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.


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Your bones influence your brain

This 2020 review subject was brain-bone crosstalk:

“Multiple stress, mood and neurodegenerative brain disorders are associated with osteoporosis. Skeletal diseases display impaired brain development and function.

Along with brain and bone pathologies, trauma events highlight strong interaction of both organs. While brain-derived molecules affecting bone include central regulators – transmitters of the sympathetic, parasympathetic and sensory nervous system – bone-derived mediators altering brain function are released from bone cells and marrow.

ijms-21-04946-g001

Osteoblast-derived hormone osteocalcin (OCN) exerts neuroprotective effects. Studies revealed a bidirectional dependence of brain and bone through bone cell-derived modulators that directly affect behavioral and cognitive function.

The main bone-derived mediator affecting the brain is OCN, which is exclusively synthesized by osteoblasts. OCN was recently discovered to transverse the BBB to enter the CNS, where it promotes spatial learning and memory while preventing anxiety-like behavior or even depression.

Cognitive function and circulating levels of OCN are proposed to inversely correlate with age. Maternal osteocalcin regulates embryonic brain development by enhancing monoamine neurotransmitters and their synthesis.

Clinical observations provide key evidence for a bidirectional communication between brain and bone tissue, which is strongly supported by experimental studies that unraveled underlying mechanistic pathways and identified molecular mediators involved in this crosstalk.”

https://www.mdpi.com/1422-0067/21/14/4946/htm “Crosstalk of Brain and Bone-Clinical Observations and Their Molecular Bases”


The first paper of Vitamin K2 – What can it do? said:

Osteocalcin γ-carboxylation is the main mechanism of action through which Vitamin K2 improves bone health.”

This paper didn’t mention Matrix Gla Protein (MGP) carboxylation, and said a contrary:

“Undercarboxylated, bioactive OCN, initially considered as an inhibitor of bone mineralization, participates in systemic body regulation and homeostasis.”

The 2019 paper cited was Osteocalcin‑GPRC6A: An update of its clinical and biological multi‑organic interactions (Review):

“Osteocalcin is a small protein present in two forms: Carboxylated (cOC) and undercarboxylated (ucOC). Only ucOC can signal as a hormone while cOC cannot.”

It went on to downplay cOC, and also didn’t mention MGP carboxylation.

I think it’s a question of balance. cOC stays in your bones. Carboxylated MGP influences calcium to go into your bones instead of your blood vessel walls. Two good things.

Chew it!

This 2020 human study examined associations between food consumption and chewing difficulty:

“Masticatory function influences not only control of chewing frequency and pressure, but also quality of life through food intake. Reduced food intake caused by chewing difficulty results in loss of eating pleasure and nutritional imbalance.

Chewing difficulty (DC) has been related to brain-related diseases such as cognitive impairment, cerebrovascular disorder, and Parkinson’s disease, increase in occurrence of diseases such as muscular dystrophy, aging acceleration, stomach, and kidney dysfunction due to reduced digestive enzyme secretion, and depression.

Subjects were divided into not difficult in chewing (NDC) and DC groups, with 24.17% being classified into DC. Average age of all subjects (n = 20,959 adult subjects aged between 19 and 64 yrs plus older) was 50.67 yrs. Average age of DC (60.5 yrs) was about 13 yrs older than NDC (47.5 yrs old).

Males and females consumed 35 and 37 items less frequently than the other sex, respectively:

nrp-14-637-g001

Subjects over 65 yrs who had chewing difficulty were 45.4% whereas that of adults was 24.3%. Items known to contain relatively high dietary fiber content or a high content of connective tissues were considered as foods to avoid by those with chewing difficulty due to strong or hard texture.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7683204/ “Food consumption frequency of Korean adults based on whether or not having chewing difficulty using 2013–2016 KNHANES by sex-stratified comparative analysis”


I’d like to know more about subjects who had unresolved dental problems. This study focused on age and sex, but I’ve known twenty-somethings who had problems such as false teeth and dentures.

I go to a dentist twice a year. Don’t think I’d make my gut microbiota happy with Avena nuda oats, broccoli and oat sprouts, and AGE-less chicken vegetable soup if I had dental problems.

One aspect of research on short-chain fatty acids

To further understand An overlooked gut microbiota product, a 2018 rodent study found:

“Microbial metabolites short-chain fatty acids (SCFAs) have been implicated in gastrointestinal functional, neuroimmune regulation, and host metabolism, but their role in stress-induced behavioural and physiological alterations is poorly understood

SCFAs are primarily derived from fermentation of dietary fibres, and play a pivotal role in host gut, metabolic and immune function. All these factors have previously been demonstrated to be adversely affected by stress.

Administration of SCFAs to mice undergoing psychosocial stress alleviated enduring alterations in anhedonia and heightened stress-responsiveness, as well as stress-induced increases in intestinal permeability.

experimental design

SCFA treatment alleviated psychosocial stress-induced alterations in reward-seeking behaviour, and increased responsiveness to an acute stressor and in vivo intestinal permeability. In addition, SCFAs exhibited behavioural test-specific antidepressant and anxiolytic effects, which were not present when mice had also undergone psychosocial stress.”

https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/JP276431 “Short-chain fatty acids: microbial metabolites that alleviate stress-induced brain–gut axis alterations”


One way researchers advance science is to relate aspects of their findings to previous studies. That approach works, but may miss items that weren’t covered in previous research.

This study fed specific quantities of three SCFAs – acetate, butyrate, and propionate – apparently due to previous research findings. If other SCFAs produced by gut microbiota were ignored – like crotonate (aka unsaturated butyrate) – how would that approach advance science?

I found this study from its citation in Harnessing endogenous defenses with broccoli sprouts.

Several diseases, one treatment?

This 2021 review summarized three dietary supplements’ effects on psychiatric symptoms:

“Upregulation of Nrf2 has been suggested as a common therapeutic target for major neuropsychiatric disorders. In this paper, evidence is presented showing how NAC [N-acetyl-cysteine], coenzyme Q10 (CoQ), and melatonin can ameliorate many important effects of oxidative stress by upregulating Nrf2.

Given its key role in governing cellular antioxidant response, upregulation of Nrf2 has been suggested as a common therapeutic target in neuropsychiatric illnesses such as major depressive disorder, bipolar disorder, and schizophrenia. These are associated with chronic oxidative and nitrosative stress, characterised by elevated levels of reactive oxygen species, nitric oxide, and peroxynitrite.

CoQ:

  • Acts as a superoxide scavenger in neuroglial mitochondria;
  • Instigates mitohormesis;
  • Ameliorates lipid peroxidation in the inner mitochondrial membrane;
  • Activates uncoupling proteins;
  • Promotes mitochondrial biogenesis; and
  • Has positive effects on the plasma membrane redox system.

Melatonin:

  • Scavenges mitochondrial free radicals;
  • Inhibits mitochondrial nitric oxidesynthase;
  • Restores mitochondrial calcium homeostasis;
  • Deacetylates and activates mitochondrial SIRT3;
  • Ameliorates increased permeability of the blood-brain barrier and intestine; and
  • Counters neuroinflammation and glutamate excitotoxicity.”

https://www.researchgate.net/publication/348309816_Increasing_Nrf2_Activity_as_a_Treatment_Approach_in_Neuropsychiatry “Increasing Nrf2 Activity as a Treatment Approach in Neuropsychiatry” (registration required)


These reviewers explored three selected supplements, citing 380 references. They overlooked something, though. There was only one mention of sulforaphane in their paper, yet four references’ titles included sulforaphane?

I take two of the three exogenous supplements discussed. The one I stopped taking over a year ago – NAC – was thoroughly discussed, but not in contexts directly related to the Nrf2 transcription factor. Why?

Switch on your Nrf2 signaling pathway pointed out:

“We use NAC in the lab all the time because it stops an Nrf2 activation. So that weak pro-oxidant signal that activates Nrf2, you switch it off by giving a dose of NAC. It’s a potent antioxidant in that right, but it’s blocking signalling. And that’s what I don’t like about its broad use.”

The current review noted that Nrf2 is activated by oxidative stress. NAC is a precursor to glutathione – our main endogenous antioxidant – and neither one activates Nrf2 pathways.

What does? Sulforaphane.

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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)

Eat broccoli sprouts for depression

This 2021 rodent study investigated sulforaphane effects on depression:

“Activation of Nrf2 by sulforaphane (SFN) showed fast-acting antidepressant-like effects in mice by:

  • Activating BDNF;
  • Inhibiting expression of its transcriptional repressors (HDAC2 [histone deacetylase 2, a negative regulator of neuroplasticity], mSin3A, and MeCP2); and
  • Revising abnormal synaptic transmission.

In a mouse model of chronic social defeat stress (CSDS), protein levels of Nrf2 and BDNF in the medial prefrontal cortex and hippocampus were lower than those of control and CSDS-resilient mice. In contrast, protein levels of BDNF transcriptional repressors in CSDS-susceptible mice were higher than those of control and CSDS-resilient mice.

These data suggest that Nrf2 activation increases expression of Bdnf and decreases expression of its transcriptional repressors, which result in fast-acting antidepressant-like actions. Furthermore, abnormalities in crosstalk between Nrf2 and BDNF may contribute to the resilience versus susceptibility of mice against CSDS.

Nrf2-induced BDNF transcription in a model of depression.

  • Stress inhibits Nrf2 expression, which inhibits BDNF transcriptional and leads to abnormal synaptic transmission, causing depression-like behaviors in mice.
  • SFN induces BDNF transcription by activating Nrf2 and correcting abnormal synaptic transmission, resulting in antidepressant-like effects.

In conclusion:

  1. Nrf2 regulates transcription of Bdnf by binding to its exon I promoter.
  2. Inhibition of Nrf2-induced Bdnf transcription may play a role in the pathophysiology of depression.
  3. Activation of Nrf2-induced Bdnf transcription promoted antidepressant-like effects.
  4. Alterations in crosstalk between Nrf2 and BDNF may contribute to resilience versus susceptibility after stress.”

https://www.nature.com/articles/s41398-021-01261-6 “Activation of BDNF by transcription factor Nrf2 contributes to antidepressant-like actions in rodents”


Can a prebiotic help you feel better?

This 2019 rodent study investigated an inulin-type fructo-oligosaccharide (FOS):

“The microbiota-gut-brain axis was used to investigate anti-depressive properties of FOS at the interface of gut microbiota. FOS was introduced via gavage to rats exposed to chronic unpredictable mild stress:

  • FOS alleviated depression-like behaviors and repaired intestinal epithelia damages.
  • FOS treatment lowered corticosterone level.
  • FOS-induced modulation of gut microbiota was more anti-depressive compared to fluoxetine, the standard antidepressant drug.

  • N-Ctrl and M-Ctrl were normal and model control groups which received only water.
  • N-FOS and M-FOS were normal and model rats administrated FOS (50 mg/kg) [human equivalent (50 mg x .162) x 70 kg = 567 mg].
  • M-Flx and M-DP5 rats were model rats given fluoxetine hydrochloride (10 mg/kg) and DP5 compound of FOS (15 mg/kg).

Villi structure was broken for rats in a depression-like state. Mucosal erosion was increased, and the crypt in the small intestinal epithelium was disrupted. Treatment with FOS, DP5 and fluoxetine relieved this damage.

However, a severe side effect was found in the colon of rats that demonstrated apposition to fluoxetine:

  • There was obvious goblet cell loss and inflammatory cells infiltration in the colonic epithelium of fluoxetine treated rats, which showed more severity than in model control rats. Although fluoxetine has high bioavailability, its irritation to gastrointestinal tract may cause inflammation reaction thus lead to colonic destruction.
  • These pathological changes in the intestine were investigated to compare the influence of stress and possible drug irritation to the gastrointestinal tract. Stress had negatively affected microstructure of the small intestine.

Anti-depressant efficacy of FOS was inseparable from and strongly associated with modulation of the host’s gut microbiota.”

https://www.sciencedirect.com/science/article/abs/pii/S0944711319304738 “Fructo-oligosaccharides from Morinda officinalis remodeled gut microbiota and alleviated depression features in a stress rat model” (not freely available)


Forcing people to learn helplessness explored human equivalents of this study’s chronic, unpredictable stress experiments. Related phenotypes and symptoms in humans and animals include:

  • “Social defeat
  • Social avoidance behavior
  • Irritable bowel syndrome
  • Depression
  • Anxiety
  • Anhedonia
  • Increased hypothalamic-pituitary-adrenal (HPA)-axis sensitivity
  • Visceral hypersensitivity.”

These researchers spent a lot of time and effort comparing microbiota categories. The point for people, though, is how we feel.

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The future of your brain is in your gut right now

A 2020 paper by the author of Sulforaphane: Its “Coming of Age” as a Clinically Relevant Nutraceutical in the Prevention and Treatment of Chronic Disease:

“The gut and brain communicate bidirectionally via several pathways which include:

  1. Neural via the vagus nerve;
  2. Endocrine via the HPA axis;
  3. Neurotransmitters, some of which are synthesized by microbes;
  4. Immune via cytokines; and
  5. Metabolic via microbially generated short-chain fatty acids.

How does nature maintain the gut-microbiome-brain axis? Mechanisms to maintain homeostasis of intestinal epithelial cells and their underlying cells are a key consideration.

The symbiotic relationship that exists between microbiota and the human host is evident when considering nutrient requirements of each. The host provides food for microbes, which consume that food to produce metabolites necessary for health of the host.

Consider function of the human nervous system, not in isolation but in integration with the gastrointestinal ecosystem of the host, in expectation of a favorable impact on human health and behavior.”

https://www.sciencedirect.com/science/article/pii/B9780128205938000148 “Chapter 14 – The gut microbiome: its role in brain health” (not freely available)


Always more questions:

  1. What did you put into your gut today?
  2. What type of internal environment did it support?
  3. What “favorable impact on human health and behavior” do you expect from today’s intake?
  4. How will you feel?
  5. Will you let evidence guide feeding your gut environment?

See Harnessing endogenous defenses with broccoli sprouts for further elaboration. See Switch on your Nrf2 signaling pathway for an interview with these papers’ author.

How will you feel?

Consider this a partial repost of Moral Fiber:

“We are all self-reproducing bioreactors. We provide an environment for trillions of microbes, most of which cannot survive for long without the food, shelter and a place to breed that we provide.

They inhabit us so thoroughly that not a single tissue in our body is sterile. Our microbiome affects our development, character, mood and health, and we affect it via our diet, medications and mood states.

The microbiome:

  • Affects our thinking and our mood;
  • Influences how we develop;
  • Molds our personalities;
  • Our sociability;
  • Our responses to fear and pain;
  • Our proneness to brain disease; and
  • May be as or more important in these respects than our genetic makeup.

Dysbiosis has become prevalent due to removal of prebiotic fibers from today’s ultra-processed foods. I believe that dietary shift has created a generation of humans less able to sustain or receive love.

They suffer from reduced motivation and lower impulse control. They are more anxious, more depressed, more selfish, more polarized, and therefore more susceptible to the corrosive politics of identity.


Other recent blog posts by Dr. Paul Clayton and team include Skin in The Game and Kenosha Kids.

Image from Thomas Cole : The Consummation, The Course of the Empire (1836) Canvas Gallery Wrapped Giclee Wall Art Print (D4060)

A case for carnitine supplementation

This 2020 review subject was carnitine, acetyl-L-carnitine, and its other molecular forms:

“Carnitine is necessary to deliver long-chain fatty acids from cytosol into mitochondria. Carnitine homeostasis is maintained by diet and renal absorption, as only a small amount (about 25%) is obtained by endogenous biosynthesis.

Defective fatty acid oxidation occurs with reduced intracellular levels of carnitine, leading to glucose consumption instead of lipid consumption, resulting in hypoglycemia. Non-metabolized lipids accumulate in tissues such as heart, skeletal muscle, and liver, resulting in myopathy and hepatic steatosis.

2000 mg/day is unlikely to provoke unwanted side effects and is safe for humans. In-depth studies are needed to identify a unique method of analysis which can guarantee efficient monitoring of supplement active component amounts.”

https://www.mdpi.com/1420-3049/25/9/2127/htm “The Nutraceutical Value of Carnitine and Its Use in Dietary Supplements”


The review listed animal studies of L-carnitine alone and in combination with:

  • Vitamin D3;
  • Coenzyme Q10;
  • Nicotinamide riboside;
  • Selenium;
  • L-arginine;
  • Anti-histamine drugs cetirizine hydrochloride and chlorpheniramine maleate; and
  • Hypertension drug olmesartan.

Human studies of its effects included:

  • Muscle soreness, damage biomarkers, and cramps;
  • Osteoarthritis knee pain and inflammation markers;
  • Ischemic cerebrovascular injury;
  • Peripheral neuropathy;
  • Nonalcoholic fatty liver disease;
  • Insulin resistance and Type 2 diabetes;
  • Kidney diseases;
  • Inherited diseases phenylketonuria and maple syrup urine;
  • Stress, depression, and anxiety;
  • Male infertility; and
  • Hepatitis C.

Clearing out the 2020 queue of interesting papers

I’ve partially read these 39 studies and reviews, but haven’t taken time to curate them.

Early Life

  1. Intergenerational Transmission of Cortical Sulcal Patterns from Mothers to their Children (not freely available)
  2. Differences in DNA Methylation Reprogramming Underlie the Sexual Dimorphism of Behavioral Disorder Caused by Prenatal Stress in Rats
  3. Maternal Diabetes Induces Immune Dysfunction in Autistic Offspring Through Oxidative Stress in Hematopoietic Stem Cells
  4. Maternal prenatal depression and epigenetic age deceleration: testing potentially confounding effects of prenatal stress and SSRI use
  5. Maternal trauma and fear history predict BDNF methylation and gene expression in newborns
  6. Adverse childhood experiences, posttraumatic stress, and FKBP5 methylation patterns in postpartum women and their newborn infants (not freely available)
  7. Maternal choline supplementation during the third trimester of pregnancy improves infant information processing speed: a randomized, double‐blind, controlled feeding study
  8. Preterm birth is associated with epigenetic programming of transgenerational hypertension in mice
  9. Epigenetic mechanisms activated by childhood adversity (not freely available)

Epigenetic clocks

  1. GrimAge outperforms other epigenetic clocks in the prediction of age-related clinical phenotypes and all-cause mortality (not freely available)
  2. Epigenetic age is a cell‐intrinsic property in transplanted human hematopoietic cells
  3. An epigenetic clock for human skeletal muscle
  4. Immune epigenetic age in pregnancy and 1 year after birth: Associations with weight change (not freely available)
  5. Vasomotor Symptoms and Accelerated Epigenetic Aging in the Women’s Health Initiative (WHI) (not freely available)
  6. Estimating breast tissue-specific DNA methylation age using next-generation sequencing data

Epigenetics

  1. The Intersection of Epigenetics and Metabolism in Trained Immunity (not freely available)
  2. Leptin regulates exon-specific transcription of the Bdnf gene via epigenetic modifications mediated by an AKT/p300 HAT cascade
  3. Transcriptional Regulation of Inflammasomes
  4. Adipose-derived mesenchymal stem cells protect against CMS-induced depression-like behaviors in mice via regulating the Nrf2/HO-1 and TLR4/NF-κB signaling pathways
  5. Serotonin Modulates AhR Activation by Interfering with CYP1A1-Mediated Clearance of AhR Ligands
  6. Repeated stress exposure in mid-adolescence attenuates behavioral, noradrenergic, and epigenetic effects of trauma-like stress in early adult male rats
  7. Double-edged sword: The evolutionary consequences of the epigenetic silencing of transposable elements
  8. Blueprint of human thymopoiesis reveals molecular mechanisms of stage-specific TCR enhancer activation
  9. Statin Treatment-Induced Development of Type 2 Diabetes: From Clinical Evidence to Mechanistic Insights
  10. Rewiring of glucose metabolism defines trained immunity induced by oxidized low-density lipoprotein
  11. Chronic Mild Stress Modified Epigenetic Mechanisms Leading to Accelerated Senescence and Impaired Cognitive Performance in Mice
  12. FKBP5-associated miRNA signature as a putative biomarker for PTSD in recently traumatized individuals
  13. Metabolic and epigenetic regulation of T-cell exhaustion (not freely available)

Aging

  1. Molecular and cellular mechanisms of aging in hematopoietic stem cells and their niches
  2. Epigenetic regulation of bone remodeling by natural compounds
  3. Microglial Corpse Clearance: Lessons From Macrophages
  4. Plasma proteomic biomarker signature of age predicts health and life span
  5. Ancestral stress programs sex-specific biological aging trajectories and non-communicable disease risk

Broccoli sprouts

  1. Dietary Indole-3-Carbinol Alleviated Spleen Enlargement, Enhanced IgG Response in C3H/HeN Mice Infected with Citrobacter rodentium
  2. Effects of caffeic acid on epigenetics in the brain of rats with chronic unpredictable mild stress
  3. Effects of sulforaphane in the central nervous system
  4. Thiol antioxidant thioredoxin reductase: A prospective biochemical crossroads between anticancer and antiparasitic treatments of the modern era (not freely available)
  5. Quantification of dicarbonyl compounds in commonly consumed foods and drinks; presentation of a food composition database for dicarbonyls (not freely available)
  6. Sulforaphane Reverses the Amyloid-β Oligomers Induced Depressive-Like Behavior (not freely available)

Natural sources of melatonin

This 2020 review subject was melatonin:

“The emergence of naturally occurring melatonin and its isomers in fermented foods has opened an exciting new research area. Melatonin is a hormone, an indolamine that predominantly appears in plants, microorganisms, and mammals.

The precursor of this molecule is solely the amino acid L‐tryptophan. Melatonin ensures a circadian and seasonal signal to vertebrate organisms; it is synthesized through a cascade of enzymatic reactions producing melatonin from serotonin in its final phases. The synthesis of melatonin is observed in almost all organs.

One melatonin molecule has the capacity to scavenge up to 10 ROS versus the other antioxidants that scavenge 1 or even less ROS. Melatonin antioxidant properties are accomplished with the indole ring that stimulates enzyme production (i.e., superoxide dismutase (SOD), glutathione‐peroxidase (Gpx), and catalase (CAT)), which mitigate free radicals to less toxic substances.

In addition to antioxidant properties, it plays a fundamental role in the modulation of various physiological functions, including circadian rhythmicity, bone integrity, and functionalization of the human reproductive system.

The presence of melatonin and its isomers is not exclusive for grapes and grape‐derived products. Other fruits such as sweet and sour cherries and fermented juices of orange and pomegranate may be also of interest.”

https://onlinelibrary.wiley.com/doi/full/10.1111/1541-4337.12639 “Naturally occurring melatonin: Sources and possible ways of its biosynthesis”


Unraveling oxytocin – is it nature’s medicine?

This 2020 review attempted to consolidate thousands of research papers on oxytocin:

“Chemical properties of oxytocin make this molecule difficult to work with and to measure. Effects of oxytocin are context-dependent, sexually dimorphic, and altered by experience. Its relationship to a related hormone, vasopressin, have created challenges for its use as a therapeutic drug.

Widely used medical interventions i.e.:

  • Exogenous oxytocin, such as Pitocin given to facilitate labor;
  • Opioid medications that block the oxytocin system; or
  • Cesarean sections that alter exposure to endogenous oxytocin

have lasting consequences for the offspring and/or mother.

Such exposures hold the potential to have epigenetic effects on the oxytocin systems, including changes in DNA methylation. These changes in turn would have lasting effects on the expression of receptors for oxytocin, leaving individuals differentially able to respond to oxytocin and also possibly to the effects of vasopressin.

Regions with especially high levels of OXTR [oxytocin receptor gene] are:

  • Various parts of the amygdala;
  • Bed nucleus of the stria terminalis;
  • Nucleus accumbens;
  • Brainstem source nuclei for the autonomic nervous system;
  • Systems that regulate the HPA axis; as well as
  • Brainstem tissues involved in pain and social attention.

Oxytocin protects neural cells against hypoxic-ischemic conditions by:

  • Preserving mitochondrial function;
  • Reducing oxidative stress; and
  • Decreasing a chromatin protein that is released during inflammation

which can activate microglia through the receptor for advanced glycation end products (RAGE). RAGE acts as an oxytocin-binding protein facilitating the transport of oxytocin across the blood-brain barrier and through other tissues.

Directionality of this transport is 5–10 times higher from the blood to the brain, in comparison with brain to blood transport. Individual differences in RAGE could help to predict cellular access to oxytocin and might also facilitate access to oxytocin under conditions of stress or illness.

Oxytocin and vasopressin and their receptors are genetically variable, epigenetically regulated, and sensitive to stressors and diet across the lifespan. As one example, salt releases vasopressin and also oxytocin.

Nicotine is a potent regulator of vasopressin. Smoking, including prenatal exposure of a fetus, holds the potential to adjust this system with effects that likely differ between males and females and that may be transgenerational.

Relative concentrations of endogenous oxytocin and vasopressin in plasma were associated with:

These studies support the usefulness of measurements of both oxytocin and vasopressin but leave many empirical questions unresolved.

The vast majority of oxytocin in biosamples evades detection using conventional approaches to measurement.”

https://pharmrev.aspetjournals.org/content/pharmrev/72/4/829.full.pdf “Is Oxytocin Nature’s Medicine?”


I appreciated efforts to extract worthwhile oxytocin research from countless poorly performed studies, research that wasted resources, and research that actually detracted from science.

I was disappointed that at least one of the reviewers didn’t take this review as an opportunity to confess their previous wastes like three flimsy studies discussed in Using oxytocin receptor gene methylation to pursue an agenda.

Frank interpretations of one’s own study findings to acknowledge limitations is one way researchers can address items upfront that will be questioned anyway. Such analyses also indicate a goal to advance science.

Although these reviewers didn’t provide concrete answers to many questions, they highlighted promising research areas, such as:

  • Improved approaches to oxytocin measurements;
  • Prenatal epigenetic experience associations with oxytocin and OXTR; and
  • Possible transgenerational transmission of these prenatal epigenetic experiences.

Sleep

If you can stand the woo of two Californians trying to outwoo each other, listen to these five podcasts with a sleep scientist.

https://peterattiamd.com/matthewwalker1/

“Ambien, sedation, hypnotives, are not sleep.

Sleep is a life support system. It’s the Swiss army knife of health.

Lack of sleep is like a broken water pipe in your home that leaks down into every nook and cranny of your physiology.

Sleep research is not being transmitted to clinical practice.”


I live on the US East Coast. Hyperbole in normal conversations outside of urban centers is an exception.

It’s different on the West Coast. For example:

  • Interviewer assertions regarding heart rate variability should be compared and contrasted with Dead physiological science zombified by psychological research evidence that:

    “A broad base of further evidence was amassed within human cardiac, circulatory, and autonomic physiology such that the hypotheses do not work as described.”

  • Interviewer favorable comments for MDMA (Ecstasy) “to deal with issues of underlying trauma, anxiety, and depression.”