Blanching broccoli sprouts

July 14, 2022July 15, 2022 gettingwell4 2-3 stars Required further work, Acetylcholine, Epigenetics, Immune system, Neurochemicals, Stress Brain neurons, Control group, Genetic factors

Three 2022 papers of interest cited Sulforaphane: Its “Coming of Age” as a Clinically Relevant Nutraceutical in the Prevention and Treatment of Chronic Disease. Let’s start with a fairly straightforward analysis of blanching broccoli sprouts to produce sulforaphane:

“We investigated the effect of blanching conditions to determine the optimal treatment that maximizes sulforaphane (SFN) content in broccoli sprouts. Broccoli seeds grown under controlled conditions were harvested after 11 days from germination and subjected to different blanching conditions based on a central composite design with temperature and time as experimental factors.

Optimum conditions were blanching at 61 °C for 4.8 min, resulting in 54.3 ± 0.20 µmol SFN/g dry weight, representing a 3.3-fold increase with respect to untreated sprouts. This is the highest SFN content reported for sprouts subjected to any treatment so far.

Broccoli sprouts (20 g) were put in plastic bags, which were vacuum-sealed, and then subjected to time (3.4–11 min)–temperature (32–88 °C) combinations.

Blanching at 60 °C for less than 8 min resulted in the highest SFN content.

Above this temperature, SFN content decreases.

The exceptionally high values obtained in this work may be related to treatment, but also to broccoli cultivar and culture conditions.

Different broccoli tissues and developmental stages express different myrosinase isoforms, and catalytic properties of the enzyme may vary among different tissues. Myrosinase found in broccoli florets has an optimal temperature of around 40 °C, and considering myrosinases from other sources, this temperature may vary between 30 and 70 °C.”

https://www.mdpi.com/2304-8158/11/13/1906/htm “Maximization of Sulforaphane Content in Broccoli Sprouts by Blanching”

This first study used heat-only techniques similar to the uncited Enhancing sulforaphane content. It similarly found a 60°C (140°F) myrosinase cliff as have many other uncited studies.

A second paper was a rodent study:

“We investigated the role of sulforaphane, a well-known NRF2 activator, on age-related mitochondrial and kidney dysfunction. Young (2–4 month) and aged (20–24 month) male Fischer 344 rats were treated with sulforaphane (15 mg/kg body wt/day) in drinking water for four weeks.

Sulforaphane significantly improved mitochondrial function and ameliorated kidney injury by increasing cortical NRF2 expression and activity and decreasing protein expression of KEAP1, a NRF2 repressor. Sulforaphane treatment did not affect renal NRF2 expression or activity and mitochondrial function in young rats.”

https://www.mdpi.com/2076-3921/11/1/156/htm “Age-Related Mitochondrial Impairment and Renal Injury Is Ameliorated by Sulforaphane via Activation of Transcription Factor NRF2”

A human equivalent to this second study’s daily dose was intolerable at (.162 x 15 mg) x 70 kg = 170 mg. I curated this study anyway just to show an example of negligible treatment effects in young animals even when a dose is too high for humans.

A third paper was a review that focused on sulforaphane and its analogs’ chemistry:

“Analysis of the Web of Science database shows that, since 1992, about 3,890 articles have been published on SFN, and over 5,600 on isothiocyanates. Its natural analogs include iberin, alyssin, iberverin, erucin, berteroin, cheirolin, and erysolin.

SFN is a biologically active, natural isothiocyanate found in cruciferous vegetables, and is non-toxic. It has been selected for phase I and II clinical trials, where it is administered in the form of an extract or broccoli sprouts. There are no differences in biological activity between SFN and its natural analogs, such as erucin or alyssin.

No synthetic analogs of SFN described in this review qualified for clinical trials. This is likely due to the toxicity of these compounds in higher doses.”

https://www.mdpi.com/1420-3049/27/5/1750/htm “Sulforaphane and Its Bifunctional Analogs: Synthesis and Biological Activity”

Supplement evidence and counter-evidence

July 9, 2022July 10, 2022 gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Immune system, Stress Control group, Genetic factors

Three 2022 papers, starting with a rabbit study of dietary supplements:

“Adding native type II collagen (NC) to the combination of chondroitin sulfate (CS), glucosamine hydrochloride (GlHCl), and hyaluronic acid (HA) showed improvements on osteoarthritis progression. Disease progression was monitored at different time points using magnetic resonance imaging biomarkers, measurement of hyaluronic acid in synovial fluid, and macroscopic and microscopic evaluations of cartilage, synovial membrane and subchondral bone.

CTR (control group–no treatment), CGH (60.38 mg/kg CS + 75.47 mg/kg GlHCl + 3.35 mg/kg HA) and CGH-NC (60.38 mg/kg CS + 75.47 mg/kg GlHCl + 3.35 mg/kg HA + 0.67 mg/kg NC). Clearer colors result in an increase of the frequency of each stage of the disease. Significant differences can be appreciated in the CGH-NC group, compared to the other groups over time.

Oral administration of CS with GlHCl and HA, with or without NC, is safe, and provides significant improvements in OA progression. Adding NC leads to better outcomes seen on macroscopic and microscopic evaluation and MRI biomarkers.”

https://www.mdpi.com/2076-2615/12/11/1401/htm “Improved Joint Health Following Oral Administration of Glycosaminoglycans with Native Type II Collagen in a Rabbit Model of Osteoarthritis”

A rodent study of bone growth and similar dietary supplements taken separately found pretty much the opposite:

“Female C57BL/6 mice bred in house were used. Starting at 11 weeks of age, animals were given dietary supplements of either hydrolyzed type I collagen at 1 g/kg, glucosamine sulfate potassium chloride at 300 mg/kg, chondroitin sulfate sodium salt at 250 mg/kg, or fish oil at 1 g/kg. These values were calculated using a body surface area (BSA) calculation from human dosage values of 81.1 mg/kg for collagen, 24.3 mg/kg for glucosamine, 20.3 mg/kg for chondroitin sulfate and 81.1 mg/kg for fish oil.

Our findings indicate that dietary supplements had little impact on bone morphology or mechanics in young female mice and cannot be used to improve bone’s fracture resistance. Bone quality, inferred from material-level mechanical properties and fracture toughness, did not improve with treatment. The only alteration in bone quality was a decrease in elastic modulus with glucosamine or fish oil, which is considered negative and would not be advantageous in preventing fracture.

These data suggest that adding more basic components of the bone matrix into the diet of growing mice does not improve quality of bone tissue. Dietary supplements may be more beneficial in individuals without a balanced diet or in those with an increased risk of fracture, such as those experiencing estrogen loss.”

https://www.nature.com/articles/s41598-022-14068-2 “Dietary supplements do not improve bone morphology or mechanical properties in young female C57BL/6 mice”

This second study cited a 2015 article Translating dosages from animal models to human clinical trials—revisiting body surface area scaling in this context:

“Dosage in this study was determined by using the BSA formula. This technique does have its drawbacks as it does not take into differences in murine metabolism as discussed more in depth elsewhere, but the lack of pharmacokinetic data for dietary supplements in mice prevented a more complex conversion.”

That article has been cited many times, including in a 2022 review:

“Dose-based methodologies for predicting human clinical doses from preclinical data were assessed for oncology drugs. BSA-based approaches were predictive for small molecule oncology drugs, in particular for kinase inhibitors and cytotoxic agents, but prediction was poor for drugs with immune and endocrine components to their mechanisms.

BSA conversion of doses was clearly inappropriate for large molecules. Direct mg/kg-based prediction was more relevant to large molecules with molecular weight > 100 kDa and in particular antibody-drug conjugates.

This approach is theoretically applicable to other therapeutic areas, and if validated in other therapeutic areas, may provide an easy estimate of clinical doses early in the drug discovery and development process to facilitate compound selection and risk management. Later in the drug development process, dose-based methods should be superseded by exposure- and mechanism-based methodologies whenever possible.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9087189/ “Predicting Approximate Clinically Effective Doses in Oncology Using Preclinical Efficacy and Body Surface Area Conversion: A Retrospective Analysis”

I’ve used body surface area calculations for human equivalent doses, for example, the small molecule sulforaphane at 177.3 g / mol or 177 Da.

Three of the first study’s human equivalent doses can be calculated by the body surface area factor 0.324 for rabbits since molecular weight of chondroitin sulfate is 463.37 g / mol, glucosamine hydrochloride is 215.63 g / mol, and hyaluronic acid is 403.31 g / mol. Human equivalent doses are:

Chondroitin sulfate (.324 x 60.38 mg) x 70 kg = 1,369 mg;
Glucosamine hydrochloride (.324 x 75.47 mg) x 70 kg = 1,712 mg; and
Hyaluronic acid (.324 x 3.35 mg) x 70 kg = 76 mg.

These three weights are all close to supplement weights advertised to be effective.

Undenatured type II collagen in the first study is 300 kDa, and hydrolyzed type I collagen in the second study varies from 0.3 to 8 kDa. Per the third paper’s recommendation of using mg/kg calculations for large molecules, human equivalent doses would be (0.67 mg x 70 kg) = 47 mg for type II and (81.1 mg x 70 kg) = 5,677 mg for type I, respectively. These two weights are also close to supplement weights advertised to be effective.

Eat broccoli sprouts for your gut

July 4, 2022August 1, 2022 gettingwell4 5+ stars Premium, Epigenetics, Immune system, Stress Control group, Genetic factors

Two 2022 papers, starting with a review of sulforaphane’s effects on intestinal inflammation:

“This review summarizes characteristics of intestinal inflammation, the anti-inflammatory mechanism of sulforaphane (SFN) and its various protective effects on intestinal inflammation, and possible future applications of SFN for promoting intestinal health.

SFN is an effective agonist of Nrf2, and it is also able to inhibit expression of inflammation-related genes by activating Nrf2. This kind of anti-inflammatory mechanism has already been confirmed in treatment of intestinal mucositis using SFN.

The main absorption site of SFN after oral administration is the small intestine, and its achievable dose for the hind intestine may be lower than the expected dose. Although absorbed SFN can reach the large intestine through intestinal blood and other transportation routes, its therapeutic effect on target tissues may not be as efficient as it would be when the expected dose is directly absorbed by hindgut cells.

Considering that there are several predisposing factors that lead to intestinal inflammation, more research on the effect of SFN on intestinal inflammation with different causes and characteristics should be carried out. Appropriate carriers should be selected according to the onset site and related physiological environment, and a scientific and effective intestinal targeted delivery system for SFN needs to be developed.”

https://pubs.rsc.org/en/content/articlelanding/2022/FO/D1FO03398K “The functional role of sulforaphane in intestinal inflammation: a review” (not freely available). Thanks to Professor Lei Zheng for providing a copy.

Reference 89 – Sulforaphane Normalizes Intestinal Flora and Enhances Gut Barrier in Mice with BBN-Induced Bladder Cancer (not freely available) – in the above graphic was cited for:

“The effect of SFN intervention on intestinal injury in mice with bladder cancer was investigated. It was found that SFN significantly reduced tissue damage in the colon and cecum of mice and normalized the imbalance in intestinal flora caused by BBN, which manifested as an increase in Bacteroides fragilis and Clostridium cluster 1, thus promoting SCFA production.

SFN administration upregulated expression of tight junction proteins including ZO-1, occludin, claudin-1 and glucagon-like peptide 2 (GLP2) to repair damage of mucosal epithelium of the colon and caecum, while reducing release of IL-6 and the secreted immunoglobulin A (SIgA). This study showed for the first time SFN’s alleviating effect on intestinal inflammation may be produced by regulating intestinal flora structure, suggesting that the protective effect of SFN on intestinal health could be multidirectional.”

That study’s 2022 follow-on rodent study also used oral sulforaphane doses:

“This study was undertaken to assess the potential efficacy of SFN in ameliorating dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice and to elucidate underlying mechanisms.

Male C57BL/6 mice were treated with various doses of SFN (2.5, 5, 10, and 20 mg/kg body weight). In DSS colitis mice, the hallmarks of disease observed as shortened colon lengths, increased disease activity index scores and pathological damage, higher proinflammatory cytokines and decreased expression of tight junction proteins, were alleviated by SFN treatment.

5, 10, and 20 mg/kg/day of SFN treatment significantly ameliorated inflammatory damage in mice colon tissue when compared to the colitis group.

5, 10, and 20 mg/kg/day of SFN remarkably mitigated morphological alterations and protected colonic tissue integrity.

Nrf2 expression was increased significantly by 5, 10, and 20 mg/kg/day of SFN treatment.

SFN partially restored perturbed gut microbiota composition, and increased production of volatile fatty acids (especially caproic acid) induced by DSS administration.

The contents of butyric acid, iso-butyric acid, valeric acid, and iso-valeric acid were all decreased in DSS-induced colitis mice and in 2.5 mg/kg/day of the SFN treatment group, whereas this decreased tendency was reversed by 10 and 20 mg/kg/day of SFN.

A proposed mechanism by which SFN protects against colitis:

Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), Signal Transducer and Activator of Transcription 3 (STAT3), and Phase II enzyme UDP-glucuronosyltransferase (UGT) were involved in the protective effect of SFN against DSS-induced colitis.

Nrf2 activation followed by STAT3 signaling pathway play a pivotal role in the protective effect of SFN on colitis. SFN can be considered a potential candidate in the treatment of IBD.”

https://www.frontiersin.org/articles/10.3389/fnut.2022.893344/full “The Protective Effect of Sulforaphane on Dextran Sulfate Sodium-Induced Colitis Depends on Gut Microbial and Nrf2-Related Mechanism”

A human equivalent dose of the second paper’s oral dose of 20 mg sulforaphane / kg body weight is (.081 x 20 mg) x 70 kg = 113 mg. Per Estimating daily consumption of broccoli sprout compounds, I ate about half that every day by microwaving 3-day-old broccoli sprouts through Week 56, when I cut back to about 35 mg a day. I dialed that back in Week 87 to about 17 mg a day (100 μmol), which is used in a plethora of studies.

I’ve never had ulcerative colitis or inflammatory bowel disease. If I would be diagnosed with either, it would take about five minutes to get back to this study’s equivalent of 10 mg / kg body weight with broccoli seeds and sprouts.

Doubling that to 20 mg may involve taking supplements, though. Haven’t checked for commercial availability lately, but I’ve read a dozen or so studies on encapsulating sulforaphane so that it could reach the colon.

Green light for BBQ?

July 4, 2022July 4, 2022 gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Stress Control group, Genetic factors

Two 2022 papers from a clinical trial investigating dietary AGEs’ effects in middle-age people:

“A 4-week diet low or high in AGEs has no effect on insulin sensitivity, secretion, or clearance; vascular function; or overall inflammation in abdominally obese but healthy individuals. These findings require validation in large prospective cohort studies and in populations with established disease such as diabetes and kidney failure.

Our broad array of null findings are not in agreement with those of previous animal and human studies. In mice, baked chow diets high in AGEs led to impaired insulin secretion, insulin resistance and T2DM, and arterial stiffness.

However, usage of baked chow diets may have led to other effects than solely increasing dietary AGEs, such as decreased vitamin bioavailability and increased acrylamide formation. Additionally, AGE levels in baked chow may be higher than those in human food.

The present study has several potential limitations. Most importantly, because of the relatively short intervention duration of 4 weeks, we are unable to draw conclusions on longer-term effects of a diet low or high in AGEs.”

https://insight.jci.org/articles/view/156950 “A 4-week high-AGE diet does not impair glucose metabolism and vascular function in obese individuals”

A second paper investigated the trial’s gut microbiota changes:

“A 4-week diet low or high in AGEs has a limited impact on gut microbial composition of abdominally obese humans, paralleling its previously observed limited biological consequences. In contrast, habitual intake of dicarbonyls, reactive precursors of AGEs, was associated with both lower and higher abundances of several genera.

We cannot exclude the possibility that increased intake of dicarbonyls in the high-AGE group influenced our results. Although we observed very limited effects of intervention diets on our outcomes overall, there was an increase in plasma adiponectin after high- compared to low-AGE diet.

Potentially, this was a result of increased intake of dicarbonyls rather than AGEs. Interestingly, most associations between habitual intake of dicarbonyls and genera abundance were not shared between individual dicarbonyls, suggesting unique relationships.

Limitations of our trial:

A 4-week diet may be too short to result in changes in the gut microbial composition;

Analysis of 16S rRNA instead of metagenomics sequencing;

Focus on markers based on relative abundance instead of absolute abundance;

It is possible that any beneficial effects of the low-AGE diet on insulin sensitivity were counteracted by less favorable effects on the gut microbiota, ultimately leading to no change in insulin sensitivity after the low- versus the high-AGE diet;

We did not measure short and branched chain fatty acids, which could have provided more insight into biological relevance of these associations as well as changes in genera abundance after the low- and high-AGE diets;

Regarding estimations of habitual dicarbonyl intake, FFQs may be prone to recall bias, and no FFQ so far has been validated for estimating dicarbonyl intake; and

Low- and high-AGE diets were not matched for their glycemic load and index, and these factors may influence endogenous formation of AGEs.”

https://www.mdpi.com/1422-0067/23/10/5328/htm “A 4-Week Diet Low or High in Advanced Glycation Endproducts Has Limited Impact on Gut Microbial Composition in Abdominally Obese Individuals: The deAGEing Trial”

Some previous curations explored topics related to these papers:

All about AGEs stated: “AGEs and their precursors cannot be grouped together. Specific, individual information is required for a proper evaluation.”
Resistant starch therapy stated: “Microbiome sequencing data are compositional, meaning that gene amplicon read counts do not necessarily reflect bacterial absolute abundances. Instead, read counts are typically normalized to sum to 100%. For this reason, relative abundances of smaller keystone communities (e.g. primary degraders) may increase, but appear to decrease simply because cross-feeders increase in relative abundance to a greater extent. These limitations illustrate the necessity of sufficiently powering RS interventions where microbiome composition is the primary endpoint, collecting critical baseline data and employing appropriate statistical techniques.”
Rodent studies mentioned in Caloric restriction’s epigenetic effects and Effects of advanced glycation end products on quality of life and lifespan relied on AGEs in baked chow diets for their findings; and
Nano-sulforaphane vs. barbecue chemicals stated: “Women at the early stage of pregnancy should avoid barbecue.”

Happy Independence Day!

The soluble receptor for AGEs

July 3, 2022 gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Immune system, Stress Control group, Genetic factors

Two 2022 human studies on sRAGE, starting with one of hypoxia-related diseases:

“The receptor for advanced glycation end products is found on endothelial and inflammatory cell surfaces. It binds to circulating advanced glycation end products, activating a proinflammatory protein cascade that contributes to systemic oxidative stress and inflammation.

sRAGE is the soluble isoform of RAGE and acts as a protective decoy by buffering inflammatory ligands, decreasing inflammatory injury. Therefore, low levels of sRAGE are a biomarker of deficient inflammatory control.

We show that plasma concentrations of the anti-inflammatory molecule sRAGE are reduced in patients with chronic obstructive pulmonary disease (COPD) and in patients with obstructive sleep apnoea (OSA). Overlap of COPD and OSA does not lead to an additive effect.

Effective treatment by continuous positive airway pressure (CPAP) of subjects with obstructive apnoeas (with or without associated COPD) increases the level of sRAGE, while in healthy subjects and COPD without OSA, these levels do not change over time. This is the first study to investigate the effect of CPAP on plasma levels of sRAGE.”

https://respiratory-research.biomedcentral.com/articles/10.1186/s12931-022-02092-9 “Soluble RAGE in COPD, with or without coexisting obstructive sleep apnoea”

A second study introduced sRAGE isoforms:

“We explored associations of circulating levels of soluble RAGE, its endogenous secretory (esRAGE) and cleaved (cRAGE) isoforms, AGEs, and their respective ratios with 15-year all-cause mortality in type 2 diabetes. The potential prognostic value of sRAGE as a marker of disease and occurrence of adverse events seems to be suitable for individuals with chronic disease or multimorbidity, and not for the general population.

Baseline AGEs and sRAGE isoforms concentration were measured by ELISA in 362 patients with type 2 diabetes and in 125 age- and gender-matched healthy control subjects. At an average follow-up of 15 years, 130 deaths [in T2D subjects] were observed.

A nomogram based on age, sex, HbA1c, systolic blood pressure, and the AGEs/cRAGE ratio was built to predict 5-, 10- and 15-year survival in type 2 diabetes. Kaplan-Meier survival function for patients with type 2 diabetes grouped according to quartiles of the nomogram-based mortality risk score:

An increase in the AGEs/cRAGE ratio was accompanied by a higher risk of all-cause mortality in patients with type 2 diabetes. The AGEs/cRAGE ratio led to a significant, albeit modest, improvement in the already established RECODe model of predicting 10-year all-cause mortality in type 2 diabetes based on age, sex, ethnicity, smoking, systolic blood pressure, history of major adverse cardiovascular events (MACE), HbA1c, total cholesterol, HDL-C, serum creatinine, and urinary albumin-to-creatinine ratio.

While none of the parameters was significantly associated with development of any complication in patients without complications at the time of enrollment, sRAGE was associated with the development of MACE over a 15-year follow-up in patients with type 2 diabetes who had no history of MACE at recruitment.”

https://cardiab.biomedcentral.com/articles/10.1186/s12933-022-01535-3 “Circulating levels of AGEs and soluble RAGE isoforms are associated with all-cause mortality and development of cardiovascular complications in type 2 diabetes: a retrospective cohort study”

AGEs in skin

July 3, 2022 gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Stress Control group, Genetic factors, Neurodegenerative disease

Here are two 2022 human studies that non-invasively measured advanced glycation end products in skin, starting with one investigating AGEs, carotenoids, and glaucoma:

“This study is the first to simultaneously estimate AGE and skin carotenoid (SC) levels using fingertip sensors in patients with glaucoma.

Elevated intraocular pressure (IOP) is a major risk factor, and lowering IOP through medication or surgery is the main therapeutic option. Numerous risk factors, such as genetics, inflammation, ocular blood flow, and oxidative stress have been proposed by diverse nonclinical and clinical studies; however, the only reliable parameter used in clinical practice is IOP.

Most carotenoids, such as α- and β-carotenes, β-cryptoxanthin, lycopene, lutein, and zeaxanthin, have a maximal absorption wavelength of around 480 nm; therefore, the carotenoid score reflects the bulk of these carotenoid molecules. Intraocular levels of lutein, (3R,3′R)-zeaxanthin, and meso-(3R,3′S)-zeaxanthin, the only carotenoids present in macular pigment, and their antioxidant activity are difficult to estimate directly.

Although carotenoid levels reflect previous intake of vegetables, this lifestyle factor is also difficult to determine. Given that SC levels were mainly associated with vegetable intake for about 1 month, SC can be a good endpoint to assess roles of carotenoids in various diseases in clinical situations.

We found that low SC levels were associated with:

Male gender;

History of intraocular surgery;

Current smoking status;

Diabetes;

Low vegetable intake score; and

High levels of AGEs.

No significant association with glaucoma type was detected. However, AGE levels were higher in exfoliation glaucoma than primary open-angle glaucoma and controls.”

https://www.mdpi.com/2076-3921/11/6/1138/htm “Fingertip-Measured Skin Carotenoids and Advanced Glycation End Product Levels in Glaucoma”

A second study focused on cardiovascular risk:

“AGEs cause arterial stiffness by two main mechanisms:

Interaction with arterial walls, which cause functional and structural changes that lead to an over production or cross-linking of collagen, and a decreased level of elastin; or

Interacting with receptors for AGEs, thereby activating different signaling pathways, which lead to enhanced production of pro-inflammatory cytokines and vascular adhesion molecules responsible for atherosclerosis.

Our results show that increases in the level of AGEs in Korean patients with type 2 diabetes is associated with arterial pulse wave velocity and vein age, i.e., measures of arterial stiffness. Consequently, subject levels of AGEs were correlated with cardiovascular risk factors. AGE levels can be used as an indicator for CVDs in clinical diagnosis.”

https://www.cell.com/heliyon/fulltext/S2405-8440(22)00859-3 “Skin accumulation of advanced glycation end products and cardiovascular risk in Korean patients with type 2 diabetes mellitus”

RIP Ex-wife

Image June 25, 2022 gettingwell4 Just me

Gut microbiota therapy

June 25, 2022 gettingwell4 4-5 stars Advanced knowledge, Brainstem, Dopamine, Epigenetics, Hippocampus, Hypothalamus, Immune system, Limbic system, Lower brain, Memory, Serotonin, Stress Control group, Genetic factors, Neural plasticity, Neurodegenerative disease

This June 2022 review cited twenty 2022 papers for relationships between Parkinson’s disease and gut microbiota:

“Clinical diagnosis of PD is based on typical motor symptoms, and novel diagnostic biomarkers have been developed such as imaging markers, and α-synuclein fluid and tissue markers. Multimorbidity of non-motor disorders heighten the risk of adverse outcomes for patients with PD, which usually appear 20 years before onset of motor symptoms.

The gut microbiota is intimately connected to occurrence, development, and progression of PD, especially in early stages. A better understanding of the microbiota–gut–brain axis in PD can provide an opportunity to monitor an individual’s health by manipulating gut microbiota composition.

Several approaches like administration of probiotics, psychobiotics, prebiotics, synbiotics, postbiotics, FMT, and dietary modifications have been tried to mitigate dysbiosis-induced ill effects and alleviate PD progression.

Epidemiological studies have reported that diet affects (positively or negatively) onset of neurodegenerative disorders. Evidence suggests that diet composition’s effects on brain health is not due to diet-induced inflammatory response, but because of its effects on the gut microbiome.

Dysbiotic gut microbiota (including altered microbial metabolites) may play crucial roles in PD via various mechanisms, such as:

Increased intestinal permeability;

Aggravated intestinal inflammation and neuroinflammation;

Abnormal aggregation of α-synuclein fibrils;

Imbalanced oxidative stress; and

Decreased neurotransmitters production.

Future studies are essential to further elucidate cause-effect relationships between gut microbiota and PD, improved PD therapeutic and diagnostic options, disease progression tracking, and patient stratification capabilities to deliver personalized treatment and optimize clinical trial designs.”

https://www.frontiersin.org/articles/10.3389/fimmu.2022.937555/full “Gut Microbiota: A Novel Therapeutic Target for Parkinson’s Disease”

Sending lifespan signals

June 18, 2022June 18, 2022 gettingwell4 4-5 stars Advanced knowledge, Epigenetics Control group, Genetic factors

A second update to Signaling pathways and aging:

“At 40 months old, 3 treated rats are still alive, and all 8 control rats have died. This study started in February of 2021 when all female subjects were 24 months old.

The study will continue until all rats are dead. Animals receive intravenous E5 every 90 days.”

The initial study was all males, and this first follow-on study is all females. Both studies’ treatment groups started at human-equivalent ages of 65-67 years.

Seven weeks ago there were 6 treated rats and 4 control rats alive. Subject deaths since then were at human-equivalent ages of 100-110 years. Rat maximum lifespan is 45 months, so we’ll find out later this year how the treatment affects lifespan.

“A new study of intravenous E5 in rats began last week, with 24 Sprague Dawley rats which are 18 to 20 months old. 12 rats are in the treated group and 12 are in the control group.

Of these, 6 are males and 6 are females in each group. The dosing cycle has been changed to 45 days.”

Taurine week #7: Brain

June 18, 2022January 19, 2025 gettingwell4 4-5 stars Advanced knowledge, Acetylcholine, Amygdala, Anterior cingulate cortex, Brain development, Cerebellum, Cerebrum, Dopamine, Epigenetics, Glutamate, Hippocampus, Hypothalamus, Immune system, Limbic system, Lower brain, Memory, Neurochemicals, Stress, Thalamus Brain neurons, Control group, Embryo development, Genetic factors, Neurodegenerative disease, Prefrontal cortex

Finishing a week’s worth of 2022 taurine research with two reviews of taurine’s brain effects:

“We provide a overview of brain taurine homeostasis, and review mechanisms by which taurine can afford neuroprotection in individuals with obesity and diabetes. Alterations to taurine homeostasis can impact a number of biological processes such as osmolarity control, calcium homeostasis, and inhibitory neurotransmission, and have been reported in both metabolic and neurodegenerative disorders.

Models of neurodegenerative disorders show reduced brain taurine concentrations. On the other hand, models of insulin-dependent diabetes, insulin resistance, and diet-induced obesity display taurine accumulation in the hippocampus. Given cytoprotective actions of taurine, such accumulation of taurine might constitute a compensatory mechanism that attempts to prevent neurodegeneration.

Taurine release is mainly mediated by volume-regulated anion channels (VRAC) that are activated by hypo-osmotic conditions and electrical activity. They can be stimulated via glutamate metabotropic (mGluR) and ionotropic receptors (mainly NMDA and AMPA), adenosine A₁ receptors (A₁R), and metabotropic ATP receptors (P2Y).

Taurine mediates its neuromodulatory effects by binding to GABA_A, GABA_B, and glycine receptors. While taurine binding to GABA_A and GABA_B is weaker than to GABA, taurine is a rather potent ligand of the glycine receptor. Reuptake of taurine occurs via taurine transporter TauT.

Cytoprotective actions of taurine contribute to brain health improvements in subjects with obesity and diabetes through various mechanisms that improve neuronal function, such as:

Modulating inhibitory neurotransmission, which promotes an excitatory–inhibitory balance;

Stimulating antioxidant systems; and

Stabilizing mitochondria energy production and Ca²⁺ homeostasis.”

https://www.mdpi.com/2072-6643/14/6/1292/htm “Taurine Supplementation as a Neuroprotective Strategy upon Brain Dysfunction in Metabolic Syndrome and Diabetes”

A second review focused on taurine’s secondary bile acids produced by gut microbiota:

“Most neurodegenerative disorders are diseases of protein homeostasis, with misfolded aggregates accumulating. The neurodegenerative process is mediated by numerous metabolic pathways, most of which lead to apoptosis. Hydrophilic bile acids, particularly tauroursodeoxycholic acid (TUDCA), have shown important anti-apoptotic and neuroprotective activities, with numerous experimental and clinical evidence suggesting their possible therapeutic use as disease-modifiers in neurodegenerative diseases.

Biliary acids may influence each of the following three mechanisms through which interactions within the brain-gut-microbiota axis take place: neurological, immunological, and neuroendocrine. These microbial metabolites can act as direct neurotransmitters or neuromodulators, serving as key modulators of the brain-gut interactions.

The gut microbial community, through their capacity to produce bile acid metabolites distinct from the liver, can be thought of as an endocrine organ with potential to alter host physiology, perhaps to their own favour. Hydrophilic bile acids, currently regarded as important hormones, exert modulatory effects on gut microbiota composition to produce secondary bile acids which seem to bind a number of receptors with a higher affinity than primary biliary acids, expressed on many different cells.

TUDCA regulates expression of genes involved in cell cycle regulation and apoptotic pathways, promoting neuronal survival. TUDCA:

Improves protein folding capacity through its chaperoning activity, in turn reducing protein aggregation and deposition;

Reduces reactive oxygen species production, leading to protection against mitochondrial dysfunction;

Ameliorates endoplasmic reticulum stress; and

Inhibits expression of pro-inflammatory cytokines, exerting an anti-neuroinflammatory effect.

Although Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, amyotrophic lateral sclerosis (ALS), and cerebral ischemia have different disease progressions, they share similar pathways which can be targeted by TUDCA. This makes this bile acid a potentially strong therapeutic option to be tested in human diseases. Clinical evidence collected so far has reported comprehensive data on ALS only.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9166453/ “Tauroursodeoxycholic acid: a potential therapeutic tool in neurodegenerative diseases”

Taurine week #6: Stress

June 17, 2022August 8, 2022 gettingwell4 4-5 stars Advanced knowledge, Cerebellum, Cerebrum, Cortisol, Epigenetics, Glutamate, Hippocampus, Immune system, Limbic system, Lower brain, Neurochemicals, Serotonin, Stress Antidepressants, Brain neurons, Control group, Genetic factors, Neural plasticity, Prefrontal cortex

Two 2022 rodent studies of taurine’s associations with long-term stress, starting with a chronic restraint stress model:

“We show that chronic restraint stress can lead to hyperalgesia accompanied by changes in gut microbiota that have significant gender differences. Corresponding changes of bacteria can further induce hyperalgesia and affect different serum metabolism in mice of the corresponding sex.

Different serum metabolites between pseudo-germ-free mice receiving fecal microbiota transplantation from the chronic restraint stress group and those from the control group were mainly involved in bile secretion and steroid hormone biosynthesis for male mice, and in taurine and hypotaurine metabolism and tryptophan metabolism for female mice.

Effects of gut microbiota transplantation on serum metabolomics of female host: Taurine and hypotaurine metabolism, tryptophan metabolism, serotonergic synapse, arachidonic acid metabolism, and choline metabolism in cancer were the five identified pathways in which these different metabolites were enriched.

Taurine and hypotaurine play essential roles in anti-inflammation, anti-hypertension, anti-hyperglycemia, and analgesia. Taurine can be used as a diagnostic index for fibromyalgia syndrome and neuropathic pain.

These findings improve our understanding of sexual dimorphism in gut microbiota in stress-induced hyperalgesia and the effect of gut microbiota on blood metabolic traits. Follow-up research will investigate causal relationships between them.”

https://www.sciencedirect.com/science/article/pii/S1043661822000743 “Gut microbiota and its role in stress-induced hyperalgesia: Gender-specific responses linked to different changes in serum metabolites”

Human equivalents:

A 7-8 month-old mouse would be a 38-42 year-old human.
A 14-day stress period is about two years for humans.

A second study used a chronic social defeat stress model:

“The level of taurine in extracellular fluid of the cerebral medial prefrontal cortex (mPFC) was significantly reduced in mice with chronic social defeat stress (CSDS)-induced depression. We found that taurine supplementation effectively rescued immobility time during a tail suspension assay and improved social avoidance behaviors in CSDS mice.

Male C57BL/6 J mice (∼ 23 g) and male CD-1 mice aged 7–8 months (∼ 45 g) were used. CD-1 mice were screened for aggressive behavior during social interactions for three consecutive days before the start of the social defeat sessions. Experimental C57BL/6 J mice were subjected to physical interactions with a novel CD-1 mouse for 10 min once per day over 10 consecutive days.

We found significant reductions in taurine and betaine levels in mPFC interstitial fluid of CSDS mice compared with control mice.

We additionally investigated levels of interstitial taurine in chronic restraint stress (CRS) mice, another depressive animal model. After 14 days of CRS treatment, mice showed typical depression-like behaviors, including decreased sucrose preference and increased immobility time. mPFC levels of interstitial taurine were also significantly decreased in CRS mice.

Taurine treatment protected CSDS mice from impairments in dendritic complexity, spine density, and proportions of different types of spines. Expression of N-methyl D-aspartate receptor subunit 2A, an important synaptic receptor, was largely restored in the mPFC of these mice after taurine supplementation.

These results demonstrated that taurine exerted an antidepressive effect by protecting cortical neurons from dendritic spine loss and synaptic protein deficits.”

https://link.springer.com/article/10.1007/s10571-022-01218-3 “Taurine Alleviates Chronic Social Defeat Stress-Induced Depression by Protecting Cortical Neurons from Dendritic Spine Loss”

Human equivalents:

A 7-8 month-old mouse would be a 38-42 year-old human.
A 500 mg/kg taurine dose injected intraperitoneally is (.081 x 500 mg) x 70KG = 2.835 g.
A 10-day stress period is about a year and a half for humans.

Don’t think aggressive humans would have to be twice as large to stress those around them. There may be choices other than enduring a year and a half of that.

Taurine week #5: Blood

June 16, 2022June 16, 2022 gettingwell4 4-5 stars Advanced knowledge, Cortisol, Epigenetics, Neurochemicals, Serotonin, Stress Control group, Genetic factors, Neurodegenerative disease

Two 2022 papers investigated taurine’s effects in blood, starting with a review of platelets:

“Taurine is the most abundant free amino acid in the human body, with a six times higher concentration in platelets than any other amino acid. It is highly beneficial for the organism, has many therapeutic actions, and is currently approved for heart failure treatment in Japan. Only the lack of large-scale phase 3 clinical trials restricts taurine use as a therapeutic agent in several other pathologies for treatment of which it has been shown to be effective (hypertension, atherosclerosis, stroke, neurodegenerative diseases, metabolic diseases, e.g., diabetes mellitus, and others).

Because taurine was seen as a non-patentable nutrient, the pharmaceutical industry has not shown much interest in its research. Considering that taurine and its analogues display permissible side effects, along with the need of finding new, alternative antithrombotic drugs with minimal side effects and long-term action, the potential clinical relevance of this fascinating nutrient and its derivatives requires further consideration.”

https://www.mdpi.com/2077-0383/11/3/666/htm “Taurine and Its Derivatives: Analysis of the Inhibitory Effect on Platelet Function and Their Antithrombotic Potential”

Figure 1 provided details of taurine and its derivatives’ effects on various processes involved in platelet activation and aggregation.

A second paper was a rodent study:

“To evaluate chronic effects of taurine on cholesterol levels, we analyzed mice fed a taurine-rich diet for 14–16 weeks. Long-term feeding of taurine lowered plasma cholesterol and bile acids without significantly changing other metabolic parameters, but hardly affected these levels in the liver.

Taurine upregulates transcriptional activity of Cyp7a1 by suppressing FGF21 production in the liver. Bile acids are converted from blood cholesterol by CYP7A1, and more efficiently enter enterohepatic circulation via taurine conjugation.

This study shows that long-term feeding of taurine lowers both plasma cholesterol and bile acids, reinforcing that taurine effectively prevents hypercholesterolemia.”

https://www.mdpi.com/1422-0067/23/3/1793/htm “Long-Term Dietary Taurine Lowers Plasma Levels of Cholesterol and Bile Acids”

A human equivalent of this male C57BL/6J mouse 16-week taurine intervention is roughly 17 years. That strain’s male maximum lifespan is around 800 days, and human maximum lifespan is currently 122.5 years.

Taurine week #4: Muscles

June 15, 2022November 7, 2022 gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Stress Control group

Two 2022 papers investigated taurine and skeletal muscles, starting with a rodent study of endurance exercise:

“This study examined effects of taurine on dynamics of blood glucose concentration (BGC) during endurance exercise in rats.

Blood was collected every 10 min from the jugular vein via cannulation.

Exercise period was divided by every 40 min into four phases.

Individual exhaustion time is indicated by arrows (white: CON group [n = 12], black: TAU group [n = 10]) under the X-axis.

120-min point is the approximate median where there were significant differences in BGC between groups at exercise point every 10 min (80–150 min).

†P < 0.05 and #P < 0.05 show significant difference to respective starting points (0 min) in TAU and CON groups.

Arrow with two heads (↔) shows a significant difference at P < 0.05 between groups at each point.

Observation of BGC confirmed that taurine supplementation delayed the decline in once-elevated BGC during endurance exercise.

Significantly higher levels of free fatty acid in plasma as well as acetyl-carnitine and N-acetyltaurine in skeletal muscle at the 120-min point suggested that taurine supplementation shifted the priority of energy substrate utilization in skeletal muscles to fatty acid oxidation during endurance exercise. Consequent sparing effect of taurine on BGC might contribute to enhancing exercise performance.”

https://link.springer.com/article/10.1007/s00726-021-03110-8 “Taurine supplementation enhances endurance capacity by delaying blood glucose decline during prolonged exercise in rats”

A second rodent study focused on injured muscle:

“We evaluated whether taurine administration in old mice counteracts physiopathological effects of aging in skeletal muscle.

Type I slow-twitch oxidative fibers (expressing the slow isoform of the myosin heavy chain, slow MHC) are more resistant to damage and a variety of atrophic conditions than type IIb fast-twitch glycolytic fibers. In several muscle pathologies, including sarcopenia, the fastest muscle phenotype is more severely compromised when compared with slow-twitch muscles.

Tibialis anterior (TA) muscles of old mice expressed very low levels of slow-MHC isoform compared to young muscles. Slow-MHC expression increased in muscles of taurine-treated mice.

Analysis of the fast-MHC isoform revealed that, in the presence of taurine, its expression was significantly upregulated compared to what was observed in TA muscles of old mice that did not receive taurine.

These results suggest that the positive effect of taurine on skeletal muscle homeostasis of aged mice may be mediated by stimulation of the PGC1-α/MEF2C pathway, favoring a possible metabolic shift of myofibers towards the oxidative phenotype, and preserving more susceptible glycolytic fibers.

In injured muscle, taurine enhances the regenerative process by downregulating inflammatory response and preserving muscle fiber integrity. Taurine attenuates ROS production in aged muscles by maintaining a proper cellular redox balance, acting as an antioxidant molecule.

These data demonstrate that taurine administration ameliorates the microenvironment, allowing an efficient regenerative process, and attenuation of catabolic pathways related to onset of sarcopenia.”

https://www.mdpi.com/2076-3921/11/5/1016/htm “Taurine Administration Counteracts Aging-Associated Impingement of Skeletal Muscle Regeneration by Reducing Inflammation and Oxidative Stress”

A human equivalent to each daily mouse taurine dose administered over five weeks was (.081 x 100 mg) x 70 kg = .567 g.

Taurine week #3: Organs

June 15, 2022January 19, 2025 gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Immune system, Stress Control group, Genetic factors

Three 2022 papers investigated taurine’s effects on organs, starting with a rodent study of sepsis:

“Sepsis usually causes multiple organ dysfunctions and high mortality. Pathogenesis of sepsis is thought to be driven by hyperactive inflammation following pathogen invasion. If the immune system fails to eradicate pathogens, immune homeostasis is disturbed, leading to an overwhelming inflammation accompanied by immunosuppression.

Metabolomic analysis showed large amounts of taurine in neutrophils and monocytes and a dramatic decrease in taurine levels after lipopolysaccharides (LPS) exposure:

Cecal ligation and puncture (CLP) model mice and CLP plus taurine mice were injected intraperitoneally with saline (200 μl) or taurine (200 mg/kg, in 200 μl) respectively at 6, 24, and 48 h after the operation. Taurine protected septic mice from death, improving tissue injuries in the lung, liver, and kidney by reducing neutrophil infiltration and TNF-α production.

Our data indicate that a supplement with taurine might be a promising therapeutic strategy for sepsis to reduce hyperactive inflammation and improve multiple organ dysfunctions.”

https://www.sciencedirect.com/science/article/abs/pii/S0008874922000272 “Mechanism of taurine reducing inflammation and organ injury in sepsis mice” (not freely available) Thanks to Dr. Liuluan Zhu for providing a copy.

Taurine demonstrated the only decrease in 17 amino acids measured in monocytes above. It was the same story for those amino acids and neutrophils.

A human equivalent to each of three mouse taurine doses administered over two days was (.081 x 200 mg) x 70 kg = 1.134 g. A second dose given at the 12-hour point may have improved treated subjects’ survival, as half of them died before the study’s 24-hour point of a second dose.

A second rodent study was on liver injury:

“We investigated the beneficial effects of taurine on fatty liver injury in vivo induced by tunicamycin, a chemical endoplasmic reticulum (ER) stressor.

The unfolded protein response (UPR) is a protein homeostasis-maintaining system that monitors ER conditions by sensing inadequacy in ER protein folding capacity. The ER is both a protein homeostasis-maintaining system and the primary site of lipid metabolism. The UPR plays vital roles in maintaining metabolic and lipid homeostasis.

Glutathione (GSH), a final byproduct of sulfur-containing amino acid metabolism, is not only a powerful antioxidant, but also a principal redox buffer in the ER. Depletion of reduced glutathione can cause additional oxidative stress.

Cysteine, the metabolic precursor of GSH, is also an essential substrate for taurine synthesis. Utilization of cysteine to generate GSH and taurine is competitive.

In this study, availability of cysteine is favored for GSH synthesis due to sufficient taurine supply. Taurine supplementation restored GSH levels, which were attenuated by tunicamycin treatment, by increasing expression of GCLC, an enzyme mediating GSH synthesis.

The protective effect of taurine on tunicamycin-induced hepatic injury results from its concurrent mitigation of both ER and oxidative stress.”

https://www.mdpi.com/2075-1729/12/3/354/htm “Taurine Ameliorates Tunicamycin-Induced Liver Injury by Disrupting the Vicious Cycle between Oxidative Stress and Endoplasmic Reticulum Stress”

This study provided further evidence for an idea in Treating psychopathological symptoms will somehow resolve causes? that:

“Such positive effects of taurine on glutathione levels may be explained by the fact that cysteine is the essential precursor to both metabolites, whereby taurine supplementation may drive metabolism of cysteine towards GSH synthesis.”

A third rodent study investigated lung pneumonia:

“We evaluated anti-inflammatory effects of taurine derivative N-chlorotaurine (also known as taurine chloramine; TauCl) against LPS-induced pneumonia in obese mice maintained on a high fat diet.

Taurine is present in immune system cells such as macrophages and neutrophils. When an organism is infected by pathogens, immune cells produce hypochlorous acid to kill pathogens. Taurine reacts with excessive hypochlorous acid to produce TauCl, which reduces high levels of hypochlorous acid and its toxicity to surrounding host cells.

Intraperitoneal TauCl suppressed excessive immune response in lungs. TauCl treatment attenuates acute pneumonia-related pulmonary and systemic inflammation, including muscle wasting.”

https://www.mdpi.com/2218-1989/12/4/349/htm “N-Chlorotaurine Reduces the Lung and Systemic Inflammation in LPS-Induced Pneumonia in High Fat Diet-Induced Obese Mice”

Taurine week #2: Bile acids

June 14, 2022January 19, 2025 gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Glutamate, Hypothalamus, Immune system, Limbic system, Neurochemicals, Testosterone Brain neurons, Control group, Genetic factors, Neurodegenerative disease

Two papers investigated taurine’s integration into bile acids, starting with a review:

“Bile acids (BAs) are produced from cholesterol in the liver and are termed primary BAs. Primary BAs are conjugated with glycine and taurine in the liver, and stored in the gallbladder. BAs are released from the gallbladder into the small intestine via food intake to facilitate digestion and absorption of lipids and lipophilic vitamins by forming micelles in the small intestine.

After deconjugation by the gut microbiome, primary BAs are converted into secondary BAs. Most BAs in the intestine are reabsorbed and transported to the liver, where both primary and secondary BAs are conjugated with glycine or taurine and rereleased into the intestine.

Some BAs reabsorbed from the intestine spill into systemic circulation, where they bind to a variety of nuclear and cell-surface receptors in tissues. Some BAs are not reabsorbed and bind to receptors in the terminal ileum.

BAs can affect cell-surface and intracellular membranes, including those of mitochondria and the endoplasmic reticulum. BAs are also hormones or signaling molecules, and can regulate BA, glucose, and lipid metabolism in various tissues, including the liver, pancreas, and both brown and white adipose tissue. BAs also affect the immune system.

BAs can affect the nervous system. More than 20 BAs have been detected in the brain of humans and rodents. The brain communicates with the gut and gut microbiome through BAs.”

https://www.mdpi.com/2076-2607/10/1/68/htm “Physiological Role of Bile Acids Modified by the Gut Microbiome”

Reference 56 was a human study:

“Centenarians (individuals aged 100 years and older) have a decreased susceptibility to ageing-associated illnesses, chronic inflammation, and infectious diseases. Centenarians have a distinct gut microbiome enriched in microorganisms that are capable of generating unique secondary bile acids.

We identified centenarian-specific gut microbiota signatures and defined bacterial species as well as genes and/or pathways that promote generation of isoLCA, 3-oxoLCA, 3-oxoalloLCA, and isoalloLCA. To our knowledge, isoalloLCA is one of the most potent antimicrobial agents that is selective against Gram-positive microorganisms, including multidrug-resistant pathogens, suggesting that it may contribute to maintenance of intestinal homeostasis by enhancing colonization-resistance mechanisms.”

https://www.nature.com/articles/s41586-021-03832-5 “Novel bile acid biosynthetic pathways are enriched in the microbiome of centenarians” (not freely available)

A few more papers will be coming on taurine and bile acids. I haven’t seen one investigate both taurine and glycine treatments to aid bile acid in achieving therapeutic results.