Dermato-protective properties of ergothioneine through induction of Nrf2/ARE-mediated antioxidant genes in UVA-irradiated Human keratinocytes

Synergistic Neuroprotective Effects of Ergothioneine and Lactoferrin in APP/PS1 Transgenic Mice and Mouse N2a Cells

Ergothioneine and lactoferrin show antioxidant and neuroprotective effects, but their interactive effects and underlying mechanisms on Alzheimer's disease are unclear. This study aims to investigate the synergistic neuroprotective effect for a combination of ergothioneine and lactoferrin and the molecular mechanisms in APP/PS1 transgenic mice and neuroblast N2a cells. In transgenic mice, the combination of ergothioneine and lactoferrin improved cognitive function and alleviated typical Alzheimer's disease's pathological characteristics of Aβ aggregation and tau phosphorylation. In N2a cells, compared with ergothioneine or lactoferrin alone, their combination synergistically increased cell viability by approximately 15% and decreased apoptosis by 5% in flow cytometry. The combination of ergothioneine and lactoferrin showed a more enhanced antioxidant efficacy through Keap1/Nrf2-mediated mechanisms in comparison to ergothioneine or lactoferrin alone. In summary, the combination of ergothioneine and lactoferrin synergistically enhances neuroprotection in APP/PS1 transgenic mice and N2a cells, providing a foundation for the development of functional foods for the prevention and control of Alzheimer's disease.

Disrupted homeostasis in sickle cells: Expanding the comprehension of metabolism adaptation and related therapeutic strategies

Sickle cell disease (SCD) is a hereditary hemolytic anemia associated with the alteration of the membrane composition of the sickle erythrocytes, the loss of glycolysis, dysregulation of the pyruvate phosphatase pathway, and changes in nucleotide metabolism of the sickle red blood cell (RBC). This review provides a comprehensive overview of the impact of the presence of Hb S, which leads to the disruption of the normal RBC metabolism. The intricate interplay between the redox and energetic balance in erythrocytic cells, where the glycolysis, pentose phosphate pathway, and methemoglobin reductase pathways are all altered in sickle RBC, is a key focus. Moreover, this review summarizes the current knowledge about the disease-modifying agents and their action mechanisms based on the sickle RBC alterations previously mentioned (i.e., their association with beneficial effects on the sickle cells' membrane, to their RBCs' energy metabolism, and to their oxidative status). Therefore, providing a comprehensive understanding of how sickle cells cope with the disruption of metabolic homeostasis and the most promising therapeutic agents able to ameliorate the various consequences of abnormal sickle RBC alterations.

The roles and functions of ergothioneine in metabolic diseases

The global prevalence of metabolic diseases is on the increase, and it has become a significant threat to the health and lives of individuals. Ergothioneine (EGT) is a natural betaine amino acid found in various foods, particularly mushrooms. EGT cannot be synthesized by mammals; it is absorbed into small intestinal epithelial cells by a cationic protein, the novel organic cation transporter 1 (OCTN1), and transported to certain organs including liver, spleen, kidney, lung, heart, eyes and brain. EGT has been reported to exhibit antioxidant, anti-inflammatory, anti-apoptotic, anti-aging, and metal-chelating effects. The unique chemical properties and biological functions of EGT position it as a promising candidate for the research and treatment of metabolic diseases. This review summarizes EGT's capacities, potential therapeutic effects on multiple metabolic diseases, and their specific mechanisms. Finally, we outline challenges for future research on EGT and aspire to establish it as a prospective therapeutic agent for metabolic diseases.

Assessment of the binding mechanism of ergothioneine to human serum albumin: Multi-spectroscopy, molecular docking and molecular dynamic simulation

Ergothioneine (EGT) has attracted great attention due to its extremely potent antioxidant properties, universally acknowledged as 'longevity vitamin'. In order to comprehensive understanding of its pharmacodynamics and pharmacokinetics, the binding mechanism of EGT with human serum albumin (HSA) was clarified by cutting-edged multi-spectroscopic approaches and in silico molecular docking coupled with molecular dynamic simulation. Our fluorescence quenching results revealed that the binding of EGT to HSA was in a static quenching mode validated by the descending Stern-Volmer constant (Ksv) values (2.82, 2.36, 1.48 × 104 L mol-1) and biomolecular quenching rate constant (Kq) values (2.82, 2.36, 1.48 × 1012 L mol-1) at 298 K, 305 K, and 310 K, respectively. van't Hoff criterion revealed the combination of EGT with HSA was a spontaneous exothermic process (ΔG = -24.16 kJ mol-1) via hydrogen bonding and van der Waals force interactions (ΔH = -60.25 kJ mol-1, ΔS = -129.44 J mol-1 K-1) at 310 K. The analysis of UV-vis absorption spectrum, synchronous fluorescence spectrum, three-dimensional fluorescence spectrum and circular dichroism indicated the addition of EGT affected the microenvironment of Trp214 and rearranged the structure of HSA. The binding replacement assay interpreted their binding site was near the subdomain IIA of HSA (Sudlow's site I), which was intuitively exhibited by molecular docking. In addition of obvious van der Wall forces, attractive charge and Pi-alkyl interactions, the chiral betaine group (N+(CH3+)3) in the side chain of EGT was inclined to form hydrogen bonds with Lys199, Ser287 and Arg257 in the hydrophobic cavity of albumin. Moreover, the dynamic simulation reinforced the equilibrium and stability of formed docking complex by four indicators (RMSD, RMSF, Rg, SASA) within 100 ns.

Characterizing the Ultraviolet (UV) Screening Ability of L-5-Sulfanylhistidine Derivatives on Human Dermal Fibroblasts

Using sunscreens is one of the most widespread measures to protect human skin from sun ultraviolet radiation (UVR) damage. However, several studies have highlighted the toxicity of certain inorganic and organic UV filters used in sunscreens for the marine environment and human health. An alternative strategy may involve the use of natural products of marine origin to counteract UVR-mediated damage. Ovothiols are sulfur-containing amino acids produced by marine invertebrates, microalgae, and bacteria, endowed with unique antioxidant and UV-absorption properties. This study aimed to evaluate the protective effect of synthetic L-5-sulfanyl histidine derivatives, inspired by natural ovothiols, on human dermal fibroblasts (HDFs) upon UVA exposure. By using a custom-made experimental set-up to assess the UV screening ability, we measured the levels of cytosolic and mitochondrial reactive oxygen species (ROS), as well as cell viability and apoptosis in HDFs, in the presence of tested compounds, after UVA exposure, using flow cytometry assays with specific fluorescent probes. The results show that L-5-sulfanyl histidine derivatives display a UV screening capacity and prevent loss in cell viability, the production of cytosolic and mitochondrial ROS induced by UVA exposure in HDFs, and subsequent apoptosis. Overall, this study sheds light on the potential applications of marine-inspired sulfur-containing amino acids in developing alternative eco-safe sunscreens for UVR skin protection.

Long-term intake of Tamogi-take mushroom (Pleurotus cornucopiae) mitigates age-related cardiovascular dysfunction and extends healthy life expectancy

Age-related declines in cardiac function and exercise tolerance interfere with healthy living and decrease healthy life expectancy in older individuals. Tamogi-take mushrooms (Pleurotus cornucopiae) are known to contain high levels of Ergothioneine (EGT), an antioxidant with potential health benefits. In this study, we assessed the possibility that long-term consumption of Tamogi-take mushrooms might attenuate age-related decline in cardiac and vascular endothelial function in mice. We found that long-term intake of Tamogi-take mushrooms significantly maintained cardiac and vascular endothelial function and improved exercise tolerance in mice. Long-term mushroom consumption also increased levels of Nrf2 (Nuclear factor E2-related factor 2) protein in heart tissues and increased translation of HO-1 (Heme Oxygenase 1) proteins, which have antioxidant effects in heart and aortic tissues. Finally, long-term Tamogi-take mushroom consumption inhibited ROS accumulation with aging and reduced expression of inflammatory biomarkers. We conclude that ingestion of Tamogi-take mushrooms could serve as a dietary intervention to promote cardiovascular health, support healthy aging and slow the progression of age-related diseases.

Ergothioneine improves cognitive function by ameliorating mitochondrial damage and decreasing neuroinflammation in a D-galactose-induced aging model

Ergothioneine (EGT) is a sulfur-containing amino acid with strong antioxidant activity. In this study, a D-galactose induced mouse aging model was used to investigate the anti-aging effects of EGT. EGT intervention could significantly improve the recognition memory of aging mice. Additionally, it improved the D-galactose induced decrease in the number of neurones, enhanced the levels of cAMP and BDNF in the brain, and increased the density and expression of PSD95 in aging mice. Meanwhile, EGT could attenuate oxidative stress by reducing the content of MDA and enhancing T-SOD activity via the Nrf2/HO-1 pathway. In addition, EGT could alleviate mitochondrial function by regulating the AMPK/SIRT1/PGC-1α pathway, which in turn attenuated D-galactose induced hippocampal neuronal injury and improved the learning and memory abilities in mice. This study provides a potential dietary strategy to improve age-induced memory impairment.

α-Arbutin ameliorates UVA-induced photoaging through regulation of the SIRT3/PGC-1α pathway

Owing to its tyrosinase inhibitory activity, α-arbutin has been added to several skin care products as a skin-lightening agent. However, the protective effect of α-arbutin against ultraviolet A (UVA)-induced photoaging has not been well investigated. The present study was designed to investigate the photoprotective effect and mechanism of α-arbutin against UVA-induced photoaging. In vitro experiments, HaCaT cells were treated with UVA at a dose of 3 J/cm2 to evaluate the anti-photoaging effect of α-arbutin. α-Arbutin was found to exhibit a strong antioxidant effect by increasing glutathione (GSH) level and inhibiting reactive oxygen species (ROS) production. Meanwhile, α-arbutin markedly improved the expression of sirtuin 3 (SIRT3) and peroxisome proliferator-activated receptor γ coactivator 1 α (PGC-1α) proteins, initiating downstream signaling to increase mitochondrial membrane potential and mediate mitochondrial biogenesis, and improve mitochondrial structure significantly. In vivo analysis, the mice with shaved back hair were irradiated with a cumulative UVA dose of 10 J/cm2 and a cumulative ultraviolet B (UVB) dose of 0.63 J/cm2. The animal experiments demonstrated that α-arbutin increased the expression of SIRT3 and PGC-1α proteins in the back skin of mice, thereby reducing UV-induced skin damage. In conclusion, α-arbutin protects HaCaT cells and mice from UVA damage by regulating SIRT3/PGC-1α signaling pathway.

The Biology and Biochemistry of Kynurenic Acid, a Potential Nutraceutical with Multiple Biological Effects

Kynurenic acid (KYNA) is an antioxidant degradation product of tryptophan that has been shown to have a variety of cytoprotective, neuroprotective and neuronal signalling properties. However, mammalian transporters and receptors display micromolar binding constants; these are consistent with its typically micromolar tissue concentrations but far above its serum/plasma concentration (normally tens of nanomolar), suggesting large gaps in our knowledge of its transport and mechanisms of action, in that the main influx transporters characterized to date are equilibrative, not concentrative. In addition, it is a substrate of a known anion efflux pump (ABCC4), whose in vivo activity is largely unknown. Exogeneous addition of L-tryptophan or L-kynurenine leads to the production of KYNA but also to that of many other co-metabolites (including some such as 3-hydroxy-L-kynurenine and quinolinic acid that may be toxic). With the exception of chestnut honey, KYNA exists at relatively low levels in natural foodstuffs. However, its bioavailability is reasonable, and as the terminal element of an irreversible reaction of most tryptophan degradation pathways, it might be added exogenously without disturbing upstream metabolism significantly. Many examples, which we review, show that it has valuable bioactivity. Given the above, we review its potential utility as a nutraceutical, finding it significantly worthy of further study and development.

Protective Effect of Ergothioneine against Oxidative Stress-Induced Chondrocyte Death

Reactive oxygen species (ROS) induce oxidative stress in cells and are associated with various diseases, including autoimmune diseases. Ergothioneine (EGT) is a natural amino acid derivative derived from the ergot fungus and has been reported to exhibit an effective antioxidant function in many models of oxidative stress-related diseases. Recently, mutations in OCTN1, a membrane transporter of EGT, have been reported to be associated with rheumatoid arthritis. Therefore, we investigated the chondrocyte-protective function of EGT using a model of oxidative stress-induced injury of chondrocytes by hydrogen peroxide (H2O2). Human chondrocytes were subjected to oxidative stress induced by H2O2 treatment, and cell viability, the activity of lactate dehydrogenase (LDH) released into the medium, dead cell ratio, intracellular ROS production, and mitochondrial morphology were assessed. EGT improved chondrocyte viability and LDH activity in the medium and strongly suppressed the dead cell ratio. EGT also exerted protective effects on intracellular ROS production and mitochondrial morphology. These results provide evidence to support the protective effects of EGT on chondrocytes induced by oxidative stress.

Ergothioneine: new functional factor in fermented foods

Ergothioneine (EGT) is a high-value natural sulfur-containing amino acid and has been shown to possess extremely potent antioxidant and cytoprotective activities. At present, EGT has been widely used in food, functional food, cosmetics, medicine, and other industries, but its low yield is still an urgent problem to overcome. This review briefly introduced the biological activities and functions of EGT, and expounded its specific applications in food, functional food, cosmetic, and medical industries, introduced and compared the main production methods of EGT and respective biosynthetic pathways in different microorganisms. Furthermore, the use of genetic and metabolic engineering methods to improve EGT production was discussed. In addition, the incorporation of some food-derived EGT-producing strains into fermentation process will allow the EGT to act as a new functional factor in the fermented foods.

The Role of Ergothioneine in Red Blood Cell Biology: A Review and Perspective

Oxidative stress can damage tissues and cells, and their resilience or susceptibility depends on the robustness of their antioxidant mechanisms. The latter include small molecules, proteins, and enzymes, which are linked together in metabolic pathways. Red blood cells are particularly susceptible to oxidative stress due to their large number of hemoglobin molecules, which can undergo auto-oxidation. This yields reactive oxygen species that participate in Fenton chemistry, ultimately damaging their membranes and cytosolic constituents. Fortunately, red blood cells contain robust antioxidant systems to enable them to circulate and perform their physiological functions, particularly delivering oxygen and removing carbon dioxide. Nonetheless, if red blood cells have insufficient antioxidant reserves (e.g., due to genetics, diet, disease, or toxin exposure), this can induce hemolysis in vivo or enhance susceptibility to a "storage lesion" in vitro, when blood donations are refrigerator-stored for transfusion purposes. Ergothioneine, a small molecule not synthesized by mammals, is obtained only through the diet. It is absorbed from the gut and enters cells using a highly specific transporter (i.e., SLC22A4). Certain cells and tissues, particularly red blood cells, contain high ergothioneine levels. Although no deficiency-related disease has been identified, evidence suggests ergothioneine may be a beneficial "nutraceutical." Given the requirements of red blood cells to resist oxidative stress and their high ergothioneine content, this review discusses ergothioneine's potential importance in protecting these cells and identifies knowledge gaps regarding its relevance in enhancing red blood cell circulatory, storage, and transfusion quality.

Ergothioneine Protects Against UV-Induced Oxidative Stress Through the PI3K/AKT/Nrf2 Signaling Pathway

Background

Ergothioneine (EGT) is an antioxidant, which could be detected in human tissues, and human skin cells could utilize EGT and play an anti-oxidative role in keratinocytes. And in this study we are going to elucidate whether EGT could protect the skin from photoaging by Ultraviolet (UV) exposure in mice and its molecule pathway.

Methods

Histological analysis was performed for evaluating the skin structure change. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were measured with biological assay for evaluating oxidative and antioxidative ability of skin exposed to UV light. And the level of marker molecules in mouse skin were detected by hydroxyproline (Hyp) assay, immunohistochemical analysis, Western blot, and quantitative real-time PCR (qRT-PCR). The markers of skin aging and cell death were tested by cell culture and treatment, Western blot and qRT-PCR.

Results

EGT decreased the levels of inflammatory factors induced by UV exposure in mouse skin. MDA and SOD activity detection showed that EGT decreased MDA levels, increased SOD activity, and upregulated PI3K/Akt/Nrf2 signals in mouse skin exposed to UV, which further activated Nrf2 in the nucleus and enhanced the expression of Nrf2 target genes. In the cell model, we revealed that EGT could inhibit the increase in senescence-associated β-galactosidase-positive cells and p16 and γ-H2A.X positive cells induced by etoposide and activate PI3K/Akt/Nrf2 signaling. Moreover, a PI3K inhibitor blocked EGT protection against etoposide-induced cell death.

Conclusion

The study showed EGT may play an important protective role against cell damage or death through the PI3K/Akt/Nrf2 signaling pathway in skin.

Are age-related neurodegenerative diseases caused by a lack of the diet-derived compound ergothioneine?

We propose that the diet-derived compound ergothioneine (ET) is an important nutrient in the human body, especially for maintenance of normal brain function, and that low body ET levels predispose humans to significantly increased risks of neurodegenerative (cognitive impairment, dementia, Parkinson's disease) and possibly other age-related diseases (including frailty, cardiovascular disease, and eye disease). Hence, restoring ET levels in the body could assist in mitigating these risks, which are rapidly increasing due to ageing populations globally. Prevention of neurodegeneration is especially important, since by the time dementia is usually diagnosed damage to the brain is extensive and likely irreversible. ET and vitamin E from the diet may act in parallel or even synergistically to protect different parts of the brain; both may be "neuroprotective vitamins". The present article reviews the substantial scientific basis supporting these proposals about the role of ET.

Low-molecular-weight thiol transferases in redox regulation and antioxidant defence

Low-molecular-weight (LMW) thiols are produced in all living cells in different forms and concentrations. Glutathione (GSH), coenzyme A (CoA), bacillithiol (BSH), mycothiol (MSH), ergothioneine (ET) and trypanothione T(SH)2 are the main LMW thiols in eukaryotes and prokaryotes. LMW thiols serve as electron donors for thiol-dependent enzymes in redox-mediated metabolic and signaling processes, protect cellular macromolecules from oxidative and xenobiotic stress, and participate in the reduction of oxidative modifications. The level and function of LMW thiols, their oxidized disulfides and mixed disulfide conjugates in cells and tissues is tightly controlled by dedicated oxidoreductases, such as peroxiredoxins, glutaredoxins, disulfide reductases and LMW thiol transferases. This review provides the first summary of the current knowledge of structural and functional diversity of transferases for LMW thiols, including GSH, BSH, MSH and T(SH)2. Their role in maintaining redox homeostasis in single-cell and multicellular organisms is discussed, focusing in particular on the conjugation of specific thiols to exogenous and endogenous electrophiles, or oxidized protein substrates. Advances in the development of new research tools, analytical methodologies, and genetic models for the analysis of known LMW thiol transferases will expand our knowledge and understanding of their function in cell growth and survival under oxidative stress, nutrient deprivation, and during the detoxification of xenobiotics and harmful metabolites. The antioxidant function of CoA has been recently discovered and the breakthrough in defining the identity and functional characteristics of CoA S-transferase(s) is soon expected.

Ergothioneine and its congeners: anti-ageing mechanisms and pharmacophore biosynthesis

Ergothioneine, Ovothiol, and Selenoneine are sulfur/selenium-containing histidine-derived natural products widely distributed across different organisms. They exhibit significant antioxidant properties, making them as potential lead compounds for promoting health. Increasing evidence suggests that Ergothioneine is positively correlated with healthy ageing and longevity. The mechanisms underlying Ergothioneine's regulation of the ageing process at cellular and molecular levels are beginning to be understood. In this review, we provide an in-depth and extensive coverage of the anti-ageing studies on Ergothioneine and discuss its possible intracellular targeting pathways. In addition, we highlight the recent efforts in elucidating the biosynthetic details for Ergothioneine, Ovothiol, and Selenoneine, with a particular focus on the study of their pharmacophore-forming enzymology.

Insights on the UV-Screening Potential of Marine-Inspired Thiol Compounds

One of the major threats to skin aging and the risk of developing skin cancer is excessive exposure to the sun's ultraviolet radiation (UVR). The use of sunscreens containing different synthetic, organic, and inorganic UVR filters is one of the most widespread defensive measures. However, increasing evidence suggests that some of these compounds are potentially eco-toxic, causing subtle damage to the environment and to marine ecosystems. Resorting to natural products produced in a wide range of marine species to counteract UVR-mediated damage could be an alternative strategy. The present work investigates marine-inspired thiol compounds, derivatives of ovothiol A, isolated from marine invertebrates and known to exhibit unique antioxidant properties. However, their potential use as photoprotective molecules for biocompatible sunscreens and anti-photo aging formulations has not yet been investigated. Here, we report on the UVR absorption properties, photostability, and in vitro UVA shielding activities of two synthetic ovothiol derivatives, 5-thiohistidine and iso-ovothiol A, by spectrophotometric and fluorimetric analysis. We found that the UVA properties of these compounds increase upon exposure to UVA and that their absorption activity is able to screen UVA rays, thus reducing the oxidative damage induced to proteins and lipids. The results of this work demonstrate that these novel marine-inspired compounds could represent an alternative eco-friendly approach for UVR skin protection.

Methyl lucidone inhibits airway inflammatory response by reducing TAK1 activity in human bronchial epithelial NCI-H292 cells

Background

Methyl lucidone (ML), a methyl derivative of lucidone, has anti-inflammatory properties. However, the molecular mechanisms that reduce the inflammatory effect of ML in human lung epithelial cells remain unkown. This study aimed to elucidate the molecular mechanisms underlying the anti-inflammatory effect of ML.

Methods

Four compounds (ML, methyl linderone, kanakugiol, and linderone) from Lindera erythrocarpa Makino were evaluated for their ability to reduce MUC5AC secretion levels in phorbol-12-myristate-13-acetate (PMA)-stimulated NCI-H292 cells using ELISA. The expression and secretion levels of inflammatory response-related proteins were analyzed using quantitative reverse transcription-PCR, ELISA, and western blotting. To determine whether ML directly regulates TGF-β-activated kinase 1 (TAK1), we performed an in vitro kinase assay.

Results

ML treatment effectively reduced the levels of inflammatory cytokines, including interleukin-1β and TNF-α, increased by stimulation. Furthermore, ML downregulated the pathway cascade of both IκB kinase (IKK)/NF-κB and p38 mitogen-activated protein (MAP) kinase/CREB by inhibiting the upstream kinase TAK1. An in vitro kinase analysis confirmed that ML treatment significantly reduced the kinase activity of TAK1.

Conclusion

ML pretreatment repressed the PMA-stimulated inflammation reaction by reducing the TAK1-mediated IKK/NF-κB and p38 MAP kinase/CREB signaling. These findings suggest that ML may improve respiratory health and can be used as a dietary supplement or functional food to prevent inflammatory lung diseases.

Liquiritigenin reverses skin aging by inhibiting UV-induced mitochondrial uncoupling and excessive energy consumption

BACKGROUND

The accumulation of reactive oxygen species (ROS) generated by UV radiation can lead to lipid, protein, nucleic acid, and organelle damage, one of the core mechanisms mediating skin aging. In the photoaging process, how ROS drives the imbalance of the body's complex repair system to induce senescence-like features is not fully understood.

METHODS

We irradiated human epidermal keratinocytes with 12 J/cm² of UVA to establish an in vitro photoaging model. Then we employed whole-transcriptome sequencing and O2K mitochondrial function assay to reveal the photoprotective mechanisms of liquiritigenin (LQ).

DISCUSSION

We found that skin reduces endogenous ROS by promoting mitochondrial oxidative phosphorylation uncoupling in response to UVA-induced damage. However, this also causes excessive consumption and idling of nutrients, leading to the inhibition of cell proliferation, and ultimately accelerating the skin aging process. Here, we demonstrated that LQ can reduce stress in keratinocytes, increase oxidative phosphorylation and ATP production efficiency, and block the massive loss of skin nutrients and net energy stress. Furthermore, LQ can promote collagen synthesis and keratinocyte proliferation through the PI3K-AKT pathway, thereby reversing photoaging.

CONCLUSION

This work provides a new skin aging mechanism and solution strategy with high clinical translation value.

Role of PI3K-AKT Pathway in Ultraviolet Ray and Hydrogen Peroxide-Induced Oxidative Damage and Its Repair by Grain Ferments

UV and external environmental stimuli can cause oxidative damage to skin cells. However, the molecular mechanisms involved in cell damage have not been systematically and clearly elucidated. In our study, an RNA-seq technique was used to determine the differentially expressed genes (DEGs) of the UVA/H₂O₂-induced model. Gene Oncology (GO) clustering and the Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway analysis were performed to determine the core DEGs and key signaling pathway. The PI3K-AKT signaling pathway was selected as playing a part in the oxidative process and was verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We selected three kinds of Schizophyllum commune fermented actives to evaluate whether the PI3K-AKT signaling pathway also plays a role in the resistance of active substances to oxidative damage. Results indicated that DEGs were mainly enriched in five categories: external stimulus response, oxidative stress, immunity, inflammation, and skin barrier regulation. S. commune-grain ferments can effectively reduce cellular oxidative damage through the PI3K-AKT pathway at both the cellular and molecular levels. Some typical mRNAs (COL1A1, COL1A2, COL4A5, FN1, IGF2, NR4A1, and PIK3R1) were detected, and the results obtained were consistent with those of RNA-seq. These results may give us a common set of standards or criteria for the screen of anti-oxidative actives in the future.

Safe and Effective Antioxidant: The Biological Mechanism and Potential Pathways of Ergothioneine in the Skin

Ergothioneine, a sulfur-containing micromolecular histidine derivative, has attracted increasing attention from scholars since it was confirmed in the human body. In the human body, ergothioneine is transported and accumulated specifically through OCTN-1, especially in the mitochondria and nucleus, suggesting that it can target damaged cells and tissues as an antioxidant. It shows excellent antioxidant, anti-inflammatory effects, and anti-aging properties, and inhibits melanin production. It is a mega antioxidant that may participate in the antioxidant network system and promote the reducing glutathione regeneration cycle. This review summarizes studies on the antioxidant effects of ergothioneine on various free radicals in vitro to date and systematically introduces its biological activities and potential mechanisms, mostly in dermatology. Additionally, the application of ergothioneine in cosmetics is briefly summarized. Lastly, we propose some problems that require solutions to understand the mechanism of action of ergothioneine. We believe that ergothioneine has good prospects in the food and cosmetics industries, and can thus meet some needs of the health and beauty industry.

Protection against Doxorubicin-Induced Cardiotoxicity by Ergothioneine

Background: Anthracyclines such as doxorubicin remain a primary treatment for hematological malignancies and breast cancers. However, cardiotoxicity induced by anthracyclines, possibly leading to heart failure, severely limits their application. The pathological mechanisms of anthracycline-induced cardiac injury are believed to involve iron-overload-mediated formation of reactive oxygen species (ROS), mitochondrial dysfunction, and inflammation. The dietary thione, ergothioneine (ET), is avidly absorbed and accumulated in tissues, including the heart. Amongst other cytoprotective properties, ET was shown to scavenge ROS, decrease proinflammatory mediators, and chelate metal cations, including Fe²⁺, preventing them from partaking in redox activities, and may protect against mitochondrial damage and dysfunction. Plasma ET levels are also strongly correlated to a decreased risk of cardiovascular events in humans, suggesting a cardioprotective role. This evidence highlights ET's potential to counteract anthracycline cardiotoxicity. Methods and Findings: We investigated whether ET supplementation can protect against cardiac dysfunction in mice models of doxorubicin-induced cardiotoxicity and revealed that it had significant protective effects. Moreover, ET administration in a mouse breast cancer model did not exacerbate the growth of the tumor or interfere with the chemotherapeutic efficacy of doxorubicin. Conclusion: These results suggest that ET could be a viable co-therapy to alleviate the cardiotoxic effects of anthracyclines in the treatment of cancers.

Potential Cytoprotective and Regulatory Effects of Ergothioneine on Gene Expression of Proteins Involved in Erythroid Adaptation Mechanisms and Redox Pathways in K562 Cells

This study aimed to establish the importance of ergothioneine (ERT) in the erythroid adaptation mechanisms by appraising the expression levels of redox-related genes associated with the PI3K/AKT/FoxO3 and Nrf2-ARE pathways using K562 cells induced to erythroid differentiation and H₂O₂-oxidative stress. Cell viability and gene expression were evaluated. Two concentrations of ERT were assessed, 1 nM (C1) and 100 µM (C2), with and without stress induction (100 µM H₂O₂). Assessments were made in three periods of the cellular differentiation process (D0, D2, and D4). The C1 treatment promoted the induction of FOXO3 (D0 and 2), PSMB5, and 6 expressions (D4); C1 + H₂O₂ treatment showed the highest levels of NRF2 transcripts, KEAP1 (D0), YWHAQ (D2 and 4), PSMB5 (D2) and PSMB6 (D4); and C2 + H₂O₂ (D2) an increase in FOXO3 and MST1 expression, with a decrease of YWHAQ and NRF2 was observed. in C2 + H₂O₂ (D2) an increase in FOXO3 and MST1, with a decrease in YWHAQ and NRF2 was observed All ERT treatments increased gamma-globin expression. Statistical multivariate analyzes highlighted that the Nrf2-ARE pathway presented a greater contribution in the production of PRDX1, SOD1, CAT, and PSBM5 mRNAs, whereas the PI3K/AKT/FoxO3 pathway was associated with the PRDX2 and TRX transcripts. In conclusion, ERT presented a cytoprotective action through Nrf2 and FoxO3, with the latter seeming to contribute to erythroid proliferation/differentiation.

Microbiota in a long survival discourse with the human host

The relationship between human health and gut microbiota is becoming more apparent. It is now widely believed that healthy gut flora plays a vital role in the overall well-being of the individual. There are spatial and temporal variations in the distribution of microbes from the esophagus to the rectum throughout an individual's lifetime. Through the development of genome sequencing technologies, scientists have been able to study the interactions between different microorganisms and their hosts to improve the health and disease of individuals. The normal gut microbiota provides various functions to the host, whereas the host, in turn, provides nutrients and promotes the development of healthy and resilient microbiota communities. Thus, the microbiota provides and maintains the gut's structural integrity and protects the gut against pathogens. The development of the normal gut microbiota is influenced by various factors. Some of these include the mode of delivery, diet, and antibiotics. In addition, the environment can also affect the development of the gut microbiota. For example, one of the main concerns of antibiotic use is the alteration of the gut microbiota, which could lead to the development of multidrug-resistant organisms. When microbes are disturbed, it can potentially lead to various diseases. Depending on the species' ability to adapt to the human body's environment, the fate of the microbes in the host and their relationship with the human body are decided. This review aims to provide a comprehensive analysis of microbe, microbes-host immune interactions, and factors that can disturb their interactions.

First evidence of dermo-protective activity of marine sulfur-containing histidine compounds

Among natural products, ovothiol (ovo), produced by marine invertebrates, bacteria, and microalgae, is receiving increasing interest for its unique antioxidant properties. Recently, ovo has been shown to exhibit anti-inflammatory activity in an in vitro model of endothelial dysfunction and in an in vivo model of liver fibrosis. The aim of this study was to evaluate the effect of ovo and its precursor 5-thiohistidine (5-thio) in comparison with ergothioneine (erg), in human skin cells and tissues upon inflammation. We used both an in vitro and ex vivo model of human skin, represented by a keratinocytes cell line (HaCaT) and skin biopsies, respectively. We observed that ovo, 5-thio, and erg were not cytotoxic in HaCaT cells, but instead exerted a protective function against TNF-α -induced inflammation. In order to get insights on their mechanism of action, we performed western blot analysis of ERK and JNK, as well as sub-cellular localization of Nrf2, a key mediator of the anti-inflammatory response. The results indicated that the pre-treatment with ovo, 5-thio, and erg differently affected the phosphorylation of ERK and JNK. However, all the three molecules promoted the accumulation of Nrf2 in the nucleus of HaCaT cells. In addition, gene expression analysis by RTqPCR and ELISA assays performed in ex vivo human skin tissues pre-treated with thiohistidines and then inflamed with IL-1β revealed a significant downregulation of IL-8, TNF-α and COX-2 genes and a concomitant significant decrease in the cytokines IL-6, IL-8 and TNF-α production. Moreover, the protective action of ovo and 5-thio resulted to be stronger when compared with dexamethasone, a corticosteroid drug currently used to treat skin inflammatory conditions. Our findings suggest that ovo and 5-thio can ameliorate skin damage and may be used to develop natural skin care products to prevent the inflammatory status induced by environmental stressors and aging.

Premna microphylla Turcz pectin protected UVB-induced skin aging in BALB/c-nu mice via Nrf2 pathway

Excessive exposure to ultraviolet B (UVB) irradiation is one of the major risk factors for skin photoaging. The aim of this study was to investigate the protective effect of Premna microphylla Turcz pectin (PMTP) against UVB-induced skin aging in BALB/c-nu mice. PMTP was characteristic of a low methoxyl RG-I pectin with Mw was 26.60 kDa, mainly composed of galacturonic acid. PMTP-containing cream efficiently inhibited the water loss, epidermal hyperplasia, matrix metalloproteinases-1 (MMP-1), and collagen destruction in UVB-induced skin injury mice. Additionally, topical administration of PMTP-containing cream significantly increased protein levels of the nuclear factor erythroid 2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1), macrophage-activating factor (Maf), and heme oxygenase 1 (HO-1), and the expression of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). In contrast, application of PMTP-containing cream on mice skin decreased the protein levels of nuclear factor-kappa B (NF-κB), inhibitor kappa B kinase β (IKKβ), and cyclooxygenase-2 (COX-2), and pro-inflammatory cytokines. Taken togethmier, these findings suggest that PMTP might protect UVB-induced skin aging via activating Nrf2 pathway and suppressing NF-κB pathway.

The Role of Organosulfur Compounds as Nrf2 Activators and Their Antioxidant Effects

Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling has become a key pathway for cellular regulation against oxidative stress and inflammation, and therefore an attractive therapeutic target. Several organosulfur compounds are reportedly activators of the Nrf2 pathway. Organosulfur compounds constitute an important class of therapeutic agents in medicinal chemistry due to their ability to participate in biosynthesis, metabolism, cellular functions, and protection of cells from oxidative damage. Sulfur has distinctive chemical properties such as a large number of oxidation states and versatility of reactions that promote fundamental biological reactions and redox biochemistry. The presence of sulfur is responsible for the peculiar features of organosulfur compounds which have been utilized against oxidative stress-mediated diseases. Nrf2 activation being a key therapeutic strategy for oxidative stress is closely tied to sulfur-based chemistry since the ability of compounds to react with sulfhydryl (-SH) groups is a common property of Nrf2 inducers. Although some individual organosulfur compounds have been reported as Nrf2 activators, there are no papers with a collective analysis of these Nrf2-activating organosulfur compounds which may help to broaden the knowledge of their therapeutic potentials and motivate further research. In line with this fact, for the first time, this review article provides collective and comprehensive information on Nrf2-activating organosulfur compounds and their therapeutic effects against oxidative stress, thereby enriching the chemical and pharmacological diversity of Nrf2 activators.

Ergothioneine Improves Aerobic Performance Without Any Negative Effect on Early Muscle Recovery Signaling in Response to Acute Exercise

Physical activity is now recognized as an essential element of healthy lifestyles. However, intensive and repeated exercise practice produces a high level of stress that must be managed, particularly oxidative damage and inflammation. Many studies investigated the effect of antioxidants, but reported only few positive effects, or even muscle recovery impairment. Secondary antioxidants are frequently highlighted as a way to optimize these interactions. Ergothioneine is a potential nutritional supplement and a secondary antioxidant that activates the cellular NRF2 pathway, leading to antioxidant response gene activation. Here, we hypothesized that ergothioneine could improve performance during aerobic exercise up to exhaustion and reduce exercise-related stress without impairing early muscle recovery signaling. To test this hypothesis, 5-month-old C56B6J female mice were divided in two groups matched for maximal aerobic speed (MAS): control group (Ctrl; n = 9) and group supplemented with 70 mg ergothioneine/kg/day (ET; n = 9). After 1 week of supplementation (or not), mice performed a maximum time-to-exhaustion test by running on a treadmill at 70% of their MAS, and gastrocnemius and soleus muscles were collected 2 h after exercise. Time to exhaustion was longer in the ET than Ctrl group (+41.22%, p < 0.01). Two hours after exercise, the ET group showed higher activation of protein synthesis and satellite cells, despite their longer effort. Conversely, expression in muscles of metabolic stress and inflammation markers was decreased, as well as oxidative damage markers in the ET group. Moreover, ergothioneine did not seem to impair mitochondrial recovery. These results suggest an important effect of ergothioneine on time-to-exhaustion performance and improved muscle recovery after exercise.

Efficient Synthesis of Food-Derived Antioxidant l-Ergothioneine by Engineered Corynebacterium glutamicum

l-Ergothioneine (EGT) is a strong antioxidant used in industry, and it is commonly extracted from mushrooms; however, its production is limited. As an alternative, we developed metabolically engineered Corynebacterium glutamicum with reinforced sulfur assimilation and pentose phosphate pathways, which led to the accumulation of 45.0 and 63.2 mg/L EGT, respectively. Additionally, the overexpression of cysEKR resulted in further promoted EGT production in ET4 (66.5 mg/L) and ET7 (85.0 mg/L). Based on this result, we developed the strain ET11, in which all sulfur assimilatory, PP, and l-cysteine synthetic pathways were reinforced, and it synthesized 264.4 mg/L EGT. This study presents the first strategy for EGT synthesis that does not require precursor addition in C. glutamicum, and the production time was shortened. In addition, the synthesized EGT showed high radical scavenging activity (70.7%), thus confirming its antioxidant function. Consequently, this study showed the possibility of EGT commercialization by overcoming the limitations of industrial processes.

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.

Cancer Chemopreventive Role of Dietary Terpenoids by Modulating Keap1-Nrf2-ARE Signaling System—A Comprehensive Update

ROS, RNS, and carcinogenic metabolites generate excessive oxidative stress, which changes the basal cellular status and leads to epigenetic modification, genomic instability, and initiation of cancer. Epigenetic modification may inhibit tumor-suppressor genes and activate oncogenes, enabling cells to have cancer promoting properties. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that in humans is encoded by the NFE2L2 gene, and is activated in response to cellular stress. It can regulate redox homoeostasis by expressing several cytoprotective enzymes, including NADPH quinine oxidoreductase, heme oxygenase-1, UDP-glucuronosyltransferase, glutathione peroxidase, glutathione-S-transferase, etc. There is accumulating evidence supporting the idea that dietary nutraceuticals derived from commonly used fruits, vegetables, and spices have the ability to produce cancer chemopreventive activity by inducing Nrf2-mediated detoxifying enzymes. In this review, we discuss the importance of these nutraceuticals in cancer chemoprevention and summarize the role of dietary terpenoids in this respect. This approach was taken to accumulate the mechanistic function of these terpenoids to develop a comprehensive understanding of their direct and indirect roles in modulating the Keap1-Nrf2-ARE signaling system.

Polypodium vulgare L. (Polypodiaceae) as a Source of Bioactive Compounds: Polyphenolic Profile, Cytotoxicity and Cytoprotective Properties in Different Cell Lines

Pteridophytes, represented by ferns and allies, are an important phytogenetic bridge between lower and higher plants. Ferns have evolved independently of any other species in the plant kingdom being its secondary metabolism a reservoir of phytochemicals characteristic of this taxon. The study of the potential uses of Polypodium vulgare L. (Polypodiaceae) as medicinal plant has increased in recent years particularly when in 2008 the European Medicines Agency published a monograph about the rhizome of this species. Our objective is to provide scientific knowledge on the polar constituents extracted from the fronds of P. vulgare, one of the main ferns of European distribution, to contribute to the validation of certain traditional uses. Specifically, we have characterized the methanolic extract of P. vulgare fronds (PVM) by HPLC-DAD and investigated its potential cytotoxicity, phototoxicity, ROS production and protective effects against oxidative stress by using in vitro methods. The 3T3, HaCaT, HeLa, HepG2, MCF-7 and A549 were the cell lines used to evaluate the possible cytotoxic behaviour of the PVM. HPLC-DAD was utilized to validate the polyphenolic profile of the extract. H₂O₂ and UVA were the prooxidant agents to induce oxidative stress by different conditions in 3T3 and HaCaT cell lines. Antioxidant activity of in vitro PVM in 3T3 and HaCaT cell lines was evaluated by ROS assay. Our results demonstrate that PVM contains significant amounts of shikimic acid together with caffeoylquinic acid derivatives and flavonoids such as epicatechin and catechin; PVM is not cytotoxic at physiological concentrations against the different cell lines, showing cytoprotective and cellular repair activity in 3T3 fibroblast cells. This biological activity could be attributed to the high content of polyphenolic compounds. The fronds of the P. vulgare are a source of polyphenolic compounds, which can be responsible for certain traditional uses like wound healing properties. In the present work, fronds of the common polypody are positioned as a candidate for pharmaceutical applications based on traditional medicine uses but also as potential food ingredients due to lack of toxicity at physiological concentrations.

Effect of ultraviolet radiation on the Nrf2 signaling pathway in skin cells

PURPOSE

Excessive exposure of skin to solar radiation is associated with greatly increased production of reactive oxygen and nitrogen species (ROS, RNS) resulting in oxidative stress (OS), inflammation, immunosuppression, the production of matrix metalloproteinase, DNA damage and mutations. These events lead to increased incidence of various skin disorders including photoaing and both non-melanoma and melanoma skin cancers. The ultraviolet (UV) part of sunlight, in particular, is responsible for structural and cellular changes across the different layers of the skin. Among other effects, UV photons stimulate oxidative damage to biomolecules via the generation of unstable and highly reactive compounds. In response to oxidative damage, cytoprotective pathways are triggered. One of these is the pathway driven by the nuclear factor erythroid-2 related factor 2 (Nrf2). This transcription factor translocates to the nucleus and drives the expression of numerous genes, among them various detoxifying and antioxidant enzymes. Several studies concerning the effects of UV radiation on Nrf2 activation have been published, but different UV wavelengths, skin cells or tissues and incubation periods were used in the experiments that complicate the evaluation of UV radiation effects.

CONCLUSIONS

This review summarizes the effects of UVB (280-315 nm) and UVA (315-400 nm) radiation on the Nrf2 signaling pathway in dermal fibroblasts and epidermal keratinocytes and melanocytes. The effects of natural compounds (pure compounds or mixtures) on Nrf2 activation and level as well as on Nrf2-driven genes in UV irradiated human skin fibroblasts, keratinocytes and melanocytes are briefly mentioned as well.HighlightsUVB radiation is a rather poor activator of the Nrf2-driven pathway in fibroblastsUVA radiation stimulates Nrf2 activation in dermal fibroblastsEffects of UVA on the Nrf2 pathway in keratinocytes and melanocytes remain unclearLong-term Nrf2 activation in keratinocytes disturbs their normal differentiationPharmacological activation of Nrf2 in the skin needs to be performed carefully.

Cardioprotective Effects and In-Silico Antioxidant Mechanism of L-Ergothioneine In Experimental Type-2 Diabetic Rats

BACKGROUND

Diabetic cardiotoxicity is commonly associated with oxidative injury, inflammation, and endothelial dysfunction. L-ergothioneine (L-egt), a diet-derived amino acid, has been reported to decrease mortality and risk of cardiovascular injury, provides cytoprotection to tissues exposed to oxidative damage, and prevents diabetes-induced perturbation.

OBJECTIVE

This study investigated the cardioprotective effects of L-egt on diabetes-induced cardiovascular injuries and its probable mechanism of action.

METHODS

Twenty-four male Sprague-Dawley rats were divided into non-diabetic (n=6) and diabetic groups (n=18). Six weeks after the induction of diabetes, the diabetic rats were divided into three groups (n=6) and administered distilled water, L-egt (35mg/kg), and losartan (20mg/kg) by oral gavage for six weeks. Blood glucose and mean arterial pressure (MAP) were recorded pre-and post-treatment, while biochemical, ELISA, and Rt-PCR analyses were conducted to determine inflammatory, injury-related and antioxidant biomarkers in cardiac tissue after euthanasia. Also, an in-silico study, including docking and molecular dynamic simulations of L-egt toward the Keap1-Nrf2 protein complex, was done to provide a basis for the molecular antioxidant mechanism of L-egt.

RESULTS

Administration of L-egt to diabetic animals reduced serum triglyceride, water intake, MAP, biomarkers of cardiac injury (CK-MB, LDH), lipid peroxidation, and inflammation. Also, L-egt increased body weight, antioxidant enzymes, upregulated Nrf2, HO-1, NQO1 expression, and decreased Keap1 expression. The in-silico study showed that L-egt inhibits Keap1-Nrf2 complex by binding to the active site of Nrf2 protein, thereby preventing its degradation.

CONCLUSION

L-egt protects against diabetes-induced cardiovascular injury via the upregulation of Keap1-Nrf2 pathway and its downstream cytoprotective antioxidants.

Kirenol Inhibits B[a]P-Induced Oxidative Stress and Apoptosis in Endothelial Cells via Modulation of the Nrf2 Signaling Pathway

Atherosclerosis is a persistent inflammatory disorder specified by the dysfunction of the arteries, the world's leading cause of cardiovascular diseases. We sought to determine the effectiveness of KRL in B[a]P-induced oxidative stress and programmed cell death in endothelial cells. Western blotting, real-time PCR, DCFH2-DA, and TUNEL staining were performed to detect pPI3K, pAKT, Nrf2, HO-1, NQO-1, Bcl2, Bax, and caspase-3 on the HUVECs. Through the pretreatment of KRL, a drastic enhancement was observed in the cell viability of HUVECs, whereas DNA damage and generation of reactive oxygen species induced by B[a]P was suppressed. KRL's potential use as an antioxidant was observed to have a direct correlation with an antioxidant gene's augmented expression and the nuclear translocation activation of Nrf2, even during the event when B[a]P was found to be absent. In addition, this study proved that the signaling cascades of PI3K/AKT mediated Nrf2 translocation. Activation of suppressed nuclear Nrf2 and reduced antioxidant genes across cells interacting with an LY294002 confirmed this phenomenon. In addition, knockdown of Nrf2 by Nrf2-siRNA transfection abolished the protective effects of KRL on HUVECs cells against oxidative damage. Finally, the expression of apoptotic proteins also supported the hypothesis that KRL may inhibit endothelial dysfunction. This study showed that KRL potentially prevents B[a]P-induced redox imbalance in the vascular endothelium by inducing the Nrf2 signaling via the PI3K/AKT pathway.

Extracts of Jasminum sambac flowers fermented by Lactobacillus rhamnosus inhibit H2 O2 - and UVB-induced aging in human dermal fibroblasts

Ultraviolet (UV) irradiation is a crucial factor that leads to skin photoaging and results in increased DNA damage, oxidative stress, and collagen degradation. Jasmine flowers have been utilized as a traditional medicine in Asia to treat various diseases, including dermatitis, diarrhea, and fever. Furthermore, the fermented broth of Lactobacillus rhamnosus has been reported to exert protective effects on the skin. In the present study, jasmine flower extract was fermented with L. rhamnosus. We investigated the antioxidant and collagen-promoting effects on UVB/H₂ O₂ -induced HS68 dermal fibroblast cell damage. The results indicated that treatment with the fermented flower extracts of Jasminum sambac (F-FEJS) could enhance the viability of HS68 cells. Furthermore, the UVB/H₂ O₂ -induced excessive production of reactive oxygen species, degradation of collagen, activation of MAPKs, including P38, ERK, and JNK, and premature senescence were remarkably attenuated by F-FEJS in dermal fibroblast cells. The nuclear accumulation of p-c-jun, which is downstream of MAPK, and the inactivation of p-smad2/3, which is one of the crucial transcription factors that enhance collagen synthesis, were reversed in response to F-FEJS treatment in UVB/H₂ O₂ -exposed cells. Notably, the expression of antioxidant genes, such as HO-1, and the nuclear translocation of Nrf2 were further enhanced by F-FEJS in UVB/H₂ O₂ -treated cells. Interestingly, the F-FEJS-induced increase in ARE luciferase activity indicated the activation of Nrf2/ARE signaling. In conclusion, our findings demonstrated that F-FEJS can effectively ameliorate UVB/H₂ O₂ -induced dermal cell aging and may be considered a promising ingredient in skin aging therapy.

Tremella fuciformis polysaccharides inhibit UVA-induced photodamage of human dermal fibroblast cells by activating up-regulating Nrf2/Keap1 pathways

BACKGROUND

UVA radiation can cause skin oxidative stress. Tremella fuciformis polysaccharides (TFPS) are the main active ingredient in Tremella. Previous studies have shown that TFPS have protective effects on UVA-induced oxidative stress cells, but the specific protective mechanism has not been clarified.

OBJECTIVE

This study aims to explore the potential protective mechanism of Tremella fuciformis polysaccharides on UVA-induced damage to human dermal fibroblasts cells.

METHODS

We evaluated the protective ability of TFPS against UVA-induced damage by detecting cell survival rate, the content of reactive oxygen species (ROS) and malondialdehyde (MDA) in the cells, and the scavenging activity of ABTS free radicals, as well as the enzyme activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), and the Nrf2-Keap-1 pathway protein and gene were measured to study the protective mechanism of TFPS from photodamage.

RESULTS

TFPS pretreatment can reduce the oxidative stress of UVA-treated human dermal fibroblasts cells. After TFPS pretreatment, the content of ROS and MDA in the cell decreased significantly and the total antioxidant activity was increased. Among them, the active of CAT, SOD, and GSH-Px in the cells increased significantly. TFPS can also protect fibroblasts by up-regulating Nrf2 and down-regulating Keap1 expression. Finally, it was also found that TFPS pretreatment increased the content of collagen I, elastin, and hyaluronic acid (HA) in skin fibroblasts treated with UVA.

CONCLUSION

These results indicate that a certain concentration of TFPS can effectively alleviate skin damage caused by UVA, and they may be used as an effective component of cosmetics.

Ergothioneine alleviates senescence of fibroblasts induced by UVB damage of keratinocytes via activation of the Nrf2/HO-1 pathway and HSP70 in keratinocytes

Ultraviolet B (UVB) irradiation induces skin damage and photoaging through several deleterious effects, including generation of reactive oxygen species (ROS), apoptosis of epidermal cells, inflammation, and collagen degradation in fibroblasts. Ergothioneine (EGT) is a naturally occurring amino acid with potential biological properties. We evaluated whether EGT protects against UVB-induced photoaging using a keratinocyte/fibroblast co-culture system. Keratinocytes were pretreated with EGT, irradiated with UVB, and co-cultured with fibroblasts. In keratinocytes, ROS production and apoptosis were assessed. We also analyzed the Nrf2/HO-1 pathway, HSP70, proapoptotic proteins, and paracrine cytokines by Western blotting and real-time PCR. Collagen degradation-related genes and senescence were also assessed in fibroblasts. EGT pretreatment of keratinocytes significantly inhibited downregulation of the Nrf2/HO-1 pathway and HSP70, and protected keratinocytes by suppressing production of ROS and cleavage of proapoptotic proteins, including caspase-8 and PARP. Furthermore, EGT significantly reduced the paracrine cytokines, including IL-1β, IL-6, and TNF-α. In co-cultures of fibroblasts with EGT-treated keratinocytes, the expression levels of collagen degradation-related genes and fibroblast senescence were significantly decreased; however, synthesis of procollagen type I was significantly increased. Our results confirm that EGT suppresses the modification of collagen homeostasis in fibroblasts by preventing downregulation of the Nrf2/HO-1 pathway and HSP70 in keratinocytes following UVB irradiation.

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.

Impact of Ergothioneine, Hercynine, and Histidine on Oxidative Degradation of Hyaluronan and Wound Healing

A high-molecular weight hyaluronan is oxidatively degraded by Cu(II) ions and ascorbate—the so called Weissberger biogenic oxidative system—which is one of the most potent generators of reactive oxygen species, namely ^•OH radicals. Ergothioneine, hercynine, or histidine were loaded into chitosan/hyaluronan composite membranes to examine their effect on skin wound healing in ischemic rabbits. We also explored the ability of ergothioneine, hercynine, or histidine to inhibit hyaluronan degradation. Rotational viscometry showed that ergothioneine decreased the degree of hyaluronan radical degradation in a dose-dependent manner. While histidine was shown to be potent in scavenging ^•OH radicals, however, hercynine was ineffective. In vivo results showed that the addition of each investigated agent to chitosan/hyaluronan membranes contributed to a more potent treatment of ischemic skin wounds in rabbits compared to untreated animals and animals treated only with chitosan/hyaluronan membranes.

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.

Protective Effects of Oenothera biennis against Hydrogen Peroxide-Induced Oxidative Stress and Cell Death in Skin Keratinocytes

BACKGROUND

Oenothera biennis (evening primrose) produces bioactive substances with a diverse range of pharmacological functions. However, it is currently unknown whether extract prepared from the aerial parts of O. biennis (APOB) can protect the skin against oxidative stress.

OBJECTIVE

The aim of this study is to investigate the protective effects of APOB against oxidative stress-induced damage in human skin keratinocytes (HaCaT) and elucidate the underlying mechanisms.

METHODS

We pretreated HaCaT cells with various concentrations of APOB or the antioxidant N-acetyl-L-cysteine before applying H₂O₂. We then compared the cell viability, intracellular reactive oxygen species (ROS) production, and DNA and mitochondrial damage between pretreated and untreated control cells using a range of assays, flow cytometry, and Western blot analysis and also examined the reducing power and DPPH free radical scavenging activity of APOB.

RESULTS

APOB pretreatment significantly increased cell viability, effectively attenuated H₂O₂-induced comet tail formation, and inhibited H₂O₂-induced phosphorylation of the histone γH2AX, as well as the number of apoptotic bodies and Annexin V-positive cells. APOB was found to have high reducing power and DPPH radical scavenging activity and also exhibited scavenging activity against intracellular ROS accumulation and restored the loss of mitochondrial membrane potential caused by H₂O₂. APOB pretreatment almost totally reversed the enhanced cleavage of caspase-3, the degradation of poly (ADP-ribose)-polymerase (PARP), DNA fragmentation that usually occurs in the presence of H₂O₂, and increased the levels of heme oxygenase-1 (HO-1), a potent antioxidant enzyme that is associated with the induction of nuclear factor-erythroid 2-related factor 2 (Nrf2).

CONCLUSIONS

APOB can protect HaCaT cells from H₂O₂-induced DNA damage and cell death by blocking cellular damage related to oxidative stress via a mechanism that affects ROS elimination and by activating the Nrf2/HO-1 signaling pathway.

Beneficial effects of Diplectria barbata (Wall. Ex C. B. Clarke) Franken et Roos extract on aging and antioxidants in vitro and in vivo

The purpose of this study is to explore the effects of Diplectria barbata (Wall. Ex C.B. Clarke) Franken & Roons (DFR) on wound healing, antioxidant and aging in Normal Human Dermal Fibroblast cell (NHDF) cells and mouse skin models. We investigated the effects of the aging process in vitro and in vivo. DFRtreated NHDF cells showed a concentration-dependent increase in the expression of extracellular matrix (ECM) proteins (Collagen-2.5-fold increase at 50 μg/ml, Elastin-1.5-fold increase at 1μg/ml) as well as an increase in proteins related to cell survival, differentiation, and development, while expression of aging proteins such as matrix metalloproteinase 3 (MMP-3) was decreased (5-fold decrease at 50 μg/ml). DFR treatment also led to enhanced expression of antioxidant proteins such as nuclear factor erythroid 2-related factor 2 (10-fold increase at 50 μg/ml) and heme oxygenase 1 (1.5-fold increase at 25 μg/ml). To further investigate the antioxidative effects of DFR extracts, the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities were also evaluated. DFR extracts improved wound healing and resulted in increased expression of ECM proteins, while enzymes involved in collagen degradation, including MMP-3, were decreased in NHDF cells as well as in a mouse model. This study demonstrates the anti-aging, antioxidant, and wound healing properties of DFR extracts. Therefore, DFR extracts present may facilitate skin protection and care.

Exploring microRNAs in diabetic chronic cutaneous ulcers: Regulatory mechanisms and therapeutic potential

Diabetic chronic cutaneous ulcers (DCU) are one of the serious complications of diabetes mellitus, occurring mainly in diabetic patients with peripheral neuropathy. Recent studies have indicated that microRNAs (miRNAs/miRs) and their target genes are essential regulators of cell physiology and pathology including biological processes that are involved in the regulation of diabetes and diabetes-related microvascular complications. in vivo and in vitro models have revealed that the expression of some miRNAs can be regulated in the inflammatory response, cell proliferation, and wound remodelling of DCU. Nevertheless, the potential application of miRNAs to clinical use is still limited. Here, we provide a contemporary overview of the miRNAs as well as their associated target genes and pathways (including Wnt/β-catenin, NF-κB, TGF-β/Smad, and PI3K/AKT/mTOR) related to DCU healing. We also summarize the current development of drugs for DCU treatment and discuss the therapeutic challenges of DCU treatment and its future research directions.

Successful biosynthesis of natural antioxidant ergothioneine in Saccharomyces cerevisiae required only two genes from Grifola frondosa

Background

Ergothioneine (EGT) has a unique antioxidant ability and diverse beneficial effects on human health. But the content of EGT is very low in its natural producing organisms such as Mycobacterium smegmatis and mushrooms. Therefore, it is necessary to highly efficient heterologous production of EGT in food-grade yeasts such as Saccharomyces cerevisiae.

Results

Two EGT biosynthetic genes were cloned from the mushroom Grifola frondosa and successfully heterologously expressed in Saccharomyces cerevisiae EC1118 strain in this study. By optimization of the fermentation conditions of the engineered strain S. cerevisiae EC1118, the 11.80 mg/L of EGT production was obtained. With daily addition of 1% glycerol to the culture medium in the fermentation process, the EGT production of the engineered strain S. cerevisiae EC1118 can reach up to 20.61 mg/L.

Conclusion

A successful EGT de novo biosynthetic system of S. cerevisiae containing only two genes from mushroom Grifola frondosa was developed in this study. This system provides promising prospects for the large scales production of EGT for human health.

Effect of UVA radiation on the Nrf2 signalling pathway in human skin cells

The harmful effects of low energy UVA photons (315-400 nm) are associated with the massive production of reactive oxygen species resulting in oxidative stress. In response to oxidative damage, NF-E2-related factor 2 (Nrf2) is translocated to the nucleus and drives the expression of detoxication and antioxidant enzymes. UVA's effect on Nrf2 has been quite well characterised in dermal fibroblasts. However, there is a dearth of such information for keratinocytes. This study aimed to evaluate and compare the effect of UVA radiation on the Nrf2 pathway and oxidative stress related proteins in primary human dermal fibroblasts (NHDF), epidermal keratinocytes (NHEK) and human keratinocyte cell line HaCaT. NHDF were exposed to doses of 2.5-7.5 J/cm², NHEK and HaCaT to 10-20 J/cm² using a solar simulator. Effects on Nrf2 translocation were evaluated after 1, 3 and 6 h and Nrf2-controlled proteins (heme oxygenase 1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1), glutathione reductase (GSR), glutathione-S-transferase (GST), interleukine-6 (IL-6), and matrix metalloproteinases (MMP-1, MMP-2)) after 3, 6 and 24 h. The results showed the fastest Nrf2 translocation was in UVA-irradiated HaCaT (1 h), persisting until the subsequent time interval (3 h), while in primary keratinocytes the effect of radiation was minimal. In NHDF, UVA-stimulated Nrf2 translocation was conspicuous 3 h after UVA treatment. In NHDF, most of the studied proteins (NQO1, HO-1, GSR, GSTM1 and MMP-1) showed the highest level 24 h after UVA exposure, except for MMP-2 and IL-6 which had their highest level at a shorter time incubation interval (3 h). In NHEK, NQO1, HO-1 and GST were increased 6 h after UVA exposure, GSR and MMP-2 level was slightly below or above the control level, and MMP-1 and IL-6 increased at shorter time intervals. When comparing NHEK and HaCaT, these cells displayed contrary responses in most of the Nrf2-controlled proteins. Thus, primary keratinocytes cannot be replaced with HaCaT when studying cell signalling such as the Nrf2 driven pathway and Nrf2-controlled proteins.

UVA Induced Oxidative Stress Was Inhibited by Paeoniflorin/Nrf2 Signaling or PLIN2

Photodamages caused by UVA radiation induced oxidative injuries are closely related to photoaging and skin cancer. Paeoniflorin (PF), extracted from the root of Paeonia lactiflora, has been reported to be an effective antioxidant. PLIN2, known as adipose differentiation-related protein, has been previously involved in the regulation of oxidative stress. In this study, we were sought to investigate the photo-protective property of PF and PLIN2 in UVA-radiated human dermal fibroblasts (HDFs). HDFs were pre-treated with PF (800 μM) followed by UVA radiation (22.5 J/cm2). MTS activity, cell apoptosis, ROS, MDA, and SOD were detected, respectively. The expressions of Nrf2, HO-1, NQ-O1, and PLIN2 were determined using RT-qPCR or western blot. Nrf2 was silenced by siRNA, and PLIN2 was overexpressed via lentiviral transduction. Comparing to the UVA radiation, PF pre-treatment could prominently increase the MTS activity, decrease cell apoptosis, reduce the generations of ROS and MDA, increase the activity of SOD and increase the expression of Nrf2 and its target genes HO-1 and NQ-O1. When Nrf2 was knocked down, PF lost above protective properties. In addition, UVA induced oxidative stress led to upregulation of PLIN2 and the latter could be decreased by PF. Overexpression of PLIN2 improved MTS activity and reduced MDA level in HDFs. The combination of PLIN2 overexpression and PF pre-treatment corporately inhibited UVA-induced injury. Besides, we also found that PF and PLIN2 had a compensatory protection against UVA induced oxidative stress. In conclusion, our study demonstrated that UVA induced photodamages could be inhibited by PF via Nrf2/HO-1/NQ-O1 signaling pathway or by PLIN2, and the combination of PLIN2 overexpression and PF played additive effects against UVA-related oxidative stress.