to why sulforaphane hasn’t been mentioned even once in Dr. Paul Clayton’s blog, which started three years ago. Do hundreds of sulforaphane studies performed in this century not contribute to his perspective? Polyphenols are mentioned a dozen times, yet they are 1% bioavailable compared with 80% “small molecule” sulforaphane.

Advice from the song depends on your definition of money:

“Know when to walk away
Know when to run
Never count your money
When you’re sitting at the table”

Gut microbiota topics

Here are thirty 2019 and 2020 papers related to Switch on your Nrf2 signaling pathway topics. Started gathering research on this particular theme three months ago.

There are more researchers alive today than in the sum of all history, and they’re publishing. I can’t keep up with the torrent of interesting papers.

on

2020 A prebiotic fructo-oligosaccharide promotes tight junction assembly in intestinal epithelial cells via an AMPK-dependent pathway

2019 Polyphenols and Intestinal Permeability: Rationale and Future Perspectives

2020 Prebiotic effect of dietary polyphenols: A systematic review

2019 Protease‐activated receptor signaling in intestinal permeability regulation

2020 Intestinal vitamin D receptor signaling ameliorates dextran sulfate sodium‐induced colitis by suppressing necroptosis of intestinal epithelial cells

2019 Intestinal epithelial cells: at the interface of the microbiota and mucosal immunity

2020 The Immature Gut Barrier and Its Importance in Establishing Immunity in Newborn Mammals

2019 Prebiotics and the Modulation on the Microbiota-GALT-Brain Axis

2019 Prebiotics, Probiotics, and Bacterial Infections

2020 Vitamin D Modulates Intestinal Microbiota in Inflammatory Bowel Diseases

2020 Microbial tryptophan metabolites regulate gut barrier function via the aryl hydrocarbon receptor

2019 Involvement of Astrocytes in the Process of Metabolic Syndrome

2020 Intestinal Bacteria Maintain Adult Enteric Nervous System and Nitrergic Neurons via Toll-like Receptor 2-induced Neurogenesis in Mice (not freely available)

2019 Akkermansia muciniphila ameliorates the age-related decline in colonic mucus thickness and attenuates immune activation in accelerated aging Ercc1−/Δ7 mice

2020 Plasticity of Paneth cells and their ability to regulate intestinal stem cells

2020 Coagulopathy associated with COVID-19 – Perspectives & Preventive strategies using a biological response modifier Glucan

2020 Synergy between Cell Surface Glycosidases and Glycan-Binding Proteins Dictates the Utilization of Specific Beta(1,3)-Glucans by Human Gut Bacteroides

2020 Shaping the Innate Immune Response by Dietary Glucans: Any Role in the Control of Cancer?

2020 Systemic microbial TLR2 agonists induce neurodegeneration in Alzheimer’s disease mice

2019 Prebiotic supplementation in frail older people affects specific gut microbiota taxa but not global diversity

2020 Effectiveness of probiotics, prebiotics, and prebiotic‐like components in common functional foods

2020 Postbiotics-A Step Beyond Pre- and Probiotics

2019 Pain regulation by gut microbiota: molecular mechanisms and therapeutic potential

2020 Postbiotics: Metabolites and mechanisms involved in microbiota-host interactions

2020 Postbiotics against Pathogens Commonly Involved in Pediatric Infectious Diseases

2019 Glutamatergic Signaling Along The Microbiota-Gut-Brain Axis

2019 Lipoteichoic acid from the cell wall of a heat killed Lactobacillus paracasei D3-5 ameliorates aging-related leaky gut, inflammation and improves physical and cognitive functions: from C. elegans to mice

2020 Live and heat-killed cells of Lactobacillus plantarum Zhang-LL ease symptoms of chronic ulcerative colitis induced by dextran sulfate sodium in rats

2019 Health Benefits of Heat-Killed (Tyndallized) Probiotics: An Overview

2020 New Horizons in Microbiota and Metabolic Health Research (not freely available)

Our first 1000 days

This 2021 review subject was a measurable aspect of our early lives:

“The first 1000 days from conception are a sensitive period for human development programming. During this period, environmental exposures may result in long-lasting epigenetic imprints that contribute to future developmental trajectories.

The present review reports on effects of adverse and protective environmental conditions occurring on glucocorticoid receptor gene (NR3C1) regulation in humans. Thirty-four studies were included.

The hypothalamic-pituitary-adrenal (HPA) axis is key in regulating mobilization of energy. It is involved in stress reactivity and regulation, and it supports development of behavioral, cognitive, and socio-emotional domains.

The NR3C1 gene encodes for specific glucocorticoid receptors (GRs) in the mammalian brain, and it is epigenetically regulated by environmental exposures.

When mixed stressful conditions were not differentiated for their effects on NR3C1 methylation, no significant results were obtained, which speaks in favor of specificity of epigenetic vestiges of different adverse conditions. Specific maternal behaviors and caregiving actions – such as breastfeeding, sensitive and contingent interactive behavior, and gentle touch – consistently correlated with decreased NR3C1 methylation.

If the neuroendocrine system of a developing fetus and infant is particularly sensitive to environmental stimulations, this model may provide the epigenetic basis to inform promotion of family-centered prevention, treatment, and supportive interventions for at-risk conditions. A more ambiguous picture emerged for later effects of NR3C1 methylation on developmental outcomes during infancy and childhood, suggesting that future research should favor epigenome-wide approaches to long-term epigenetic programming in humans.”

https://www.sciencedirect.com/science/article/abs/pii/S0149763421001081 “Glucocorticoid receptor gene (NR3C1) methylation during the first thousand days: Environmental exposures and developmental outcomes” (not freely available). Thanks to Dr. Livio Provenci for providing a copy.


I respectfully disagree with recommendations for an EWAS approach during infancy and childhood. What happened to each of us wasn’t necessarily applicable to a group. Group statistics may make interesting research topics, but they won’t change anything for each individual.

Regarding treatment, our individual experiences and needs during our first 1000 days should be repeatedly sensed and felt in order to be therapeutic. Those memories are embedded in our needs because cognitive aspects of our brains weren’t developed then.

To become curative, we first sense and feel early needs and experiences. Later, we understand their contributions and continuations in our emotions, behavior, and thinking.

And then we can start to change who we were made into.