Prolonging healthy aging: Longevity vitamins and proteins

Vitamin D3 promotes longevity in Caenorhabditis elegans

Vitamin D deficiency is associated with a variety of age-related diseases and is becoming increasingly more prevalent in the population over time. Some diseases associated with deficiency are cardiovascular disease, cancer, and neurodegeneration. This association, as well as the fact that vitamin D has been demonstrated to play an important role in a variety of extraskeletal processes, has led some to claim that vitamin D is an essential longevity vitamin. However, the role of vitamin D in healthy aging has been difficult to determine. In order to study vitamin D in the context of aging, the model organism, Caenorhabditis elegans (C. elegans), was employed. To study vitamin D's impact on aging and age-related disease, lifespan and health span were measured across three different genetic strains of C. elegans. Strains investigated were wildtype (N2), worms with a mutant vitamin D receptor ortholog (nhr-8), and worms engineered to represent Alzheimer disease (gnals2). Bioinformatic analysis of available public data was also performed in order to identify the transcriptional response produced in N2 worms treated with vitamin D₃. Treatment with vitamin D₃ significantly extended the lifespan of N2 worms and rescued nhr-8 worms, which typically have decreased lifespans compared to N2. Treatment with vitamin D₃ minimally extended the lifespan of gnals2 worms. Similar results were obtained for measures of health span, quantified as motility through time. Differentially expressed genes upon treatment with vitamin D₃ were largely associated with biological processes such as the innate immune response and metabolism of xenobiotic compounds in the worms, which may explain the observed increase in lifespan and health span.

Enhancement of ergothioneine production by discovering and regulating its metabolic pathway in Cordyceps militaris

Background

Cordyceps militaris is a traditional medicinal fungus contains a variety of functional ingredients and has been developed as an important mushroom food recently. Ergothioneine, one of the antioxidative compounds in C. militaris, is benefits on aging-related diseases and therefore became a novel functional food nutritive fortifier. Currently, the main diet source of ergothioneine is mushroom food. However, the mushroom farming faces the problems such as rather low ingredient yield and spontaneous degeneration associated fruiting body that restricts large scale production of ergothioneine.

Results

In this study, we excavated the ergothioneine synthetases in mushroom and modified the genes in C. militaris to construct a new ergothioneine synthesis pathway. By further introducing this pathway into C. militaris genome, we succeeded to increase the ingredients’ production of engineering strain, the highest amount of ergothioneine and cordycepin were up to 2.5 g/kg dry weight and 2 g/L, respectively. Additionally, the expression of ergothioneine synthetase genes in the shape-mutated degenerative C. militaris could recover the ability of degenerative strain to produce high amount of ingredients, suggesting the metabolic regulation of ergothioneine might release the symptom of mushroom degeneration.

Conclusion

This study reveals a new pathway to fulfill the market needs of functional mushroom food and food fortifier ergothioneine. It implied the mycelium of C. militaris could be engineered as a novel medicinal mushroom food which could produce higher amount of valuable ingredients.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-022-01891-5.

Hormesis and Oxidative Distress: Pathophysiology of Reactive Oxygen Species and the Open Question of Antioxidant Modulation and Supplementation

Alterations of redox homeostasis leads to a condition of resilience known as hormesis that is due to the activation of redox-sensitive pathways stimulating cell proliferation, growth, differentiation, and angiogenesis. Instead, supraphysiological production of reactive oxygen species (ROS) exceeds antioxidant defence and leads to oxidative distress. This condition induces damage to biomolecules and is responsible or co-responsible for the onset of several chronic pathologies. Thus, a dietary antioxidant supplementation has been proposed in order to prevent aging, cardiovascular and degenerative diseases as well as carcinogenesis. However, this approach has failed to demonstrate efficacy, often leading to harmful side effects, in particular in patients affected by cancer. In this latter case, an approach based on endogenous antioxidant depletion, leading to ROS overproduction, has shown an interesting potential for enhancing susceptibility of patients to anticancer therapies. Therefore, a deep investigation of molecular pathways involved in redox balance is crucial in order to identify new molecular targets useful for the development of more effective therapeutic approaches. The review herein provides an overview of the pathophysiological role of ROS and focuses the attention on positive and negative aspects of antioxidant modulation with the intent to find new insights for a successful clinical application.

The Role of Antioxidants in the Interplay between Oxidative Stress and Senescence

Cellular senescence is an irreversible state of cell cycle arrest occurring in response to stressful stimuli, such as telomere attrition, DNA damage, reactive oxygen species, and oncogenic proteins. Although beneficial and protective in several physiological processes, an excessive senescent cell burden has been involved in various pathological conditions including aging, tissue dysfunction and chronic diseases. Oxidative stress (OS) can drive senescence due to a loss of balance between pro-oxidant stimuli and antioxidant defences. Therefore, the identification and characterization of antioxidant compounds capable of preventing or counteracting the senescent phenotype is of major interest. However, despite the considerable number of studies, a comprehensive overview of the main antioxidant molecules capable of counteracting OS-induced senescence is still lacking. Here, besides a brief description of the molecular mechanisms implicated in OS-mediated aging, we review and discuss the role of enzymes, mitochondria-targeting compounds, vitamins, carotenoids, organosulfur compounds, nitrogen non-protein molecules, minerals, flavonoids, and non-flavonoids as antioxidant compounds with an anti-aging potential, therefore offering insights into innovative lifespan-extending approaches.

Ergothioneine: A Stress Vitamin with Antiaging, Vascular, and Neuroprotective Roles?

Significance: Ergothioneine (ET) is an unusual sulfur-containing amino acid derived from histidine, acquired predominantly from food. Its depletion is associated with deleterious consequences in response to stress stimuli in cell culture models, prompting us to classify it as a vitamin in 2010, which was later supported by in vivo studies. ET is obtained from a variety of foods and is taken up by a selective transporter. ET possesses antioxidant and anti-inflammatory properties that confer cytoprotection. ET crosses the blood-brain barrier and has been reported to have beneficial effects in the brain. In this study, we discuss the cytoprotective and neuroprotective properties of ET, which may be harnessed for combating neurodegeneration and decline during aging. Recent Advances: The designation of ET as a stress vitamin is gaining momentum, opening a new field of investigation involving small molecules that are essential for optimal physiological functioning and maintenance of health span. Critical Issues: Although ET was discovered more than a century ago, its physiological functions are still being elucidated, especially in the brain. As ET is present in most foods, toxicity associated with its deprivation has been difficult to assess. Future Directions: Using genetically engineered cells and mice, it may now be possible to elucidate roles of ET. This coupled with advances in genomics and metabolomics may lead to identification of ET function. As ET is a stable antioxidant with anti-inflammatory properties, whose levels decline during aging, supplementing ET in the diet or consuming an ET-rich diet may prove beneficial. Antioxid. Redox Signal. 36, 1306-1317.

Association of Gut Microbiota With Metabolism in Rainbow Trout Under Acute Heat Stress

Global warming is one of the most common environmental challenges faced by cold-water fish farming. Heat stress seriously affects the feeding, growth, immunity, and disease resistance of fish. These changes are closely related to the destruction of intestinal barrier function, the change of intestinal microbiota, and metabolic dysfunction. However, the causal relationship between the phenotypic effects of heat stress as well as intestinal and metabolic functions of fish is unknown. In the current study, the optimal growth temperature (16°C) of rainbow trout was used as the control group, while the fish treated at 22.5°C, 23.5°C, and 24.5°C for 24 h, respectively, were the treatment groups. The 16S rRNA gene sequencing analysis showed that with the increase in temperature, the relative abundance and diversity of intestinal microbiota decreased significantly, while the number of Mycoplasma, Firmicutes, and Tenericutes increased significantly. Non-targeted metabolomics analysis by liquid chromatography-mass spectrometry analysis and correlation analysis showed that the changes of metabolites related to amino acids, vitamins, and short-chain fatty acids in serum of rainbow trout under acute heat stress were strongly correlated with the decrease of relative abundance of various intestinal microbiota, especially Morganella, Enterobacter, Lactobacillus, Lawsonia, and Cloacibacterium. In addition, we also found that acute heat stress seriously affected the intestinal structure and barrier function, and also caused the pathological damage of epithelial cells. These results indicate that the gut microbiome of acute heat-stressed rainbow trout could mediate metabolite transfer through the gut barrier by affecting its integrity. Significant changes in gut morphology, permeability, antioxidant capacity, and pro-inflammatory cytokine levels were observed. Therefore, it is necessary to explore the changes of intestinal microbiota under heat stress to help understand the regulatory mechanism of heat stress and protect the intestinal health of rainbow trout from the negative effects of rising water temperature.

Blood-Based Biomarkers for Alzheimer's Disease Diagnosis and Progression: An Overview

Alzheimer’s Disease (AD) is a progressive neurodegenerative disease characterized by amyloid-β (Aβ) plaque deposition and neurofibrillary tangle accumulation in the brain. Although several studies have been conducted to unravel the complex and interconnected pathophysiology of AD, clinical trial failure rates have been high, and no disease-modifying therapies are presently available. Fluid biomarker discovery for AD is a rapidly expanding field of research aimed at anticipating disease diagnosis and following disease progression over time. Currently, Aβ_1–42, phosphorylated tau, and total tau levels in the cerebrospinal fluid are the best-studied fluid biomarkers for AD, but the need for novel, cheap, less-invasive, easily detectable, and more-accessible markers has recently led to the search for new blood-based molecules. However, despite considerable research activity, a comprehensive and up-to-date overview of the main blood-based biomarker candidates is still lacking. In this narrative review, we discuss the role of proteins, lipids, metabolites, oxidative-stress-related molecules, and cytokines as possible disease biomarkers. Furthermore, we highlight the potential of the emerging miRNAs and long non-coding RNAs (lncRNAs) as diagnostic tools, and we briefly present the role of vitamins and gut-microbiome-related molecules as novel candidates for AD detection and monitoring, thus offering new insights into the diagnosis and progression of this devastating disease.

OvoAMtht from Methyloversatilis thermotolerans ovothiol biosynthesis is a bifunction enzyme: thiol oxygenase and sulfoxide synthase activities

Mononuclear non-heme iron enzymes are a large class of enzymes catalyzing a wide-range of reactions. In this work, we report that a non-heme iron enzyme in Methyloversatilis thermotolerans, OvoA_Mtht, has two different activities, as a thiol oxygenase and a sulfoxide synthase. When cysteine is presented as the only substrate, OvoA_Mtht is a thiol oxygenase. In the presence of both histidine and cysteine as substrates, OvoA_Mtht catalyzes the oxidative coupling between histidine and cysteine (a sulfoxide synthase). Additionally, we demonstrate that both substrates and the active site iron's secondary coordination shell residues exert exquisite control over the dual activities of OvoA_Mtht (sulfoxide synthase vs. thiol oxygenase activities). OvoA_Mtht is an excellent system for future detailed mechanistic investigation on how metal ligands and secondary coordination shell residues fine-tune the iron-center electronic properties to achieve different reactivities.

Modulation of OvoA_Mtht's dual activities: sulfoxide synthase and thiol oxygenase.

Effects of 1α,25-dihydroxyvitamin D3 on the pharmacokinetics and biodistribution of ergothioneine, an endogenous organic cation/carnitine transporter 1 substrate, in rats

Purpose

This study aimed to investigate the effects of 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) on the expression levels of organic cation/carnitine transporter 1 (OCTN1) as well as the pharmacokinetics and biodistribution of ergothioneine, an OCTN1 substrate, in rats.

Methods

Rats pretreated with 1,25(OH)₂D₃ (2.56 nmol/kg/day) for four days were administered ergothioneine (2 mg/kg) intravenously. The expression levels of rat OCTN1 (rOCTN1) in organs were determined using real-time quantitative polymerase chain reaction. Ergothioneine levels in plasma, urine, and organs (with and without intravenous injection of exogenous ergothioneine) were determined using liquid chromatography-tandem mass spectrometry.

Results

1,25(OH)₂D₃ pretreatment resulted in a significant decrease in rOCTN1 mRNA expression levels in the kidney and brain, a significant increase in basal plasma levels of ergothioneine (from 48 h), and a significant decrease in the tissue-plasma partition coefficient (K_p) in all tissues (except the heart and lungs) and the basal urine levels of ergothioneine. After intravenous administration, the pharmacokinetic profiles of ergothioneine were consistent with the basal levels of endogenous ergothioneine, with an increase in AUC_∞ by 85%, a significant decrease in total clearance by 49%, and a decrease in V_ss by 32% in 1,25(OH)₂D₃-treated rats. The K_p value and urinary recovery of ergothioneine also decreased in the 1,25(OH)₂D₃-treated group.

Conclusion

This study showed the effects of 1,25(OH)₂D₃ on the expression and function of rOCTN1 by investigating the interaction between 1,25(OH)₂D₃ and ergothioneine. Dose adjustment and possible changes in bioavailability should be considered before the co-administration of vitamin D or its active forms and OCTN1 substrates.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40005-022-00563-1.

PQQ Supplementation and SARS-CoV-2 Spike Protein-Induced Heart Inflammation

SARS-CoV-2 spike protein-induced heart inflammation may originate from either COVID-19 infection or the administration of COVID-19 mRNA vaccines. As pyrroloquinoline quinone (PQQ) is a scavenger of free radicals, redox cofactor, and antioxidant which supports cognitive and mitochondrial functions, supplementation with PQQ could have a positive effect to reduce heart inflammation after COVID-19 mRNA vaccines. However, there is no evidence yet for this opportunity in the literature. Cellular and animal model results are missing. Similarly, no clinical trials have been conducted. While it is recommended to measure the levels of the cardiac biomarkers before and after COVID-19 vaccination, no recommendation can be made about supplementation with PQQ, which, however, we note has no contraindication.

Mineral requirements for mitochondrial function: A connection to redox balance and cellular differentiation

Professor Bruce Ames demonstrated that nutritional recommendations should be adjusted in order to 'tune-up' metabolism and reduce mitochondria decay, a hallmark of aging and many disease processes. A major subset of tunable nutrients are the minerals, which despite being integral to every aspect of metabolism are often deficient in the typical Western diet. Mitochondria are particularly rich in minerals, where they function as essential cofactors for mitochondrial physiology and overall cellular health. Yet substantial knowledge gaps remain in our understanding of the form and function of these minerals needed for metabolic harmony. Some of the minerals have known activities in the mitochondria but with incomplete regulatory detail, whereas other minerals have no established mitochondrial function at all. A comprehensive metallome of the mitochondria is needed to fully understand the patterns and relationships of minerals within metabolic processes and cellular development. This brief overview serves to highlight the current progress towards understanding mineral homeostasis in the mitochondria and to encourage more research activity in key areas. Future work may likely reveal that adjusting the amounts of specific nutritional minerals has longevity benefits for human health.

Pyrroloquinoline Quinone Chemistry, Biology, and Biosynthesis

The widely distributed, essential redox factor pyrroloquinoline quinone (PQQ, methoxatin) (1) was discovered in the mid-1960s. The breadth and depth of its biological effects are steadily being revealed, and understanding its biosynthesis at the genomic level is a continuing process. In this review, aspects of the chemistry, biology, biosynthesis, and commercial production of 1 at the gene level, and some applications, are presented from discovery through to mid-2021.

Coffee-Derived Phenolic Compounds Activate Nrf2 Antioxidant Pathway in I/R Injury In Vitro Model: A Nutritional Approach Preventing Age Related-Damages

Age-related injuries are often connected to alterations in redox homeostasis. The imbalance between free radical oxygen species and endogenous antioxidants defenses could be associated with a growing risk of transient ischemic attack and stroke. In this context, a daily supply of dietary antioxidants could counteract oxidative stress occurring during ischemia/reperfusion injury (I/R), preventing brain damage. Here we investigated the potential antioxidant properties of coffee-derived circulating metabolites and a coffee pulp phytoextract, testing their efficacy as ROS scavengers in an in vitro model of ischemia. Indeed, the coffee fruit is an important source of phenolic compounds, such as chlorogenic acids, present both in the brewed seed and in the discarded pulp. Therefore, rat brain endothelial cells, subjected to oxygen and glucose deprivation (OGD) and recovery (ogR) to mimic reperfusion, were pretreated or not with coffee by-products. The results indicate that, under OGD/ogR, the ROS accumulation was reduced by coffee by-product. Additionally, the coffee extract activated the Nrf2 antioxidant pathway via Erk and Akt kinases phosphorylation, as shown by increased Nrf2 and HO-1 protein levels. The data indicate that the daily intake of coffee by-products as a dietary food supplement represents a potential nutritional strategy to counteract aging.

Decline of ergothioneine in frailty and cognition impairment

Ergothioneine is a well-known anti-oxidant that is abundant in both human red blood cells and in fission yeast responding to nutritional stress. In frail elderly people, whose aging organs undergo functional decline, there is a correlation between ergothioneine levels and cognitive, but not skeletal muscle decline. In patients suffering from dementia, including Alzheimer's disease with hippocampal atrophy, deteriorating cognitive ability is correlated with declining ergothioneine levels. S-methyl-ergothioneine, trimethyl-histidine, and three other trimethyl-ammonium compounds also decrease sharply in dementia, whereas compounds such as indoxyl-sulfate and quinolinic acid increase, possibly exacerbating the disease. Using these opposing dementia markers, not only diagnosis, but also therapeutic interventions to mitigate cognitive decline may now become possible.

Oxidized Forms of Ergothioneine Are Substrates for Mammalian Thioredoxin Reductase

Ergothioneine (EGT) is a sulfur-containing amino acid analog that is biosynthesized in fungi and bacteria, accumulated in plants, and ingested by humans where it is concentrated in tissues under oxidative stress. While the physiological function of EGT is not yet fully understood, EGT is a potent antioxidant in vitro. Here we report that oxidized forms of EGT, EGT-disulfide (ESSE) and 5-oxo-EGT, can be reduced by the selenoenzyme mammalian thioredoxin reductase (Sec-TrxR). ESSE and 5-oxo-EGT are formed upon reaction with biologically relevant reactive oxygen species. We found that glutathione reductase (GR) can reduce ESSE, but only with the aid of glutathione (GSH). The reduction of ESSE by TrxR was found to be selenium dependent, with non-selenium-containing TrxR enzymes having little or no ability to reduce ESSE. In comparing the reduction of ESSE by Sec-TrxR in the presence of thioredoxin to that of GR/GSH, we find that the glutathione system is 10-fold more efficient, but Sec-TrxR has the advantage of being able to reduce both ESSE and 5-oxo-EGT directly. This represents the first discovered direct enzymatic recycling system for oxidized forms of EGT. Based on our in vitro results, the thioredoxin system may be important for EGT redox biology and requires further in vivo investigation.

Pyrroloquinoline quinone inhibits ligature-induced alveolar bone loss through regulation of redox balance and cell senescence

It has been demonstrated that oxidative stress is related to periodontitis, and that pyrroloquinoline quinine (PQQ) acts as a powerful antioxidant. This study aimed to explore the effect of PQQ on ligature-induced alveolar bone loss in experimental periodontitis (EP) mice with/without PQQ in the diet. EP mice received a diet supplemented with PQQ for 2 weeks and were compared with sham (control) mice as well as untreated EP mice. Additionally, human periodontal ligament cells (hPDLCs) were treated with PQQ in the presence or absence of lipopolysaccharide (LPS). We found that the bone volume fraction, alkaline phosphatase activity, and the number of antioxidant cells were significantly decreased in EP mice compared with the sham mice, whereas PQQ administration rescued the above effects. In contrast, alveolar bone loss, osteoclast number, cell senescence-associated cells, and cytokines' expression were significantly increased in EP mice compared with the sham mice but were significantly decreased with PQQ supplementation in periodontal tissues. Furthermore, we found that antioxidant enzymes and Bmi-1 protein expression levels were downregulated, whereas the protein expression levels of cell senescence-related proteins including γ-H2AX, IL-6, IL-1β, p16, and p21 were significantly up-regulated in LPS-induced hPDLCs compared with the control cells. However, PQQ administration partially prevented these changes. These findings suggest that PQQ may alleviate periodontal damage through regulation of the redox balance and cell senescence.

One-Carbon Metabolism: Pulling the Strings behind Aging and Neurodegeneration

One-carbon metabolism (OCM) is a network of biochemical reactions delivering one-carbon units to various biosynthetic pathways. The folate cycle and methionine cycle are the two key modules of this network that regulate purine and thymidine synthesis, amino acid homeostasis, and epigenetic mechanisms. Intersection with the transsulfuration pathway supports glutathione production and regulation of the cellular redox state. Dietary intake of micronutrients, such as folates and amino acids, directly contributes to OCM, thereby adapting the cellular metabolic state to environmental inputs. The contribution of OCM to cellular proliferation during development and in adult proliferative tissues is well established. Nevertheless, accumulating evidence reveals the pivotal role of OCM in cellular homeostasis of non-proliferative tissues and in coordination of signaling cascades that regulate energy homeostasis and longevity. In this review, we summarize the current knowledge on OCM and related pathways and discuss how this metabolic network may impact longevity and neurodegeneration across species.

Ergothioneine exhibits longevity-extension effect in Drosophila melanogaster via regulation of cholinergic neurotransmission, tyrosine metabolism, and fatty acid oxidation

Many studies have demonstrated the protective effect of ergothioneine (EGT), the unique sulfur-containing antioxidant found in mushrooms, on several aging-related diseases. Nevertheless, to date, no single study has explored the potential role of EGT in the lifespan of animal models. We show here that EGT consistently extends fly lifespan in diverse genetic backgrounds and both sexes, as well as in a dose and gender-dependent manner. Additionally, EGT is shown to increases the climbing activity of flies, enhance acetylcholinesterase (AchE) activity, and maintain the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG)of aged flies. The increase in lifespan by EGT is gut microorganism dependent. We proposed potential mechanisms of lifespan extension in Drosophila by EGT through RNA-seq analysis: preservation of the normal status of the central nervous system via the coordination of cholinergic neurotransmission, tyrosine metabolism, and peroxisomal proteins, regulation of autophagic activity by altering the lysosomal protein CTSD, and the preservation of normal mitochondrial function through controlled substrate feeding into the tricarboxylic acid (TCA) cycle, the major energy-yielding metabolic process in cells.

Musings in the twilight of my career

I present a summary of my research during the last few decades of research which focused on understanding the biochemical basis for maintaining an optimum metabolism to support long-term health. I realized that adequate levels of ∼40 vitamins and minerals needed as cofactors in thousands of metabolic reactions were critical for maintaining a healthy metabolism, and thus for longevity and prevention of chronic disease. Inadequate dietary intake of vitamins and minerals accelerates the risk of aging-associated diseases, leading to insidious damage. The Triage Theory provides a mechanistic rationale for such damage: shortage of a nutrient triggers a built-in rationing mechanism that allocates the scarce nutrient to proteins needed for immediate survival (survival proteins), at the expense of those needed for long-term survival (longevity proteins). Many as-yet-unknown longevity vitamins and proteins likely remain to be discovered. The fiber and nutrient-rich CHORI-bar was developed to fill gaps in inadequate diets; it yielded broadscale metabolic improvements. The health-related damages resulting from vitamin D deficiency and the positive effects of vitamin D supplementation were connected to numerous health-related problems, including the higher level of deficiency in people of color residing at northern latitudes. In general, prevention of degenerative diseases of aging requires expertise in metabolism, nutrition, biochemistry and regulatory functions.

The Ergothioneine Transporter (ETT): Substrates and Locations, an Inventory

In all vertebrates including mammals, the ergothioneine transporter ETT (obsolete name OCTN1; human gene symbol SLC22A4) is a powerful and highly specific transporter for the uptake of ergothioneine (ET). ETT is not expressed ubiquitously and only cells with high ETT cell-surface levels can accumulate ET to high concentration. Without ETT, there is no uptake because the plasma membrane is essentially impermeable to this hydrophilic zwitterion. Here, we review the substrate specificity and localization of ETT, which is prominently expressed in neutrophils, monocytes/macrophages, and developing erythrocytes. Most sites of strong expression are conserved across species, but there are also major differences. In particular, we critically analyze the evidence for the expression of ETT in the brain as well as recent data suggesting that the transporter SLC22A15 may transport also ET. We conclude that, to date, ETT remains the only well-defined biomarker for intracellular ET activity. In humans, the ability to take up, distribute, and retain ET depends principally on this transporter.

Health Consequences of Improving the Content of Ergothioneine in the Food Supply

Ergothioneine (ERGO) is a potent antioxidant and anti-inflammatory amino acid that is highly bioavailable to humans from the diet. ERGO is now regarded by some as a "longevity vitamin" that has the potential to mitigate some chronic diseases of aging and thereby increase life expectancy when present in adequate amounts. However, only limited knowledge exists regarding ERGO content in the human diet. Since ERGO is produced primarily by fungi, mushrooms are known to be the leading dietary source, but ERGO is found in relatively low amounts throughout the food chain as a result of soil-borne fungi or bacteria passing it on to plants through their roots. Some conventional agricultural practices that negatively impact soil fungi, such as excessive soil disturbance (plowing), can significantly reduce ERGO content of food crops when compared to regenerative practices such as eliminating tillage of the soil (No-Till). This has led us to the concept that ERGO may be a definitive connection between soil health and human health.

Matching chemical properties to molecular biological activities opens a new perspective on L-ergothioneine

L-ergothioneine is a low-molecular weight natural product, the chemical structure of which comprises oxygen-, nitrogen- and sulfur-containing functional groups. This gives L-ergothioneine specific physicochemical properties and allows to better understanding its chemical reactivity, which is primarily due to the 2-thio-imidazole group. Here, I review how different modes of chemical reactivity account for the reported molecular biological activities of L-ergothioneine. By matching the physicochemical properties to the biological properties of L-ergothioneine, a new perspective of the function and the mode of action of this enigmatic molecule emerges into the limelight.

Pyrroloquinoline quinone extends Caenorhabditis elegans' longevity through the insulin/IGF1 signaling pathway-mediated activation of autophagy

Aging is the leading cause of human morbidity and death worldwide. Pyrroloquinoline quinone (PQQ) is a water-soluble vitamin-like compound that has strong anti-oxidant capacity. Beneficial effects of PQQ on lifespan have been discovered in the model organism Caenorhabditis elegans (C. elegans), yet the underlying mechanisms remain unclear. In the current study, we hypothesized that the longevity-extending effect of PQQ may be linked to autophagy and insulin/IGF1 signaling (IIS) in C. elegans. Our data demonstrate that PQQ at a concentration of 1 mM maximally extended the mean life of C. elegans by 33.1%. PQQ increased locomotion and anti-stress ability, and reduced fat accumulation and reactive oxygen species (ROS) levels. There was no significant lifespan extension in PQQ-treated daf-16, daf-2, and bec-1 mutants, suggesting that these IIS- and autophagy-related genes may mediate the anti-aging effects of the PQQ. Furthermore, PQQ raised mRNA expression and the nuclear localization of the pivotal transcription factor daf-16, and then activated its downstream targets sod-3, clt-1, and hsp16.2. Enhanced activity of the autophagy pathway was also observed in PQQ-fed C. elegans, as evidenced by increased expression of the key autophagy genes including lgg-1, and bec-1, and also by an increase in the GFP::LGG-1 puncta. Inactivation of the IIS pathway-related genes daf-2 or daf-16 by RNAi partially blocked the increase in autophagy activity caused by PQQ treatment, suggesting that autophagy may be regulated by IIS. This study demonstrates that anti-aging properties of PQQ, in the C. elegans model, may be mediated via the IIS pathway and autophagy.

Ergothioneine supplementation in people with metabolic syndrome (ErgMS): protocol for a randomised, double-blind, placebo-controlled pilot study

Background

Ergothioneine is a naturally occurring metabolite of histidine found in many foods and in high amounts in mushrooms. In vivo, ergothioneine acts as an antioxidant and is widely distributed in most mammalian tissues. While ergothioneine is sold as a dietary supplement for its antioxidant and anti-inflammatory properties, to date there are no published intervention trials examining its health benefits in humans. The aim of this work was to develop a study protocol for a pilot interventional trial that will establish the primary and secondary outcomes, and the power required, for a definitive randomised controlled trial to test the hypothesis that ergothioneine supplementation is beneficial for people with metabolic syndrome.

Methods

We have designed the ErgMS study as a single-centre, randomised, double-blind, placebo-controlled, 3-arm parallel, pilot intervention trial, which aims to supplement participants with either placebo, 5 or 30 mg/day ergothioneine for 12 weeks. Measurements of metabolic syndrome risk factors, serum markers of oxidative stress (lipid peroxidation), inflammation, blood platelet function and liver function will take place at baseline, and after 6 weeks and 12 weeks of supplementation. In addition, we will examine if there are any changes in the serum metabolome in response to ergothioneine supplementation. Linear regression and two-way ANOVA will be utilised to analyse the association between ergothioneine and measured variables.

Discussion

The ErgMS study will be the first study to address the question does ergothioneine supplementation have health benefits for people with metabolic syndrome. Study results will provide preliminary data as to which dose may improve inflammatory markers in adults with metabolic syndrome and will inform dose and primary outcome selection for a definitive randomised controlled trial.

Trial registration

ISRCTN, ISRCTN25890011 Registered February 10^th, 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00929-6.

Vitamin A and Vitamin E: Will the Real Antioxidant Please Stand Up?

Vitamin A, acting through its metabolite, all-trans-retinoic acid, is a potent transcriptional regulator affecting expression levels of hundreds of genes through retinoic acid response elements present within these genes. However, the literature is replete with claims that consider vitamin A to be an antioxidant vitamin, like vitamins C and E. This apparent contradiction in the understanding of how vitamin A acts mechanistically within the body is a major focus of this review. Vitamin E, which is generally understood to act as a lipophilic antioxidant protecting polyunsaturated fatty acids present in membranes, is often proposed to be a transcriptional regulator. The evaluation of this claim is another focus of the review. We conclude that vitamin A is an indirect antioxidant, whose indirect function is to transcriptionally regulate a number of genes involved in mediating the body's canonical antioxidant responses. Vitamin E, in addition to being a direct antioxidant, prevents the increase of peroxidized lipids that alter both metabolic pathways and gene expression profiles within tissues and cells. However, there is little compelling evidence that vitamin E has a direct transcriptional mechanism like that of vitamin A. Thus, we propose that the term antioxidant not be applied to vitamin A, and we discourage the use of the term transcriptional mediator when discussing vitamin E.

Prospective study of dietary mushroom intake and risk of mortality: results from continuous National Health and Nutrition Examination Survey (NHANES) 2003-2014 and a meta-analysis

Background

Whether mushroom consumption, which is a rich source of potent antioxidants ergothioneine and glutathione, vitamins, and minerals (e.g., selenium & copper), is associated with a lower mortality risk is not well understood. This study aimed to examine the association between mushroom consumption and risk of mortality in a prospective cohort study and a meta-analysis of prospective cohort studies.

Methods

We followed 30,378 participants from the continuous National Health and Nutrition Examination Survey (NHANES) extant data (2003-2014). Dietary mushroom intake was assessed using up to two 24-h recalls. Mortality was evaluated in all participants linked to the National Death Index mortality data through December 31, 2015. We used Cox proportional hazards regression models to calculate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs). We also conducted a meta-analysis, including results from our present study and 4 other cohort studies.

Results

During a mean (SD) of 6.7 (3.4) years of follow-up, a total of 2855 death cases were documented among NHANES participants. In our analysis of continuous NHANES, we found a non-significant association between mushroom consumption and all-cause mortality (adjusted hazard ratio (HR) = 0.84; 95% CI: 0.67-1.06) after adjusting for demographic, major lifestyle factors, overall diet quality, and other dietary factors, including total energy. The meta-analysis of prospective cohort studies, including 601,893 individuals, showed that mushroom consumption was associated with a lower risk of all-cause mortality (pooled risk ratio: 0.94; 95% CI: 0.91, 0.98).

Conclusion

In a meta-analysis of prospective cohort studies, mushroom consumption was associated with a lower risk of all-cause mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00738-w.

The role of biofactors in the prevention and treatment of age-related diseases

The present demographic changes toward an aging society caused a rise in the number of senior citizens and the incidence and burden of age-related diseases (such as cardiovascular diseases [CVD], cancer, nonalcoholic fatty liver disease [NAFLD], diabetes mellitus, and dementia), of which nearly half is attributable to the population ≥60 years of age. Deficiencies in individual nutrients have been associated with increased risks for age-related diseases and high intakes and/or blood concentrations with risk reduction. Nutrition in general and the dietary intake of essential and nonessential biofactors is a major determinant of human health, the risk to develop age-related diseases, and ultimately of mortality in the older population. These biofactors can be a cost-effective strategy to prevent or, in some cases, even treat age-related diseases. Examples reviewed herein include omega-3 fatty acids and dietary fiber for the prevention of CVD, α-tocopherol (vitamin E) for the treatment of biopsy-proven nonalcoholic steatohepatitis, vitamin D for the prevention of neurodegenerative diseases, thiamine and α-lipoic acid for the treatment of diabetic neuropathy, and the role of folate in cancer epigenetics. This list of potentially helpful biofactors in the prevention and treatment of age-related diseases, however, is not exhaustive and many more examples exist. Furthermore, since there is currently no generally accepted definition of the term biofactors, we here propose a definition that, when adopted by scientists, will enable a harmonization and consistent use of the term in the scientific literature.

DNA damage is inversely associated to blood levels of DHA and EPA fatty acids in Brazilian children and adolescents

This study aimed to investigate the association between DNA damage and blood levels of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), retinol, beta-carotene and riboflavin in Brazilian children and adolescents. Subjects (n = 140) were healthy boys and girls aged 9 to 13 years in Ribeirão Preto (SP, Brazil). Data collection included anthropometry, assessment of energy intake and blood sampling. DNA damage was evaluated by single-cell gel electrophoresis (comet assay). Principal component analysis (PCA) was used to verify associations between blood concentrations of vitamins, polyunsaturated fatty acids and DNA damage. Multiple regression analyses, k-means cluster, and analysis of covariance (ANCOVA), adjusted for confounding variables such as age, sex, energy intake, body mass index and total cholesterol (when needed), were applied to confirm the associations. PCA explained 69.4% of the inverse relationships between DNA damage and blood levels of DHA, EPA, retinol, and beta-carotene. Results were confirmed by ANCOVA and multiple regression analyses for DHA and EPA. In conclusion, omega-3-fatty acids were inversely associated with DNA damage in Brazilian children and adolescents and may be a protective factor against the development of future diseases.

Association of mushroom consumption with all-cause and cause-specific mortality among American adults: prospective cohort study findings from NHANES III

BACKGROUND

Whether mushroom consumption, which is rich in several bioactive compounds, including the crucial antioxidants ergothioneine and glutathione, is inversely associated with low all-cause and cause-specific mortality remains uncertain. This study aimed to prospectively investigate the association between mushroom consumption and all-cause and cause-specific mortality risk.

METHODS

Longitudinal analyses of participants from the Third National Health and Nutrition Examination Survey (NHANES III) extant data (1988-1994). Mushroom intake was assessed by a single 24-h dietary recall using the US Department of Agriculture food codes for recipe foods. All-cause and cause-specific mortality were assessed in all participants linked to the National Death Index mortality data (1988-2015). We used Cox proportional hazards regression models to calculate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for all-cause and cause-specific mortality.

RESULTS

Among 15,546 participants included in the current analysis, the mean (SE) age was  44.3 (0.5) years. During a mean (SD) follow-up duration of 19.5 (7.4) years , a total of 5826 deaths were documented. Participants who reported consuming mushrooms had lower risk of all-cause mortality compared with those without mushroom intake (adjusted hazard ratio (HR) = 0.84; 95% CI: 0.73-0.98) after adjusting for demographic, major lifestyle factors, overall diet quality, and other dietary factors including total energy. When cause-specific mortality was examined, we did not observe any statistically significant associations with mushroom consumption. Consuming 1-serving of mushrooms per day instead of 1-serving of processed or red meats was associated with lower risk of all-cause mortality (adjusted HR = 0.65; 95% CI: 0.50-0.84). We also observed a dose-response relationship between higher mushroom consumption and lower risk of all-cause mortality (P-trend = 0.03).

CONCLUSION

Mushroom consumption was associated with a lower risk of total mortality in this nationally representative sample of US adults.

Metabolomics and cardiovascular imaging: a combined approach for cardiovascular ageing

The purpose of this review is to explore how metabolomics can help uncover new biomarkers and mechanisms for cardiovascular ageing. Cardiovascular ageing refers to cardiovascular structural and functional alterations that occur with chronological ageing and that can lead to the development of cardiovascular disease. These alterations, which were previously only detectable on tissue histology or corroborated on blood samples, are now detectable with modern imaging techniques. Despite the emergence of powerful new imaging tools, clinical investigation into cardiovascular ageing is challenging because ageing is a life course phenomenon involving known and unknown risk factors that play out in a dynamic fashion. Metabolomic profiling measures large numbers of metabolites with diverse chemical properties. Metabolomics has the potential to capture changes in biochemistry brought about by pathophysiologic processes as well as by normal ageing. When combined with non-invasive cardiovascular imaging tools, metabolomics can be used to understand pathological consequences of cardiovascular ageing. This review will summarize previous metabolomics and imaging studies in cardiovascular ageing. These methods may be a clinically relevant and novel approach to identify mechanisms of cardiovascular ageing and formulate or personalize treatment strategies.

Implications for an imidazol-2-yl carbene intermediate in the rhodanase-catalyzed C-S bond formation reaction of anaerobic ergothioneine biosynthesis

In the anaerobic ergothioneine biosynthetic pathway, a rhodanese domain containing enzyme (EanB) activates tne hercynine's sp² ε-C-H Dona ana replaces it with a C-S bond to produce ergothioneine. The key intermediate for this trans-sulfuration reaction is the Cys412 persulfide. Substitution of the EanB-Cys412 persulfide with a Cys412 perselenide does not yield the selenium analog of ergothioneine, selenoneine. However, in deuterated buffer, the perselenide-modified EanB catalyzes the deuterium exchange between hercynine's sp² ε-C-H bond and D₂O. Results from QM/MM calculations suggest that the reaction involves a carbene intermediate and that Tyr353 plays a key role. We hypothesize that modulating the pK_a of Tyr353 will affect the deuterium-exchange rate. Indeed, the 3,5-difluoro tyrosine containing EanB catalyzes the deuterium exchange reaction with k _ex of ~10-fold greater than the wild-type EanB (EanB_WT). With regards to potential mechanisms, these results support the involvement of a carbene intermediate in EanB-catalysis, rendering EanB as one of the few carbene-intermediate involving enzymatic systems.

Higher Mushroom Consumption Is Associated with Lower Risk of Cancer: A Systematic Review and Meta-Analysis of Observational Studies

Mushrooms are rich in bioactive compounds. The potential health benefits associated with mushroom intake have gained recent research attention. We thus conducted a systematic review and meta-analysis to assess the association between mushroom intake and risk of cancer at any site. We searched MEDLINE, Web of Science, and Cochrane Library to identify relevant studies on mushroom intake and cancer published from 1 January, 1966, up to 31 October, 2020. Observational studies (n = 17) with RRs, HRs, or ORs and 95% CIs of cancer risk for ≥2 categories of mushroom intake were eligible for the present study. Random-effects meta-analyses were conducted. Higher mushroom consumption was associated with lower risk of total cancer (pooled RR for the highest compared with the lowest consumption groups: 0.66; 95% CI: 0.55, 0.78; n = 17). Higher mushroom consumption was also associated with lower risk of breast cancer (pooled RR for the highest compared with the lowest consumption groups: 0.65; 95% CI: 0.52, 0.81; n = 10) and nonbreast cancer (pooled RR for the highest compared with the lowest consumption groups: 0.80; 95% CI: 0.66, 0.97; n = 13). When site-specific cancers were examined, a significant association with mushroom consumption was only observed with breast cancer; this could be due to the small number of studies that were conducted with other cancers. There was evidence of a significant nonlinear dose-response association between mushroom consumption and the risk of total cancer (P-nonlinearity = 0.001; n = 7). Limitations included the potential for recall and selection bias in case-control designs, which comprised 11 out of the 17 studies included in this meta-analysis, and the large variation in the adjustment factors used in the final models from each study. The association between higher mushroom consumption and lower risk of cancer, particularly breast cancer, may indicate a potential protective role for mushrooms in the diet.

An isocaloric moderately high-fat diet extends lifespan in male rats and Drosophila

The health effect of dietary fat has been one of the most vexing issues in the field of nutrition. Few animal studies have examined the impact of high-fat diets on lifespan by controlling energy intake. In this study, we found that compared to a normal diet, an isocaloric moderately high-fat diet (IHF) significantly prolonged lifespan by decreasing the profiles of free fatty acids (FFAs) in serum and multiple tissues via downregulating FFA anabolism and upregulating catabolism pathways in rats and flies. Proteomics analysis in rats identified PPRC1 as a key protein that was significantly upregulated by nearly 2-fold by IHF, and among the FFAs, only palmitic acid (PA) was robustly and negatively associated with the expression of PPRC1. Using PPRC1 transgenic RNAi/overexpression flies and in vitro experiments, we demonstrated that IHF significantly reduced PA, which could upregulate PPRC1 through PPARG, resulting in improvements in oxidative stress and inflammation and prolonging the lifespan.

Chemical modifications of proteins and their applications in metalloenzyme studies

Protein chemical modifications are important tools for elucidating chemical and biological functions of proteins. Several strategies have been developed to implement these modifications, including enzymatic tailoring reactions, unnatural amino acid incorporation using the expanded genetic codes, and recognition-driven transformations. These technologies have been applied in metalloenzyme studies, specifically in dissecting their mechanisms, improving their enzymatic activities, and creating artificial enzymes with non-natural activities. Herein, we summarize some of the recent efforts in these areas with an emphasis on a few metalloenzyme case studies.

In Vitro Reconstitution of a Five-Step Pathway for Bacterial Ergothioneine Catabolism

Ergothioneine is a histidine-derived sulfur metabolite that is biosynthesized by bacteria and fungi. Plants and animals absorb ergothioneine as a micronutrient from their environment or nutrition. Several different mechanisms of microbial ergothioneine production have been described in the past ten years. Much less is known about the genetic and structural basis for ergothioneine catabolism. In this report, we describe the in vitro reconstitution of a five-step pathway that degrades ergothioneine to l-glutamate, trimethylamine, hydrogen sulfide, carbon dioxide, and ammonia. The first two steps are catalyzed by the two enzymes ergothionase and thiourocanate hydratase. These enzymes are closely related to the first two enzymes in histidine catabolism. However, the crystal structure of thiourocanate hydratase from the firmicute Paenibacillus sp. reveals specific structural features that strictly differentiate the activity of this enzyme from that of urocanate hydratases. The final two steps are catalyzed by metal-dependent hydrolases that share most homology with the last two enzymes in uracil catabolism. The early and late part of this pathway are connected by an entirely new enzyme type that catalyzes desulfurization of a thiohydantoin intermediate. Homologous enzymes are encoded in many soil-dwelling firmicutes and proteobacteria, suggesting that bacterial activity may have a significant impact on the environmental availability of ergothioneine.

Does the High Prevalence of Vitamin D Deficiency in African Americans Contribute to Health Disparities?

African Americans have higher incidence of, and mortality from, many health-related problems than European Americans. They also have a 15 to 20-fold higher prevalence of severe vitamin D deficiency. Here we summarize evidence that: (i) this health disparity is partly due to insufficient vitamin D production, caused by melanin in the skin blocking the UVB solar radiation necessary for its synthesis; (ii) the vitamin D insufficiency is exacerbated at high latitudes because of the combination of dark skin color with lower UVB radiation levels; and (iii) the health of individuals with dark skin can be markedly improved by correcting deficiency and achieving an optimal vitamin D status, as could be obtained by supplementation and/or fortification. Moderate-to-strong evidence exists that high 25-hydroxyvitamin D levels and/or vitamin D supplementation reduces risk for many adverse health outcomes including all-cause mortality rate, adverse pregnancy and birth outcomes, cancer, diabetes mellitus, Alzheimer's disease and dementia, multiple sclerosis, acute respiratory tract infections, COVID-19, asthma exacerbations, rickets, and osteomalacia. We suggest that people with low vitamin D status, which would include most people with dark skin living at high latitudes, along with their health care provider, consider taking vitamin D3 supplements to raise serum 25-hydroxyvitamin D levels to 30 ng/mL (75 nmol/L) or possibly higher.

Ergothioneine, recent developments

There has been a recent surge of interest in the unique low molecular weight dietary thiol/thione, ergothioneine. This compound can accumulate at high levels in the body from diet and may play important physiological roles in human health and development, and possibly in prevention and treatment of disease. Blood levels of ergothioneine decline with age and onset of various diseases. Here we highlight recent advances in our knowledge of ergothioneine.

Fluorescence assay for the determination of glutathione based on a ring-fused 2-pyridone derivative in dietary supplements

Herein, a novel fluorescent method for the determination of GSH levels in aqueous solutions involving the utilization of citric acid as a derivatization reagent was developed. Therefore, the crucial parameters of the derivatization process were established from what has resulted in the development of a sensitive, reproducible, and accurate GSH assay. The method was validated, and its applicability in the characterization of the GSH concentration in dietary supplements concerning the selectivity in the determination of GSH over GSSG was both confirmed. The chemical structure of the new fluorophore 3-[(carboxymethyl)carbamoyl]-5-oxo-2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyridine-7-carboxylic acid - CTPC was elucidated using detailed NMR: one-dimensional (¹H, ¹³C), as well as two-dimensional NMR spectra (¹H-¹H COSY, ¹H-¹³C HSQC, ¹H-¹³C HMBC, ¹H-¹⁵N HSQC, ¹H-¹⁵N HMBC) experiments. Besides, the essential optical, biological and antioxidative properties of CTPC were investigated.

In Vitro Production of Ergothioneine Isotopologues

Ergothioneine is an emerging component of the redox homeostasis system in human cells and in microbial pathogens, such as Mycobacterium tuberculosis and Burkholderia pseudomallei. The synthesis of stable isotope-labeled ergothioneine derivatives may provide important tools for deciphering the distribution, function, and metabolism of this compound in vivo. We describe a general protocol for the production of ergothioneine isotopologues with programmable ² H, ¹⁵ N, ¹³ C, ³⁴ S, and ³³ S isotope labeling patterns. This enzyme-based approach makes efficient use of commercial isotope reagents and is also directly applicable to the synthesis of radio-isotopologues.

Roles of interacting stress-related genes in lifespan regulation: insights for translating experimental findings to humans

AIM

Experimental studies provided numerous evidence that caloric/dietary restriction may improve health and increase the lifespan of laboratory animals, and that the interplay among molecules that sense cellular stress signals and those regulating cell survival can play a crucial role in cell response to nutritional stressors. However, it is unclear whether the interplay among corresponding genes also plays a role in human health and lifespan.

METHODS

Literature about roles of cellular stressors have been reviewed, such as amino acid deprivation, and the integrated stress response (ISR) pathway in health and aging. Single nucleotide polymorphisms (SNPs) in two candidate genes (GCN2/EIF2AK4 and CHOP/DDIT3) that are closely involved in the cellular stress response to amino acid starvation, have been selected using information from experimental studies. Associations of these SNPs and their interactions with human survival in the Health and Retirement Study data have been estimated. The impact of collective associations of multiple interacting SNP pairs on survival has been evaluated, using a recently developed composite index: the SNP-specific Interaction Polygenic Risk Score (SIPRS).

RESULTS

Significant interactions have been found between SNPs from GCN2/EIF2AK4 and CHOP/DDI3T genes that were associated with survival 85+ compared to survival between ages 75 and 85 in the total sample (males and females combined) and in females only. This may reflect sex differences in genetic regulation of the human lifespan. Highly statistically significant associations of SIPRS [constructed for the rs16970024 (GCN2/EIF2AK4) and rs697221 (CHOP/DDIT3)] with survival in both sexes also been found in this study.

CONCLUSION

Identifying associations of the genetic interactions with human survival is an important step in translating the knowledge from experimental to human aging research. Significant associations of multiple SNPxSNP interactions in ISR genes with survival to the oldest old age that have been found in this study, can help uncover mechanisms of multifactorial regulation of human lifespan and its heterogeneity.

Bruce Nathan Ames - Paradigm shifts inside the cancer research revolution

Dr. Bruce Ames turned 92 on December 16, 2020. He considers his most recent work linking adequate consumption of 30 known vitamins and minerals with successful aging to be his most important contribution. With the passage of time, it is not uncommon for the accomplishments of a well-known scientist to undergo a parsimonious reductionism in the public mind - Pasteur's vaccine, Mendel's peas, Pavlov's dogs, Ames' test. Those of us in the research generation subsequent to Dr. Ames' are undoubtedly affected by our own unconscious tendencies toward accepting the outstanding achievements of the past as commonplace. In doing so, seminal advances made by earlier investigators are often inadvertently subsumed into common knowledge. But having followed Ames' work since the mid-1970s, we are cognizant that the eponymous Ames Test is but a single chapter in a long and rich narrative. That narrative begins with Ames' classic studies on the histidine operon of Salmonella, for which he was elected to the National Academy of Sciences. A summary of the historical progression of the understanding of chemical carcinogenesis to which Ames and his colleagues contributed is provided. Any summary of a topic as expansive and complex as the ongoing unraveling of the mechanisms underlying chemical carcinogenesis will only touch upon some of the major conceptual advances to which Ames and his colleagues contributed. We hope that scientists of all ages familiar with Ames only through the eponymous Ames Test will further investigate the historical progression of the conceptualization of cancer caused by chemical exposure. As the field of chemical carcinogenesis gradually moves away from primary reliance on animal testing to alternative protocols under the rubric of New Approach Methodologies (NAM) an understanding of where we have been might help to guide where we should go.

Ergothioneine Mitigates Telomere Shortening under Oxidative Stress Conditions

Shortened telomeres are associated with aging and age-related diseases. Oxidative stress is thought to be a major contributor to telomere shortening, and antioxidants may be able to mitigate these effects. Ergothioneine is a naturally occurring amino acid with potent antioxidant properties. In order to investigate ergothioneine's effects on telomere length, we cultured primary human fibroblasts under standard and oxidative (10 µM H₂O₂) conditions and treated cells with 0.04, 0.1, 0.3, or 1.0 mg/ml ergothioneine for 8 weeks. Telomere length measurements were performed using high-throughput quantitative fluorescent in situ hybridization (HT Q-FISH). Treatment with ergothioneine transiently increased relative telomerase activity after 24 h (p < 0.05 for all concentrations). Under oxidative conditions, ergothioneine treatment resulted in significantly longer median telomere length and 20^th percentile telomere length, and significantly reduced the percentage of short telomeres (<3 kilobase pairs) for all treatment concentrations after 8 weeks. Telomere shortening rate was also reduced. Overall, ergothioneine demonstrated beneficial effects by decreasing the rate of telomere shortening and preserving telomere length under oxidative stress conditions. Our data support a potential role for ergothioneine in oxidative stress-related conditions and healthy aging.

The biology of ergothioneine, an antioxidant nutraceutical

Ergothioneine (ERG) is an unusual thio-histidine betaine amino acid that has potent antioxidant activities. It is synthesised by a variety of microbes, especially fungi (including in mushroom fruiting bodies) and actinobacteria, but is not synthesised by plants and animals who acquire it via the soil and their diet, respectively. Animals have evolved a highly selective transporter for it, known as solute carrier family 22, member 4 (SLC22A4) in humans, signifying its importance, and ERG may even have the status of a vitamin. ERG accumulates differentially in various tissues, according to their expression of SLC22A4, favouring those such as erythrocytes that may be subject to oxidative stress. Mushroom or ERG consumption seems to provide significant prevention against oxidative stress in a large variety of systems. ERG seems to have strong cytoprotective status, and its concentration is lowered in a number of chronic inflammatory diseases. It has been passed as safe by regulatory agencies, and may have value as a nutraceutical and antioxidant more generally.