Impact of aging and ergothioneine pre-treatment on naphthalene toxicity in lung.

Aging increases susceptibility to lung disease, but the topic is understudied, especially in relation to environmental exposures with the bulk of rodent studies using young adults. This study aims to define the pulmonary toxicity of naphthalene (NA) and the impacts of a dietary antioxidant, ergothioneine (ET), in the liver and lungs of middle-aged mice. NA causes a well-characterized pattern of conducting airway epithelial injury in the lung in young adult mice, but NA's toxicity has not been characterized in middle-aged mice, aged 1-1.5 years. ET is a dietary antioxidant that is synthesized by bacteria and fungi. The ET transporter (ETT), SLC22A4, is upregulated in tissues that experience high levels of oxidative stress. In this study, middle-aged male and female C57BL/6 J mice, maintained on an ET-free synthetic diet from conception, were gavaged with 70 mg/kg of ET for five consecutive days. On day 8, the mice were exposed to a single intraperitoneal NA dose of 50, 100, 150, or 200 mg/kg. At 24 hours post NA injection samples were collected and analyzed for ET concentration and reduced (GSH) and oxidized glutathione (GSSG) concentrations. Histopathology, morphometry, and gene expression were examined. Histopathology of mice exposed to 100 mg/kg of NA suggests reduction in toxicity in the terminal airways of both male (p ≤ 0.001) and female (p ≤ 0.05) middle-aged mice by the ET pretreatment. Our findings in this study are the first to document the toxicity of NA in middle-aged mice and show some efficacy of ET in reducing NA toxicity.

Ergothioneine inhibits the progression of osteoarthritis via the Sirt6/NF-κB axis both in vitro and in vivo.

Osteoarthritis (OA), which is a major cause of serious arthralgia and disability among the elderly, has long plagued numerous populations. However, the specific molecular mechanisms involved in the etiology of OA are unclear. SIRT6 plays a critical function in the development of several inflammatory and aging-associated diseases. A study by D'Onofrio demonstrates that ergothioneine (EGT) is an effective activator of SIRT6. As revealed by previous reports, EGT exerts beneficial effects on the mouse body, including resistance to oxidation, tumor, and inflammation. Therefore, this work attempted to identify the inflammatory resistance of EGT and explore its effects on the incidence and development of OA. Mouse chondrocyte stimulation using varying levels of EGT and 10 ng/mL IL-1ß. According to in vitro experiments, EGT significantly reduced the decomposition of collagen II and aggrecan in OA chondrocytes, as well as inhibited the overexpression of PGE2, NO, IL-6, TNF-α, iNOs, COX-2, MMP-13, and ADAMTS5. In the present work, EGT hindered the NF-κB activity by activating the SIRT6 pathway in OA chondrocytes, which in turn, significantly attenuated the inflammatory response resulting from IL to 1ß. The inhibitory effect of EGT on the progression of OA was demonstrated by the mouse DMM model experiment. Thus, this study revealed that EGT was effective in anti-OA treatment.

Ergothioneine improves myocardial remodeling and heart function after acute myocardial infarction via S-glutathionylation through the NF-ĸB dependent Wnt5a-sFlt-1 pathway.

Myocardial infarction (MI) remains the leading cause of cardiovascular death worldwide. Studies have shown that soluble fms-like tyrosine kinase-1 (sFlt-1) has a harmful effect on the heart after MI. However, ergothioneine (ERG) has been shown to have protective effects in rats with preeclampsia by reducing circulating levels of sFlt-1. In this study, we aimed to investigate the mechanism by which ERG protects the heart after MI in rats. Our results indicate that treatment with 10 mg/kg ERG for 7 days can improve cardiac function as determined by echocardiography. Additionally, ERG can reduce the size of the damaged area, prevent heart remodeling, fibrosis, and reduce cardiomyocyte death after MI. To explain the mechanism behind the cardioprotective effects of ERG, we conducted several experiments. We observed a significant reduction in the expression of monocyte chemoattractant protein-1 (MCP-1), p65, and p-p65 proteins in heart tissues of ERG-treated rats compared to the control group. ELISA results also showed that ERG significantly reduced plasma levels of sFlt-1. Using Glutaredoxin-1 (GLRX) and CD31 immunofluorescence, we found that GLRX was expressed in clusters in the myocardial tissue surrounding the coronary artery, and ERG can reduce the expression of GLRX caused by MI. In vitro experiments using a human coronary artery endothelial cell (HCAEC) hypoxia model confirmed that ERG can reduce the expression of sFlt-1, GLRX, and Wnt5a. These findings suggest that ERG protects the heart from MI damage by reducing s-glutathionylation through the NF-ĸB-dependent Wnt5a-sFlt-1 pathway.

Protective Effect of Ergothioneine Against Stroke in Rodent Models.

Ergothioneine (ET) is a naturally occurring antioxidant and cytoprotective agent that is synthesized by fungi and certain bacteria. Recent studies have shown a beneficial effect of ET on neurological functions, including cognition and animal models of depression. The aim of this study is to elucidate a possible effect of ET in rodent models of stroke. Post-ischemic intracerebroventricular (i.c.v.) infusion of ET significantly reduced brain infarct volume by as early as 1 day after infusion in rats, as shown by triphenyltetrazolium chloride (TTC) assay. There was a dose-dependent increase in protection, from 50 to 200 ng of ET infusion. These results suggest that ET could have a protective effect on CNS neurons. We next elucidated the effect of systemic ET on brain infarct volume in mice after stroke. Daily i.p. injection of 35 mg/kg ET (the first dose being administered 3 h after stroke) had no significant effect on infarct volume. However, daily i.p. injections of 70 mg/kg, 100 mg/kg, 125 mg/kg and 150 mg/kg ET, with the first dose administered 3 h after stroke, significantly decreased infarct volume at 7 days after vessel occlusion in mice. In order to elucidate at what time interval during the 7 days there could be effective protection, a second set of experiments was carried out in mice, using one of the effective loading protocols, i.e. 125 mg/kg i.p. ET but the brains were analyzed at 1, 4 and 7 days post-stroke by MRI. We found that ET was already protective against neuronal injury and decreased the size of the brain infarct from as early as 1 day post-stroke. Behavioral experiments carried out on a third set of mice (using 125 mg/kg i.p. ET) showed that this was accompanied by significant improvements in certain behaviors (pole test) at 1 day after stroke. Together, results of this study indicate that i.c.v. and systemic ET are effective in reducing brain infarct volume after stroke in rodent models.

L-ergothioneine and metformin alleviates liver injury in experimental type-2 diabetic rats via reduction of oxidative stress, inflammation, and hypertriglyceridemia.

Type-2 diabetes (T2D) is associated with liver toxicity. L-ergothioneine (L-egt) has been reported to reduce toxicity in tissues exposed to injury, while metformin is commonly prescribed to manage T2D. Hence, this study evaluates the hepatoprotective role of L-egt, with or without metformin, in T2D male rats. A total of 36 adult male Sprague-Dawley rats were randomly divided into non-diabetic (n = 12) and diabetic (n = 24) groups. After induction of diabetes, animals were divided into six groups (n = 6) and treated orally either with deionized water, L-egt (35 mg/kg bodyweight (bwt)), metformin (500 mg/kg bwt), or a combination of L-egt and metformin for 7 weeks. Body weight and blood glucose were monitored during the experiment. Thereafter, animals were euthanized and liver tissue was excised for biochemical, ELISA, real-time quantitative PCR, and histopathological analysis. L-egt with or without metformin reduced liver hypertrophy, liver injury, triglycerides, oxidative stress, and inflammation. Also, L-egt normalized mRNA expression of SREBP-1c, fatty acid synthase, nuclear factor kappa B, transforming growth factor ß1, nuclear factor erythroid 2-related factor 2, and sirtuin-1 in diabetic rats. Furthermore, co-administration of L-egt with metformin to diabetic rats reduced blood glucose and insulin resistance. These results provide support to the therapeutic benefits of L-egt in the management of liver complications associated with T2D.

Examining the health effects and bioactive components in Agaricus bisporus mushrooms: a scoping review.

There is evidence from both in vitro and animal models that the consumption of edible mushrooms has beneficial effects on health. It is unclear whether similar effects exist in humans and which bioactive compounds are present. This review synthesises the evidence on the world's most commonly consumed mushroom, Agaricus bisporus to (i) examine its effect on human health outcomes; and (ii) determine the nutrient density of its bioactive compounds, which may explain their health effects. A systematic literature search was conducted on the consumption of A. bisporus, without date and study design limits. Bioactive compounds included ergosterol, ergothioneine, flavonoids, glucans and chitin. Two authors independently identified studies for inclusion and assessed methodological quality. Beneficial effects of A. bisporus on metabolic syndrome, immune function, gastrointestinal health and cancer, with the strongest evidence for the improvement in Vitamin D status in humans, were found. Ultraviolet B (UVB) exposed mushrooms may increase and maintain serum 25(OH)D levels to a similar degree as vitamin D supplements. A. bisporus contain beta-glucans, ergosterol, ergothioneine, vitamin D and an antioxidant compound usually reported as flavonoids; with varying concentrations depending on the type of mushroom, cooking method and duration, and UVB exposure. Further research is required to fully elucidate the bioactive compounds in mushrooms using vigorous analytical methods and expand the immunological markers being tested. To enable findings to be adopted into clinical practice and public health initiatives, replication of existing studies in different population groups is required to confirm the impact of A. bisporus on human health.

Ergothioneine Antioxidant Function: From Chemistry to Cardiovascular Therapeutic Potential.

Ergothioneine (ESH), the betaine of 2-mercapto-L-histidine, is a water-soluble naturally occurring amino acid with antioxidant properties. ESH accumulates in several human and animal tissues up to millimolar concentration through its high affinity transporter, namely the organic cation transporter 1 (OCTN1). ESH, first isolated from the ergot fungus (Claviceps purpurea), is synthesized only by Actinomycetales and non-yeast-like fungi. Plants absorb ESH via symbiotic associations between their roots and soil fungi, whereas mammals acquire it solely from dietary sources. Numerous evidence demonstrated the antioxidant and cytoprotective effects of ESH, including protection against cardiovascular diseases, chronic inflammatory conditions, ultraviolet radiation damages, and neuronal injuries. Although more than a century after its discovery has gone by, our understanding on the in vivo ESH mechanism is limited and this compound still intrigues researchers. However, recent evidence about differences in chemical redox behavior between ESH and alkylthiols, such as cysteine and glutathione, has opened new perspectives on the role of ESH during oxidative damage. In this short review, we discuss the role of ESH in the complex machinery of the cellular antioxidant defense focusing on the current knowledge on its chemical mechanism of action in the protection against cardiovascular disease.

A Safety Evaluation of a Nature-Identical l-Ergothioneine in Sprague Dawley Rats.

l-(+) Ergothioneine is a naturally occurring thiol amino acid with antioxidant properties and potential benefits as a dietary supplement. Despite its century-old identification and wide distribution in human food, little is known of its mechanism of action and safety. The nature-identical biomimetic of l-(+) ergothioneine, produced by Mironova Labs and supplied as Mironova (EGT+), has been investigated in the present studies for its mutagenic and toxicologic potential. In a plate incorporation and preincubation assay with Salmonella typhimurium strains TA98, 100, 1,535, and 1,537 and Escherichia coli WP2uvrA strain, at dose concentrations of 1.58, 5, 15.8, 50, 158, 500, 1,580, and 5,000 µg/plate with and without metabolic activation, no cytotoxicity or mutagenicity was observed. Following a preliminary 28-day study, a repeated dose 90-day gavage study at dose levels of 0, 400, 800, and 1,600 mg/kg body weight (bw)/d in Sprague Dawley rats, in which dose-proportional systemic absorption was confirmed by plasma analysis, no adverse clinical, body weight/gain, food consumption and efficiency, clinical pathology, or histopathological changes associated with the administration of the nature-identical ergothioneine were observed. In conclusion, EGT+ administered over 90 days was well tolerated with a no adverse effect level at 1,600 mg/kg bw/d, the highest dose tested for male and female rats. In addition, the nature-identical test substance, EGT+ was not mutagenic in a bacterial reverse mutation assay at plate concentrations of up to 5,000 µg/mL in the presence or absence of metabolic activation.

Top 10 botanical ingredients in 2010 anti-aging creams.

New developments in the realm of skin rejuvenation such as phytotherapy are at an astounding increasing pace in the cosmeceutical market. Yet, many of these products that are classified as cosmeceuticals are tested less vigorously and do not have to be approved by the Food and Drug Administration to establish efficacy and safety. Thus, as clinicians, we must ask the question, "Is there science-based evidence to validate the mechanism of these new treatments?" We assessed the top anti-aging creams currently on the market specifically evaluating their botanical ingredients. Some of the most common botanicals that are hot off the market are: Rosmarinus officinalis, Vitis vinifera (grape seed extract), Citronellol, Limonene, Oenothera biennis (evening primrose), Glycyrrhiza glabra (licorice extract), Aframomum angustifolium seed extract, Diosgenin (wild yam), N6 furfuryladenine (kinetin), and Ergothioneine. Through researching each of these botanical ingredients, we have concluded that randomized controlled trials are still needed in this area, but there is promise in some of these ingredients and science to validate them.

Ergothioneine treatment protects neurons against N-methyl-D-aspartate excitotoxicity in an in vivo rat retinal model.

Injection of the glutamate agonist N-methyl-D-aspartate into the vitreous body of the rat eye resulted in a number of morphological changes in the retina. Most apparent was a dramatic reduction in the density and sizes of neurons accompanied by a decrease in amyloid precursor protein and glial fibrillary acidic protein immunoreactivity. Cell counts revealed that 81% of ganglion cells and 43% of non-ganglion cells were lost as a result of the treatment. However, in animals treated with the antioxidant ergothioneine, these figures dropped to 44 and 31%, respectively. Thus, ergothioneine appears to be neuroprotective in this system and the data suggest that antioxidants may provide a useful means of modulating glutamate-based toxicity.

UV-radiation protecting efficacy of thiols, studied with UVA-induced binding of 8-MOP and CPZ to rat epidermal biomacromolecules in vivo.

The following topically-applied thiols were investigated with regard to their possible UV-radiation protective properties: captopril, cysteamine, ergothioneine, mesna, mercaptopropionylglycine, N-acetyl-cysteine and penicillamine. As a measure for protection the inhibition of in vivo irreversible photobinding of the labelled phototoxic drugs chlorpromazine (CPZ) and 8-methoxypsoralen (8-MOP) to rat epidermal biomacromolecules was used. Ergothioneine, mesna and penicillamine did not show any effect; probably, as a result of their charge they are not able to enter the stratum corneum. Captopril, cysteamine, mercaptopropionylglycine and N-acetylcysteine showed a considerable inhibition of CPZ and 8-MOP photobinding. Captopril and N-acetylcysteine were clearly the most potent whereas cysteamine was the least effective. Captopril, mercaptopropionylglycine and N-acetylcysteine appeared to have a wider action range and to be a more effective protector than dl-alpha-tocopherol and di-butyl-hydroxytoluene. Cysteamine and mercaptopropionylglycine were only capable of protecting the stratum corneum. Captopril and N-acetylcysteine on the other hand showed an additional dose-dependent inhibition of photobinding to the viable epidermis. Gradually with increasing time after application, the protecting efficacy with regard to the viable layer of the epidermis decreased; the duration of protection depending on the dose.

[Studies of sulfhemoglobin formation by various drugs (4). Influences of various antidotes on chemically induced methemoglobinemia and sulfhemoglobinemia (author's transl)].

The influences of methylene blue (MB), thionine, ascorbic acid (ASA), sodium thiosulfate (STS), N-(2-mercaptopropionyl)-glycine (MPG) and reduced glutathione (GSH) on methemoglobin-(MHb)-emia and sulf-hemoglobin (SHb)-emia induced by 4-chloroaniline (4-Cl-A) i.p. were studied. Preventive or therapeutic effect on MHb-emia and preventive effect on SHb-emia in mice: MHb formation was inhibited by MB i.p. whether it was administered simultaneously with or after 4-Cl-A, but SHb formation was increased. Similar effects were seen with thionine. Both compounds proved to have MHb and SHb forming activities. STS or MPG, if administered i.p. simultaneously with 4-Cl-A, inhibited formation of MHb, but exerted no effect on delayed SHb formation. However, if administered i.p. or i.v. 120 minutes after 4-Cl-A when the peak of MHb formation had passed, there was a preventive effect on delayed SHb formation. GSH inhibited MHb formation and prevented SHb formation only when it was administered i.v. 120 minutes after 4-Cl-A. ASA did not inhibit MHb formation when it was administered either i.p. or i.v., but showed a preventive effect on SHb formation, if administered 120 minutes after 4-Cl-A. Combined i.v. administration of the corresponding doses to the clinical ones of MB and ASA 120 minutes after 4-Cl-A showed a therapeutic effect on MHb-emia and a preventive effect on SHb-emia. However, at higher dose levels, MB masked the preventive effect of ASA on SHb-emia. Therapeutic effect on SHb-emia in mice and rats: None of MB, STS, GSH and ASA proved to have any therapeutic effects for established SHb-emia. On the basis of these results, significance of clinical usage of drugs in the treatment of chemically induced MHb-emia and SHb-emia is discussed.