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L-Ergothioneine modulates oxidative damage in the kidney and liver of rats in vivo: Studies upon the profile of polyunsaturated fatty acids
Abstract
L-ergothioneine is a fungal metabolite exhibiting antioxidant functions in cells. The aim of this study was to assess the effect of oral administration of L-ergothioneine on the oxidative damage in vivo caused by the Fenton reagent ferric-nitrilotriacetate.
Rats were supplemented with L-ergo prior to the administration of acute dose of ferric-nitrilotriacetate. Kidney and liver levels of L-ergothioneine, glutathione, alpha-tocopherol, polyunsaturated fatty acids and conjugated dienes were assessed.
Oral administration of 70 mg L-ergo/kg body weight of rats for 7 days prior to the injection of ferric-nitrilotriacetate protected the fatty acids against oxidation, with notable protections directed to: 20:5 (eicosapentaenoic acid) (23%), 22:6 (docosahexaenoinic acid) (30%), 20:3 n6 (eicosatrienoic acid) (22%), 20:4 (arachidonic acid) (25%), 18:2 linoleic acid (25%) and 18:1 oleic acid (14%) in the kidney. The protection of 20:5, 20:3 n6 and 18:1 in the liver by 32%, 20% and 11%, respectively, were statistically significant. L-ergothioneine significantly reduced kidney and liver levels of conjugated dienes and conserved the concentrations of alpha-tocopherol and glutathione in the kidney and liver in the ferric-nitrilotriacetate/L-ergothioneine treated rats.
Supplementation with L-ergothioneine not only protects the organs against the lipid peroxidation but conserves the consumption of endogenous glutathione and alpha-tocopherol. However consumption of mushrooms may have better promise as dietary sources of L-ergothioneine to humans.
... Conversely, silencing the gene encoding OCTN1 predisposes cells and animals to higher levels of oxidative damage [101][102][103]. This suggests that elevating tissue levels of ET in the body will be beneficial in protecting from oxidative damage [57,104]. Moreover, ET has a high bioavailability, being actively taken up into cells and tissues where it is needed. ...
... Indeed, ET would suit this therapeutic role. Studies in rodents have demonstrated that ET decreases oxidative damage in the kidneys and liver from the ROS-generating agent ferric-nitrilotriacetate [104]. By contrast, knocking out the ET transporter in murine models of chronic kidney disease increased kidney damage and fibrosis and elevated oxidative damage [105]. ...
... Like the kidney, ET may also be beneficial in the liver, where earlier studies have demonstrated that it is the first site of rapid ET accumulation following oral administration in mice [32]. Additionally, we have shown that the liver can upregulate the ET transporter in response to damage, further increasing tissue ET levels, where it may be protective against oxidative damage, inflammation, and fibrosis formation [56,104]. Similarly, studies by Tang et al. [55] identified that human hepatic stellate cells upregulated OCTN1 following administration of dimethylnitrosamine (DMN), a hepatotoxin that increased levels of both oxidative damage and α-smooth muscle actin, the latter being a marker for activated stellate cells and liver fibrosis. Supplementation with ET decreased oxidative damage and DMN-induced activation of liver fibrosis, while conversely, knocking out OCTN1 resulted in a significant elevation of liver fibrosis markers, oxidative damage, and inflammation in mice [55]. ...
Infection with SARS-CoV-2 causes the coronavirus infectious disease 2019 (COVID-19), a pandemic that has, at present, infected more than 11 million people globally. Some COVID-19 patients develop a severe and critical illness, spurred on by excessive inflammation that can lead to respiratory or multiorgan failure. Numerous studies have established the unique array of cytoprotective properties of the dietary amino acid ergothioneine. Based on studies in a range of in vitro and in vivo models, ergothioneine has exhibited the ability to modulate inflammation, scavenge free radicals, protect against acute respiratory distress syndrome, prevent endothelial dysfunction, protect against ischemia and reperfusion injury, protect against neuronal damage, counteract iron dysregulation, hinder lung and liver fibrosis, and mitigate damage to the lungs, kidneys, liver, gastrointestinal tract, and testis, amongst many others. When compiled, this evidence suggests that ergothioneine has a potential application in the treatment of the underlying pathology of COVID-19. We propose that ergothioneine could be used as a therapeutic to reduce the severity and mortality of COVID-19, especially in the elderly and those with underlying health conditions. This review presents evidence to support that proposal.
... In addition, studies in various animal models have demonstrated antioxidant and cytoprotective actions of ET, including protection against ischemia-reperfusion injury (6,50), acute lung injury (48), damage caused by the pro-oxidants ferric-NTA (14) and b-amyloid (63), and d-galactose-induced exists as a thiol-thione; however, at physiological pH, the thione tautomeric form is favored, conferring greater stability. The structures for precursor and possible metabolic derivatives, hercynine (B), S-methylergothioneine (C), and ergothioneine sulfonate (D) are also shown. ...
... Indeed, studies have revealed that when animals are placed under oxidative stress, for example, administration of ferricnitrilotriacetate (14), ischemia-reperfusion injury (6,50), induced acute respiratory distress (48), or induced neurodegeneration (55,63), ET supplementation was able to decrease oxidative stress and inflammation, and to increase survival. In the absence of the ET transporter, OCTN1, the knockout animals devoid of tissue ET also appear normal until placed under stress (11,32,45). ...
... Other aspects of study compliance, including review of abstinence from ETrich foods, and administration of any medications were conducted during study visits. Blood and urine samples were collected on days 1, 3,5,8,14,21,28, and 35 (Fig. 2). Venous blood (8 ml) was collected in K 2 EDTA vacutainers (Becton Dickinson). ...
Aim:
We investigated the uptake and pharmacokinetics of ergothioneine (ET), a dietary thione with free radical scavenging and cytoprotective capabilities, after oral administration to humans, and its effect on biomarkers of oxidative damage and inflammation.
Results:
Following oral administration, ET is avidly absorbed and retained by the body with significant elevations in plasma and whole blood concentrations, and relatively low urinary excretion (less than 4% of administered ET). ET levels in whole blood were highly correlated to levels of hercynine and S-methyl-ergothioneine, suggesting that they may be metabolites. After ET administration, some decreasing trends were seen on biomarkers of oxidative damage and inflammation, including allantoin (urate oxidation), 8-hydroxy-2-deoxyguanosine (DNA damage), 8-iso-PGF2α (lipid peroxidation), protein carbonylation, and C-reactive protein. However, most of the changes were non-significant.
Innovation:
This is the first study investigating the administration of pure ET to healthy human volunteers, and monitoring its uptake and pharmacokinetics. This compound is rapidly gaining attention due to its unique properties, and this study lays the foundation for future studies.
Conclusion:
The uptake and retention of ET by the body suggests an important physiological function. The decreasing trend of oxidative damage biomarkers is consistent with animal studies suggesting that ET may function as a major antioxidant but perhaps only under conditions of oxidative stress.
... studies have highlighted the possible antioxidant and hepatoprotective capabilities of this compound [1,2,[34][35][36][37][38]. Many of these earlier studies supplemented animal models placed under stress (e.g. ...
... Numerous in vitro and a handful of in vivo studies have demonstrated the potentially beneficial properties of ET, in neurodegeneration [43,44] and cardiovascular disorders [45,46] and as an antioxidant [2,36,47], a metal chelator [4,5], and an anti-inflammatory agent [48,49]. ...
... that ET supplementation in rats protected the animal livers from lipid peroxidation following the administration of the Fenton catalyst ferric-nitrilotriacetate or ethionine, respectively [36,38]. ...
L-ergothioneine (ET), a putative antioxidant compound acquired by animals through dietary sources, has been suggested to accumulate in certain cells and tissues in the body that are predisposed to high oxidative stress. In the present study, we identified an elevation of ET in the liver of a guinea pig model of non-alcoholic fatty liver disease (NAFLD), elucidated a possible mechanism for the increased uptake and investigated the possible role for this accumulation. This increase in liver ET levels correlated with cholesterol accumulation and disease severity. We identified an increase in the transcriptional factor, RUNX1, which has been shown to upregulate the expression of the ET-specific transporter OCTN1, and could consequently lead to the observable elevation in ET. An increase was also seen in heat shock protein 70 (HSP70) which seemingly corresponds to ET elevation. No significant increase was observed in oxidative damage markers, F2-isoprostanes, and protein carbonyls, which could possibly be attributed to the increase in liver ET through direct antioxidant action, induction of HSP70, or by chelation of Fe(2+), preventing redox chemistry. The data suggest a novel mechanism by which the guinea pig fatty liver accumulates ET via upregulation of its transporter, as a possible stress response by the damaged liver to further suppress oxidative damage and delay tissue injury. Similar events may happen in other animal models of disease, and researchers should be aware of the possibility.
... In addition, little, or no, tritiated ESH disappeared from the blood in vivo after 1 week of fasting [23]. Moreover, dietary ESH in rats protected their kidneys and liver against Fenton reaction-derived oxidative damage, particularly against lipid peroxidation [24]. ...
... Using rats as a model organism, dietary supplementation with ESH protected kidney and liver tissues, and the polyunsaturated fatty acids (PUFAs) in their cellular membranes, from Fenton reaction-derived damage and lipid peroxidation [24]. In addition, ESH ameliorated iron-induced liver toxicity, perhaps by both scavenging ROS and binding iron [42]. ...
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.
... As we originally proposed [798], its anti-inflammatory potency has been established in a model of pre-eclampsia [799]. It is strongly protective against diseases of oxidative stress affecting the heart [793,800], liver [801,802], kidney [802], CNS [803,804], and other tissues (e.g. [794,805]. ...
... As we originally proposed [798], its anti-inflammatory potency has been established in a model of pre-eclampsia [799]. It is strongly protective against diseases of oxidative stress affecting the heart [793,800], liver [801,802], kidney [802], CNS [803,804], and other tissues (e.g. [794,805]. ...
Ischaemia-reperfusion (I-R) injury, initiated via bursts of reactive oxygen species produced during the reoxygenation phase following hypoxia, is well known in a variety of acute circumstances. We argue here that I-R injury also underpins elements of the pathology of a variety of chronic, inflammatory diseases, including rheumatoid arthritis, ME/CFS and, our chief focus and most proximally, Long COVID. Ischaemia may be initiated via fibrin amyloid microclot blockage of capillaries, for instance as exercise is started; reperfusion is a necessary corollary when it finishes. We rehearse the mechanistic evidence for these occurrences here, in terms of their manifestation as oxidative stress, hyperinflammation, mast cell activation, the production of marker metabolites and related activities. Such microclot-based phenomena can explain both the breathlessness/fatigue and the post-exertional malaise that may be observed in these conditions, as well as many other observables. The recognition of these processes implies, mechanistically, that therapeutic benefit is potentially to be had from antioxidants, from anti-inflammatories, from iron chelators, and via suitable, safe fibrinolytics, and/or anti-clotting agents. We review the considerable existing evidence that is consistent with this, and with the biochemical mechanisms involved.
... Exposure of tissues to chronic inflammation and persistent oxidative stress due to environmental (chemical or radiation) insults, allergies, persistent infections, autoimmune reactions, and so on, can lead to damage and remodelling of tissue, eventually triggering fibrosis, which may ultimately lead to organ failure [74]. Multiple studies in cell cultures and animal models have demonstrated that ET not only modulates levels of inflammatory cytokines and mitigates oxidative or nitrosative damage [75][76][77], but may also slow or prevent fibrosis [26,78,79]. ...
... Moreover, OCTN1 expression in hepatocytes was elevated in wild-type mice following DMN treatment [78], which is consistent with an earlier study demonstrating an increase of liver OCTN1 expression and tissue ET in a guinea pig model of fatty liver disease [25]. Another study claimed that ET protected rat kidney and liver against oxidative damage caused by ferric-nitrilotriacetate [75]. Conversely, OCTN1-knockout in mice exacerbated indoxyl sulfate-induced kidney [26] and DMN-induced liver injury [78] and aggravated oxidative damage, inflammation and fibrosis in both models. ...
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.
... There is some in vivo evidence to suggest ERG acts as an anti-oxidant in animal models of lung injury [90], hepatorenal dysfunction [40], and ischaemia/reperfusion injury to the liver [37] and small intestine [50]. Studies using SLC22A4 -/mice show a deficiency of ERG in both serum and tissue. ...
... No difference was observed between lipid peroxidation biomarkers. Finally, Deiana et al. [40] detected ERG in the tissue of rats following oral supplementation (70 mg/kg/d). After one week of treatment the levels reported were 0.66 μg/mg tissue in the kidney and 1.33 μg/mg tissue in the liver. ...
Ergothioneine (ERG), is a water-soluble amino acid that is derived entirely from dietary sources. It has received much attention as a therapeutic agent due to its anti-oxidant properties, and there are claims of preferential accumulation within high oxidative stress organs. Pre-eclampsia, a condition accompanied by increased oxidative stress, is one of the leading causes of maternal morbidity and mortality. Despite intense research efforts, its aetiologies remain somewhat unclear and there are still no effective treatment options. Clinical trials of the anti-oxidants vitamin C and vitamin E have proven largely ineffective with little improvement in clinical outcome or even a negative response. This could be explained in part by their inability to permeate the plasma and mitochondrial membranes and scavenge mitochondria-derived superoxide species, and for the former by the fact that it is actually a pro-oxidant in the presence of unliganded iron. ERG accumulates within tissues through the action of a specific organic cation transporter, SLC22A4 (previously referred to as OCTN1), which is possibly also expressed in mammalian mitochondria. Mitochondrial dysfunction has been implicated in a variety of vascular diseases including pre-eclampsia. This review discusses the use of ERG as a possibly mitochondrial-targeted anti-oxidant, focusing on its physical properties, potential mechanisms of action, safety profile and administration in relation to pregnancies complicated by pre-eclampsia.
... In particular, the plasma levels of creatinine, SDMA, urea, and ADMA, which are markers of renal dysfunction were suppressed by daily ERGO intake ( Fig. 4a-d) [27][28][29]. This finding may be compatible with the previous reports indicating that ERGO modulates oxidative damage of the kidney in rats and that decreased ERGO levels may contribute to chronic kidney disease progression implying beneficial roles of ERGO in the kidney [80,81]. The National Institute on Aging Interventions Testing Program evaluates agents hypothesized to increase healthy lifespan in genetically heterogeneous mice (https:// www. ...
Healthy aging has emerged as a crucial issue with the increase in the geriatric population worldwide. Food-derived sulfur-containing amino acid ergothioneine (ERGO) is a potential dietary supplement, which exhibits various beneficial effects in experimental animals although the preventive effects of ERGO on aging and/or age-related impairments such as frailty and cognitive impairment are unclear. We investigated the effects of daily oral supplementation of ERGO dissolved in drinking water on lifespan, frailty, and cognitive impairment in male mice from 7 weeks of age to the end of their lives. Ingestion of 4 ~ 5 mg/kg/day of ERGO remarkably extended the lifespan of male mice. The longevity effect of ERGO was further supported by increase in life and non-frailty spans of Caenorhabditis elegans in the presence of ERGO. Compared with the control group, the ERGO group showed significantly lower age-related declines in weight, fat mass, and average and maximum movement velocities at 88 weeks of age. This was compatible with dramatical suppression by ERGO of the age-related increments in plasma biomarkers (BMs) such as the chemokine ligand 9, creatinine, symmetric dimethylarginine, urea, asymmetric dimethylarginine, quinolinic acid, and kynurenine. The oral intake of ERGO also rescued age-related impairments in learning and memory ability, which might be associated with suppression of the age-related decline in hippocampal neurogenesis and TDP43 protein aggregation and promotion of microglial shift to the M2 phenotype by ERGO ingestion. Ingestion of ERGO may promote longevity and healthy aging in male mice, possibly through multiple biological mechanisms.
Supplementary Information
The online version contains supplementary material available at 10.1007/s11357-024-01111-5.
... Functioning as an antioxidant, EGT plays a crucial role in preventing cell and tissue damage, a significant factor for ageing, by neutralizing free radicals and mitigating oxidative stress (Borodina et al., 2020;Kerley et al., 2018;Samuel et al., 2022). This adaptive antioxidant capacity for the protection of injured tissues possibly explains the observations that the highest concentration of EGT is usually found in the red blood cells of elderly individuals (Kumosani, 2001), liver , brain (Nakamichi et al., 2016), ocular tissues (Shires et al., 1997), kidney (Deiana, 2004) and damaged tissues. Further insights indicate that EGT could target mitochondria and dampen the excess production of mitochondria-specific ROS in response to oxidative stress (Lamhonwah and Tein, 2006). ...
... Research by (20) in-vitro study found terpenoids, steroids, phenols, and flavonoid compounds resulting from HPLC hydro-ethanol extract G. lucidum and proved that dose 100µg/ml could suppress the expression of proinflammatory cytokines, decreased NF-κB expression and suppress Nitric Oxide (NO-) the product of iNOS without giving toxicity effect. The bioactive compound G. lucidum can downregulate the expression of the COX-2 enzyme (21), iNOS, suppress excess free radical production (22), inactivation of NF-κB, and suppress macrophage cells which cause inflammatory symptoms and cell damage. The use of a dose of 600-1600 mg/kg.BW extract of G. lucidum, according to (23) using CCL4 induction that makes liver injury of rats showed a significant increase of A/G ratio compared with test animal Wistar rat. ...
Abstrak: Inflammation is one of the immune system's responses to infection, irritation, also cell damage. Inflammation stimulates pro-inflammatory biomarkers. Albumin and globulin are included as inflammatory biomarkers, albumin is a negative acute phase protein (-APP), which will decrease, and globulin is a positive acute phase protein (+APP), which will increase due to inflammation. Ganoderma lucidum is a medicinal mushroom with anti-inflammatory potential that could increase the albumin level in blood due to inflammation. This research aimed to examine the effect of G. lucidum extract on the albumin and globulin level of inflamed white rats anddetermine the most effective dose of extract to be an anti-inflammatory agent. The study was conducted with a completely randomized design (CRD) consisting of 6 treatments of healthy control (HC), inflamed rats as negative control (C-), inflamed rats with Na-diclofenac administration (C+), and inflamed rats with G. lucidum extract administration with a dose of 250, 500, 750 mg/kg BW (T1, T2, and T3) with four replications each. The independent variable is the dose variant of G. lucidum (250, 500, 750 mg/kg BW), with the dependent variable being the changesin albumin and globulin levels. The main parameters are albumin and globulin levels, and the support parameter is the GC-MS test. The data were processed using Analysis of Variance (ANOVA) at an error rate of 5%, followed by Duncan's analysis at 95% confidence level. The results show that mushroom G. lucidum extract administration with a dose of 250 mg/kg BW is the most effective dose to be ana dose of 250 mg/kg BW, which is the most effective anti-inflammatory agent.
... Closely associated with cardiometabolic disease, NAFLD is an independent risk factor CVD (92) , and a prevalent co-morbidity of type 2 diabetes (93) , with recent estimates suggesting 47-64 % of individuals with type 2 diabetes have NAFLD globally (94) . While ergothioneine has been demonstrated to be protective in a number of other in vivo models of liver injury (46,66,95,96) , including the aforementioned model of diabetic liver damage (91) ; to date, only one study has examined SLC22A4 and ergothioneine in a preclinical model of NAFLD (53) . In this study, guinea pigs fed diets with either moderate or high levels of fat and cholesterol diets, increased liver expression of SLC22A4 mRNA, and had increased liver ergothioneine contents after 2 and 6 months of diet. ...
Ergothioneine is a naturally occurring amino acid and thiol antioxidant found in high amounts in mushrooms and fermented foods. Humans and animals acquire ergothioneine from the diet through the pH-dependent activity of a membrane transporter, the large solute carrier 22A member 4 (SLC22A4), expressed on the apical membrane of the small intestine. The SLC22A4 transporter also functions in the renal reabsorption of ergothioneine in the kidney, with avid absorption and retention of ergothioneine from the diet observed in both animals and humans. Ergothioneine is capable of scavenging a diverse range of reactive oxygen and nitrogen species, has metal chelation properties, and is predicted to directly regulate nuclear factor erythroid 2-related factor 2 (Nrf2) activity. Although not lethal, the genetic knockout of the SLC22A4 gene in multiple organisms increases susceptibility to oxidative stress, damage and inflammation; in agreement with a large body of preclinical data suggesting the physiological function of ergothioneine is as a cellular antioxidant and cytoprotectant agent. In humans, blood levels of ergothioneine decline after the age of 60 years, and lower levels of ergothioneine are associated with more rapid cognitive decline. Conversely, high plasma ergothioneine levels have been associated with significantly reduced cardiovascular mortality and overall mortality risks. In this horizon’s manuscript, we review evidence suggesting critical roles for dietary ergothioneine in healthy ageing and the prevention of cardiometabolic disease. We comment on some of the outstanding research questions in the field and consider the question of whether or not ergothioneine should be considered a conditionally essential micronutrient.
... Further, the relatively little amount of ergothioneine that is present in younger individuals diminishes with age, a phenomenon that has prompted some experts in the scientific community to suggest a role for ergothioneine in the aging process. [24][25][26][27][28][29][30] Finally, glutathione is known as the body's "master antioxidant" and a key component of the glutathione redox cycle. Like ergothioneine, glutathione is a sulfur-containing molecule present in every cell of the body. ...
... Accumulating evidence indicates that ERGO in particular is a physiological antioxidant cytoprotectant [22][23][24][25], existing in the body as a water-soluble zwitterion ( Figure 1A). ERGO protection against cytotoxicity elicited by Cu 2+ , H 2 O 2 , Fe, and sodium nitrite (NaNO 2 ) [26][27][28][29] is derived from its conspicuous affinity for metal cations, such as Fe and Cu, permitting the capture and neutralization of associated radicals [30]. Humans obtain ERGO through the diet, but blood ERGO concentration decreases significantly with age, and markedly lower levels have been found in individuals with mild cognitive impairment compared to healthy counterparts. ...
Background: Ergothioneine (ERGO) is a unique antioxidant and a rare amino acid available in fungi and various bacteria but not in higher plants or animals. Substantial research data indicate that ERGO is a physiological antioxidant cytoprotectant. Different from other antioxidants that need to breach the blood–brain barrier to enter the brain parenchyma, a specialized transporter called OCTN1 has been identified for transporting ERGO to the brain. Purpose: To assess whether consumption of ERGO can prevent the progress of Alzheimer’s disease (AD) on young (4-month-old) 5XFAD mice. Methods and materials: Three cohorts of mice were tested in this study, including ERGO-treated 5XFAD, non-treated 5XFAD, and WT mice. After the therapy, the animals went through various behavioral experiments to assess cognition. Then, mice were scanned with PET imaging to evaluate the biomarkers associated with AD using [11C]PIB, [11C]ERGO, and [18F]FDG radioligands. At the end of imaging, the animals went through cardiac perfusion, and the brains were isolated for immunohistology. Results: Young (4-month-old) 5XFAD mice did not show a cognitive deficit, and thus, we observed modest improvement in the treated counterparts. In contrast, the response to therapy was clearly detected at the molecular level. Treating 5XFAD mice with ERGO resulted in reduced amyloid plaques, oxidative stress, and rescued glucose metabolism. Conclusions: Consumption of high amounts of ERGO benefits the brain. ERGO has the potential to prevent AD. This work also demonstrates the power of imaging technology to assess response during therapy.
... Research on the role of EGT in the liver is limited. It has been shown that the liver is the main site to accumulate EGT, and a previous animal study found that supplementation of EGT [70 mg/kg body weight (bw)] in rats for 7 days before injection of ferric-nitrilotriacetate could protect the liver from the injury of lipid peroxidation (Deiana et al., 2004). The indexes detection of the NAFLD animal model established by cholesterol showed that under stress, the liver could up-regulate the expression of OCTN1 to increase the uptake and accumulation of EGT, and there was a significant correlation between the liver level of EGT and cholesterol and iron, although there was no difference in the diet content of EGT (Cheah et al., 2016b). ...
L-Ergothioneine (EGT) is a natural antioxidant derived from microorganisms, especially in edible mushrooms. EGT is found to be highly accumulated in tissues that are susceptible to oxidative damage, and it has attracted extensive attention due to its powerful antioxidant activity and the tight relationships of this natural product with various oxidative stress-related diseases. Herein, we 1) introduce the biological source and in vivo distribution of EGT; 2) review the currently available evidence concerning the relationships of EGT with diabetes, ischemia-reperfusion injury-related diseases like cardiovascular diseases and liver diseases, neurodegenerative diseases, and other diseases pathogenically associated with oxidative stress; 3) summarize the potential action mechanisms of EGT against these diseases; 4) discuss the advantages of EGT over other antioxidants; and 5) also propose several future research perspectives for EGT. These may help to promote the future application of this attractive natural antioxidant.
... The alleviation of the organic cation transporter N1 (OCTN1) which is the particular ergothioneine transporter was also confirmed the cytoprotective effects of ergothioneine in hepatic tissues (Cheah et al. 2016). Ergothioneine for instance, was reported to inhibit the formation of hydroxyl radicals and lipid peroxidation (Deiana et al. 2004;Li et al. 2014). The ion chelating activity posses by ergothioneine allays the involvement of divalent cation in oxidation cycle. ...
Pleurotus pulmonarius crude aqueous (CA) extract was previously reported to have therapeutic potential, thus its ability to alleviate serum total cholesterol, vasodilation, and improve the aortic tissue structure in hypercholesterolemia rat model was studied. Eight groups of Wistar-Kyoto rats were involved including normal (G1), hypercholesterolemia (G2), treatment (G3 to G5) and prevention (G6 to G8). Two doses of CA; 0.5 g/kg body weight (BW), 2.0 g/kg BW, and simvastatin 10 mg/kg BW were orally fed to the rats (G3 to G8). Treatment groups were induced with hypercholesterolemia and later treated with CA/simvastatin, while prevention groups were given both hypercholesterolemia-diet and CA/simvastatin simultaneously. The thoracic aortic rings (TAR) were subjected to contractility study and histopathology examination. In organ bath analysis, pre-contracted TAR of G1 with phenylephrine (PE) achieved 60% vasodilation response towards acetylcholine (ACh) whereas TAR of G2 unable to respond to ACh. G3 to G5 groups failed to dilate when induced with ACh whereas G6 to G8 groups showed a slight improvement. The repeated precontracted TAR of G1 and G2 significantly dilated with the presence of CA and simvastatin. TAR of G1 achieved 100% vasodilation at 3.0 mg/mL CA and 2.4 mg/mL simvastatin. TAR of G2 achieved 73% vasodilation at 6.0 mg/mL CA whereas 76.8% dilation recorded for simvastatin at 4.8 mg/mL. Histopathological examination found that CA was able to improve the structure of the aortic cells. These observations suggest that CA helps to improve tissue condition and vasodilation of the hypercholesterolemic aorta.
... Ergothioneine (ERG) is a water-soluble amino acid derived from dietary sources usually synthesized by fungi and bacteria [85]. The antioxidant potential of ERG has been evaluated in several disease models [86,87]. The ability of ERG to localize and accumulate within mitochondria has been previously shown [88]. ...
Despite considerable research efforts over the past few decades, the pathology of preeclampsia (PE) remains poorly understood with no new FDA-approved treatments. There is a substantial amount of work being conducted by investigators around the world to identify targets to develop therapies for PE. Oxidative stress has been identified as one of the crucial players in pathogenesis of PE and has garnered a great deal of attention by several research groups including ours. While antioxidants have shown therapeutic benefit in preclinical models of PE, the clinical trials evaluating antioxidants (vitamin E and vitamin C) were found to be disappointing. Although the idea behind contribution of mitochondrial oxidative stress in PE is not new, recent years have seen an enormous interest in exploring mitochondrial oxidative stress as an important pathological mediator in PE. We and others using animals, cell models, and preeclamptic patient samples have shown the evidence for placental, renal, and endothelial cell mitochondrial oxidative stress, and its significance in PE. These studies offer promising results; however, the important and relevant question is can we translate these results into clinical efficacy in treating PE. Hence, the purpose of this review is to review the existing literature and offer our insights on the potential of mitochondrial antioxidants in treating PE.
... L-egt (as shown in Fig. 1) possesses antioxidant and anti-inflammatory properties, while its accumulation at the sites of tissue injury has been hypothesized as an adaptive mechanism of protecting tissues at risk of damage and regenerating injured tissues [21,42]. Also, L-egt has been reported to activate the Nrf2 (nuclear factor erythroid-2 related factor-2) antioxidant signaling pathway to protect against cellular injury, enhance glutathione level and reduce oxidative damage in the kidney as well as activates sirt1 and 6 to protect against high glucose-induced cell senescence [12,13,22]. Furthermore, coadministration of L-egt with existing therapy (such as melatonin and hispidin) significantly increases treatment benefits both in-vitro and in-vivo [52,53], suggesting that L-egt may improve the efficacy of available treatment options. ...
L-ergothioneine (L-egt) is a bioactive compound recently approved by the food and drug administration as a supplement. L-egt exerts potent cyto-protective, antioxidant and anti-inflammatory properties in tissues exposed to injury, while metformin is a first-line prescription in type-2 diabetes. Therefore, the present study investigated the protective effect of L-egt alone, or combined with metformin, on renal damage in a type-2 diabetic (T2D) rat model. T2D was induced in male Sprague-Dawley rats using the fructose-streptozotocin rat model. L-egt administration, alone or combined with metformin, began after confirming diabetes and was administered orally for seven weeks. After the experiment, all animals were euthanized by decapitation, blood samples were collected, and both kidneys were excised. Biochemical analysis, Enzyme-link Immunoassay (ELISA), Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR), western blotting, and histological analyses were done to evaluate various biomarkers and structural changes associated with renal damage. Untreated diabetic rats showed loss of kidney functions characterized by increased serum creatinine, blood urea nitrogen, proteinuria, triglycerides, lipid peroxidation, inflammation, and decreased antioxidant enzymes. Histological evaluation showed evidence of fibrosis, mesangial expansion, and damaged basement membrane in the nephrons. However, L-egt alleviates these functional and structural derangements in the kidney, while co-administration with metformin reduced hyperglycemia and improves therapeutic outcomes. Furthermore, L-egt treatment significantly increased the expression of major antioxidant transcription factors, cytoprotective genes and decreased the expression of inflammatory genes in the kidney. Thus, combining L-egt and metformin may improve therapeutic efficacy and be used as an adjuvant therapy to alleviate renal damage in type-2 diabetes.
... The used ergothioneine dose is consistent with a previously published work. [27] The Fe group was treated with ip injection of 30 mg/kg iron-dextransaline every other day over the 10-day experimental period (150 mg/kg total injected iron). [8,28] The Fe + Erg group received both iron (30 mg/kg) and ergothioneine (70 mg/kg) the same way as the Fe and Erg groups. ...
The liver is highly susceptible to iron overload-evoked oxidative injury. Ergothioneine is a thio-histidine amino acid that has exhibited strong antioxidant and metal chelating activities. This study aimed at exploring the potential modulating effects of ergothioneine on iron-triggered liver injury. The results showed that ergothioneine inhibited iron-evoked inflammation and apoptosis as demonstrated by a significant reduction in tumor necrosis factor-α and interleukin-6 levels and in caspase-3 activity. Ergothioneine significantly improved liver cell survival as indicated by modulating phosphatidylinositol 3-kinase/protein kinase B signaling. Consistent with reduced necrotic cell death, ergothioneine diminished the iron-evoked histopathological changes and decreased serum activity of the liver enzymes. Mechanistically, ergothioneine reduced nuclear translocation of nuclear factor kappa B p65 and modulated p38 mitogen-activated protein kinase/c-Fos signaling. In addition, it enhanced the liver tissue antioxidant potential and curbed hepatic iron load. Together, these results point out the modulatory effects of ergothioneine on iron-evoked liver cell injury that are possibly mediated via anti-inflammatory, antioxidant, and possible iron chelation capabilities.
... In addition to its anti-oxidative actions, ergothioneine also exerts several cytoprotective functions such as lipid peroxidation inhibition 46,47 and DNA/protein damage control 23,48 . A study using control mice reported the antidepressant-like effects of ergothioneine in forced swim and tail suspension tests 30 ; however, to our knowledge, no study has examined the effect of ergothioneine in stressed animal models. ...
The relationships between depression and gut microbiota, particularly those involving the immune system, have become a major focus of recent research. Here, we analyzed changes in gut microbiota and their sulfur metabolites in the feces of a depression rat model using the modified 14-day social defeat stress (SDS) paradigm. Our results showed that SDS increased fecal Lactobacillus reuteri in correlation with ergothioneine levels at around day 11, which continued for at least 1 month following SDS administration. In vitro study further revealed that L. reuteri is capable of producing ergothioneine. Although the known anti-inflammatory and anti-oxidative actions of ergothioneine suggested that the increased fecal ergothioneine levels may be related to intestinal anti-inflammatory defense mechanisms, no change was observed in the plasma ergothioneine levels during the same observation period, indicating that the defense mechanisms may not be sufficiently reflected in the body. As ergothioneine is a natural ingredient that is absorbed mainly from the upper gastrointestinal tract, we hypothesized that oral ergothioneine may exert antidepressant effects. As expected, oral administration of ergothioneine prior to and during the SDS paradigm had a preventative effect on SDS-induced depressive behaviors, such as social avoidance and depression-like sleep abnormalities, particularly those of rapid eye movement sleep. These findings indicate that ergothioneine, a metabolite of L. reuteri, may be a common substance in the microbiota-gut-brain axis that prevents stress-induced sleep disturbances, especially those associated with depression.
... The effect of the ET treatment was explored using four experimental groups (Table 1): Sham control (SC, n = 5), RUPP control (RC, n = 5), Sham + ET (ST, n = 5), RUPP + ET (RT, n = 5). From GD11-GD19, ET was added to the drinking water at 25mg/kg/day, as reported in previous animal studies [25,26]. Blood was collected on GD19 into EDTA vacutainers, these were ...
Introduction
Pre-eclampsia is a major cause of maternal and fetal mortality and morbidity worldwide. Its pathophysiology remains unclear, but mitochondrial dysfunction and oxidative stress have been implicated. L-Ergothioneine is a naturally occurring, water-soluble betaine, that has demonstrated antioxidant properties. Using the reduced uterine perfusion pressure (RUPP) rat model of pre-eclampsia, this study aimed to define the plasma metabolic profile following treatment with L-Ergothioneine.
Methods
The effect of L-Ergothioneine (ET) treatment was explored using in vivo treatment in rats: Sham control (SC, n = 5), RUPP control (RC, n = 5), Sham +ET (ST, n = 5), RUPP +ET (RT, n = 5). Differential expression of plasma metabolites were obtained using untargeted liquid chromatography coupled to mass spectrometry. Statistical analysis was performed on normalised data comparing RC to SC, RT to RC, and RT to ST. Metabolites significantly altered (FDR < 0.05) were identified through database search.
Results
We report significantly lower levels of L-palmitoylcarnitine in RC compared to SC, a fatty acyl substrate involved in beta-oxidation in the mitochondria. We report that a metabolite that has been associated with oxidative stress (Glutamylcysteine) was detected at significantly higher levels in RT vs RC and RT vs ST. Five metabolites associated with inflammation were significantly lower in RT vs RC and three metabolites in RT vs ST, demonstrating the anti-inflammatory effects of ET in the RUPP rat model of pre-eclampsia.
Conclusions
L-Ergothioneine may help preserve mitochondrial function by increasing antioxidant levels, and reducing inflammatory responses associated with pre-eclampsia. This study shows the potential of L-Ergothioneine as a treatment for pre-eclampsia.
... In conclusion, it was determined that T. virgatum mushroom is a suitable source of some phenolic compounds including chlorogenic acid, catechin, and gallic acid. The presence of considerable antioxidant contents in mushrooms may confer protection against many chronic diseases such as cardiovascular disease (CVD), neurodegenerative disease, and other oxidative stress related diseases [26][27][28]. Their health promotion effects on oxidative stress-related diseases such as CVD are often attributed to their antioxidant capabilities, in particular their free radical scavenging ability plus metal ion homoeostasis via chelating activities. [29][30][31] 3.2. ...
Tricholoma is one of the famous genera of Basidiomycota division. Although some species of this genus have been used as culinary mushrooms, very negligible investigations have been conducted on Tricholoma genus phenolic contents and their biological activities. In the present study, the antioxidant, antimicrobial, and DNA protection properties of total phenolic contents of Tricholoma virgatum (Fr.) P. Kumm. (54% methanolic extract) were assessed. T. virgatum phenolic content was determined by an analytic high-performance liquid chromatography (HPLC) method based on compression with standard phenolic compounds including gallic acid, catechin, chlorogenic acid, epicatechin, and coumaric acid. Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) values were determined using Rel Assay kits. For DNA protective potential assay, pBR322 supercoiled DNA method was used. The antimicrobial activity assay was done based on the agar dilution method on six different microorganisms include Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Candida tropicalis. The total phenolic contents of this mushroom lied within range of 2.02-56.85 ppm based on coumaric acid and chlorogenic acid as standards. TAS, TOS, and OSI values were determined as 3.754±0.088 mmol/L, 8.362 ±0.085 μmol/L, and 0.223 ±0.007, respectively. T. virgatum methanol extract could exhibit a protective effect on DNA against the hydroxyl radical at 100 μg/mL concentration. Although T. virgatum is not recommended as an edible mushroom, according to our results, this mushroom could be considered as valuable source for phenolic compounds with significant antioxidant/antimicrobial effects.
... Oxidative stress can be defined and measured in many ways (461)(462)(463)(464)(465)(466)(467)(468) , but is broadly taken to involve a dysregulation in the various redox systems of the organism of interest, coupled to the production of various 'reactive oxygen species', principally peroxide, superoxide, hydroxyl radical, and singlet oxygen. ERG has been shown to decrease oxidative stress in the liver and kidney of rats (469) , rescued cells from β-amyloid-induced apoptotic death (231) , protected against palmitic acid-induced cell death (470) , mercuric chloride-induced cellular dysfunction (471) , and prevented Cu-induced oxidative damage to DNA (472,473) . It is protective against the oxidation of various kinds of molecule (251,474) , including astaxanthin (475) , and accumulates in a guinea-pig model of non-alcoholic fatty liver disease (476) , massively so in mouse models of myocardial infarction and heart failure (477) , and in a rat model of optic nerve crush (478) . ...
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.
... The dose for ERG (25 mg/kg per day) was selected based on previously published rodent studies using this antioxidant. 22,23 ERG was provided by Tetrahedron (Paris, France; www.tetrahedron.fr). ...
Preeclampsia is a multifactorial hypertensive disorder of pregnancy founded on abnormal placentation, and the resultant placental ischemic microenvironment is thought to play a crucial role in its pathophysiology. Placental ischemia because of fluctuations in the delivery of oxygen results in oxidative stress, and recent evidence suggests that mitochondrial dysfunction may be a prime mediator. However, large clinical trials of therapeutic antioxidants such as vitamins C and E for the treatment of preeclampsia have been disappointing. L-(+)-ergothioneine (ERG)-an unusual amino acid betaine derived from histidine-has important cytoprotective and antioxidant properties under conditions of high oxidative stress. In this study, we investigated the potential therapeutic effects of administration of ERG in the reduced uterine perfusion pressure (RUPP) rat model of preeclampsia. ERG (25 mg/kg per day) was administered to rats on gestational day 11. On gestational day 14, RUPP surgery was performed, and on gestational day 19, blood pressure (mean arterial pressure) and fetal growth were measured. Production of mitochondria-specific H2O2 was analyzed in vivo in kidney samples. ERG ameliorated the hypertension (129±3 versus 115±4 mm Hg; P=0.01; n=8) and significantly increased pup weight in RUPP rats. ERG also significantly decreased circulating levels of antiangiogenic sFlt-1 (soluble fms-like tyrosine kinase-1) in RUPP rats (1367±245 pg/mL; P=0.04). Mitochondria-specific H2O2 (0.022±0.003 versus 0.029±0.001; MitoP/B ratio, n=3; P=0.05) was also significantly decreased in kidney tissue in RUPP rats treated with ERG. These data support the potential use of ERG for the treatment of preeclampsia.
... The antioxidant properties of ERG include the scavenging of free radicals and reactive oxygen species (Akanmu et al., 1991;Park et al., 2010;Ta et al., 2011) and the chelation of divalent metal ions (Hanlon, 1971). ERG has been shown to reduce oxidative damage in a variety of mammals (Deiana et al., 2004;Cheah and Halliwell, 2012). In humans, ERG is mainly accumulated in the liver, the kidneys, in erythrocytes, the eye lens, and in seminal fluid (Leone and Mann, 1951;Melville et al., 1954;Shires et al., 1997). ...
L-(+)-Ergothioneine (ERG) is an unusual, naturally occurring antioxidant nutraceutical that has been shown to help reduce cellular oxidative damage. Humans do not biosynthesise ERG, but acquire it from their diet; it exploits a specific transporter (SLC22A4) for its uptake. ERG is considered to be a nutraceutical and possible vitamin that is involved in the maintenance of health, and seems to be at too low a concentration in several diseases in vivo. Ergothioneine is thus a potentially useful dietary supplement. Present methods of commercial production rely on extraction from natural sources or on chemical synthesis. Here we describe the engineering of the baker's yeast Saccharomyces cerevisiae to produce ergothioneine by fermentation in defined media. After integrating combinations of ERG biosynthetic pathways from different organisms, we screened yeast strains for their production of ERG. The highest-producing strain was also engineered with known ergothioneine transporters. The effect of amino acid supplementation of the medium was investigated and the nitrogen metabolism of S. cerevisiae was altered by knock-out of TOR1 or YIH1. We also optimized the media composition using fractional factorial methods. Our optimal strategy led to a titer of 598 ± 18 mg/L ergothioneine in fed-batch culture in 1 L bioreactors. Because S. cerevisiae is a GRAS (“generally recognized as safe”) organism that is widely used for nutraceutical production, this work provides a promising process for the biosynthetic production of ERG.
... From previous studies, it is apparent that mushrooms have great potential as a source of novel compounds (Deiana et al., 2004;Lee and Yun, 2006;Chen et al., 2012). For instance, ergothionine was isolated from Pleurotus citrinopileatus Singer, P. ostreatus (Jacq. ...
A cupric reducing antioxidant capacity (CUPRAC)-guided purification approach was performed on a methanol extract of Lentinus squarrosulus (LsqMeOH) by using reversed phase-high performance liquid chromatography. Using reversed phase-high performance liquid chromatography, three fractions were separated arbitrarily named FR1, FR2 and FR3. Results showed that FR2 exhibited the highest antioxidant activity in CUPRAC assay (A450, 0.86) but not significantly different from LsqMeOH (A450, 0.84). FR1 and FR3 showed much lower absorbance, with values (A450, 0.21) and (A450, 0.36) respectively at 1 mg ml⁻¹. The most active fraction (F3) was further subjected to LC-MS/MS to obtain its detailed chemical profile. Uridine, ganoderic acid derivative, and flavonoids were the first time being found in L. squarrosulus antioxidative fractions. The present results indicate that the fraction extracts of L. squarrosulus possess antioxidant properties and can be used as free radical inhibitors. Therefore, this research suggested the potentials of L. squarrosulus as a source of antioxidant extract to be used in food industries (functional food).
... Actually, the i.p. injection of arzanol (DMSO, 4%) reduced the inflammatory reaction in an in vivo model of acute inflammation (Bauer et al., 2011). The Fe-NTA model is an excellent model of in vivo free radical induced damage associated with extensive peroxidation of membrane lipids (Ikeda et al., 1998;Deiana et al., 2001;Rosa et al., 2005a), and is widely used to evaluate the antioxidant properties of phenolic compounds (Deiana et al., 2004Rosa et al., 2005b). In particular, the Fe-NTA oxidative damage starts from the plasma compartment, where Fe-NTA finds the ideal environment to react with oxidizable lipids, and next continues with a similar pattern but a different speed and severity in the kidney and liver (Deiana et al., 2001Rosa et al., 2005a). ...
The heterodimeric phloroglucinyl pyrone arzanol (Arz) has raised considerable interest because of its antiviral, anti-inflammatory, and antioxidant activity. We have investigated the effect of methylation of the pyrone moiety on the antioxidant activity and cytotoxicity of Arz. This manoeuvre, that left the polyphenolic moiety unscathed, was nevertheless detrimental for antioxidant activity in both the cholesterol thermal degradation- and the Cu²⁺-induced liposome oxidation assays, providing evidence of structure-activity relationships that go beyond the preservation of the polyphenolic pharmacophore. The antioxidant activity of Arz was retained also in the Fe-NTA model of in vivo oxidative stress, with protective effect on the oxidative degradation of plasmatic lipids, unsaturated fatty acids and cholesterol. Both Arz and methylarzanol (Me-Arz) were devoid of toxic effect on colonic differentiated Caco-2 cells up to 100 μM, but significantly reduced cancer Caco-2 cell viability at lower dosages. Arz could also selectively reduce viability of other cancer cell lines, [murine melanoma cells (B16F10 cells), human cervical carcinoma cells (HeLa cells)], suggesting that it can act as a selective modulator of cell processes typical of cancer cells. Taken together, our results qualify Arz as a lead structure for further in vivo investigation of its pharmacological potential.
... Similarly, age-related declines in glutathione (GSH) and glutathione peroxidase (GPx) have been observed [28,29]. Studies with ferric nitrotriacetate-induced oxidative stress in rats demonstrated that ET supplementation played a role in preserving GSH [24], while The total monthly mushroom consumption was tallied and correlated to blood ergothioneine levels of each individual. The self-reported consumption of mushrooms by the subject was found to significantly correlate (P < 0.001; r ¼ 0.491) to blood ergothioneine levels. ...
Ergothioneine (ET), a naturally occurring thione, can accumulate in the human body at high concentrations from diet. Following absorption via a specific transporter, OCTN1, ET may accumulate preferentially in tissues predisposed to higher levels of oxidative stress and inflammation. Given its potential cytoprotective effects, we examined how ET levels change with age. We found that whole blood ET levels in elderly individuals decline significantly beyond 60 years of age. Additionally, a subset of these subjects with mild cognitive impairment had significantly lower plasma ET levels compared with age-matched subjects. This decline suggests that deficiency in ET may be a risk factor, predisposing individuals to neurodegenerative diseases.
... Ergothioneine is a stable amino acid and can be produced by certain fungi and actinobacteria. Many studies have demonstrated that ergothioneine possessed multiple physiological activities, such as antioxidation (Deiana et al. 2004), anti-inflammatory (Rahman et al. 2003) and UV-irradiated skin cells repair (Markova et al. 2009); and the compound has been widely used in cosmetic products. In addition, phenolic compounds have been confirmed to exhibit multiple physiological benefits, such as anti-inflammation, antioxidant, antimicrobial and anti-cancer (Cheung et al. 2003;Rathee et al. 2009). ...
Intense pulsed light irradiation is used in food decontamination and in production of mushrooms with high level of ergocalciferol. Lentinula edodes (Berk.) Pegler, shiitake, was freeze-dried and milled into powder and irradiated with 20, 40 and 60 pulses of pulsed light at a distance of 6 cm and the irradiation energy were 26.2, 52.4 and 78.5 kJ/m2, respectively. The contents of ergocalciferol and total phenols increased dose-dependently whereas ergothioneine contents were not affected. The most effective conversion of ergosterol to ergocalciferol was 20-pulse treatment. Further, irradiated and nonirradiated shiitake showed a moderate inhibition in decreasing nitric oxide and interleukin-6 productions but no effect on tumor necrosis factor-alpha production. In addition, pulse light treatment could improve antioxidant activities. Overall, using pulsed light irradiation could produce irradiated shiitake as an excellent vitamin D2 supplement with similar ergothioneine and higher total phenols contents as well as similar anti-inflammatory and better antioxidant activities. Using intense pulsed light irradiation, ergosterol could be efficiently transformed into ergocalciferol in freeze-dried shiitake powder at proper distance and treatment time. The content of ergocalciferol in freeze-dried shiitake powder could be increased from 5.91 to 37.17 μg/g after irradiating for 20 pulses (near 7 s), which is sufficient for the daily requirement of 15 μg for human body upon consumption of 0.4 g powder. In addition, the content of total phenol would be increased from 6.91 to 7.42 mg/g after 60 pulses of pulsed light irradiation, and the content of ergothioneine was similar during the different pulse treatments. Therefore, the irradiated shiitake powder could be a beneficial supplement which contains abundant vitamin D and exhibits good antioxidant activities.
... We identified ergothioneine to be most strongly associated with reported consumption of mushrooms-a novel finding. Ergothioneine is a thiol compound with demonstrated in vivo protection against lipid peroxidation [54] found in high concentrations in specialty mushrooms, in particular oyster and king bolete, and in lower amounts in oat bran and beans [55]. Recent data supports the notion that ergothioneine may prevent against vascular dysfunction [56]. ...
Using dietary biomarkers in nutritional epidemiological studies may better capture exposure and improve the level at which diet-disease associations can be established and explored. Here, we aimed to identify and evaluate reproducibility of novel biomarkers of reported habitual food intake using targeted and non-targeted metabolomic blood profiling in a large twin cohort. Reported intakes of 71 food groups, determined by FFQ, were assessed against 601 fasting blood metabolites in over 3500 adult female twins from the TwinsUK cohort. For each metabolite, linear regression analysis was undertaken in the discovery group (excluding MZ twin pairs discordant [≥1 SD apart] for food group intake) with each food group as a predictor adjusting for age, batch effects, BMI, family relatedness and multiple testing (1.17x10-6 = 0.05/[71 food groups x 601 detected metabolites]). Significant results were then replicated (non-targeted: P
... [37][38][39] Early in vivo studies in rats at 70 to 100 mg/kg confirm Lergothioneine's rapid urinary clearance (e.g., excretion into the urine by the kidneys) and its accumulation in the liver where, with the kidney, it is reported to modulate oxidative damage from polyunsaturated fatty acids. 40,41 Most recently, preclinical studies testing the genotoxicity of L-ergothioneine showed no mutagenic or clastogenic activity in in vitro Ames and chromosome aberration assays up to 5,000 mg/mL or in an in vivo mouse micronucleus test at concentrations of up to 150 mg/ mL or 1,500 mg/kg. 42,43 No adverse effects were reported during a 2,000 mg/kg oral acute limit test, a 14-day toxicity test, or reproductive fertility or developmental toxicity test in rats at concentrations of 0.1%, 0.3%, or 0.9% in the diet. ...
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.
... The discovery of OCTN1/ETT resulted in a renewed interest in L-ergothioneine as it also supports a beneficial role of this micronutrient in human metabolism. This is corroborated by the protective and antioxidant effects of L-ergothioneine that have been demonstrated in in vitro and in vivo studies (see Cheah and Halliwell 2012 for review; Akanmu et al. 1991;Aruoma et al. 1997Aruoma et al. , 1999Deiana et al. 2004;Hartman 1990). Moreover, recent studies have shown that L-ergothioneine is a safe compound (Schauss et al. 2010(Schauss et al. , 2011Forster et al. 2015). ...
L-ergothioneine is an amino acid synthetized by fungi and mycobacteria that cannot be synthesized by other species. It has been detected in plants, animals, and the human body. In the last few years, it has been recognized as a good antioxidant and, recently, it has also been related to other properties besides antioxidant properties. Even though few studies on the toxicity of L-ergothioneine have been carried out, evidence suggests that L-ergothioneine is not harmful to health. Considering that L-ergothioneine has increasingly been linked to positive effects on human health, coupled with the fact that it seems to be safe for human consumption, this molecule may be suitable for use as an ingredient in foods. On the other hand, despite the positive effects reported for this molecule, no estimate of L-ergothioneine intake has been carried out until now. Thus, the aim of this work is to estimate the intake of L-ergothioneine through food consumption of several European countries and the United States. Values were estimated by using the deterministic and probabilistic approach. Results show that the populations with the highest intake of L-ergothioneine correspond to Italian population, both for children and adults.
... Ergothioneine (EGT) is a naturally occurring chiral amino acid that has been used as an antioxidant (1)(2)(3), radical scavenger, metal-ion chelator (4), ultraviolet ray filter (5) and regulator of oxidation-reduction reactions and cellular bioenergetics (6)(7)(8); it is a multifunctional physiological cytoprotector (9). EGT can be easily assimilated and exploited, and many research findings have revealed no harmful responses in humans or animals after EGT administration. ...
A hydrophilic interaction liquid chromatography method has been established for the quantification of ergothioneine (EGT)
in fermentation broth. Chromatographic separation was conducted on a Venusil hydrophilic interaction liquid chromatography
(HILIC) column (250 × 4.6 mm, 5 µm) at an elution rate of 1.0 mL/min with an isocratic mobile phase consisting of acetonitrile/20
mmol/L ammonium acetate solution (85 : 15, v/v) adjusted to pH 6.0 with acetic acid. Analytes were detected at 254 nm using
a UV–VIS detector. The injection volume was 10 µL, and the column temperature was 40°C. The limits of detection and limits
of quantification were 63 and 21 µg/L, respectively. Excellent linearity [correlation coefficient (R2) = 0.9999] was achieved for EGT quantification in the range of 5–400 mg/L. The relative standard deviations of repeatability,
intermediate precision and stability were 1.47, 1.03 and 1.66%, respectively, and EGT recoveries were within 99.2–100.8%.
The chromatographic peak corresponding to EGT in the HILIC spectrum was confirmed using ESI–MS. In general, the method developed
here is simple, reliable, accurate, and stable and may be useful for routine analyses in EGT biosynthesis research.
Ergothioneine (EGT) is a diet-derived natural sulfur-containing amino acid that exhibits strong anti-oxidant and anti-inflammation activities. Oxidative stress and chronic inflammatory injury are predominant pro-fibrogenic factors. Therefore, EGT may have therapeutic potential against liver fibrosis; however, its underlying mechanism is incompletely understood. This study aimed at investigating the protective effects of EGT on liver fibrosis based on metabonomics and network pharmacology. A mouse model of liver fibrosis was established by intraperitoneal injection with 40% CCl4 solution (2 mL/kg, twice a week) and intragastric administration with EGT (5, 10 mg/kg/d) for six weeks. Results showed that EGT improved liver function by reducing serum levels of ALT (alanine aminotransferase), AST (aspartate aminotransferase), and TBIL (total bilirubin), and alleviated liver fibrosis by reducing LN (laminin) and HyP (hydroxyproline) levels, decreasing expressions of α-SMA (α-smooth muscle actin), Col-I (collagen type I), and Col-III (collagen type III), and improving pathological changes. EGT also significantly inhibited CCl4-induced hepatic inflammation and TGF-β/Smads signaling pathway. Metabolomics identified six key metabolic pathways, such as purine metabolism, glycerophospholipid metabolism, and sphingolipid metabolism, and eight key metabolites, such as xanthine, guanine, ATP, phosphatidylcholine, and sphingosine. Network pharmacology analysis showed that IL-17, cAMP and NF-κB signaling pathways were potential key mechanisms. Integrated analysis revealed that PLA2G2A might be a potential target of EGT against liver fibrosis. EGT may inhibit the glycerophospholipid metabolism through PLA2G2A to inhibit the TGF-β/Smads signaling pathway, thereby alleviating fibrosis. The present study indicates that EGT may be considered a valid therapeutic strategy to regress liver fibrosis, and provides novel insights into the pharmacological mechanism of EGT against liver fibrosis.
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.
Oxidative stress (OS) develops in critically ill patients as a metabolic consequence of the immunoinflammatory and degenerative processes of the tissues. These induce increased and/or dysregulated fluxes of reactive species enhancing their pro‐oxidant activity and toxicity. At the same time, OS sustains its own inflammatory and immunometabolic pathogenesis, leading to a pervasive and vitious cycle of events that contribute to defective immunity, organ dysfunction and poor prognosis. Protein damage is a key player of these OS effects; it generates increased levels of protein oxidation products and misfolded proteins in both the cellular and extracellular environment, and contributes to forms DAMPs and other proteinaceous material to be removed by endocytosis and proteostasis processes of different cell types, as endothelial cells, tissue resident monocytes‐macrophages and peripheral immune cells. An excess of OS and protein damage in critical illness can overwhelm such cellular processes ultimately interfering with systemic proteostasis, and consequently with innate immunity and cell death pathways of the tissues thus sustaining organ dysfunction mechanisms. Extracorporeal therapies based on biocompatible/bioactive membranes and new adsorption techniques may hold some potential in reducing the impact of OS on the defective proteostasis of patients with critical illness. These can help neutralizing reactive and toxic species, also removing solutes in a wide spectrum of molecular weights thus improving proteostasis and its immunometabolic corelates. Pharmacological therapy is also moving steps forward which could help to enhance the efficacy of extracorporeal treatments. This narrative review article explores the aspects behind the origin and pathogenic role of OS in intensive care and critically ill patients, with a focus on protein damage as a cause of impaired systemic proteostasis and immune dysfunction in critical illness.
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.
Ovothiol and ergothioneine are powerful antioxidants that readily react with oxidants by forming their respective disulfides. In fact, ovothiol is widely considered one of the most powerful natural antioxidants. However, for these antioxidants to be again involved in reacting with oxidants, they must be regenerated via the reduction of the disulfide bonds. In the present work, the regeneration of the antioxidants ovothiol and ergothioneine and their selenium analogues, by the closed-shell nucleophilic attack of glutathione, was investigated using density functional theory. From the calculated thermodynamic data, the attack of glutathione on OSSO and EYYE (where Y = S and/or Se) will readily occur in solution. Moreover, in comparison to the reference reaction GSH + GSSG → GSSG + GSH, all reactions are expected to be faster. Overall, the results presented herein show that the key antioxidant GSH should readily recycle ovothiol, ovoselenol, ergothioneine, and ergoseloneine from OYYO and EYYE (where Y = S and/or Se).
Hibiscus rosasinensis and Butea monosperma have been traditionally claimed to be protective against liver injury. However, the hepatoprotective effect against iron overload is not yet validated scientifically. The present study was undertaken to evaluate the possible ameliorating effect of aqueous extract of Hibiscus rosasinensis (AQEHR) and Butea monosperma (AQEBM) against ferric nitrilotriacetate (Fe-NTA) induced hepatotoxicity in rats. After extraction, total phenolics and flavonoids content of AQEHR and AQEBM were estimated. Further, antioxidant effect followed by hepatoprotective efficacy of AQEHR and AQEBM were evaluated against chronic iron overload by administering Fe-NTA for 8 successive days to rats in increasing order of doses from 6-15mg Fe/kg. Treatments with both the extracts were started 3 days before the administration of iron and together with iron administration for 8 days. Level of liver function tests, triglycerides, protein, and lipid were recorded. Oxidative biomarkers and histopathology were performed to find out the level of protection by extracts. AQEBM contains a high amount of total phenolic and flavonoids contents and exhibited potent antioxidant effects in all assays. Supplementation of both the extract showed hepatoprotective effect by amelioration of biochemical changes and oxidative biomarkers. AQEBM possesses a higher amount of phenolic components and exhibited better therapeutic potential than AQEHR.
This study aimed to evaluate the impact of ergothioniene (ESH) concentrated extract (CE) to lipid anti‐oxidation and γ‐aminobutyric acid (GABA), γ‐oryzanol (GORZ) biosynthesis during germinated brown rice (GBR) processing. To do that 0, 2, 4 and 6% ESH CE was supplemented to soaking stage of brown rice for 6 hr and determined changes about the quality of GBR during processing. The results showed when added 4% of ESH CE to soaking stage, total lipid was stable during four stages of GBR processing as 1.96, 1.87, 1.77, and 1.67 g/100 g corresponding to less increasing peroxide and thiobarbituric acid–reactive substances (TBARs) as 0.53, 0.54, 0.55, and 0.55 meq/kg lipid and 0.21, 0.23, 0.25, and 0.26 µmol TBARs/g while GABA and GORZ increased considerably to 2378.63 mg/kg and 222 mg/kg, respectively. The results indicated that ESH CE helps to increase GABA, GORZ and prevent lipid oxidation that contributes to improving the quality of GBR. GBR contains various bioactive compounds such as GABA, GORZ, which have positive effects for human health. So, it becomes one of the value‐added products from rice. However, in GBR processing, there are still some problems that impact negatively on the quality of GBR such as low levels of GABA, GORZ and high levels of peroxide and TBAR values that may occur during processing. To address these problems, this study used ESH, a powerful antioxidant compound, which was biosynthesized from Aspergillus oryzae applying to GBR processing. The results show that ESH CE not only inhibits fat oxidation during GBR processing but also increases significantly GABA, GORZ level. So, this study contributed one of great solutions for improving the quality of GBR products.
Ergothioneine (ERGO) is a rare amino acid mostly found in fungi, including mushrooms, with recognized antioxidant activity to protect tissues from damage by reactive oxygen species (ROS) components. Prior to this publication, the biodistribution of ERGO has been performed solely in vitro using extracted tissues. The aim of this study was to develop a feasible chemistry for the synthesis of an ERGO PET radioligand, [11C]ERGO, to facilitate in vivo study. The radioligand probe was synthesized with identical structure to ERGO by employing an orthogonal protection/deprotection approach. [11C]methylation of the precursor was performed via [11C]CH3OTf to provide [11C]ERGO radioligand. The [11C]ERGO was isolated by RP-HPLC with a molar activity of 690 TBq/mmol. To demonstrate the biodistribution of the radioligand, we administered approximately 37 MBq/0.1 mL in 5XFAD mice, a mouse model of Alzheimer’s disease via the tail vein. The distribution of ERGO in the brain was monitored using 90-min dynamic PET scans. The delivery and specific retention of [11C]ERGO in an LPS-mediated neuroinflammation mouse model was also demonstrated. For the pharmacokinetic study, the concentration of the compound in the serum started to decrease 10 min after injection while starting to distribute in other peripheral tissues. In particular, a significant amount of the compound was found in the eyes and small intestine. The radioligand was also distributed in several regions of the brain of 5XFAD mice, and the signal remained strong 30 min post-injection. This is the first time the biodistribution of this antioxidant and rare amino acid has been demonstrated in a preclinical mouse model in a highly sensitive and non-invasive manner.
Aim
Cisplatin is a potent chemotherapeutic agent whose therapeutic application is hindered by the associated nephrotoxicity. Cisplatin-evoked nephrotoxicity has been largely attributed to the induction of oxidative stress and inflammatory responses. The current study aimed at investigating the ability of ergothioneine to mitigate cisplatin-evoked nephrotoxicity and to elucidate the underlining molecular mechanisms.
Main methods
Wistar rats were treated with a daily dose of ergothioneine (70 mg/kg, po) for fourteen days and a single dose of cisplatin (5 mg/kg, ip) on day ten. On day fifteen, kidneys and blood specimens were collected and subjected to Western blotting, ELISA, histopathological, and spectrophotometric analysis.
Key findings
Ergothioneine significantly enhanced renal function in cisplatin-treated rats as manifested by increased GFR and decreased serum creatinine and blood urea nitrogen. Ergothioneine effectively reduced the cisplatin-induced oxidative stress and mitigated apoptosis and the histopathological changes. Mechanistically, ergothioneine induced the expression of the antioxidant transcription factor Nrf2 and up-regulated its downstream targets NQO1 and HO-1. Equally important, ergothioneine inhibited γ-glutamyl transpeptidase that plays crucial roles in biotransformation of cisplatin into a toxic metabolite. Additionally, it reduced the pro-apoptotic protein p53 and the inflammatory transcription factor NF-κB along with its downstream pro-inflammatory cytokines TNF-α and IL-1β.
Significance
The results of the current work shed the light on the ameliorating effect of ergothioneine on cisplatin-evoked nephrotoxicity that is potentially mediated through modulation of Nrf2, p53, and NF-κB signaling and inhibition of γ-glutamyl transpeptidase. This findings support the potential application of ergothioneine in controlling cisplatin-associated nephrotoxicity although clinical investigations are warranted.
L-(+)-Ergothioneine is an unusual, naturally occurring antioxidant nutraceutical that has been shown to help reduce cellular oxidative damage. Humans do not biosynthesise it, so can acquire it only from their diet; it exploits a specific transporter (SLC22A4) for its uptake. ERG is considered to be a nutraceutical and possible vitamin that is involved in the maintenance of health, and seems to be at too low a concentration in several diseases in vivo. Ergothioneine is thus a potentially useful dietary supplement. Present methods of commercial production rely on extraction from natural sources or on chemical synthesis. Here we describe the engineering of the baker's yeast Saccharomyces cerevisiae to produce ergothioneine by fermentation in defined media. After integrating combinations of ERG biosynthetic pathways from different organisms, we screened yeast strains for their production of ERG. The highest-producing strain was also engineered with known ergothioneine transporters. The effect of amino acid supplementation of the medium was investigated and the nitrogen metabolism of S. cerevisiae was altered by knock-out of TOR1 or YIH1. We also optimized the media composition using fractional factorial methods. Our optimal strategy led to a titer of 598 ± 18 mg/L ergothioneine in fed-batch culture in bioreactors. Because S. cerevisiae is a GRAS ('generally recognised as safe') organism that is widely used for nutraceutical production, this work provides a promising process for the biosynthetic production of ERG.
The effects of supplementing ergothioneine-rich mushroom extracts (ME) on discoloration and lipid oxidation in astaxanthin-pigmented salmon muscles were evaluated. ME (Flammulina velutipes) were added (in vitro) to minced Oncorhynchus mykiss muscles and stored at -10°C. During several weeks of storage, the ME-treated group showed lower lipid hydroperoxide (HPO) accumulation and higher retained astaxanthin levels than in the control group. The effects of adding concentrated ME (Pleurotus cornucopiae) to Oncorhynchus kisutch diets were also tested over a 2-month feeding trial. No adverse effects on fish growth or pigmentation were observed. Muscle samples were collected, stored (-2 or -18°C), and evaluated. At the end of the storage period, the ME-treated group had lower HPO and higher retained astaxanthin levels in the muscle samples than the levels in the control group. Thus, the addition of ergothioneine from MEs successfully controlled lipid oxidation and stabilized astaxanthin during post-harvest storage at low temperatures
Ergothioneine (EGT; 2-mercaptohistidine trimethylbetaine) is a trimethylated and sulphurised histidine derivative which exhibits antioxidant properties. Here we report that deletion of Aspergillus fumigatus egtA (AFUA_2G15650), which encodes a trimodular enzyme, abrogated EGT biosynthesis in this opportunistic pathogen. EGT biosynthetic deficiency in A. fumigatus significantly reduced resistance to elevated H2O2 and menadione, respectively, impaired gliotoxin production and resulted in attenuated conidiation. Quantitative proteomic analysis revealed substantial proteomic remodelling in ΔegtA compared to wild-type under both basal and ROS conditions, whereby the abundance of 290 proteins was altered. Specifically, the reciprocal differential abundance of cystathionine γ-synthase and β-lyase, respectively, influenced cystathionine availability to effect EGT biosynthesis. A combined deficiency in EGT biosynthesis and the oxidative stress response regulator Yap1, which led to extreme oxidative stress susceptibility, decreased resistance to heavy metals and production of the extracellular siderophore triacetylfusarinine C and increased accumulation of the intracellular siderophore ferricrocin. EGT dissipated H2O2in vitro, and elevated intracellular GSH levels accompanied abrogation of EGT biosynthesis. EGT deficiency only decreased resistance to high H2O2 levels which suggests functionality as an auxiliary antioxidant, required for growth at elevated oxidative stress conditions. Combined, these data reveal new interactions between cellular redox homeostasis, secondary metabolism and metal ion homeostasis.
Previous studies have demonstrated a number of physiological functions for shiitake mushroom (Lentinula edodes), among which the antioxidant activity has been evaluated primarily using conventional chemical techniques. To date, there have been no reports on the anti-oxidative stress effect or on the antioxidant enzyme induction activity of shiitake/shiitake artifact. Therefore, in this study, we evaluated the anti-oxidative stress effect of shiitake grown in Miyazaki Prefecture and shiitake artifact from luminescence values obtained using a HepG2-ARE luciferase reporter assay system. The results showed that shiitake exhibited an anti-oxidative stress effect and, based on western blot analysis, was able to induce the expression of the antioxidant enzyme HO-1. Moreover, the anti-oxidative stress effect was found to be retained in dried shiitake. It is possible that the anti-oxidative stress effect of shiitake might be increased via heat processing or lactic acid fermentation.
An efficient and sensitive method was established for quantitative analysis of L-Ergothioneine during fermentation analyze by reversed-phase-high performance liquid chromatography (RP-HPLC). The method was carried out on two C18 columns (4.6 × 250 mm, 5 um), and the isocratic mobile phase was 1 % methanol containing boric acid adjusted to a pH of 5.0 with a flow rate of 0.7 mL/min. An UV-VIS detector equipped with a wavelength of 257 nm was employed. The injection volume was 5 μL, with the columns temperature being 25 °C. The linearity, recovery, limit of detection (LOD) and quantification (LOQ), precision, repeatability, stability, and recovery were all tested and good results were obtained. The method was simple, rapid, accurate, and high sensitivity and could be utilized for the research and development of L-Ergothioneine in industry.
Ergothioneine is widely distributed in biological systems, particularly in red blood cells of animals. However, it's functional role in human body is not well understood. In order to investigate the biochemical effect of L-ergothioneine, its concentration changes in human blood with respect to ages in healthy individuals was first investigated. L-ergothioneine concentrations in the blood of Saudi males from western province at different stages of life were measured by the procedure of Carlsson et al., 1974. At early stages of life (1-10 years), the concentrations of LER is 1.5-2.0 mg/100 ml. It increases gradually at the age of 11-18 years where it reaches the maximum value of 3.7 mg/100 ml. Then, it declines gradually to 3.0-2.3 mg/ 100 ml during the period of 19-50 years. An increase in the level of LER (2.8 mg/100 ml) was seen at the age of 51+.
Ergothioneine (ESH) is a low-molecular-mass thiol present in millimolar concentrations in a limited number of tissues, including erythrocytes, kidney, seminal fluid and liver; however, its biological function is still unclear. In the present study we investigated the role of ESH in the catabolism of S-nitrosoglutathione (GSNO). The results show that: (1) GSNO decomposition is strongly influenced by ESH (k"=0.178+/-0.032 M(-1) x s(-1)); (2) ammonia is the main nitrogen-containing compound generated by the reaction; and (3) nitrite is practically absent under both aerobic and anaerobic conditions. These findings are markedly different from those reported for the GSH-induced decomposition of GSNO, in which the nitrogen-containing end products are nitrite, ammonia and nitrous oxide (N(2)O) under aerobic conditions but nitrite, ammonia, nitric oxide (NO) and small quantities of hydroxylamine under anaerobic conditions. Considering the high concentration of ESH in specific cells, the reaction with GSNO should be considered as an important molecular event occurring in the cell.
Intraperitoneal injection of the iron-complex, ferric-nitrilotriacetate (Fe-NTA), induces renal proximal tubular damage associated with oxidative damage in vivo. Fe-NTA induced a time-dependent decrease of several polyunsaturated fatty acids (PUFA), together with increased conjugated diene values and decreased cellular levels of α-tocopherol and glutathione. At the time of maximum detectable oxidation (3 h), after the injection of a sublethal dose of Fe-NTA there were clear reductions in the peak values over the controls for several fatty acids notably, 20:5 (eicosapentaenoic acid) (36%), 22:6 (docosahexanoic acid) (30%), 20:3 n6 (eicosatrienoic acid) (30%) and 20:4 (arachidonic acid) (28%) in the kidney. Fewer fatty acids showed a reduction in their residual values in the liver. 20:5 was reduced by 45% and for the 18:3 n3 and 18:3 n6, reductions of 35%, respectively. The profile of PUFAs is sensitive to the oxidative damage due to Fe-NTA and this may find applications as oxidative biomarker model.
Weaning mice were fed a diet supplemented with beef tallow (BT) or BT plus docosahexaenoic acid (DHA) containing 100 mg α-tocopherol/kg (α-Toc100) or 500 mg α-tocopherol/kg (α-Toc500) for 4 wk to modify membrane fatty acid unsaturation, and then were administered ferric nitrilotriacetate (Fe-NTA). The mortality caused by Fe-NTA was higher in the group fed the DHA (α-Toc100) diet than in the BT diet groups but the DHA (α-Toc500) diet suppressed this increase. Serum and kidney α-tocopherol contents were slightly influenced by the dietary fatty acids but not significantly. These results indicate that the increased unsaturation of tissue lipids enhances oxidative damage induced by Fe-NTA in mice fed DHA (α-Toc100) but not when additional α-tocopherol is supplemented. The apparent discrepancy between the observed enhancement by dietary DHA of oxidative damage and the beneficial effects of dietary DHA on the so-called free radical diseases is discussed in terms of strong bolus oxidative stress and moderate chronic oxidative stress.
Conjugated diene isomers of linoleic acid (CLA), possess anticarcinogenic and antiatherogenic properties, but little is known about their metabolism. We have recently obtained evidence that CLA present in partially hydrogenated oil can be metabolized to conjugated linolenic and eicosatrienoic acids in rat liver. In the present study, we have investigated whether CLA are metabolized in the liver of lambs, which normally consume high levels of CLA produced in the rumen and present in their diet, consisting exclusively of milk. Conjugated linolenic, eicosatrienoic, and arachidonic acids were detected in lamb liver phospholipids showing that elongation and desaturation of CLA occur also in lamb tissues, and that all metabolites maintain the conjugated diene structure.
A commercially available partially hydrogenated fat was analyzed for fatty acids containing conjugated dienes. The fatty acids
were isolated by high-performance liquid chromatography (HPLC), and analyzed with a photodiode array detector and an atmospheric-pressure
ionization mass spectrometer. Conventional and second-derivative ultraviolet (UV) spectra of the peaks eluting from the HPLC
were recorded with the photodiode array detector, and peaks displaying second-derivative UV spectra characteristic of the
conjugated diene chromophore were analyzed by mass spectrometry. The UV and mass spectra of the fatty acids with conjugated
dienes, present in the partially hydrogenated fat, were identical to those of reference preparations of linoleic acid isomers
with conjugated dienes. The results obtained emphasize that care must be exercised in the interpretation of clinical and experimental
data concerning the detection of conjugated dienes in tissues or body fluids of humans and experimental animals. The conjugated
dienes may not reflect an ongoing process of lipid peroxidation, but may be of dietary origin.
Free radicals and other reactive oxygen species (ROS) are constantly formed in the human body. Free-radical mechanisms have
been implicated in the pathology of several human diseases, including cancer, atherosclerosis, malaria, and rheumatoid arthritis
and neurodegenerative diseases. For example, the superoxide radical (O
2
·−
) and hydrogen peroxide (H2O2) are known to be generated in the brain and nervous system in vivo, and several areas of the human brain are rich in iron, which appears to be easily mobilizable in a form that can stimulate
free-radical reactions. Antioxidant defenses to remove O
2
·−
and H2O2 exist. Superoxide dismutases (SOD) remove O
2
·−
by greatly accelerating its conversion to H2O2. Catalases in peroxisomes convert H2O2 into water and O2 and help to dispose of H2O2 generated by the action of the oxidase enzymes that are located in these organelles. Other important H2O2-removing enzymes in human cells are the glutathione peroxidases. When produced in excess, ROS can cause tissue injury. However,
tissue injury can itself cause ROS generation (e.g., by causing activation of phagocytes or releasing transition metal ions
from damaged cells), which may (or may not, depending on the situation) contribute to a worsening of the injury. Assessment
of oxidative damage to biomolecules by means of emerging technologies based on products of oxidative damage to DNA (e.g.,
8-hydroxydeoxyguanosine), lipids (e.g., isoprostanes), and proteins (altered amino acids) would not only advance our understanding
of the underlying mechanisms but also facilitate supplementation and intervention studies designed and conducted to test antioxidant
efficacy in human health and disease.
Oxidative damage by free radicals, which is the basis for the free radical theory of aging, has been well investigated within the context of oxidant/antioxidant balance. Age-associated disorders are believed to be associated with the time-dependent shift in the antioxidant/prooxidant balance in favor of oxidative stress. In this brief review, the importance of dietary antioxidant intervention on longevity and age-associated changes in bodily functions and diseases are discussed. Evidence has indicated that increasing the endogenous antioxidants defense system and modulation of free radical production by dietary restrictions contribute to increased longevity in animal models. Thus, increasing dietary intake of antioxidants is believed to increase longevity. Earlier studies have shown some increase in median life span in animal models. It was found that supplementing middle-aged (18 months) C57/BL mice with various antioxidants (vitamin E, glutathione, melatonin, and strawberry extract) had no effect on longevity as measured by the average age of death. Therefore, dietary antioxidant supplementation seems unlikely to increase longevity when begun in middle age; supplementation started in early life might be more effective. However, in middle-aged mice, vitamin E was effective in reducing lung viral titer when animals were exposed to influenza virus. Vitamin E supplementation improves cell-mediated immunity in mice and in humans. In addition to modulating the oxidation of low-density lipoproteins, vitamin E can modulate immune/endothelial cells interactions, thus reducing the risk of cardiovascular disease (CVD), a major cause of morbidity and mortality in elderly. Thus, antioxidants such as vitamin E from food sources or supplements appear to be promising for successful aging by improving immune function, and reducing the risk of several age-associated chronic diseases, such as CVD.
Both aging and age-associated neurodegenerative diseases are associated with various degrees of behavioral impairments, and among the prime candidates responsible for producing the neuronal changes mediating these behavioral deficits appear to be free radicals and the oxidative stress they generate. Therefore, there have been a number of studies which have examined the putative positive benefits of antioxidants in altering, reversing, or forestalling these neuronal/behavioral decrements, with varying degrees of success. Additional experiments have examined the effects of diets rich in fruits and vegetables or herbal extracts in reducing certain types of cancer and cardiovascular diseases, and evidence emerging from such experiments suggests that these kinds of dietary modifications may be beneficial in altering neuronal/behavioral deficits in aging, as well. These kinds of diets are particularly rich in antioxidants such as vitamins A, C, E, and bioflavonoids (such as flavones, tannins, and anthocyanins), and thus, there may be synergistic effects among them. The present paper will review studies concerning the influence of dietary and synthetic antioxidants on normal, pathological age-related, and reactive oxygen species-induced behavioral changes in human and animal subjects. The antioxidants reviewed are vitamin E, α-lipoic acid, and the phytochemicals contained in herbals, fruits and vegetables.
Laboratory studies with classical renal carcinogens in the rat and mouse, as well as research investigation with some of the chemicals proving positive for the kidney in National Toxicology Program carcinogenicity bioassays, have demonstrated the existence of a range of diverse mechanisms underlying rodent kidney carcinogenesis. The classical carcinogens used as experimental models for studying renal tumor pathogenesis, such as the nitrosamines, are genotoxic and interact directly with DNA, forming DNA adducts with mutagenic potential. In contrast, potassium bromate and ferric nitrilotriacetate (Fe-NTA), also effective renal carcinogens, appear to cause indirect damage to DNA mediated by oxidative stress. A number of nongenotoxic chemicals are associated with epigenetic renal tumor induction in rodents, and the activity of these tends to involve prolonged stimulation of cell proliferation throughout the duration of exposure. This mode of action reflects a sustained regenerative response, either due to direct chemical toxicity to the tubule cells, as with chloroform, or to indirect cytotoxicity associated with lysosomal overload, as in alpha2u-globulin accumulation in male rats resulting from the administration of such chemicals as d-limonene and tetrachloroethylene. The histopathologic nature of hydroquinone renal carcinogenesis suggests that an additional epigenetic pathway to renal tubule tumor formation in rats may be through chemical-mediated exacerbation of, and interaction with, the age-related spontaneous renal disease, chronic progressive nephropathy. These various mechanistic pathways have implications for the nature of the induced cancer process with respect to tumor incidence, latency, malignancy, and sex predisposition.
Rats and rabbits parenterally treated with a large daily dose of ferric nitrilotriacetate manifested diabetic symptoms such as hypergycemia, glycosuria, ketonemia, and ketonuria after approximately 60 days fo treatment. The blood insulin response to oral glucose loading was poor. Heavy iron deposits were found in liver parenchymal cells and in pancreatic exocrine cells, although some iron was deposited in the macrophages and reticuloendothelial cells of the organs. Faint iron staining was found in some pancreatic islet cells, with a reduction in beta granules and weak zinc staining. Cirrhotic liver changes and skin pigment deposition were not observed. Repeated blood withdrawals from ferric-nitrilotriacetate-treated animals resulted in disappearance of hypergycmia, glycosuria, ketonemia, and ketonuria; disappearance of iron from the liver and pancreas; and restoration of islet beta granules to the control level.
The high performance liquid chromatographic procedure was established for the determination of ergothioneine in biological materials. The procedure is also applicable to the purification of 3H-ergothioneine. The metabolism of ergothioneine given to rats was very slow ; the ergothioneine was not disappear even after 1 week fasting. The ergothioneine administrated was mostly concentrated in the liver and the level was 10 times as high as that in blood. All ergothioneine in the blood was found in blood corpuscles 24 hr after the administration.
A sensitive, highly reproducible method for tissue tocopherol analysis that combines saponification in the presence of large nmount of ascorbic acid to remove interfering substances, extraction fo the nonsponifiable lipids with hexane, and fluorometric measurement of the tocopherol is presented. The nonsaponifiable lipids phase contained only one fluorochrome in the 290 am excitation and 330 nm emission range, and it was identified as tocopherol by thin layer and column chromatography. Column chromatography of the hexane extract of a saponified, 14C-tocopherolspiked microsomal fraction showed that no measurable oxidation to tocopherylquinone had occurred. The flurometric method for tocopherol analysis was applied to homogenates and subcellular fractions from rat liver, kidney, lung, and heart and red blood cells. The heavy mitochondrial and microsomal fractions had the highest subcellular concentrations of tocopherol.
Ergothioneine is a product of plant origin that accumulates in animal tissues. Its suggested ability to act as an antioxidant has been evaluated. Ergothioneine is a powerful scavenger of hydroxyl radicals (.OH) and an inhibitor of iron or copper ion-dependent generation of .OH from hydrogen peroxide (H2O2). It is also an inhibitor of copper ion-dependent oxidation of oxyhaemoglobin, and of arachidonic acid peroxidation promoted by mixtures of myoglobin (or haemoglobin) and H2O2. Ergothioneine is a powerful scavenger of hypochlorous acid, being able to protect alpha 1-antiproteinase against inactivation by this molecule. By contrast, it does not react rapidly with superoxide (O2-) or hydrogen peroxide (H2O2) and it does not inhibit microsomal lipid peroxidation in the presence of iron ions. Overall, our results show that ergothioneine at the concentrations present in vivo could act as an antioxidant.
The effects of thiols and thiocarbamides on hydroxyl radical (.OH) formation by the hypoxanthine(HYP)-xanthine oxidase(XOD)-Fe3+ .EDTA system were investigated in the range of 0.5-5 mM by colorimetrically measuring salicylate hydroxylation. Thiocarbamides powerfully inhibited the hydroxylation while thiols showed a paradoxical effect, enhancing it at low concentrations, but inhibiting it at high ones. Thiols in the presence of Fe3+ .EDTA generated superoxide anions (O2-.) and .OH during the oxidation, but thiocarbamides did not. A study of the effect of ergothioneine, a thiocarbamide present in mammals, on the .OH spin adduct of 5,5-dimethyl-1-pyrroline-N-oxide(DMPO) by EPR spectrometry showed that it effectively decreased the .OH spin adduct without causing the appearance of other signals. Reaction mechanisms are proposed for the O2-. evolution and .OH formation by the thiols themselves in the presence of Fe3+ .EDTA and .OH with thiols and thiocarbamides.
Wistar male rats were tested for nephrotoxicity and carcinogenicity after administration of ferric nitrilotriacetate [(NTA) CAS: 139-13-9] (Fe-NTA) [No. of rats (n) = 24] and Al-NTA (n = 24). The control rats were given AlCl3 (n = 10), NTA (n = 10), and saline (n = 10). Sublethal doses of Fe-NTA [5-7 mg Fe/kg (body wt)] and Al-NTA [1.5-2.0 mg Al/kg (body wt)] were chosen and injected ip for 3 months. AlCl3 and NTA were given in equivalent doses and saline was given in equivalent volumes. All the rats given Fe-NTA or Al-NTA had a depressed weight gain, polyuria, and glucosuria from the 1st week. Histologically, acute tubular necrosis and regenerating epithelial cells were observed. Regenerative atypical epithelial cells in the renal cortex were seen at the termination of Fe-NTA or Al-NTA administration. Control rats had no remarkable changes. After 1 year, primary renal cell carcinoma and metastases to liver, lung, and peritoneum were observed only in Fe-NTA-treated rats (14 of 18 surviving rats). On the contrary, there were no tumors in Al-NTA-treated rats (none of 12 surviving rats). The results suggest that nephrotoxicity and renal cell carcinoma are two independent phenomena from Al-NTA treatment and that a long-term sublethal dose of Al-NTA is not related to renal carcinogenicity.
This laboratory has previously postulated that bromobenzene-induced hepatic necrosis results from the formation of a reactive metabolite that arylates vital cellular macromolecules. Accordingly, the severity of liver necrosis has been compared with the formation of metabolites of bromobenzene and with covalent binding of metabolites in vivo and in vitro after various pretreatment regimens that alter hepatotoxicity. These data provide direct kinetic evidence that 3,4-bromobenzene oxide is the reactive hepatotoxic metabolite. The studies also demonstrate that the hepatotoxic metabolite is preferentially conjugated (detoxified) with glutathione, thereby depleting glutathione from the liver. Liver necrosis and arylation of cellular macromolecules occur only when glutathione is no longer available. Thus, a dose threshold exists for bromobenzene-induced hepatic necrosis.
The interaction of ergothioneine (I) with a number of divalent metal ions was determined using a pH titration method. Formation constants for complexes containing 2 moles of ligand and 1 mole of metal ion were found to be 1018.2 (Cu2+) 1011.6 (Zn2+), 108.2 (Ni2+), and 108.2 (Co2+). A study of the inhibitory power of I on selected Zn and Cu metalloenzymes was made. None of the 4 Zn-containing enzymes, including 3 dehydrogenases and alkaline phosphatase, were inhibited even if preincubated for 6 hr with 10-2 M I. Four different Cu enzyme systems were investigated, including uricase, ascorbate oxidase, MAO, and a number of polyphenol oxidases. Of these, only the polyphenol oxidases were inhibited by I. Kinetic measurements using Psalliota campestris (mushroom) polyphenol oxidase showed that inhibition by I does not involve removal of Cu from the enzyme, but is reversible and displays characteristics of both competitive and noncompetitive inhibition. This type of inhibition may result from the presence of Cu at noncatalytic as well as catalytic sites of mushroom polyphenol oxidase.
When ergothioneine was administered to rats for 7 d, the pentobarbital sleeping time was reduced significantly. This action was specific to ergothioneine and was not shown by various ergothioneine-related compounds (cysteine, glutathione, carnitine and histidine). This action of ergothioneine did not appear to be caused by induction of the drug-metabolizing enzyme system. The level of ergothioneine in the liver decreased markedly when phenobarbital or ethionine was administered to rats. Ergothioneine inhibited hepatic injury and significantly decreased the level of lipid peroxide induced by ethionine administration.
(1) Ergothioneine is contained as a component of the organella membranes in the rat liver, and is liberated by heat treatment or dithiothreitol treatment. The amount of bound form increases with aging up to 11 weeks of age, and then decreases. All of the ergothioneine measured by the normal determination procedures can be considered to be free form. (2) Ergothioneine is bound to proteins in the blood plasma, but is present in free form in erythrocytes. (3) Biosynthesis of ergothioneine from amino acids in rats was not detectable. Ergothioneine is ingested from the diet and accumulated in the body. (4) When dietary ergothioneine is restricted for 18 weeks, the amount in the liver falls to a threshold value but apparently does not fall further, and no deficiency symptoms are observed. (5) Experimental ergothioneine-free rats were successfully produced in the second generation (born to parent rats fed on ergothioneine-free diet).
This chapter discusses the detection of conjugated dienes by second derivative ultraviolet spectrophotometry. Conjugated dienes (CD) refers to two double bonds separated by a single bond. This structure is unusual in polyunsaturated fatty acids (PUFA). It is generally accepted that the occurrence of conjugated dienes in lipids means autoxidation of lipids. In fact, because of the divinylmethane structure, PUFA are particularly susceptible to hydrogen abstraction by free radical attack, becoming themselves free radical intermediates. This results in the rearrangement of the double bond to conjugated dienes and, in the presence of O2, the formation of fatty acid hydroperoxides. The conjugated diene moiety is a strong chromophore that can be detected spectrophotometrically. When present in fatty acids they show a characteristic absorption in the UV region at around 234 nm. However, detection and quantitation of conjugated dienes in mixtures of peroxidized and nonperoxidized lipids, by means of simple UV spectrophotometry, is complicated by the end absorption exhibited by naturally occurring and nonperoxidized lipids.
An iron chelate, ferric nitrilotriacetate (Fe-NTA), induces proximal tubular necrosis, a consequence of lipid peroxidation, that finally leads to a high incidence of renal adenocarcinoma in rodents. Lipid peroxidation as monitored by formation of thiobarbituric acid-reactive substances and free 4-hydroxy-2-nonenal (HNE) was observed in the kidney homogenates of rats treated with Fe-NTA. Based on the fact that HNE is capable of reacting with cellular proteins, we attempted to detect the localization of HNE-modified proteins in rat kidney tissues with an immunohistochemical procedure. By means of an immunohistochemical technique using polyclonal antibody against the HNE-modified proteins, it was shown that HNE-modified proteins are formed in the target cells of this carcinogenesis model. HNE-modified proteins were detected in the renal proximal tubules 1 hr after i.p. administration of Fe-NTA (15 mg of iron per kg). Intense positivity was found in the cells with degeneration. After 6 hr, the level of HNE-protein conjugates decreased due to the subsequent necrosis. The intensity of the immunochemical reaction with HNE-modified proteins increased in parallel with an increase in the amounts of thiobartituric acid-reactive substances and free HNE that were found. Furthermore, histochemical detection of aldehydes by cold Schiff's reagent demonstrated that location of aldehydes was identical to that of the HNE-modified proteins determined by immunohistochemical procedures. It would thus appear that the production of HNE, a genotoxic and mutagenic aldehyde, and its reaction with proteins may play a role in Fe-NTA-induced renal carcinogenesis.
The following thiols were investigated with regard to their possible UV-radiation protective properties: captopril, cysteamine, ergothioneine, mesna, mercaptopropionylglycine, N-acetylcysteine, and penicillamine. As a measure for protection, the inhibition of in vitro irreversible photobinding of the labeled phototoxic drugs chlorpromazine (CPZ) and 8-methoxypsoralen (8-MOP) to protein and DNA was used. Besides photobinding to biomacromolecules, the photodegradation of CPZ and the formation of promazine (PZH) and hydroxypromazine (PZOH) were measured as well. Because of the H-atom and electron donating capacity of the thiols, the ratio [PZOH]/[PZH] was expected to be decreased and the photodegradation of CPZ was expected to be higher in the presence of thiols. Maximum inhibition of CPZ photobinding ranged for the different thiols between 21-100% (DNA) and 17-87% (human serum albumin). All thiols enhanced the photodegradation of CPZ (19-84%) and inhibited the ratio [PZOH]/[PZH] (90-97%). 8-MOP photobinding to human serum albumin was also clearly inhibited (75-96%), but remarkably less to DNA (2-41%). This study indicates that thiols are able to cope with a variety of reactive species. Scavenging of radicals, quenching of singlet molecular oxygen species and reaction with excited states seem to be essential mechanisms involved with this process.
Redox reactions of endogenous and exogenous sulphur-containing compounds are involved in protection against oxidative damage arising from the incidence and/or treatment of many diseases, including cancer. We have investigated, via pulse radiolysis, the one-electron oxidation of ergothioneine, a molecule with antioxidant properties which is detected at millimolar concentrations in certain tissues and fluids subject to oxidative stress, including erythrocytes and plasma. The spectrum of the transient species, assigned to the product of one-electron oxidation, observed after reaction of ergothioneine with the oxidizing radicals OH., N3. and CCl3O2. has a maximum absorption at 520 nm and is very similar to that obtained by oxidation of analogous molecules such as 2-mercaptoimidazole, 1-methyl-2-mercaptoimidazole, S-methyl- and S,N-dimethyl-ergothioneine. In the presence of vitamin C, the oxidized form of ergothioneine is repaired by a rapid reduction (k = 6.3 x 10(8) M(-1).s(-1)) producing ascorbyl radicals. This co-operative interaction between ergothionine and ascorbate, similar to that previously observed between vitamin E and ascorbate, may contribute to essential biological redox protection.
Systemic administration of copper, an essential trace metal in the human body, has never been reported to be carcinogenic in animals. We investigated the induction of tumors by the cupric complex of nitrilotriacetic acid (Cu-NTA) in male Wistar rats. Thirty-two animals received ip injections of Cu-NTA, 3 to 5 mg of copper/kg body weight 5 days a week for 12 weeks, and were kept under close observation. For comparison, 31 animals received ip injections of ferric nitrilotriacetate (Fe-NTA), 5 to 10 mg of iron/kg body weight, and 16 animals received nitrilotriacetic acid (NTA) alone at the molar dose equivalent to Cu-NTA for the same period of time. Sixteen animals were left untreated as controls. Fourteen animals in the Cu-NTA group died of hepatic failure during the treatment period, and renal cell carcinoma (RCC) was induced in eight animals (25%). Of these, four animals died of either pulmonary metastasis or intraperitoneal hemorrhage. A total of 12 RCC were obtained, of which six tumors were > or = 5 mm. The Cu-NTA group yielded fewer RCC and required a longer latent period for their incubation than the Fe-NTA group. Furthermore, the Cu-NTA group showed one hepatocellular carcinoma and one high-grade sarcoma of hepatic origin. No renal or hepatic tumor was observed in the NTA or control groups. The nontumorous part of the kidney treated with Cu-NTA presented hemosiderosis caused by copper-induced hemolytic anemia. This is the first report that systemic administration of copper compounds can induce malignant tumors in animals. Not only copper but also iron may play a role in the Cu-NTA-induced renal carcinogenesis model.
Free radicals and antioxidants are widely discussed in the clinical and nutritional literature. Antioxidants are needed to prevent the formation and oppose the actions of reactive oxygen and nitrogen species, which are generated in vivo and cause damage to DNA, lipids, proteins, and other biomolecules. Endogenous antioxidant defenses (superoxide dismutases, H2O2-removing enzymes, metal binding proteins) are inadequate to prevent damage completely, so diet-derived antioxidants are important in maintaining health. Many dietary compounds have been suggested to be important antioxidants: The evidence for a key role of vitamins E and C is strong, but that for carotenoids and related plant pigments is weaker. Interest is also growing in the role of plant phenolics, especially flavonoids. Some antioxidants can exert prooxidant effects in vitro, but their physiological relevance is uncertain. Experimental approaches to the optimization of antioxidant nutrient intake are proposed.
The superoxide radical (O.2-) and nitric oxide (NO.) combine very rapidly to form peroxynitrite (ONOO-), a reactive tissue damaging nitrogen species thought to be involved in the pathology of several chronic diseases. The natural product ergothioneine protects against the nitration of tyrosine and the inactivation of alpha 1-antiproteinase by ONOO-. Ergothioneine merits further investigation as a biological and therapeutic antioxidant agent.
Ergothioneine (ERT), is a low molecular weight, sulfur-containing antioxidant occurring in up to millimolar amounts in mammalian tissues. Using an improved HPLC assay, ERT levels have been measured and compared in bovine and porcine eyes and erythrocytes. The rank order of ERT levels in bovine ocular tissue was lens > retina = cornea > pigmented retinal epithelium (RPE) > aqueous humor (AQ) > vitreous humor (VIT) > sclera. In porcine ocular tissue, the rank order was retina > AQ > VIT > RPE > cornea > lens > sclera. ERT levels in bovine lens were about 250 x > that in porcine lens. Porcine erythrocyte levels were 5.5 x > bovine levels. Species differences were also observed in the retina, VIT and AQ where porcine levels were 2 to 10-fold greater than bovine levels. ERT in bovine lens and cornea was 35 and 14 times greater than the corresponding level of reduced glutathione (GSH). Porcine lens had 45 times more GSH than ERT. Values for ERT and GSH in other tissues from both species were of the same order of magnitude. These results are consistent with a role for ERT in prevention of oxidative damage to the eye.
Two hours after an intraperitoneal injection of ferric nitrilotriacetate to rats at a dose of 15 mg of Fe/kg of body weight, the level of lipid hydroperoxides, which was determined by a specific method involving chemical conversion into 1-naphthyldiphenylphosphine oxide and HPLC, had increased significantly in the liver (from 190.1 +/- 58.8 of the control to 467.1 +/- 175.8 pmol/mg of protein) and kidney (from 181.8 +/- 52.3 of the control to 405.9 +/- 22.7 pmol/mg of protein). These results demonstrate that oxidative stress was transiently increased by an iron overload in these tissues.