Article

Hydrogen-rich water prevents progression of nonalcoholic steatohepatitis and accompanying hepatocarcinogenesis in mice

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Abstract

Unlabelled: Oxidative stress is a strong contributor to the progression from simple fatty liver to nonalcoholic steatohepatitis (NASH). Molecular hydrogen is an effective antioxidant that reduces cytotoxic reactive oxygen species. In this study, we investigated the effects of hydrogen-rich water and the drug pioglitazone on the progression of NASH in mouse models. A methionine-choline-deficient (MCD) diet mouse model was prepared. Mice were divided into three experimental groups and fed for 8 weeks as follows: (1) MCD diet + control water (CW group); (2) MCD diet + hydrogen-rich water (HW group); and (3) MCD diet mixed with pioglitazone (PGZ group). Plasma alanine aminotransferase levels, hepatic expression of tumor necrosis factor-α, interleukin-6, fatty acid synthesis-related genes, oxidative stress biomarker 8-hydroxydeoxyguanosine (8-OHdG), and apoptosis marker terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL)-positive cells in the liver were decreased in the HW and PGZ groups. The HW group showed a smaller decrease in hepatic cholesterol; however, stronger antioxidative effects in serum and lower peroxisome proliferator-activated receptor-α expression in the liver were seen in comparison with the PGZ group. We then investigated the effects of hydrogen in the prevention of hepatocarcinogenesis in STAM mice, known as the NASH-related hepatocarcinogenesis model. Eight-week-old male STAM mice were divided into three experimental groups as follows: (1) control water (CW-STAM); (2) hydrogen-rich water (HW-STAM); and (3) pioglitazone (PGZ-STAM). After 8 weeks, hepatic tumors were evaluated. The number of tumors was significantly lower in the HW-STAM and PGZ-STAM groups than in the CW-STAM group. The maximum tumor size was smaller in the HW-STAM group than in the other groups. Conclusion: Consumption of hydrogen-rich water may be an effective treatment for NASH by reducing hepatic oxidative stress, apoptosis, inflammation, and hepatocarcinogenesis.

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... Intraperitoneal injection of H 2 gas had the therapeutic effect on methionine-choline-deficient (MCD) diet-induced NAFLD in mice via inhibiting hepatic MDA levels and JNK phosphorylation (Zhou et al., 2020). Daisuke Kawai et al. revealed that H 2 rich water improved MCD diet-induced nonalcoholic steatohepatitis (NASH) in mice by decreasing plasma ALT levels, hepatic TNF-a and IL-6, oxidative stress and apoptosis related markers, free fatty acid (FFA) uptakerelated gene fatty acid translocase (FAT) (Kawai et al., 2012). H 2 rich water also reduced tumor numbers and maximum tumor size in STZ-induced NASH-related hepatocarcinogenic mice model (Kawai et al., 2012). ...
... Daisuke Kawai et al. revealed that H 2 rich water improved MCD diet-induced nonalcoholic steatohepatitis (NASH) in mice by decreasing plasma ALT levels, hepatic TNF-a and IL-6, oxidative stress and apoptosis related markers, free fatty acid (FFA) uptakerelated gene fatty acid translocase (FAT) (Kawai et al., 2012). H 2 rich water also reduced tumor numbers and maximum tumor size in STZ-induced NASH-related hepatocarcinogenic mice model (Kawai et al., 2012). However, they found that H 2 decreased hepatic PPARa and its targeted gene FFA boxidation-related gene acyl-CoA oxidase expression in MCD diet-induced NASH mice model (Kawai et al., 2012). ...
... H 2 rich water also reduced tumor numbers and maximum tumor size in STZ-induced NASH-related hepatocarcinogenic mice model (Kawai et al., 2012). However, they found that H 2 decreased hepatic PPARa and its targeted gene FFA boxidation-related gene acyl-CoA oxidase expression in MCD diet-induced NASH mice model (Kawai et al., 2012). Therefore, the regulated effects of H 2 on PPARa might be dependent on the animal models examined, it is possible that H 2 regulates hepatic lipid metabolism via maintaining the balance of hepatic de novo lipogenesis/FFAs uptake and b-oxidation. ...
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Basic and clinical studies have shown that hydrogen (H2), the lightest gas in the air, has significant biological effects of anti-oxidation, anti-inflammation, and anti-apoptosis. The mammalian cells have no abilities to produce H2 due to lack of the expression of hydrogenase. The endogenous H2 in human body is mainly produced by anaerobic bacteria, such as Firmicutes and Bacteroides, in gut and other organs through the reversible oxidation reaction of 2 H+ + 2 e- ⇌ H2. Supplement of exogenous H2 can improve many kinds of liver injuries, modulate glucose and lipids metabolism in animal models or in human beings. Moreover, hepatic glycogen has strong ability to accumulate H2, thus, among the organs examined, liver has the highest concentration of H2 after supplement of exogenous H2 by various strategies in vivo. The inadequate production of endogenous H2 play essential roles in brain, heart, and liver disorders, while enhanced endogenous H2 production may improve hepatitis, hepatic ischemia and reperfusion injury, liver regeneration, and hepatic steatosis. Therefore, the endogenous H2 may play essential roles in maintaining liver homeostasis.
... The former can be categorized into investigations using cultured cancer cells, transplants of animal-specific tumor lines (allogeneic transplants), xenografts of human tumor lines in immunocompromised animals, or tumors induced in animals via exposure to UV or ionizing irradiation [25][26][27][28][29][30][31][32][33][34][35][36]. There are also reports of animals fed with a high-fat diet to induce nonalcoholic steatohepatitis (NASH) and evaluate its efficacy in the progression of liver cancer [37]. In addition, since the growth of cancer is accompanied by angiogenesis, the efficacy of cultured cells on angiogenesis has also been reported [38]. ...
... [36] High-fat diet-induced liver cancer H2-rich water showed carcinogenic effects in an experimental system that progressed from NASH to fibrosis and liver cancer. [37] Angiogenesis Co-culture experiment of 2 cell lines Electrolyzed reduced H2 water inhibited lumen formation via suppression of VEGF expression in cultured cells. Inhalation of H2 gas prolonged progression-free survival and overall survival in patients with stage IV, and the mechanism involved the recovery of CD8 + T cells. ...
... Oxidative stress has been strongly implicated in the pathogenesis from simple fatty livers to NASH, fibrosis, and hepatocarcinoma. Kawai et al. investigated the inhibitory effect of H2 on the progression to hepatocarcinogenesis in a STAM mouse model [37]. Two-day-old mice were treated with a single dose of streptozotocin to reduce insulin secretion and fed a high-fat diet from 4 weeks of age. ...
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While many antitumor drugs have yielded unsatisfactory therapeutic results, drugs are one of the most prevalent therapeutic measures for the treatment of cancer. The development of cancer largely results from mutations in nuclear DNA, as well as from those in mitochondrial DNA (mtDNA). Molecular hydrogen (H2), an inert molecule, can scavenge hydroxyl radicals (·OH), which are known to be the strongest oxidizing reactive oxygen species (ROS) in the body that causes these DNA mutations. It has been reported that H2 has no side effects, unlike conventional antitumor drugs, and that it is effective against many diseases caused by oxidative stress and chronic inflammation. Recently, there has been an increasing number of papers on the efficacy of H2 against cancer and its effects in mitigating the side effects of cancer treatment. In this review, we demonstrate the efficacy and safety of H2 as a novel antitumor agent and show that its mechanisms may not only involve the direct scavenging of ·OH, but also other indirect biological defense mechanisms via the regulation of gene expression.
... Oral administration of H2-rich water (HRW) was easier, safer and more economical as a means to protect against oxidative stress-induced injury in multiple animal models of human diseases. H2 was successfully used in a number of in vivo studies of hepatic injury, which examined conditions such as ischemia reperfusion injury, obstructive jaundice, acute hepatic failure and nonalcoholic steatohepatitis [19][20][21][22][23][24][25] . ...
... Additionally, consumption of more than 20 mL/kg per day of HRW had no observable adverse effects, which suggests a 60-kg human could safely drink at least 1.2 L/d of HRW [28] . Thus, HRW could be used in preventive and clinical applications as a safe and effective antioxidant with minimal side effects [17][18][19][20][21]23,[28][29][30][31] . Recent clinical studies found that HRW reduced oxidative stress in persons with chronic hepatitis B [32] and metabolic syndrome [31] . ...
... These effects were abolished by HRW pretreatment, particularly in combination with silymarin treatment. HRW prevented progression of nonalcoholic steatohepatitis [19,40] and metabolic syndrome in previous studies which suggests that anti-fatty liver benefits are regulated by fatty acid and steroid metabolism through the peroxisome proliferator-activated receptor α (PPARα) signaling pathway [30] . Our results also indicate that prevention of ALD by HRW is partially mediated by lipid metabolism. ...
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AIM To investigate the effects of hydrogen-rich water (HRW) treatment on prevention of ethanol (EtOH)-induced early fatty liver in mice. METHODS In vitro reduction of hydrogen peroxide by HRW was determined with a chemiluminescence system. Female mice were randomly divided into five groups: control, EtOH, EtOH + silymarin, EtOH + HRW and EtOH + silymarin + HRW. Each group was fed a Lieber-DeCarli liquid diet containing EtOH or isocaloric maltose dextrin (control diet). Silymarin was used as a positive control to compare HRW efficacy against chronic EtOH-induced hepatotoxicity. HRW was freshly prepared and given at a dosage of 1.2 mL/mouse trice daily. Blood and liver tissue were collected after chronic-binge liquid-diet feeding for 12 wk. RESULTS The in vitro study showed that HRW directly scavenged hydrogen peroxide. The in vivo study showed that HRW increased expression of acyl ghrelin, which was correlated with food intake. HRW treatment significantly reduced EtOH-induced increases in serum alanine aminotransferase, aspartate aminotransferase, triglycerol and total cholesterol levels, hepatic lipid accumulation and inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6. HRW attenuated malondialdehyde level, restored glutathione depletion and increased superoxide dismutase, glutathione peroxidase and catalase activities in the liver. Moreover, HRW reduced TNF-α and IL-6 levels but increased IL-10 and IL-22 levels. CONCLUSION HRW protects against chronic EtOH-induced liver injury, possibly by inducing acyl ghrelin to suppress the pro-inflammatory cytokines TNF-α and IL-6 and induce IL-10 and IL-22, thus activating antioxidant enzymes against oxidative stress.
... Les résultats de dosages d'ALT obtenus lors de cette étude, s'ils présentent des variations cohérentes entre les groupes, présentent toutefois des valeurs brutes faibles par rapport aux valeurs observées habituellement dans la littérature. Ici les groupes ayant reçu un régime MCD présentent à 4 et 8 semaines environ 50 UI/L d'activité ALT, alors que de manière générale, dans la littérature, les valeurs se situent généralement entre 200 et 300 UI/L (Caballero et al., 2010;Ip et al., 2004a;Itagaki et al., 2013;Kawai et al., 2012;Machado et al., 2015). Cette différence est difficilement explicable. ...
... C'est la raison pour laquelle différentes études se sont intéressées aux thiazolidinédiones dans le traitement de la NASH. Certaines de ces études ont montré que la pioglitazone permettait, dans un modèle de NASH induite par un régime MCD, de réduire le profil inflammatoire et les dommages hépatiques (Kawai et al., 2012). Un autre effet observé dans la NASH est la relocalisation des acides gras hépatiques vers les adipocytes (Ip et al., 2004b). ...
... Les effets de la pioglitazone ont également été évalués sur un modèle murin de NASH induite par un régime MCD (page 109). Il a ainsi été montré que la pioglitazone diminue le profil inflammatoire et les dommages hépatiques induits par le régime MCD(Kawai et al., 2012).Parmi les concurrents actuels à l'élaboration d'un agent thérapeutique approuvé pour le traitement de la NASH, on retrouve un activateur des PPARδ et PPARα. Il s'agit de l'acide 2-(2,6-diméthyl-4-{3-[4-(méthylsulfanyl)phényl]-3oxoprop-1-én-1-yl}phénoxy)-2-méthylpropanoïque ou GFT505 ou Elafibranor. ...
Thesis
Le syndrome métabolique est une association de plusieurs troubles métaboliques tels que l'obésité, la résistance à l'insuline, l'hypertension artérielle, des taux élevés de triglycérides, de cholestérol et de glucose sanguins. Ces anomalies métaboliques sont de réels facteurs de risques de diabète de type 2 et de maladies cardiovasculaires.L'apparition d'une résistance à l'insuline semble être l'un des éléments clés des pathologies métaboliques. Elle précède le développement du diabète de type 2 et est présente chez de nombreuses personnes obèses. Sa prévalence est difficile à apprécier et elle est probablement sous-estimée, d'une part car elle se situe en amont des signes cliniques qui conduisent le patient chez le médecin, et d'autre part car il n'existe pas de technique de mesure simple et robuste de l'IR utilisable en routine clinique. Le dépistage précoce de l'insulinorésistance et l’étude des mécanismes qui la sous-tendent sont donc essentiels en termes de santé publique.Le syndrome métabolique se caractérise également par des phénomènes hépatiques, les stéato-hépatopathies non alcooliques (ou NAFLD pour Non Alcoholic Fatty Liver Disease). Les NAFLD sont étroitement liées à l’obésité et à l’insulinorésistance, dont la prévalence n’a cessé d’augmenter ces dernières décennies, et représentent ainsi la première cause des maladies chroniques du foie. On admet qu’aujourd’hui, 25% de la population mondiale serait touchée par les NAFLD. Il est probable que cette prévalence soit sous-estimée compte tenu du manque d’outils diagnostiques, particulièrement pour les premiers stades asymptomatiques de la maladie.L'insulinorésistance et les stéatohépatopathies apparaissent donc comme deux composantes importantes du syndrome métabolique, présentant chacune une phase silencieuse. Ces travaux de thèse ont pour objectif le développement de techniques diagnostiques précoces, en imagerie nucléaire, à la fois pour une utilisation clinique mais aussi pour l'évaluation de nouvelles thérapeutiques en recherche préclinique.
... HFD-32 food was prepared as described previously [29] and comprised (w/w) 5% egg white powder (MM Ingredients, Wimborne, UK); 6.928% lactose (Sigma); 15.88% beef fat (saturated) powder (containing 80% beef fat) (MP Biomedical, Illkirch, France); 24.5% milk casein (Shaanxi Fuheng Biotechnology, Xi'an, China); 20% safflower oil (high oleic acid type) (Bustan a Briut, Galil, Israel); 6.45% sucrose (Sigma); 0.36% choline bitartrate (Bulk Powders, Colchester, UK); 5.5% crystalline cellulose (Sigma); 0.43% L-cysteine (Source Naturals, Scotts Valley, Santa Cruz, CA); 8.25% maltodextrin (Bulk Powders); 5% AIN93G-mineral mixture (MP Biomedical); 1.4% AIN93VX-vitamin mix (MP Biomedical); and 0.002% tertiary butyl hydroquinone (MP Biomedical). C57Bl/6 control mice were fed a standard chow diet. ...
... (b) HFD-32-induced HCC, known as the STAM mouse model, was produced as described previously [29]. post-cell inoculation, tumors were measured using a digital caliper, and volumes were calculated using the formula: r 1 2 × r 2 /2 (r 1 is the shortest and r 2 is the longest diameter). ...
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Conclusion: These results show that the VDAC1-based peptide R-Tf-D-LP4 has multiple effects on liver cancer cells, leading to impairment of cell energy and metabolism homeostasis, induction of apoptosis, and elimination of liver cancer-associated processes, and thus represents a promising therapeutic approach for liver cancer.
... For example, one study [31] using hydrogen-rich saline in a NAFLD rat model induced with hyperglycemia and hyperlipidemia, found H2 significantly lowered levels of oxidative stress and inflammation [31] . In another study using a methioninecholine-deficient diet-induced NASH model, ingestion of HRW significantly attenuated steatohepatitis to a degree comparable to the drug pioglitazone and suppressed hepatic tumorigenesis in a streptozotocin-induced NASH-related hepatocarcinogenic mouse model [32] . Similar positive effects of H2 have also been reported in other studies [33,34] . ...
... In our study, we found that mice that drank HRW showed an increase in the mRNA expression of adiponectin and a decrease in the mRNA expression of TNF-α. The reduction in TNF-α mRNA expression caused by H2 in a similar model has been previously reported [32] . In a double-blinded, human crossover study, drinking HRW for eight weeks also increased adiponectin levels [23] . ...
Article
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AIM To identify the effect of hydrogen-rich water (HRW) and electrolyzed-alkaline water (EAW) on high-fat-induced non-alcoholic fatty acid disease in mice. METHODS Mice were divided into four groups: (1) Regular diet (RD)/regular water (RW); (2) high-fat diet (HFD)/RW; (3) RD/EAW; and (4) HFD/EAW. Weight and body composition were measured. After twelve weeks, animals were sacrificed, and livers were processed for histology and reverse-transcriptase polymerase chain reaction. A similar experiment was performed using HRW to determine the influence and importance of molecular hydrogen (H2) in EAW. Finally, we compared the response of hepatocytes isolated from mice drinking HRW or RW to palmitate overload. RESULTS EAW had several properties important to the study: (1) pH = 11; (2) oxidation-reduction potential of -495 mV; and (3) H2 = 0.2 mg/L. However, in contrast to other studies, there were no differences between the groups drinking EAW or RW in either the RD or HFD groups. We hypothesized that the null result was due to low H2 concentrations. Therefore, we evaluated the effects of RW and low and high HRW concentrations (L-HRW = 0.3 mg H2/L and H-HRW = 0.8 mg H2/L, respectively) in mice fed an HFD. Compared to RW and L-HRW, H-HRW resulted in a lower increase in fat mass (46% vs 61%), an increase in lean body mass (42% vs 28%), and a decrease in hepatic lipid accumulation (P < 0.01). Lastly, exposure of hepatocytes isolated from mice drinking H-HRW to palmitate overload demonstrated a protective effect from H2 by reducing hepatocyte lipid accumulation in comparison to mice drinking regular water. CONCLUSION H2 is the therapeutic agent in electrolyzed-alkaline water and attenuates HFD-induced nonalcoholic fatty liver disease in mice.
... By reducing hepatic oxidative stress, apoptosis, and inflammation, H 2 prevents progression of nonalcoholic steatohepatitis-related hepatocarcinogenesis [180]. However, a previous study has found that combining H 2 with platinum nanocolloids exerts carcinostatic and carcinocidal effects by increasing H 2 peroxide generation and cell death in a human gastric cancer cell line NUGC-4 [181]. ...
... human;[176] Sprague-Dawley rats, C57BL/6 mice, and db/db mice; and[177] Sprague-Dawley rats.Inhibits ROS, apoptosis, and inflammation in lesion tissue; downregulates chromosome 3; enhances anticancer effects; alleviates side effects of anticancer therapies; modulates immune function; and restores exhausted CD8+ T cells.[127] A549 and H1975 cells;[180] C57BL/6 mice;[182] mouse colon carcinoma cell line and BALB/c mice;[185] C57BL/6J mice and human lung cancer cell lines A549;[186] Wistar albino rats;[187] human; and[189] human. ...
Article
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Ageing is a physiological process of progressive decline in the organism function over time. It affects every organ in the body and is a significant risk for chronic diseases. Molecular hydrogen has therapeutic and preventive effects on various organs. It has antioxidative properties as it directly neutralizes hydroxyl radicals and reduces peroxynitrite level. It also activates Nrf2 and HO-1, which regulate many antioxidant enzymes and proteasomes. Through its antioxidative effect, hydrogen maintains genomic stability, mitigates cellular senescence, and takes part in histone modification, telomere maintenance, and proteostasis. In addition, hydrogen may prevent inflammation and regulate the nutrient-sensing mTOR system, autophagy, apoptosis, and mitochondria, which are all factors related to ageing. Hydrogen can also be used for prevention and treatment of various ageing-related diseases, such as neurodegenerative disorders, cardiovascular disease, pulmonary disease, diabetes, and cancer. This paper reviews the basic research and recent application of hydrogen in order to support hydrogen use in medicine for ageing prevention and ageing-related disease therapy.
... Inhaled H 2 suppresses oxidative stress-induced injury in several organs, such as ischaemia/reperfusion injury in the brain, 18 liver 19 and heart, 20 and irradiation-induced injury in the lungs. 21 Furthermore, continuous consumption of H 2 -rich water protects against oxidative damage, including manifestations of oxidative stress associated with diabetes in humans, 22 cisplatin-induced renal injury in mice, 23 naphthalene-evoked acute lung injury in mice 24 and non-alcoholic steatohepatitis 25,26 in animal models. ...
... Furthermore, we demonstrated that Consistent with these results, we observed that H 2 protects against lung damage by decreasing soluble collagen levels and TNF-α, IL-6, BAX and TGF-β expression (Figures 4 and 5). These inflammatory, We previously reported a study using a nephrotoxic mouse 25,26 In this study, the RA-ILD model is a chronic lung fibrosis model induced by the immunization of D1CC mice via several type II collagen injections; however, the precise molecular mechanisms underlying the protective effects of H 2 remain to be elucidated. There is no satisfactory in vitro cell culture model of RA, although H 2 has been reported to inhibit the lipopolysaccharide (LPS)-and IFN-γ-induced production of nitric oxide in macrophages in vitro by controlling signal transduction. ...
Article
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Rheumatoid arthritis (RA)‐associated interstitial lung disease (ILD), a primary cause of mortality in patients with RA, has limited treatment options. A previously established RA model in D1CC transgenic mice aberrantly expressed major histocompatibility complex class II genes in joints, developing collagen II‐induced polyarthritis and anti‐cyclic citrullinated peptide antibodies and interstitial pneumonitis, similar to those in humans. Molecular hydrogen (H2) is an efficient antioxidant that permeates cell membranes and alleviates the reactive oxygen species‐induced injury implicated in RA pathogenesis. We used D1CC mice to analyse chronic lung fibrosis development and evaluate H2 treatment effects. We injected D1CC mice with type II collagen and supplied them with H2‐rich or control water until analysis. Increased serum surfactant protein D values and lung densities images were observed 10 months after injection. Inflammation was patchy within the perilymphatic stromal area, with increased 8‐hydroxy‐2ʹ‐deoxyguanosine‐positive cell numbers and tumour necrosis factor‐α, BAX, transforming growth factor‐β, interleukin‐6 and soluble collagen levels in the lungs. Inflammatory and fibrotic changes developed diffusely within the perilymphatic stromal area, as observed in humans. H2 treatment decreased these effects in the lungs. Thus, this model is valuable for studying the effects of H2 treatment and chronic interstitial pneumonia pathophysiology in humans. H2 appears to protect against RA‐ILD by alleviating oxidative stress.
... Excessive lipid droplet accumulation in NAFL patients can result in oxidative stress, inflammation, and hepatocyte injury, eventually leading to NASH [40]. Because NAFLD is a multifactorial disease, different mouse models are used to study NAFLD pathogenesis, including methionine-choline diet-induced NASH, high-fat diet-induced NAFLD, and streptozotocin-induced NASH-related hepatocarcinogenic models [27,[36][37][38]48]. Several of these studies used hydrogen therapy, which demonstrated a therapeutic effect against NAFLD (Table 1). ...
... Interestingly, HRW treatment also modulates transcriptional changes in lipid metabolic genes by increasing peroxisomal fatty acyl-CoA oxidase (ACOX), a rate-limiting enzyme for beta-oxidation of very-long-chain fatty acids. It also inhibits the transcription of CD36, a key protein in fatty acid uptake [38]. ...
Article
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Our body composition is enormously influenced by our lifestyle choices, which affect our health and longevity. Nutrition and physical activities both impact overall metabolic condition, thus, a positive energy balance causes oxidative stress and inflammation, hastening the development of metabolic syndrome. With this knowledge, boosting endogenous and exogenous antioxidants has emerged as a therapeutic strategy for combating metabolic disorders. One of the promising therapeutic inventions is the use of alkaline reduced water (ARW). Aside from its hydrating and non-caloric properties, ARW has demonstrated strong antioxidant and anti-inflammatory properties that can help stabilize physiologic turmoil caused by oxidative stress and inflammation. This review article is a synthesis of studies where we elaborate on the intra- and extracellular effects of drinking ARW, and relate these to the pathophysiology of common metabolic disorders, such as obesity, diabetes mellitus, non-alcoholic fatty liver disease, and some cancers. Highlighting the health-promoting benefits of ARW, we also emphasize the importance of maintaining a healthy lifestyle by incorporating exercise and practicing a balanced diet as forms of habit.
... Hydrogen (H 2 ), the most abundant element in the universe, has been shown to be a potent antioxidant and can effectively protect against tissue damage such as liver injury, renal injury, and lung injury [17][18][19]. Xu et al. confirm that hydrogenrich saline treatment reduces kidney fibrosis and infiltration of macrophages induced by unilateral ureteric obstruction (UUO) in rats [18]. However, whether hydrogen-rich saline can affect the pathogenesis of pulmonary fibrosis remains largely unknown. ...
... Sun et al. [29] demonstrated that hydrogen-rich saline prevents ROS accumulation in various types of liver injury and liver fibrosis. Kawai et al. [17] reported that consumption of hydrogen-rich water can decrease the oxidative stress biomarker 8-hydroxydeoxyguanosine (8-OHdG) and thus may be an effective treatment for nonalcoholic steatohepatitis by reducing hepatic oxidative stress. Consistent with these findings, the present study provides evidence that hydrogen-rich saline significantly attenuates LPS-induced oxidative stress in lung tissues. ...
Article
Background Fibrotic change is one of the important reasons for the poor prognosis of patients with acute respiratory distress syndrome (ARDS). The present study investigated the effects of hydrogen-rich saline, a selective hydroxyl radical scavenger, on lipopolysaccharide (LPS)-induced pulmonary fibrosis. Material/Methods Male ICR mice were divided randomly into 5 groups: Control, LPS-treated plus vehicle treatment, and LPS-treated plus hydrogen-rich saline (2.5, 5, or 10 ml/kg) treatment. Twenty-eight days later, fibrosis was assessed by determination of collagen deposition, hydroxyproline, and type I collagen levels. Development of epithelial-to-mesenchymal transition (EMT) was identified by examining protein expressions of E-cadherin and α-smooth muscle actin (α-SMA). Transforming growth factor (TGF)-β1 content, total antioxidant capacity (T-AOC), malondialdehyde (MDA) content, catalase (CAT), and superoxide dismutase (SOD) activity were determined. Results Mice exhibited increases in collagen deposition, hydroxyproline, type I collagen contents, and TGF-β1 production in lung tissues after LPS treatment. LPS-induced lung fibrosis was associated with increased expression of α-SMA, as well as decreased expression of E-cadherin. In addition, LPS treatment increased MDA levels but decreased T-AOC, CAT, and SOD activities in lung tissues, indicating that LPS induced pulmonary oxidative stress. Hydrogen-rich saline treatment at doses of 2.5, 5, or 10 ml/kg significantly attenuated LPS-induced pulmonary fibrosis. LPS-induced loss of E-cadherin in lung tissues was largely reversed, whereas the acquisition of α-SMA was dramatically decreased by hydrogen-rich saline treatment. In addition, hydrogen-rich saline treatment significantly attenuated LPS-induced oxidative stress. Conclusions Hydrogen-rich saline may protect against LPS-induced EMT and pulmonary fibrosis through suppressing oxidative stress.
... Liu, et al. demonstrated that intraperitoneal injection of HS might be a widely applicable method to attenuate hepatic I/R injury in a rat model [130]. Additionally, many studies have demonstrated protective effects of H 2 in other liver diseases, such as radiation-induced damage in liver tumor patients [131], acetaminophen-induced hepatotoxicity [132], obstructive jaundice-induced liver damage [45,133], nonalcoholic steatohepatitis and hepatocarcinogenesis [134], postoperative liver failure after major hepatectomy [135], liver regeneration after partial hepatectomy [39], and acute hepatic injury in acute necrotizing pancreatitis [136] in murine models. Recent work confirmed that HS improved nonalcoholic fatty liver disease by alleviating oxidative stress and activating peroxisome proliferatoractivated receptor α (PPARα) and PPARγ expression in rat hepatocytes [137]. ...
... Ionizing radiation can lead to carcinogenesis, and in 2011, Zhao and colleagues first reported that HS injection protected BALB/c mice against radiation-induced thymic lymphoma [246]. Other studies demonstrated that drinking HW prevented progression of nonalcoholic steatohepatitis and accompanying hepatocarcinogenesis in mice by reducing hepatic oxidative stress, inflammation, and apoptosis [134], and protected against ferric nitrilotriacetate-induced nephrotoxicity and early tumor promotional events in rats [179]. ...
Article
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Since the 2007 discovery that molecular hydrogen (H2) has selective antioxidant properties, multiple studies have shown that H2 has beneficial effects in diverse animal models and human disease. This review discusses H2 biological effects and potential mechanisms of action in various diseases, including metabolic syndrome, organ injury, and cancer; describes effective H2 delivery approaches; and summarizes recent progress toward H2 applications in human medicine. We also discuss remaining questions in H2 therapy, and conclude with an appeal for a greater role for H2 in the prevention and treatment of human ailments that are currently major global health burdens. This review makes a case for supporting hydrogen medicine in human disease prevention and therapy.
... Non-alcoholic steatohepatitis (NASH) due to oxidative stress induced by various stimuli, is one of the reasons that cause hepatocarcinogenesis (94,95). In a mouse model, hydrogen-rich water administration lowered the hepatic cholesterol, peroxisome proliferator-activated receptor-α (PPARα) expression, and increased the anti-oxidative effects in the liver when compared with control and pioglitazone treated group (96). Hydrogen-rich water exhibited strong inhibitory effects to inflammatory cytokines TNF-α and IL-6, oxidative stress and apoptosis biomarker. ...
... As shown in NASH-related hepatocarcinogenesis model, in the group of hydrogen-rich water treatment, tumor incidence was lower and the tumor volumes were smaller than control and pioglitazone treated group. The above findings indicated that hydrogen-rich water had potential in liver protection and liver cancer treatment (96). ...
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Gas signaling molecules (GSMs), composed of oxygen, carbon monoxide, nitric oxide, hydrogen sulfide, etc., play critical roles in regulating signal transduction and cellular homeostasis. Interestingly, through various administrations, these molecules also exhibit potential in cancer treatment. Recently, hydrogen gas (formula: H2) emerges as another GSM which possesses multiple bioactivities, including anti-inflammation, anti-reactive oxygen species, and anti-cancer. Growing evidence has shown that hydrogen gas can either alleviate the side effects caused by conventional chemotherapeutics, or suppress the growth of cancer cells and xenograft tumor, suggesting its broad potent application in clinical therapy. In the current review, we summarize these studies and discuss the underlying mechanisms. The application of hydrogen gas in cancer treatment is still in its nascent stage, further mechanistic study and the development of portable instruments are warranted.
... Subsequent in vitro studies showed that molecular hydrogen could inhibit cancer cell proliferation [9][10][11], migration, invasion [9,11], and colony formation [11] and induce cancer cell apoptosis [9,10]. Several in vivo studies have demonstrated that molecular hydrogen could prevent carcinogenesis [12][13][14], inhibit cancer progression [9,11], relieve the side effects of chemotherapy or radiotherapy [15][16][17], and enhance the anti-tumor effects of chemotherapeutic drugs [10,18]. Although molecular hydrogen has shown potential in the field of cancer therapy, its anti-cancer properties are limited to only a few tumor types, and the underlying molecular mechanisms remain to be established. ...
... The effects of molecular hydrogen on cancer have been reported in several types of tumors including skin squamous cell carcinomas [7], lung cancer [9,10], ovarian cancer [11], thymic lymphoma [12], liver tumors [13,17], renal cell carcinoma [14], and colon cancer [16,18]. However, whether molecular hydrogen has an anti-tumor effect on GBM has remained unknown. ...
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Background Glioblastoma (GBM) is the most common type of primary malignant brain tumor. Molecular hydrogen has been considered a preventive and therapeutic medical gas in many diseases including cancer. In our study, we sought to assess the potential role of molecular hydrogen on GBM. Methods The in vivo studies were performed using a rat orthotopic glioma model and a mouse subcutaneous xenograft model. Animals inhaled hydrogen gas (67%) 1 h two times per day. MR imaging studies were performed to determine the tumor volume. Immunohistochemistry (IHC), immunofluorescence staining, and flow cytometry analysis were conducted to determine the expression of surface markers. Sphere formation assay was performed to assess the cancer stem cell self-renewal capacity. Assays for cell migration, invasion, and colony formation were conducted. Results The in vivo study showed that hydrogen inhalation could effectively suppress GBM tumor growth and prolong the survival of mice with GBM. IHC and immunofluorescence staining demonstrated that hydrogen treatment markedly downregulated the expression of markers involved in stemness (CD133, Nestin), proliferation (ki67), and angiogenesis (CD34) and also upregulated GFAP expression, a marker of differentiation. Similar results were obtained in the in vitro studies. The sphere-forming ability of glioma cells was also suppressed by hydrogen treatment. Moreover, hydrogen treatment also suppressed the migration, invasion, and colony-forming ability of glioma cells. Conclusions Together, these results indicated that molecular hydrogen may serve as a potential anti-tumor agent in the treatment of GBM.
... Oxidative stress, which results from an imbalance between free radical production and scavenging, induces the formation of autophagy [11]. Oxidative stress also accelerates lipid accumulation by disrupting mitochondrial functions and reducing oxidation of fatty acids [12][13][14]. The ER is the intracellular important organelle for the synthesis and folding of proteins. ...
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High-carbohydrate diets (HCD) can induce the occurrence of nonalcoholic fatty liver disease (NAFLD), characterized by dramatic accumulation of hepatic lipid droplets (LDs). However, the potential molecular mechanisms are still largely unknown. In this study, we investigated the role of autophagy in the process of HCD-induced changes of hepatic lipid metabolism, and to examine the process of underlying mechanisms during these molecular contexts. We found that HCD significantly increased hepatic lipid accumulation and activated autophagy. Using primary hepatocytes, we found that HG increased lipid accumulation and stimulated the release of NEFA by autophagy-mediated lipophagy, and that lipophagy significantly alleviated high glucose (HG)-induced lipid accumulation. Oxidative and endoplasmic reticulum (ER) stress pathways played crucial regulatory roles in HG-induced lipophagy activation and HG-induced changes of lipid metabolism. Further investigation found that HG-activated lipophagy and HG-induced changes of lipid metabolism were via enhancing carbohydrate response element-binding protein (ChREBP) DNA binding capacity at PPARγ promoter region, which in turn induced transcriptional activation of the key genes related to lipogenesis and autophagy. The present study, for the first time, revealed the novel mechanism for lipophagy mediating HCD-induced changes of lipid metabolism by oxidative stress and ER stress, and ChREBP/PPARγ pathways. Our study provided innovative evidence for the direct relationship between carbohydrate and lipid metabolism via ChREBP/PPARγ pathway.
... Oxidative stress is considered to be a strong contributor to the progression from fatty liver to nonalcoholic steatohepatitis (NASH), and even hepatocarcinogenesis. It was reported that hydrogen water was effective in the treatment of NASH in mice, and may prevent the progression of hepatocarcinogenesis [20]. ...
... 20 In terms of metabolic diseases, that is, NAFLD, molecular hydrogen was proved to be effective in preventing liver fat accumulation in a HepG2 cell model 21 and animal models. [22][23][24] A randomized controlled pilot study was reported by Korovljev et al. that hydrogen-rich water improved mild-to-moderate NAFLD. 25 Though the number of cases in this study was limited, a prospect of molecular hydrogen as an adjuvant treatment is promising. ...
Article
Non‐alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide with increasing incidence consistent with obesity, type 2 diabetes and cardiovascular diseases. No approved medication was currently available for NAFLD treatment. Molecular hydrogen (H2), an anti‐oxidative, anti‐inflammatory biomedical agent is proved to exhibit therapeutic and preventive effect in various diseases. The purpose of this study was to investigate the effect of hydrogen/oxygen inhalation on NAFLD subjects and explore the mechanism from the perspective of hepatocyte autophagy. We conducted a randomized, placebo‐controlled clinical trial of 13‐week hydrogen/oxygen inhalation (China Clinical Trial Registry [#ChiCTR‐IIR‐16009114]) including 43 subjects. We found that inhalation of hydrogen/oxygen improved serum lipid and liver enzymes. Significantly improved liver fat content detected by ultrasound and CT scans after hydrogen/oxygen inhalation was observed in moderate–severe cases. We also performed an animal experiment based on methionine and choline‐deficient (MCD) diet‐induced mice model to investigate effect of hydrogen on mouse NASH. Hydrogen/oxygen inhalation improved systemic inflammation and liver histology. Promoted autophagy was observed in mice inhaled hydrogen/oxygen and treatment with chloroquine blocked the beneficial effect of hydrogen. Moreover, molecular hydrogen inhibited lipid accumulation in AML‐12 cells. Autophagy induced by palmitic acid (PA) incubation was further promoted by 20% hydrogen incubation. Addition of 3‐methyladenine (3‐MA) partially blocked the inhibitory effect of hydrogen on intracellular lipid accumulation. Collectively, hydrogen/oxygen inhalation alleviated NAFLD in moderate–severe patients. This protective effect of hydrogen was possibly by activating hepatic autophagy.
... Although preliminary, our trial perhaps nominates HRW as Please cite this article in press as: Korovljev Over the past decade, several animal trials have demonstrated beneficial effects of HRW on liver health and viability. HRW prevented progression of nonalcoholic steatohepatitis and accompanying hepatocarcinogenesis in mice [15]. Koyama and co-workers [9] found that oral intake of hydrogen water significantly suppressed liver fibrogenesis in mice with experimentally induced liver fibrosis. ...
Article
Background and aims: While non-alcoholic fatty liver disease (NAFLD) is rapidly becoming the most common liver disease worldwide, its treatment remains elusive. Since metabolic impairment plays a major role in NAFLD pathogenesis, any pharmaceuticals, such as molecular hydrogen (H2), that advance lipid and glucose metabolism could be appropriate to tackle this complex condition. The aim of this study was to analyze the effects of 28-day hydrogen-rich water intake on liver fat deposition, body composition and lab chemistry profiles in overweight patients suffering from mild-to-moderate NAFLD. Methods: Twelve overweight outpatients with NAFLD (age 56.2 ± 10.0 years; body mass index 37.7 ± 5.3 kg/m2; 7 women and 5 men) voluntarily participated in this double-blind, placebo-controlled, crossover trial. All patients were allocated to receive either 1 L per day of hydrogen-rich water (HRW) or placebo water for 28 days. The study was registered at ClinicalTrials.gov (ID NCT03625362). Results: Dual-echo MRI revealed that HRW significantly reduced liver fat accumulation in individual liver regions-of-interest at 28-day follow-up, as compared to placebo administration (P < 0.05). Baseline liver fat content was reduced from 284.0 ± 118.1 mM to 256.5 ± 108.3 mM after hydrogen treatment at 28-day follow-up (percent change 2.9%; 95% CI from 0.5 to 5.5). Serum aspartate transaminase levels dropped by 10.0% (95% CI; from -23.2 to 3.4) after hydrogen treatment at 28-day follow-up. No significant differences were observed between treatment groups in either weight or body composition among participants. Conclusions: Although preliminary, the results of this trial perhaps nominate HRW as an adjuvant treatment for mild-to-moderate NAFLD. These observations provide a rationale for further clinical trials to establish safety and efficacy of molecular hydrogen in NAFLD.
... Saitoh et al. reported that molecular hydrogen caused growth inhibition of human tongue carcinoma cells HSC-4 and human fibrosarcoma cells HT-1080 but did not compromise growth of normal human tongue epithelial-like cells DOK (11). In another report, Kawai et al. established a streptozotocin-induced nonalcoholic steatohepatitis (NASH)-related hepatocarcinogenic mouse model and found that drinking hydrogen-rich water for 8 weeks could improve NASH-related hepatocarcinogenesis, as evidenced by the reduction of both tumor number and tumor size; however, this study did not provide evidence for the inhibitory effect on tumor growth (12). ...
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Background: To investigate the potential effects of molecular hydrogen on ovarian cancer. Methods: The in vivo study was performed using Hs38.T xenografted BALB/c nude mice. The mean tumor volume was monitored during 6 weeks of hydrogen inhalation. Immunohistochemistry (IHC) staining was performed to determine the Ki67 and CD34 expression. The in vitro effects of molecular hydrogen on proliferation of Hs38.T and PA-1 were determined by Cell Counting Kit (CCK)-8 assay. Matrigel invasion assay was performed to determine the cell invasion ability. Wounding assay was employed to examine the motile nature of ovarian cancer cells. Colony formation assay was performed to investigate the effect of molecular hydrogen in tumorigenicity. To further investigate the effects of molecular hydrogen on cancer stem cells (CSCs) properties, we performed sphere-formation assays. Results: The in vivo study demonstrated that 6 weeks of hydrogen inhalation significantly inhibited tumor growth, as evidenced by decreased mean tumor volume (32.30%) and Ki67 expression (30.00%). Hydrogen treatment decreased the expression of CD34 (74.00%) demonstrating its anti-angiogenesis effects. The in vitro study showed that hydrogen treatment significantly inhibits cancer cell proliferation, invasion, migration and colony formation both in Hs38.T and PA-1 cells. An important finding in this study was that molecular hydrogen could also markedly inhibit sphere-forming ability of both PA-1 and Hs38.T cells. Conclusions: Molecular hydrogen may exert anti-tumor role in ovarian cancer through suppressing the proliferation of CSCs-like cells and angiogenesis.
... Similar therapeutic effects of hydrogen were also reported in common senile diseases concomitant with decubitus, such as cerebral or myocardial infarctions, COPD, diabetes, hyperlipaemia, malignant tumours. 11,36,[49][50][51][52][53][54] Furthermore, H 2 had no cytotoxicity in vivo in human body even at a high concentration. 17 Therefore, hydrogen gas has a great potential for preventing and/or treating pressure ulcer. ...
Article
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Pressure ulcer formation depends on various factors among which repetitive ischaemia/reperfusion(I/R) injury plays a vital role. Molecular hydrogen (H2) was reported to have protective effects on I/R injuries of various internal organs. In this study, we investigated the effects of H2 inhalation on pressure ulcer and the underlying mechanisms. H2 inhalation significantly reduced wound area, 8‐oxo‐dG level (oxidative DNA damage) and cell apoptosis rates in skin lesions. H2 remarkably decreased ROS accumulation and enhanced antioxidant enzymes activities by up‐regulating expression of Nrf2 and its downstream components in wound tissue and/or H2O2‐treated endothelia. Meanwhile, H2 inhibited the overexpression of MCP‐1, E‐selectin, P‐selectin and ICAM‐1 in oxidant‐induced endothelia and reduced inflammatory cells infiltration and proinflammatory cytokines (TNF‐α, IL‐1, IL‐6 and IL‐8) production in the wound. Furthermore, H2 promoted the expression of pro‐healing factors (IL‐22, TGF‐β, VEGF and IGF1) and inhibited the production of MMP9 in wound tissue in parallel with acceleration of cutaneous collagen synthesis. Taken together, these data indicated that H2 inhalation suppressed the formation of pressure ulcer in a mouse model. Molecular hydrogen has potentials as a novel and alternative therapy for severe pressure ulcer. The therapeutic effects of molecular hydrogen might be related to its antioxidant, anti‐inflammatory, pro‐healing actions.
... Kawai ve ark. 2012 [22], hidrojenle zenginleştirilmiş su (HRW) ve pioglitazon (PGZ) ilacının farelerde yağlı karaciğer iltihaplanma hastalığı olan Alkolsüz steatohepatit (NASH) ilerlemesi üzerindeki etkilerini incelemişlerdir. Oksidatif stres biyobelirteçleri, interlökin-6 ve tümör nekroz faktörü-α gibi inflamatuar faktörler ve apoptoz HRW ve PGZ gruplarında azalma göstermiştir. ...
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ABSTRACT: Molecular hydrogen, which has the H2 formula, is a colorless, odorless, tasteless, non-metallic and non-toxic gas. Molecular hydrogen has a high diffusion rate and spreads rapidly in biological tissues and cells. Molecular hydrogen does not change the body's redox reactions and does not cause any side effects. H2 is a selective antioxidant due to its ability to neutralize strong oxidants such as hydroxyl radicals in cells. This case increases the potential use of molecular hydrogen for preventative and therapeutic applications. In addition, by regulating various gene expressions, H2 exhibits anti-inflammatory and anti-apoptotic properties. At the same time, unlike the drugs used in the treatment of diseases, H2 penetrates the cell membrane easily. Inhaling hydrogen gas, drinking hydrogen water, injection of hydrogen-enriched saline, bathing with a hydrogen-rich water, and hydrogen-rich eye drops are the common methods of molecular hydrogen applications in the health field. Numerous studies on the biological and medical benefits of hydrogen have been carried out up to date, and research is still ongoing. As a result; due to its beneficial effects on the body and the absence of side effects, molecular hydrogen can have promising potential applications against many diseases. ÖZET: H2 formülüne sahip olan moleküler hidrojen, renksiz, kokusuz, tatsız, metalik olmayan ve toksik olmayan bir gazdır. Moleküler hidrojen (H2), yüksek difüzyon hızına sahiptir ve biyolojik doku ve hücrelerde hızla yayılır. Moleküler hidrojen, vücudun redoks reaksiyonlarını değiştirmemekte ve hiçbir yan etki göstermemektedir. Hücrelerdeki hidroksil radikal gibi güçlü oksidanları inhibe etme özelliğinden dolayı seçici bir antioksidandır. Bu durum, moleküler hidrojenin önleyici ve tedavi edici uygulamalar için potansiyelini arttırmaktadır. Ek olarak, çeşitli gen ifadelerini düzenleyerek, antiinflamatuar ve antiapoptik özellik sergilemektedir. Aynı zamanda hastalıkların tedavisinde kullanılan ilaçların aksine moleküler hidrojen, hücre zarına kolaylıkla nüfuz etmektedir. Hidrojen gazı solumak, hidrojenle zenginleştirilmiş su içmek, hidrojenle zenginleştirilmiş salin enjeksiyonu, hidrojenli su banyosu yapmak ve hidrojenli göz damlaları kullanmak sağlık alanında moleküler hidrojen uygulamasının yaygın yöntemleridir. Bugüne kadar hidrojenin biyolojik ve tıbbi faydaları üzerine çok sayıda çalışma yapılmıştır ve araştırmalar halen devam etmektedir. Sonuç olarak; vücuttaki olumlu etkileri, yan etkisinin bulunmaması sebebiyle, moleküler hidrojen birçok hastalığa karşı umut verici bir potansiyele sahiptir.
... The pharmacological effects of pioglitazone on NASH treatment have been reported in some animal models, such as the methionine-choline deficient (MCD) diet-induced model and STAM mice. In those models, pioglitazone treatment improved hepatic NASH-like lesions, but did not result in changes in body weight [13,15]. Animal models demonstrating obesity and insulin resistance are essential for the pharmacological assessment of anti-NASH drugs. ...
Article
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Nonalcoholic steatohepatitis (NASH) is a progressive liver disease, and some patients develop hepatic cirrhosis/carcinoma. Animal models play key roles in the development of new therapies for NASH. In this study, the pharmacological effects of metformin and pioglitazone were investigated in female Spontaneously Diabetic Torii (SDT) fatty rats to verify the utility of this model. The anti-diabetic drugs were administered to SDT fatty rats fed a cholesterol-enriched diet from 4 to 25 weeks, and changes in food intake, body weight, and blood chemistry parameters were evaluated every 4 weeks. The hepatic lipid content, mRNA expression in relation to lipid synthesis, inflammation, and fibrosis, and histopathological analyses were performed at 25 weeks. Pioglitazone improved hyperglycemia, hyperlipidemia, and abnormalities in hepatic parameters. The insulin levels were lower than those in the control rats before 16 weeks. Plasma glucose levels in the metformin-treated rats were lower than those in the control rats, and plasma triglyceride and alanine aminotransferase levels temporarily decreased. The lipid content and some mRNA expression in relation to fibrosis in the liver decreased with pioglitazone treatment, and the mRNA expression of microsomal triglyceride transfer protein increased. Hepatic fibrosis observed in the SDT fatty rats improved with pioglitazone treatment; however, the effect with metformin treatment was partial. These results in both drugs are in line with results in the human study, suggesting that the SDT fatty rat is useful for developing new anti-NASH drugs that show potential to regulate glucose/lipid metabolism.
... This analysis confirmed previous studies using the whole-body deletion of Akt2 allele of Pparg sensitized mice to chemically induced liver tumorigenesis (20). Similarly, in the STAM mouse model of liver cancer, combining diabetes and high-fat diet, pharmacological activation of PPARγ significantly ameliorated liver damage and reduced tumor numbers without affecting tumor size or hepatocyte proliferation in nontumoral liver tissue (21). One possible explanation for these contradictory findings is the distinction between steatosis induced by genetic insults and that induced by environmental factors. ...
Article
Worldwide epidemics of metabolic diseases, including liver steatosis, are associated with an increased frequency of malignancies, showing the highest positive correlation for liver cancer. The heterogeneity of liver cancer represents a clinical challenge. In liver, the transcription factor PPARγ promotes metabolic adaptations of lipogenesis and aerobic glycolysis under the control of Akt2 activity, but the role of PPARγ in liver tumorigenesis is unknown. Here we have combined preclinical mouse models of liver cancer and genetic studies of a human liver biopsy atlas with the aim of identifying putative therapeutic targets in the context of liver steatosis and cancer. We have revealed a protumoral interaction of Akt2 signaling with hepatocyte nuclear factor 1α (HNF1α) and PPARγ, transcription factors that are master regulators of hepatocyte and adipocyte differentiation, respectively. Akt2 phosphorylates and inhibits HNF1α, thus relieving the suppression of hepatic PPARγ expression and promoting tumorigenesis. Finally, we observed that pharmacological inhibition of PPARγ is therapeutically effective in a preclinical murine model of steatosis-associated liver cancer. Taken together, our studies in humans and mice reveal that Akt2 controls hepatic tumorigenesis through crosstalk between HNF1α and PPARγ.
... To further confirm this Nur77 inhibitory effect on HCC, we also utilized a streptozotocin (STZ) and high-fat diet (HFD)-induced hepatocarcinogenic mouse model, which mimics the nonalcoholic steatohepatitis (NASH)-hepatocarcinogenic process and closely follows human HCC progression 25 . In this model, Nur77 knockout promoted steatosis ( Supplementary Fig. 1e), in accordance with a previous report 14,15 . ...
Article
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Gluconeogenesis, an essential metabolic process for hepatocytes, is downregulated in hepatocellular carcinoma (HCC). Here we show that the nuclear receptor Nur77 is a tumour suppressor for HCC that regulates gluconeogenesis. Low Nur77 expression in clinical HCC samples correlates with poor prognosis, and a Nur77 deficiency in mice promotes HCC development. Nur77 interacts with phosphoenolpyruvate carboxykinase (PEPCK1), the rate-limiting enzyme in gluconeogenesis, to increase gluconeogenesis and suppress glycolysis, resulting in ATP depletion and cell growth arrest. However, PEPCK1 becomes labile after sumoylation and is degraded via ubiquitination, which is augmented by the p300 acetylation of ubiquitin-conjugating enzyme 9 (Ubc9). Although Nur77 attenuates sumoylation and stabilizes PEPCK1 via impairing p300 activity and preventing the Ubc9-PEPCK1 interaction, Nur77 is silenced in HCC samples due to Snail-mediated DNA methylation of the Nur77 promoter. Our study reveals a unique mechanism to suppress HCC by switching from glycolysis to gluconeogenesis through Nur77 antagonism of PEPCK1 degradation.
... Pregnant female C57BL/6J mice (180-250 days old) were purchased from the Laboratory Animal Centre of Guangzhou University of Chinese Medicine (Guangzhou, China) and used to establish a model of STAM in which mice are treated to induce diabetes and fed a high-fat diet [47,48]. In brief, pups birthed within 5 days were injected with 200 µg of streptozotocin (Sigma-Aldrich) and fed with a diet with 60% fat content (D12492; Research Diets). ...
Article
Non-alcoholic fatty liver disease (NAFLD) is a relevant risk factor for developing hepatocellular carcinoma (HCC). Steatohepatitic HCC (SH-HCC), characterized by HCC with steatosis, is influenced by lipid metabolism disorders. A hypoxic microenvironment is common in HCC and affects lipid metabolism. However, whether hypoxia-induced HIF-2α upregulation exacerbates lipid accumulation to contribute to SH-HCC progression remains unclear. In this study, we demonstrated that HIF-2α was elevated in tissues from NAFLD-HCC patients and was associated with survival. Under hypoxic conditions, upregulated HIF-2α was accompanied by lipid accumulation and PI3K-AKT-mTOR pathway activation. HIF-2α knockdown (KD) in steatotic HCC ameliorated triglyceride accumulation and steatosis. HIF-2α-KD steatotic HCC showed minimal lipid synthesis in a hypoxic environment, which contributes to a reduction in malignant behaviours. However, treatment with MHY1485 restored these behaviours. STAM mice, a mouse model that develops NAFLD-HCC, exhibit more rapid tumour progression upon exposure to hypoxia. STAM mice treated with INK-128 presented abrogated mTOR expression and tumour progression under hypoxic conditions with lower triglycerides and steatosis. In conclusion, in a hypoxic microenvironment, HIF-2α upregulation promotes steatotic HCC progression by activating lipid synthesis via the PI3K-AKT-mTOR pathway. Therefore, HIF-2α can be a biomarker and target in developing specific therapeutic measures for NAFLD-HCC patients.
... found that intraperitoneal application of hydrogenenriched fluid could improve the antioxidant capacity of the liver and reduce the inflammatory response, which is of great clinical significance (26). Current studies show that long-term consumption of hydrogen-enriched water can improve the symptoms of non-alcoholic steatohepatitis by improving both liver function and liver morphology (in terms of preventing fibrosis) (27). In this same study, the authors demonstrate not only the long-term effects of hydrogen-enriched water to improve liver function, but also to reduce the risk of developing malignancies. ...
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Background: Liver resection is a surgical procedure associated with a high risk of hepatic failure that can be fatal. One of the key mechanisms involves ischemia-reperfusion damage. Building on the wellknown positive effects of hydrogen at mitigating this damage, the goal of this work was to demonstrate the antioxidant, anti-inflammatory, and anti-apoptotic effects of inhaled hydrogen in domestic pigs during major liver resection. Methods: The study used a total of 12 domestic pigs, 6 animals underwent resection with inhaled hydrogen during general anesthesia, and 6 animals underwent the same procedure using conventional, unsupplemented, general anesthesia. Intraoperative preparation of the left branch of the hepatic portal vein and the left hepatic artery was performed, and a tourniquet was applied. Warm ischemia was induced for 120 minutes and then followed by liver reperfusion for another 120 minutes. Samples from the ischemic and non-ischemic halves of the liver were then removed for histological and biochemical examinations. Results: An evaluation of histological changes was based on a numerical expression of damage based on the Suzuki score. Liver samples in the group with inhaled hydrogen showed a statistically significant reduction in histological changes compared to the control group. Biochemical test scores showed no statistically significant difference in hepatic transaminases, alkaline phosphatase (ALP), lactate dehydrogenase (LD), and lactate. However, a surprising result was a statistically significant difference in gamma-glutamyl-transferase (GMT). Marker levels of oxidative damage varied noticeably in plasma samples. Conclusions: In this experimental study, we showed that inhaled hydrogen during major liver resection unquestionably reduced the level of oxidative stress associated with ischemia-reperfusion damage. We confirmed this phenomenon both histologically and by direct measurement of oxidative stress in the organism.
... 92 Hydrogen can also reduce 8-hydroxy-deoxyguanine, decreasing DNA oxidation. 93,111 Peroxynitrite is a strong biological oxidant which could induce neuronal death. The removal of peroxynitrite is related to hydrogen, so molecular hydrogen could directly reduce peroxynitrite to protect nerve cells. ...
Article
Medical gas is a large class of bioactive gases used in clinical medicine and basic scientific research. At present, the role of medical gas in neuroprotection has received growing attention. Stroke is a leading cause of death and disability in adults worldwide, but current treatment is still very limited. The common pathological changes of these two types of stroke may include excitotoxicity, free radical release, inflammation, cell death, mitochondrial disorder, and blood-brain barrier disruption. In this review, we will discuss the pathological mechanisms of stroke and the role of two medical gases (hydrogen and hydrogen sulfide) in stroke, which may potentially provide a new insight into the treatment of stroke.
... The oxidative stress status has been analyzed in NAFLD and NAFLD-related HCC. Limited antioxidant defenses contribute to the processes of both NASH and hepatocarcinogenesis [92,93]. In liver mitochondria from NASH patients and mouse models, ultrastructural alterations, impairment of ATP synthesis and increased production of ROS have been reported [94,95]. ...
Article
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Chronic viral hepatitis B and C and non-alcoholic fatty liver disease (NAFLD) have been widely acknowledged to be the leading causes of liver cirrhosis and hepatocellular carcinoma. As anti-viral treatment progresses, the impact of NAFLD is increasing. NAFLD can coexist with chronic viral hepatitis and exacerbate its progression. Oxidative stress has been recognized as a chronic liver disease progression-related and cancer-initiating stress response. However, there are still many unresolved issues concerning oxidative stress, such as the correlation between the natural history of the disease and promising treatment protocols. Recent findings indicate that oxidative stress is also an anti-cancer response that is necessary to kill cancer cells. Oxidative stress might therefore be a cancer-initiating response that should be down regulated in the pre-cancerous stage in patients with risk factors for cancer, while it is an anti-cancer cell response that should not be down regulated in the post-cancerous stage, especially in patients using anti-cancer agents. Antioxidant nutrients should be administered carefully according to the patients’ disease status. In this review, we will highlight these paradoxical effects of oxidative stress in chronic liver diseases, pre- and post-carcinogenesis.
... In a previous study, drinking H 2 -rich water was shown to slightly decrease the levels of hepatic cholesterol and triglycerides without any statistical significance in a methionine-choline-deficient diet-induced nonalcoholic steatohepatitis mouse model (53). The present study revealed the dose-dependent effect of H 2 inhalation on the alleviation of liver lipid accumulation and 66% H 2 inhalation was found to significantly decrease hepatic cholesterol and triglycerides. ...
Article
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Hydrogen exhibits therapeutic and preventive effects against various diseases. The present study investigated the potential protective effect and dose‑dependent manner of hydrogen inhalation on high fat and fructose diet (HFFD)‑induced nonalcoholic fatty liver disease (NAFLD) in Sprague‑Dawley rats. Rats were randomly divided into four groups: i) Control group, regular diet/air inhalation; ii) model group, HFFD/air inhalation; iii) low hydrogen group, HFFD/4% hydrogen inhalation; and iv) high hydrogen group, HFFD/67% hydrogen inhalation. After a 10‑week experiment, hydrogen inhalation ameliorated weight gain, abdominal fat index, liver index and body mass index of rats fed with HFFD and lowered the total area under the curve in an oral glucose tolerance test. Hydrogen inhalation also ameliorated the increase in liver lipid content and alanine transaminase and aspartate transaminase activities. Liver histopathologic changes evaluated with hematoxylin and eosin as well as Oil Red O staining revealed lower lipid deposition in hydrogen inhalation groups, consistent with the decrease in the expression of the lipid synthesis gene SREBP‑1c. The majority of the indicators were affected following treatment with hydrogen in a dose‑dependent manner. In conclusion, hydrogen inhalation may play a protective role by influencing the general state, lipid metabolism parameters, liver histology and liver function indicators in the rat model of metabolic syndrome with NAFLD.
... Kawai ve ark. 2012 [22], hidrojenle zenginleştirilmiş su (HRW) ve pioglitazon (PGZ) ilacının farelerde yağlı karaciğer iltihaplanma hastalığı olan Alkolsüz steatohepatit (NASH) ilerlemesi üzerindeki etkilerini incelemişlerdir. Oksidatif stres biyobelirteçleri, interlökin-6 ve tümör nekroz faktörü-α gibi inflamatuar faktörler ve apoptoz HRW ve PGZ gruplarında azalma göstermiştir. ...
... Many models of severe inflammation such as the MCD diet model, cholesterol and cholate model, and PTEN null mice do not develop insulin resistance. Nonetheless, they are considered useful for evaluating NASH histopathology and the effects of various substances on NASH [50][51][52]. Therefore, the present model is thought to be a robust model for analyzing the histopathology of NASH, but it may not be appropriate for analyzing the pathophysiology of the disease. ...
Article
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Several recent experimental studies have investigated the effects of caffeine and chlorogenic acid (CGA), representative ingredients of coffee, on nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). However, the results are conflicting, and their effects are yet to be clarified. In the present study, we examined the effects of caffeine and CGA on choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD)-fed mice, relatively new model mice of NASH. Seven-week-old male C57BL/6J mice were divided into the following groups: Control diet (control), CDAHFD (CDAHFD), CDAHFD supplemented with 0.05% (w/w) caffeine (caffeine), and CDAHFD supplemented with 0.1% (w/w) CGA (CGA). After seven weeks, the mice were killed and serum biochemical, histopathological, and molecular analyses were performed. Serum alanine aminotransferase (ALT) levels were significantly higher in the caffeine and CGA groups than in the CDAHFD group. On image analysis, the prevalence of Oil red O-positive areas (reflecting steatosis) was significantly higher in the caffeine group than in the CDAHFD group, and that of CD45R-positive areas (reflecting lymphocytic infiltration) in the hepatic lobule was significantly higher in the caffeine and CGA groups than in the CDAHFD group. Hepatic expression of interleukin (IL)-6 mRNA was higher in the caffeine and CGA groups than in the CDAHFD group, and the difference was statistically significant for the caffeine group. In conclusion, in the present study, caffeine and CGA significantly worsened the markers of liver cell injury, inflammation, and/or steatosis in NASH lesions in mice.
... At the stage of 2009-2012, many studies about drinking H 2 -rich water (hydrogen water) and injecting H 2 -rich saline began to appear, 9,10 and there were also studies to increase the supplementation of H 2 through intestinal bacteria. 11 That was a period when scientists were discovering and using different H 2 -intake methods to testify the medical effects. ...
Article
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Gas medicine, including O 2 , NO, H 2 S, CO, CH 4 , has played important roles in prevention and treatment of diseases for a long time. Molecular hydrogen (H 2 ), the smallest diatomic molecule in nature, has become a rising star in gas medicine in the past decades. Many studies have shown that H 2 has preventive and therapeutic effects on various diseases through its selective antioxidant activity. H 2 , as a non-toxic gas for the human body and convenience to obtain, has provided a great possibility to be used widely. Currently, the main difficulties in hydrogen medicine are lack of definitive clinical evidence and the molecular basis of hydrogen effects. In this paper, the authors have conducted a comprehensive review and analysis of these issues, and also proposed the possibility of developing Hydrogen Biology and Hydrogen Medicine as new disciplines of biology and medicine.
... Many models of severe inflammation such as the MCD diet model, cholesterol and cholate model, and PTEN null mice do not develop insulin resistance. Nonetheless, they are considered useful for evaluating NASH histopathology and the effects of various substances on NASH [50][51][52]. Therefore, the present model is thought to be a robust model for analyzing the histopathology of NASH, but it may not be appropriate for analyzing the pathophysiology of the disease. ...
... In mice, H2-rich water appears to prevent the evolution of hepatocarcinogenesis induced in mice. It was suggested that these positive outcomes were partly due to a reduction in CSCs [55] Recent experimental results indicate that H2 is an antitumor agent in the treatment of glioblastoma. The invasive properties of glioblastoma are a key problem for curative treatment if a surgical resection is impracticable. ...
Article
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Understanding the structure and dynamics of the various hydrogen forms has been a subject of numerous studies. Protons (H+) and molecular hydrogen (H2) in the cell are critical in a wide variety of processes. A new cancer treatment uses H2, a biologically inactive gas. Due to its small molecular weight, H2 can rapidly penetrate cell membranes and reach subcellular components to protect nuclear DNA and mitochondria. H2 reduces oxidative stress, exerts anti-inflammatory effects, and acts as a modulator of apoptosis. Exogenous H2, administered by inhalation, drinking H2-rich water, or injecting H2-rich saline solution, is a protective therapy that can be used in multiple diseases, including cancer. In particle therapy, cyclotrons and synchrotrons are the accelerators currently used to produce protons. Proton beam radiotherapy (PBT) offers great promise for the treatment of a wide variety of cancers due to the sharp decrease in the dose of radiation at a defined point. In these conditions, H2 and different types of H2 donors may represent a novel therapeutic strategy in cancer treatment.
... It can be absorbed into the blood circulation, such that it reaches the target organ either by blood circulation or free diffusion (11). Therefore, treatments involving exogenous H 2 , including breathing H 2 gas, injection with H 2 -rich saline and drinking H 2 -rich water, may protect against excessive oxidative stress-and inflammation-related liver damage, including liver injury induced by drugs, sepsis, bile duct ligation, ischemia/reperfusion (I/R), CO 2 pneumoperitoneum and chronic intermittent hypoxia, in addition to non-alcoholic fatty liver disease (NAFLD) (12)(13)(14)(15)(16)(17). Furthermore, drinking H 2 -rich water has been indicated to protect against chronic ethanol-induced hepatotoxicity (18). ...
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... The mild reducibility of H 2 contributes to its selective reduction of hydroxyl radicals ($OH) and its low disturbance of redox balance in vivo (194,299). Clinical trials have also observed no obvious side effects or H 2 toxicity. H 2 -rich water, H 2 -rich saline, and H 2 inhalation have antioxidant activities similar to those of molecular H 2 (262). ...
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... 27 The genes of oxidoreduction-related proteins, including hydroxymethylglutaryl co-enzyme-A reductase, were significantly enriched in the livers of rats after drinking HRW. 28 Hepatocyte death induced by antimycin A was significantly suppressed after culturing in hydrogen-rich medium. However, this did not suppress hepatic stellate cell activation. ...
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Hydrogen therapy is a very promising treatment against several diseases due to its mild attributes, high affinity and inherent biosafety. However, there is little elaboration about current hydrogen treatment in liver diseases. This article introduces the administration of hydrogen and mechanisms of hydrogen therapy in vivo, including modulating reactive oxygen species, apoptosis and autophagy, and inflammation, affecting mitochondria, as well as protein transporters. The major focus is clinical hydrogen use and related mechanisms in liver dysfunction or diseases, including non-alcoholic fatty liver disease, hepatitis B, liver dysfunction caused by liver tumour and colorectal tumour chemotherapy. Further, the article reveals ex vivo hydrogen application in liver protection. Finally, the article discusses the current and future challenges of hydrogen therapy in liver diseases, aiming to improve knowledge of hydrogen therapy and provide some insights into this burgeoning field.
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Purpose: To evaluate the hepatic metabolic alterations in nonalcoholic fatty liver disease (NAFLD) by using 1 H-MRS (proton magnetic resonance spectroscopy) with long echo time and to test the reproducibility of human study in an animal model. Liver biopsy is the gold standard for diagnosing NAFLD but with practical constraints. 1 H-MRS allows in vivo assessment of hepatocellular metabolism and has shown potential for biochemical differentiation in diffuse liver disease. Materials and methods: In all, 32 subjects (11 patients with nonalcoholic steatohepatitis [NASH], 15 with simple steatosis [SS], and six healthy controls) were studied. For test reproducibility, 36 C57BL/6 mice, including 10 mice with streptozotocin-induced NASH, 15 with SS, and 11 high-fat diet controls, were studied. 1 H-MRS measurements at 3T and 4.7T MRI were performed on a localized voxel of the liver using PRESS sequence. Hepatic alanine (Ala), lactate+triglyceride (Lac+TG), and TG levels were compared between NASH, SS, and control groups using analysis of variance (ANOVA) tests. Diagnostic accuracy was determined by calculating the area under the receiver operating characteristics (ROC) curve. The associations between metabolite levels and pathologic grades or NAFLD activity scores (NAS) were assessed using Pearson's correlation. Results: NASH patients had higher levels of Ala (P < 0.001), Lac+TG (P < 0.001), and TG (P < 0.05) than SS patients or controls. The AUROC curve to distinguish NASH from SS was 1.00 (95% confidence interval [CI] 1.00-1.00) for Ala and 0.782 (95% CI 0.61-0.96) for Lac+TG. Ala and Lac+TG concentrations were positively correlated with steatosis grade (Ala Pearson's r = 0.723; Lac+TG r = 0.446), lobular inflammation (Ala r = 0.513), and NAS (Ala r = 0.743; Lac+TG r = 0.474). Conclusion: 1 H-MRS is potentially useful for noninvasive diagnosis of NASH and simple steatosis by hepatic metabolite quantification. Level of evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1298-1310.
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Ethnopharmacological relevance Nonalcoholic fatty liver disease (NAFLD) is a prevalent liver disease, but currently has no specific medication in clinic. Antrodia cinnamomea (AC) is a medicinal fungus and it has been shown that AC can inhibit high fat diet (HFD)-induced lipid deposition in mouse livers, but the effective monomer in AC and mechanism against NAFLD remain unclear. It has been reported that aldehyde dehydrogenase 2 (ALDH2) activation shows protective effects on NAFLD. Our previous study demonstrates that AC and its monomer dehydroeburicoic acid (DEA) can upregulate the ALDH2 activity on alcoholic fatty liver disease mouse model, but it is not clear whether the anti-NAFLD effects of AC and DEA are mediated by ALDH2. Aim to study To elucidate the active compound in AC against NAFLD, study whether ALDH2 mediates the anti-NAFLD effects of AC and its effective monomer. Materials and methods WT mice, ALDH2−/− mice and ALDH2−/− mice re-expressed ALDH2 by lentivirus were fed with a methionine-choline deficient (MCD) diet or high fat diet (HFD) to induce NAFLD, and AC at the different doses (200 and/or 500 mg/kg body weight per day) was administrated by gavage at the same time. Primary hepatocytes derived from WT and ALDH2−/−mice were stimulated by oleic acid (OA) to induce lipid deposition, and the cells were treated with AC or DEA in the meantime. Lentivirus-mediated ALDH2-KD or ALDH2-OE were used to knock down or overexpress ALDH2 expression in HepG2 cells, respectively. Finally, the effects of DEA against NAFLD as well as its effects on upregulating liver ALDH2 and removing the harmful aldehyde 4-hydroxynonenal (4-HNE) were studied in the MCD diet-induced NAFLD mouse model. Results In WT mice fed with a MCD diet or HFD, AC administration reduced hepatic lipid accumulation, upregulated ALDH2 activity in mouse livers, decreased 4-HNE contents both in mouse livers and serum, inhibited lipogenesis, inflammation and oxidative stress and promoted fatty acid β-oxidation. These effects were abolished in ALDH2 KO mice but could be restored by re-expression of ALDH2 by lentivirus. In primary hepatocytes of WT mice, AC and DEA inhibited OA-induced lipid accumulation and triglyceride (TG) synthesis, promoting the β-oxidation of fatty acid in the meantime. However, these effects were lost in primary hepatocytes of ALDH2 KO mice. Moreover, the expression level of ALDH2 significantly affected the inhibitory effects of AC and DEA on OA-induced lipid deposition in HepG2 cells. The effects of AC and DEA on suppressing lipid deposition, inhibiting mitochondrial ROS levels, reducing TG synthesis, and promoting β-oxidation of fatty acid were all enhanced with the overexpression of ALDH2 and reduced with the knockdown of ALDH2 expression. DEA showed dose-dependent effects on inhibiting liver lipid deposition, elevating ALDH2 activity and reducing 4-HNE levels in the livers of MCD diet-induced NAFLD mice. Conclusion DEA is the effective compound in AC against NAFLD. The related anti-NAFLD mechanisms of AC and DEA were through upregulating ALDH2 expression and activity, thus enhancing the elimination of 4-HNE in the livers, and sequentially alleviating oxidative stress and inflammation, promoting fatty acid β-oxidation and decreasing lipogenesis.
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This study was aimed to investigate the potential regulatory mechanism of high-content hydrogen water (HHW) in non-alcoholic fatty liver disease (NAFLD). A high-fat diet (HFD)-induced NAFLD mice model and cellular model were prepared. The serum levels of alanine transaminase (ALT), aspartate transaminase (AST), total cholesterol (TCH) and triglycerides (TG) were measured. The expression levels of representative 5 miRNAs (miR-103, miR-488, miR-136, miR-505 and miR-148a) in liver tissues were determined by quantitative real-time PCR (qRT-PCR). The target of miR-136 was validated by RNA immunoprecipitation (RIP) and pull-down assay. MiR-136, MEG3 and nuclear factor erythroid 2-related factor 2 (Nrf2) expression levels following cell treatment were detected in hepatocytes using qRT-PCR and western blotting. Moreover, cell viability and TG content were conducted. MiR-136 was downregulated, MEG3 as well as Nrf2 was upregulated and serum lipid level was reduced in NAFLD mice model after HHW treatment which exerted the same effect in cellular model. RIP and RNA pull down assay confirmed that MEG2 was a downstream target of miR-136. What's more, HHW ameliorated lipid accumulation by regulating miR-136/MEG3/Nrf2 axis in vitro and in vivo. Hence, HHW alleviated NAFLD by downregulation of miR-136 through mediating Nrf2 via targeting MEG3.
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Background It has been suggested that dysregulation of long non-coding RNAs (lncRNAs) could be associated with the incidence and development of metabolic disorders.Aim Accordingly, this narrative review described the molecular mechanisms of lncRNAs in the development of metabolic diseases including insulin resistance, diabetes, obesity, non-alcoholic fatty liver disease (NAFLD), cirrhosis, and coronary artery diseases (CAD). Furthermore, we investigated the up-to-date findings on the association of deregulated lncRNAs in the metabolic disorders, and potential use of lncRNAs as biomarkers and therapeutic targets.Conclusion LncRNAs/miRNA/regulatory proteins axis plays a crucial role in progression of metabolic disorders and may be used in development of therapeutic and diagnostic approaches.
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Sodium glucose cotransporter 2 (SGLT2) inhibitors, an antidiabetic drug, promotes urinary excretion of glucose by blocking its reabsorption in the renal proximal tubules. It is unclear whether SGLT2 inhibition could attenuate nonalcoholic steatohepatitis (NASH) and NASH-associated hepatocellular carcinoma. We examined the preventive effects of an SGLT2 inhibitor canagliflozin (CANA) in Western diet (WD)-fed melanocortin 4 receptor-deficient (MC4R-KO) mice, a mouse model of human NASH. An eight-week CANA treatment attenuated hepatic steatosis in WD-fed MC4R-KO mice, with increased epididymal fat mass without inflammatory changes. CANA treatment for 20 weeks inhibited the development of hepatic fibrosis in WD-fed MC4R-KO mice. After one year of CANA treatment, the number of liver tumors was significantly reduced in WD-fed MC4R-KO mice. In adipose tissue, CANA suppressed the ratio of oxidative to reduced forms of glutathiones (GSSG/GSH) in WD-fed MC4R-KO mice. Treatment with GSH significantly attenuated the H2O2-induced upregulation of genes related to NADPH oxidase in 3T3-L1 adipocytes, and that of Il6, Tgfb, and Pdgfb in RAW264.7 cells. This study provides evidence that SGLT2 inhibitors represent the unique class of drugs that can attenuate or delay the onset of NASH and eventually hepatocellular carcinoma, at least partly, through "healthy adipose expansion".
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Nonalcoholic steatohepatitis (NASH) could progress to hepatic fibrosis when absence of effective control. The purpose of our experiment was to investigate the protective effect of drinking water with high concentration of hydrogen in our study named hydrogen rich water (HRW) on mice with non-alcoholic fatty liver disease to elucidate the mechanism underlying the molecular hydrogen therapeutic action. The choline-supplemented, L-amino acid-defined (CSAA) or choline-deficient, L-amino acid-defined (CDAA) diet for 20 weeks were used to induce NASH and fibrosis in the mice model and simultaneously treated with HRW for different periods of time. Primary hepatocytes were stimulated by palmitate in order to mimic a liver lipid metabolism during fatty liver formation. Mice in the CSAA + HRW group had lower serum levels of ALT and AST and milder histological damage. The inflammatory cytokines were expressed at lower levels in the HRW group than in the CSAA group. Importantly, HRW reversed hepatocyte apoptosis as well as hepatic inflammation and fibrosis in pre-existing hepatic fibrosis specimens. Molecular hydrogen inhibits the lipopolysaccharide-induced production of inflammation cytokines through an HO-1/IL-10-independent pathway. Furthermore, HRW improved hepatic steatosis in the CSAA + HRW group. Sirt1 induction by molecular hydrogen via the HO-1/AMPK/PPARα/PPARγ pathway suppresses palmitate-mediated abnormal fat metabolism. Orally administered HRW suppressed steatosis induced by CSAA and attenuated fibrosis induced by CDAA, possibly by reducing oxidative stress and the inflammation response.
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Water‐splitting has been extensively studied especially for energy applications. It is often not paid with enough attention for biomedical applications. In fact, several innovative breakthroughs have been achieved in the past few years by employing water‐splitting for treating cancer and other diseases. Interestingly, among these important works, only two reports have mentioned the term “water‐splitting.” For this reason, the importance of water‐splitting for biomedical applications is significantly underestimated. This progress work is written with the aims to explain and summarize how the principle of water‐splitting is employed to achieve therapeutic results not offered by conventional approaches. It is expected that this progress report will not only explain the importance of water‐splitting to scientists in the biomedical fields, it should also draw attention from scientists working on energy applications of water‐splitting. A new therapeutic concept of water‐splitting is summarized by collecting the recent progress in this field. Upon activation of energy stimuli, water‐splitting enables local in situ generation of species, such as H2, O2, and •OH that perform therapeutic effects. Water‐splitting entirely runs in a sustainable way and fully utilizes the ambient surroundings to realize the “water economy.”
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Molecular hydrogen (H2 ) was long regarded as non-functional in mammalian cells. We overturned the concept by demonstrating that H2 exhibits antioxidant effects and protects cells against oxidative stress. Subsequently, it has been revealed that H2 has multiple functions in addition to antioxidant effects, including ant-inflammatory, anti-allergic functions, and as a cell death and autophagy regulation. Additionally, H2 stimulates energy metabolism. Because H2 does not readily react with most biomolecules without a catalyst, it is essential to identify the primary targets with which H2 reacts or interacts directly. As a first event, H2 may react directly with strong oxidants such as hydroxyl radicals (•OH) in vivo. This review addresses the key issues related to this in vivo reaction. •OH may have a physiological role because it triggers a free radical chain reaction and may be involved in the regulation of Ca2+ - or mitochondrial ATP-dependent K+ - channeling. In the subsequent pathway, H2 suppressed a free radical chain reaction, leading to decreases in lipid peroxide and its end products. Derived from the peroxides, 4-hydroxy-2-nonenal functions as a mediator that up-regulates multiple functional PGC-1α. As the other direct target in vitro and in vivo, H2 intervenes in the free radical chain reaction to modify oxidized phospholipids, which may act as an antagonist of Ca2+ -channels. The resulting suppression of Ca2+ - signaling inactivates multiple functional NFAT and CREB transcription factors, which may explain H2 multifunctionality. This review also addresses the involvement of NFAT in the beneficial role of H2 in COVID-19, Alzheimer’s disease and advanced cancer. We discuss some unsolved issues of H2 action on lipopolysaccharide signaling, MAPK and NF-κB pathways and the Nrf2 paradox. Finally, as a novel idea for the direct targeting of H2 , this review introduces the possibility that H2 causes structural changes in proteins via hydrate water changes.
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Obesity, a major health concern, results from an imbalance between energy intake and expenditure. Leptin-deficient ob/ob mice are paradigmatic of obesity, resulting from excess energy intake and storage. Mice lacking acyl-CoA oxidase 1 (Acox1), the first enzyme of the peroxisomal fatty acid β-oxidation system, are characterized by increased energy expenditure and a lean body phenotype caused by sustained activation of peroxisome proliferator-activated receptor α (PPARα) by endogenous ligands in liver that remain unmetabolized in the absence of Acox1. We generated ob/ob mice deficient in Acox1 (Acox1(-/-)) to determine how the activation of PPARα by endogenous ligands might affect the obesity of ob/ob mice. In contrast to Acox1(-/-) (14.3±1.2 g at 6 mo) and the Acox1-deficient (ob/ob) double-mutant mice (23.8±4.6 g at 6 mo), the ob/ob mice are severely obese (54.3±3.2 g at 6 mo) and had significantly more (P<0.01) epididymal fat content. The resistance of Acox1(-/-)/ob/ob mice to obesity is due to increased PPARα-mediated up-regulation of genes involved in fatty acid oxidation in liver. Activation of PPARα in Acox1-deficient ob/ob mice also reduces serum glucose and insulin (P<0.05) and improves glucose tolerance and insulin sensitivity. Further, PPARα activation reduces hepatic steatosis and increases hepatocellular regenerative response in Acox1(-/-)/ob/ob mice at a more accelerated pace than in mice lacking only Acox1. However, Acox1(-/-)/ob/ob mice manifest hepatic endoplasmic reticulum (ER) stress and also develop hepatocellular carcinomas (8 of 8 mice) similar to those observed in Acox1(-/-) mice (10 of 10 mice), but unlike in ob/ob (0 of 14 mice) and OB/OB (0 of 6 mice) mice, suggesting that superimposed ER stress and PPARα activation contribute to carcinogenesis in a fatty liver. Finally, absence of Acox1 in ob/ob mice can impart resistance to high-fat diet (60% fat)-induced obesity, and their liver had significantly (P<0.01) more cell proliferation. These studies with Acox1(-/-)/ob/ob mice indicate that sustained activation of lipid-sensing nuclear receptor PPARα attenuates obesity and restores glucose homeostasis by ameliorating insulin resistance but increases the risk for liver cancer development, in part related to excess energy combustion.
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Acute oxidative stress induced by ischemia-reperfusion or inflammation causes serious damage to tissues, and persistent oxidative stress is accepted as one of the causes of many common diseases including cancer. We show here that hydrogen (H(2)) has potential as an antioxidant in preventive and therapeutic applications. We induced acute oxidative stress in cultured cells by three independent methods. H(2) selectively reduced the hydroxyl radical, the most cytotoxic of reactive oxygen species (ROS), and effectively protected cells; however, H(2) did not react with other ROS, which possess physiological roles. We used an acute rat model in which oxidative stress damage was induced in the brain by focal ischemia and reperfusion. The inhalation of H(2) gas markedly suppressed brain injury by buffering the effects of oxidative stress. Thus H(2) can be used as an effective antioxidant therapy; owing to its ability to rapidly diffuse across membranes, it can reach and react with cytotoxic ROS and thus protect against oxidative damage.
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The methionine choline-deficient (MCD) diet results in liver injury similar to human nonalcoholic steatohepatitis (NASH). The aims of this study were to define mechanisms of MCD-induced steatosis in insulin-resistant db/db and insulin-sensitive db/m mice. MCD-fed db/db mice developed more hepatic steatosis and retained more insulin resistance than MCD-fed db/m mice. Both subcutaneous and gonadal fat were reduced by MCD feeding: gonadal fat decreased by 23% in db/db mice and by 90% in db/m mice. Weight loss was attenuated in the db/db mice, being only 13% compared with 35% in MCD-fed db/db and db/m mice, respectively. Both strains had upregulation of hepatic fatty acid transport proteins as well as increased hepatic uptake of [14C]oleic acid: 3-fold in db/m mice (P < 0.001) and 2-fold in db/db mice (P < 0.01) after 4 weeks of MCD feeding. In both murine strains, the MCD diet reduced triglyceride secretion and downregulated genes involved in triglyceride synthesis. Therefore, increased fatty acid uptake and decreased VLDL secretion represent two important mechanisms by which the MCD diet promotes intrahepatic lipid accumulation in this model. Feeding the MCD diet to diabetic rodents broadens the applicability of this model for the study of human NASH.
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Recent extensive studies have revealed that molecular hydrogen (H(2)) has great potential for improving oxidative stress-related diseases by inhaling H(2) gas, injecting saline with dissolved H(2), or drinking water with dissolved H(2) (H(2)-water); however, little is known about the dynamic movement of H(2) in a body. First, we show that hepatic glycogen accumulates H(2) after oral administration of H(2)-water, explaining why consumption of even a small amount of H(2) over a short span time efficiently improves various disease models. This finding was supported by an in vitro experiment in which glycogen solution maintained H(2). Next, we examined the benefit of ad libitum drinking H(2)-water to type 2 diabetes using db/db obesity model mice lacking the functional leptin receptor. Drinking H(2)-water reduced hepatic oxidative stress, and significantly alleviated fatty liver in db/db mice as well as high fat-diet-induced fatty liver in wild-type mice. Long-term drinking H(2)-water significantly controlled fat and body weights, despite no increase in consumption of diet and water. Moreover, drinking H(2)-water decreased levels of plasma glucose, insulin, and triglyceride, the effect of which on hyperglycemia was similar to diet restriction. To examine how drinking H(2)-water improves obesity and metabolic parameters at the molecular level, we examined gene-expression profiles, and found enhanced expression of a hepatic hormone, fibroblast growth factor 21 (FGF21), which functions to enhance fatty acid and glucose expenditure. Indeed, H(2) stimulated energy metabolism as measured by oxygen consumption. The present results suggest the potential benefit of H(2) in improving obesity, diabetes, and metabolic syndrome.
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Liver fibrogenesis is sustained by myofibroblast-like cells originating from hepatic stellate cells (HSC/MFs), portal fibroblasts or bone marrow-derived cells, including mesenchymal stem cells (MSCs). Herein, we investigated the mechanistic role of intracellular generation of reactive oxygen species (ROS) and redox-sensitive signal transduction pathways in mediating chemotaxis, a critical profibrogenic response for human HSC/MFs and for MSC potentially engrafting chronically injured liver. Intracellular generation of ROS and signal transduction pathways were evaluated by integrating morphological and molecular biology techniques. Chemokinesis and chemotaxis were evaluated by wound healing assay and modified Boyden's chamber assay, respectively. Additional in vivo evidence was obtained in human specimens from HCV-related cirrhosis. Human MSCs and HSC/MFs migrate in response to a panel of polypeptide chemoattractants and extracellularly generated superoxide anion. All polypeptides induced a NADPH-oxidase-dependent intracellular rise in ROS, resulting in activation of ERK1/2 and JNK1/2. Moreover, menadione or 2,3-dimethoxy-1,4-naphthoquinone, which generate intracellular superoxide anion or hydrogen peroxide, respectively, induced ERK1/2 and JNK1/2 activation and migration. JNK1 activation was predominant for migration as shown by specific silencing. Finally, activation of ERK1/2 and JNK1/2 was found in extracts obtained from HSC/MFs during the course of an oxidative stress-mediated model of liver injury and phosphorylated JNK1/2 isoforms were detected in α-smooth muscle actin-positive myofibroblasts lining fibrotic septa in human cirrhotic livers. Intracellular generation of ROS, through activation of specific signaling pathways, is a critical event for directional migration of HSC/MFs and MSCs.
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Unlabelled: Nonalcoholic fatty liver disease (NAFLD) encompasses a histological spectrum ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). NAFLD carries a higher risk of cardio-metabolic and liver-related complications, the latter being confined to NASH and demanding specific treatment. We assessed the efficacy of proposed treatments for NAFLD/NASH by reviewing reports of randomized controlled trials (RCTs) on online databases and national and international meeting abstracts through January 2010. Primary outcome measure was histological improvement; secondary outcome was biochemical improvement; improvement in radiological steatosis was also evaluated. Two reviewers extracted articles using predefined quality indicators, independently and in duplicate. Main outcomes of randomized controlled trials (RCTs) were pooled using random-effects or fixed-effects models. Publication bias was assessed by funnel plots. Forty-nine RCTs (30 in NASH) were included: 23 RCTs (22 in NASH, 1 in NAFLD) had post-treatment histology. Most RCTs were small and did not exceed 1-year duration. Weight loss, thiazolidinediones (especially pioglitazone), and antioxidants were most extensively evaluated. Weight loss was safe and dose-dependently improved histological disease activity in NASH, but more than 50% of patients failed to achieve target weight loss. Thiazolidinediones improved steatosis and inflammation but yielded significant weight gain. RCTs with antioxidants yielded conflicting results and were heterogeneous with respect to type and dose of drug, duration, implementation of lifestyle intervention. Among the other agents, pentoxifylline, telmisartan and L-carnitine improved liver histology in at least 1 RCT in NASH; polyunsaturated fatty acid (PUFA) ameliorated biochemical and radiological markers of NAFLD. Other approaches yielded negative results. Conclusion: Well-designed RCTs of adequate size and duration, with histological endpoints, are needed to assess long-term safety and efficacy of proposed treatments on patient-oriented clinical outcomes.
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Reactive oxygen species (ROS) contribute to the development of interstitial fibrosis and tubular atrophy seen in chronic allograft nephropathy (CAN). As molecular hydrogen gas can act as a scavenger of ROS, we tested the effect of treatment with hydrogen water (HW) in a model of kidney transplantation, in which allografts from Lewis rats were orthotopically transplanted into Brown Norway recipients that had undergone bilateral nephrectomy. Molecular hydrogen was dissolved in water and recipients were given HW from day 0 until day 150. Rats that were treated with regular water (RW) gradually developed proteinuria and their creatinine clearance declined, ultimately leading to graft failure secondary to CAN. In contrast, treatment with HW improved allograft function, slowed the progression of CAN, reduced oxidant injury and inflammatory mediator production, and improved overall survival. Inflammatory signaling pathways, such as mitogen-activated protein kinases, were less activated in renal allografts from HW-treated rats as compared with RW-treated rats. Hence, oral HW is an effective antioxidant and antiinflammatory agent that prevented CAN, improved survival of rat renal allografts, and may be of therapeutic value in the setting of transplantation.
Article
Aims: Hepatic steatosis and iron cause oxidative stress, thereby progressing steatosis to steatohepatitis. We quantified the expression of genes involved in the metabolism of fatty acids and iron in patients with nonalcoholic fatty liver disease (NAFLD). Methods: The levels of transcripts for the following genes were quantified from biopsy specimens of 74 patients with NAFLD: thioredoxin (Trx), fatty acid transport protein 5 (FATP5), sterol regulatory element-binding protein 1c (SREBP1c), fatty acid synthase (FASN), acetyl-coenzyme A carboxylase (ACAC), peroxisome proliferative activated receptor α (PPARα), cytochrome P-450 2E1 (CYP2E1), acyl-coenzyme A dehydrogenase (ACADM), acyl-coenzyme A oxidase (ACOX), microsomal triglyceride transfer protein (MTP), transferrin receptor 1 (TfR1), transferrin receptor 2 (TfR2) and hepcidin. Twelve samples of human liver RNA were used as controls. Histological evaluation followed the methods of Brunt. Results: The levels of all genes were significantly higher in the NAFLD patients than in controls. The Trx level increased as the stage progressed. The levels of FATP5, SREBP1c, ACAC, PPARα, CYP2E1, ACADM and MTP significantly decreased as the stage and grade progressed (P < 0.05). Hepatic iron score (HIS) increased as the stage progressed. The TfR1 level significantly increased as the stage progressed (P < 0.05), whereas TfR2 level significantly decreased (P < 0.05). The ratio of hepcidin mRNA/ferritin (P < 0.001) or hepcidin mRNA/HIS (P < 0.01) was significantly lower in NASH patients than simple steatosis patients. Conclusions: Steatosis-related metabolism is attenuated as NAFLD progresses, whereas iron-related metabolism is exacerbated. Appropriate therapies should be considered on the basis of metabolic changes.
Article
Ethnic differences in non-alcoholic steatohepatitis (NASH) are well-documented, but there has been no study on the prognosis of Japanese NASH patients with cirrhosis. Accordingly, we compared cirrhotic NASH with liver cirrhosis caused by chronic hepatitis C (LC-C) to clarify its clinical features and define the risk factors for death. A prospective evaluation of the outcomes of NASH patients with severe fibrosis was started in 1990. Data on age- and sex-matched patients with biopsy-proven LC-C were collected retrospectively and used as the control. There were 68 patients with cirrhotic NASH and 69 with LC-C. The Child-Turcotte-Pugh (CTP) class was similar in these two groups. Although the outcome of the NASH group was better than that of the LC-C group, cirrhotic NASH followed a similar course to that of LC-C; that is, complications of cirrhosis developed, including hepatocellular carcinoma (HCC; the 5-year HCC rate was 11.3% for NASH and 30.5% for HCV) and death (the 5-year survival rates were 75.2% and 73.8%, respectively). HCC was the leading cause of death in both groups (NASH, 47%; HCV, 68%). The occurrence of HCC and the CTP class were significant risk factors for mortality in NASH patients according to a multivariate analysis (HCC: hazard ratio [HR] 7.96, 95% confidence interval [CI] 2.45-25.88, CTP class A: HR 0.17, 95% CI 0.06-0.50). In conclusion, the present study confirmed that cirrhotic NASH has a similar course to LC-C. The occurrence of HCC was the strongest predictor of mortality in the NASH groups. These findings may be helpful when deciding on therapeutic interventions for NASH and also for the daily management of these patients.
Article
Development of hepatocellular carcinomas in rats caused by a choline-deficient, L-amino acid-defined (CDAA) diet, usually associated with fatty liver, fibrosis, cirrhosis and oxidative DNA damage, has been recognized as a useful model of hepatocarcinogenesis caused by endogenous factors. In the present study, in order to further explore involved factors and genes, we established an equivalent model in spontaneous liver tumor-resistant C57BL/6J mice. Six-week-old males and females were continuously fed the CDAA diet and histological liver lesions and oxidative DNA damage due to 8-hydroxydeoxyguanosine (8-OHdG) were examined after 22, 65 and 84 weeks. In male mice, fatty change and fibrosis were evident at 22 weeks, and preneoplastic foci of altered hepatocytes were seen at an incidence of 8/8 (100%) and a multiplicity of 6.6 +/- 4.0 per mouse at 65 weeks. Hepatocellular adenomas and carcinomas developed at incidences of 16/24 (66.7%) and 5/24 (20.8%), and multiplicities of 1.42 +/- 1.32 and 0.29 +/- 0.62, respectively, at 84 weeks. The female mice exhibited resistance to development of these lesions. The CDAA diet also increased 8-OHdG levels in male but not female mice. These results indicate that a CDAA diet causes hepatocellular preneoplastic foci, adenomas and carcinomas associated with fibrosis and oxidative DNA damage in mice, as in rats, providing a hepatocarcinogenesis model caused by endogenous factors in mice.
Article
Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis in the absence of a history of significant alcohol use or other known liver disease. Nonalcoholic steatohepatitis (NASH) is the progressive form of NAFLD. The Pathology Committee of the NASH Clinical Research Network designed and validated a histological feature scoring system that addresses the full spectrum of lesions of NAFLD and proposed a NAFLD activity score (NAS) for use in clinical trials. The scoring system comprised 14 histological features, 4 of which were evaluated semi-quantitatively: steatosis (0-3), lobular inflammation (0-2), hepatocellular ballooning (0-2), and fibrosis (0-4). Another nine features were recorded as present or absent. An anonymized study set of 50 cases (32 from adult hepatology services, 18 from pediatric hepatology services) was assembled, coded, and circulated. For the validation study, agreement on scoring and a diagnostic categorization ("NASH," "borderline," or "not NASH") were evaluated by using weighted kappa statistics. Inter-rater agreement on adult cases was: 0.84 for fibrosis, 0.79 for steatosis, 0.56 for injury, and 0.45 for lobular inflammation. Agreement on diagnostic category was 0.61. Using multiple logistic regression, five features were independently associated with the diagnosis of NASH in adult biopsies: steatosis (P = .009), hepatocellular ballooning (P = .0001), lobular inflammation (P = .0001), fibrosis (P = .0001), and the absence of lipogranulomas (P = .001). The proposed NAS is the unweighted sum of steatosis, lobular inflammation, and hepatocellular ballooning scores. In conclusion, we present a strong scoring system and NAS for NAFLD and NASH with reasonable inter-rater reproducibility that should be useful for studies of both adults and children with any degree of NAFLD. NAS of > or =5 correlated with a diagnosis of NASH, and biopsies with scores of less than 3 were diagnosed as "not NASH."
Article
Oxidative DNA damage is considered to play an important role in pathophysiological processes, ageing and cancer. So far major interest has been on measuring 8-hydroxy-2'-deoxyguanosine (8-OHdG), the preferred methods relying on HPLC or GC-mass spectrometry. The high biological relevance of 8-OHdG is due to its ability to induce G-->T transversions, which are among the most frequent somatic mutations found in human cancers. Effects of workplace exposures on the level of white blood cell 8-OHdG or urinary 8-OHdG have been reported with controversial results. Exposures examined include asbestos, azo-dyes, benzene, fine particulate matter (PM(2.5)), glassworks, polycyclic aromatic hydrocarbons (PAHs), rubber manufacturing, silica, metals, styrene, toluene and xylenes. The available data indicate that there is still a lack of well established dose-response relations between occupational or environmental exposures and the induction of 8-OHdG. Smoking has been most consistently identified as a confounder for 8-OHdG, but various occupational studies did not reveal higher levels of 8-OHdG in smokers. Despite the conflicting results, the reported studies show promise for 8-OHdG as a biomarker of oxidative stress associated with chemical exposure. However, there are critical aspects related to the analytical challenge, artifactual production of 8-OHdG, inter- and intra-individual variation, confounding factors and inter-laboratory differences, implying that further work is needed to reach a consensus on the background level of 8-OHdG.
Article
C-Reactive Protein (CRP), a nonspecific marker of inflammation that is moderately elevated in obesity, metabolic syndrome (MS), and type 2 diabetes, has been proposed as a surrogate marker of nonalcoholic steatohepatitis (NASH). Its clinical usefulness in the diagnosis of NASH was evaluated in severely obese patients without or with MS, diabetes, and NASH and the potential roles of the liver and of the adipose tissue in CRP production were characterized. Severely obese patients without NASH (without MS [N = 13], with MS [N = 11], or with MS and diabetes [N = 7]) and with NASH (without [N = 8] or with [N = 7] MS) were studied. For each patient, liver and adipose tissue biopsies were collected during a bariatric surgery and were used to determine the CRP gene expression by real-time PCR. The role of interleukin-6 (IL6) and lipopolysaccharide in CRP expression was also evaluated in subcutaneous adipose tissue obtained during cosmetic abdominoplasty. Plasma CRP levels were elevated in severely obese patients independently from the presence or absence of MS, diabetes, or NASH. CRP gene expression was not only increased in livers but also in adipose tissues of obese patients compared with controls subjects. In human adipose tissue, CRP mRNA levels were positively correlated with those of IL-6 and the CRP expression was enhanced in vitro by IL-6 and lipopolysaccharide. Plasma CRP levels are not predictive of the diagnosis of NASH in severely obese patients. The liver but also the adipose tissue can produce CRP, a process which could be dependent on IL6. Therefore, both tissues might contribute to the elevated plasma CRP levels found in obesity. In addition, the large amount of body fat may well produce an important part of the circulating CRP, further limiting its clinical usefulness in the evaluation of NASH in severely obese patients.
Article
Insulin resistance (IR) is commonly associated with non-alcoholic steatohepatitis (NASH). Peroxisome proliferator-activated receptor-alpha (PPAR-alpha) may also play a role in the pathogenesis of NASH. A pivotal role in NASH pathogenesis depends on the hypothesis of increased oxidative stress. The aim of our study was to evaluate the effects of supplemental oral vitamin E, a potent antioxidant, on liver functions, PPAR-alpha expression and IR in patients with NASH. Nine patients with biopsy-proven NASH were given oral vitamin E 800 mg daily for 24 weeks. Liver functions, lipid parameters, IR index with homeostatic metabolic assessment and liver histology and PPAR-alpha staining index in biopsy specimens were detected before and after the treatment. Seven patients (78%) had IR initially. After 6 months of therapy in nine patients, fasting insulin improved (P = 0.01), but serum cholesterol, triglyceride, fasting blood glucose levels and body mass index remained unchanged. Aspartate aminotransferase and alanine aminotransferase levels decreased (P = 0.01 and P = 0.01, respectively). IR index with homeostatic metabolic assessment resistance improved (P = 0.01), but PPAR-alpha staining index did not change (P = 0.37). Although the histological grade of steatosis decreased (P = 0.01), necroinflammation and fibrosis remained unchanged. In seven patients with IR, however, necroinflammation and PPAR-alpha staining index were improved (P = 0.04 and P = 0.02). Vitamin E treatment, in addition to its previously shown beneficial effect by suppressing oxidative stress, may also achieve improvement by reducing IR and PPAR-alpha expression in NASH.
Article
Mitochondrial dysfunction is involved in the three stages of the transition from lack of exercise and excessive food intake to insulin resistance, diabetes and non-alcoholic steatohepatitis (NASH). In muscle, lack of exercise, a fat-rich diet, a polymorphism in peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1), and possibly age-related mitochondrial DNA (mtDNA) mutations may variously combine their effects to decrease PGC-1 expression, mitochondrial biogenesis and fat oxidation. Together with excessive food intake, insufficient fat oxidation causes fat accumulation and cellular stress in myocytes. The activation of Jun N-terminal kinase and protein kinase C-theta triggers the serine phosphorylation and inactivation of the insulin receptor substrate, and hampers the insulin-mediated translocation of glucose transporter-4 to the plasma membrane. Initially, the trend for increased blood glucose increases insulin secretion by pancreatic beta-cells. High plasma insulin levels compensate for insulin resistance in muscle and maintain normal blood glucose levels. Eventually, however, increased uncoupling protein-2 expression and possibly acquired mtDNA mutations in pancreatic beta-cells can blunt glucose-mediated adenosine triphosphate (ATP) formation and insulin secretion, to cause diabetes in some patients. High plasma glucose and/or insulin levels induce hepatic lipogenesis and cause hepatic steatosis. In fat-engorged hepatocytes, several vicious cycles involving tumor necrosis factor-alpha, reactive oxygen species (ROS), peroxynitrite, and lipid peroxidation products alter respiratory chain polypeptides and mtDNA, thus partially blocking the flow of electrons in the respiratory chain. The overreduction of upstream respiratory chain complexes increases mitochondrial ROS and peroxynitrite formation. Oxidative stress increases the release of lipid peroxidation products and cytokines, which together trigger the liver lesions of NASH.
Article
Nonalcoholic fatty liver disease (NAFLD) is one of the most frequent causes of abnormal liver dysfunction, and its prevalence has markedly increased. We previously evaluated the expression of fatty acid metabolism-related genes in NAFLD and reported changes in expression that could contribute to increased fatty acid synthesis. In the present study, we evaluated the expression of additional fatty acid metabolism-related genes in larger groups of NAFLD (n=26) and normal liver (n=10) samples. The target genes for real-time PCR analysis were as follows: acetyl-CoA carboxylase (ACC) 1, ACC2, fatty acid synthase (FAS), sterol regulatory element-binding protein 1c (SREBP-1c), and adipose differentiation-related protein (ADRP) for evaluation of de novo synthesis and uptake of fatty acids; carnitine palmitoyltransferase 1a; (CPT1a), long-chain acyl-CoA dehydrogenase (LCAD), long-chain L-3-hydroxyacylcoenzyme A dehydrogenase alpha (HADHalpha), uncoupling protein 2 (UCP2), straight-chain acyl-CoA oxidase (ACOX), branched-chain acyl-CoA oxidase (BOX), cytochrome P450 2E1 (CYP2E1), CYP4A11, and peroxisome proliferator-activated receptor (PPAR)alpha for oxidation in the mitochondria, peroxisomes and microsomes; superoxide dismutase (SOD), catalase, and glutathione synthetase (GSS) for antioxidant pathways; and diacylglycerol O-acyltransferase 1 (DGAT1), PPARgamma, and hormone-sensitive lipase (HSL) for triglyceride synthesis and catalysis. In NAFLD, although fatty acids accumulated in hepatocytes, their de novo synthesis and uptake were up-regulated in association with increased expression of ACC1, FAS, SREBP-1c, and ADRP. Fatty acid oxidation-related genes, LCAD, HADHalpha, UCP2, ACOX, BOX, CYP2E1, and CYP4A11, were all overexpressed, indicating that oxidation was enhanced in NAFLD, whereas the expression of CTP1a and PPARalpha was decreased. Furthermore, SOD and catalase were also overexpressed, indicating that antioxidant pathways are activated to neutralize reactive oxygen species (ROS), which are overproduced during oxidative processes. The expression of DGAT1 was up-regulated without increased PPARgamma expression, whereas the expression of HSL was decreased. Our data indicated the following regarding NAFLD: i) increased de novo synthesis and uptake of fatty acids lead to further fatty acid accumulation in hepatocytes; ii) mitochondrial fatty acid oxidation is decreased or fully activated; iii) in order to complement the function of mitochondria (beta-oxidation), peroxisomal (beta-oxidation) and microsomal (omega-oxidation) oxidation is up-regulated to decrease fatty acid accumulation; iv) antioxidant pathways including SOD and catalase are enhanced to neutralize ROS overproduced during mitochondrial, peroxisomal, and microsomal oxidation; and v) lipid droplet formation is enhanced due to increased DGAT expression and decreased HSL expression. Further studies will be needed to clarify how fatty acid synthesis is increased by SREBP-1c, which is under the control of insulin and AMP-activated protein kinase.
Article
Antioxidant therapies have been evaluated in placebo-controlled trials involving tens of thousands of patients. Despite pathophysiologic, epidemiologic, and mechanistic data suggesting otherwise, these clinical trial results have been, to date, mostly negative in the setting of chronic preventative therapy. On the other hand, a much smaller number of trials involving handfuls of patients have been much more encouraging in terms of the acute benefit of antioxidants reflected by the data on N-acetylcysteine. However, the seemingly overwhelmingly data not supporting a role for antioxidants in the chronic suppression of atherosclerosis must be kept in perspective. Most antioxidant therapies that have been tested were not chosen because they were proved to be the best antioxidants, but rather because of their easy availability. An excellent example is vitamin E. Although easily available, it has many limitations as an antioxidant. In fact, in some studies, vitamin E has been shown to have some prooxidant effects. Another possible explanation for the lack of benefit in clinical trials is that the trials have not lasted long enough. It may be impossible to show the benefits of antioxidant therapy over several years if the therapy is trying to reverse the results of several decades of oxidative stress. It is critical to remember that the lack of benefits seen in clinical trials to date does not disprove the central role of oxidative stress in atherosclerosis. Rather, these results challenge us to evaluate optimal antioxidant therapies, the ideal study patients to study, and the appropriate trial duration.