Icariin Supplementation Suppresses the Markers of Ferroptosis and Attenuates the Progression of Nonalcoholic Steatohepatitis in Mice Fed a Methionine Choline-Deficient Diet.

Icariin, a flavonoid abundant in the herb Epimedium, exhibits anti-ferroptotic activity. However, its impact on nonalcoholic steatohepatitis (NASH) development remains unclear. This study aimed to investigate the potential role of icariin in mitigating methionine choline-deficient (MCD) diet-induced NASH in C57BL/6J mice. The results showed that icariin treatment significantly reduced serum alanine aminotrasferase and aspartate aminotransferase activities while improving steatosis, inflammation, ballooning, and fibrosis in the liver tissues of mice fed the MCD diet. These improvements were accompanied by a substantial reduction in the hepatic iron contents and levels of malondialdehyde and 4-hydroxynonenal, as well as an increase in the activities of catalase and superoxide dismutase. Notably, icariin treatment suppressed the hepatic protein levels of ferroptosis markers such as acyl-CoA synthetase long-chain family member 4 and arachidonate 12-lipoxygenase, which were induced by the MCD diet. Furthermore, transmission electron microscopy confirmed the restoration of morphological changes in the mitochondria, a hallmark characteristic of ferroptosis, by icariin. Additionally, icariin treatment significantly increased the protein levels of Nrf2, a cystine/glutamate transporter (xCT), and glutathione peroxidase 4 (GPX4). In conclusion, our study suggests that icariin has the potential to attenuate NASH, possibly by suppressing ferroptosis via the Nrf2-xCT/GPX4 pathway.

Effects of maternal genetic polymorphisms in vitamin D-binding protein and serum 25-hydroxyvitamin D concentration on infant birth weight.

OBJECTIVE: Vitamin D deficiency is a common problem during pregnancy and might contribute to adverse birth outcomes. Vitamin D-binding protein plays a key role in regulating vitamin D metabolism. We investigated whether maternal genetic variation in GC, the gene encoding vitamin-D binding protein, modulates the relationship between 25-hydroxyvitamin D [25(OH)D] levels and infant birth weight. METHODS: We measured 25(OH)D concentrations in maternal and umbilical cord blood from 356 pregnant women and their infants by liquid chromatography tandem mass spectrometry. We extracted DNA from the maternal blood for genotyping GC single-nucleotide polymorphisms (SNPs). RESULTS: The 25(OH)D concentrations were significantly higher in the maternal blood than in the cord blood, although the concentrations from each source were positively correlated with one another among individuals. Maternal GC SNPs rs12512631 and rs7041 were not significantly associated with infant birth weight. On the other hand, the GC SNPs rs12512631 and rs7041 significantly modified the relationships between the maternal and cord-blood concentrations of 25(OH)D and birth weight. Low 25(OH)D levels in the maternal and cord blood were significantly associated with decreased birth weight among infants born to mothers carrying the rs12512631 'C' allele but not in those born to mothers homozygous for the 'T' allele (P-interaction = 0.043 and 0.0008 for the maternal and cord blood, respectively). Low 25(OH)D levels in the cord blood were significantly associated with decreased birth weight only among infants born to mothers carrying the rs7041 'G' allele (P-interaction = 0.009). CONCLUSIONS: Our findings suggest that the interaction between 25(OH)D status and some maternal GC variants influence the birth weight of infants.

Hepatic iron storage is related to body adiposity and hepatic inflammation.

BACKGROUND: Obesity has been reported to be associated with iron deficiency. However, few studies have investigated iron status in low adiposity. To investigate whether body adiposity was associated with altered hepatic iron status, we compared liver iron levels and markers involved in inflammation and iron absorption in obese, control, and mildly calorie restricted mice. METHODS: Seven week old C57BL/6 mice were fed control (10% kcal fat, Control) or high fat (60% kcal fat, HFD) diets, or reduced amount of control diet to achieve 15% calorie restriction (CR) for 16 weeks. Hepatic non-heme iron content and ferritin protein level, and hematocrit and hemoglobin levels were determined to assess iron status. Hepatic expression of Mcp-1 and Tnf-α were measured as hepatic inflammatory markers. Hepatic hepcidin (Hamp) and Bmp6, and duodenal Dmt1, Dcyt1b, hephaestin (Heph) and ferroportin mRNA levels were measured as factors involved in regulation of iron absorption. RESULTS: Hepatic non-heme iron and ferritin protein levels were significantly higher in the CR group compared with the Control group, and significantly lower in the HFD group. These two iron status markers showed significantly negative correlations with the amount of white adipose tissue (r = -0.689 for hepatic non-heme iron and r = -0.740 for ferritin). Hepatic Mcp-1 and Tnf-α mRNA levels were significantly lower in the CR compared with the HFD (74 and 47% lower) and showed significantly negative correlations with hepatic non-heme iron levels (Mcp-1: r = -0.557, P < 0.05; Tnf-α: r = -0.464, P < 0.05). Hepatic Hamp mRNA levels were lower in the HFD and higher in the CR groups compared with the Control group, which could be a response to maintain iron homeostasis. Duodenal Dcyt1b mRNA levels were higher in the CR group compared with the HFD group and duodenal Heph mRNA levels were higher in the CR group than the Control group. CONCLUSION: We showed that body adiposity was inversely correlated with liver iron status. Low inflammation levels in hepatic milieu and enhanced expression of duodenal oxidoreductases induced by calorie restriction could have contributed to higher iron status.

Iron Supplementation Reverses the Reduction of Hydroxymethylcytosine in Hepatic DNA Associated With Chronic Alcohol Consumption in Rats.

BACKGROUND: Alcohol is known to affect two epigenetic phenomena, DNA methylation and DNA hydroxymethylation, and iron is a cofactor of ten-eleven translocation (TET) enzymes that catalyze the conversion from methylcytosine to hydroxymethylcytosine. In the present study we aimed to determine the effects of alcohol on DNA hydroxymethylation and further effects of iron on alcohol associated epigenetic changes. METHODS: Twenty-four male Sprague-Dawley rats were fed either Lieber-DeCarli alcohol diet (36% calories from ethanol) or Lieber-DeCarli control diet along with or without iron supplementation (0.6% carbonyl iron) for 8 weeks. Hepatic non-heme iron concentrations were measured by colorimetric assays. Protein levels of hepatic ferritin and transferrin receptor were determined by Western blotting. Methylcytosine, hydroxymethylcytosine and unmodified cytosine in DNA were simultaneously measured by liquid chromatography/mass spectrometry method. RESULTS: Iron supplementation significantly increased hepatic non-heme iron contents (P < 0.05) but alcohol alone did not. However, both alcohol and iron significantly increased hepatic ferritin levels and decreased hepatic transferrin receptor levels (P < 0.05). Alcohol reduced hepatic DNA hydroxymethylation (0.21% ± 0.04% vs. 0.33% ± 0.04%, P = 0.01) compared to control, while iron supplementation to alcohol diet did not change DNA hydroxymethylation. There was no significant difference in methylcytosine levels, while unmodified cytosine levels were significantly increased in alcohol-fed groups compared to control (95.61% ± 0.08% vs. 95.26% ± 0.12%, P = 0.03), suggesting that alcohol further increases the conversion from hydroxymethylcytosine to unmodified cytosine. CONCLUSIONS: Chronic alcohol consumption alters global DNA hydroxymethylation in the liver but iron supplementation reverses the epigenetic effect of alcohol.

Effects of developmental iron deficiency and post-weaning iron repletion on the levels of iron transporter proteins in rats.

BACKGROUND/OBJECTIVES: Iron deficiency in early life is associated with developmental problems, which may persist until later in life. The question of whether iron repletion after developmental iron deficiency could restore iron homeostasis is not well characterized. In the present study, we investigated the changes of iron transporters after iron depletion during the gestational-neonatal period and iron repletion during the post-weaning period. MATERIALS/METHODS: Pregnant rats were provided iron-deficient (< 6 ppm Fe) or control (36 ppm Fe) diets from gestational day 2. At weaning, pups from iron-deficient dams were fed either iron-deficient (ID group) or control (IDR group) diets for 4 week. Pups from control dams were continued to be fed with the control diet throughout the study period (CON). RESULTS: Compared to the CON, ID rats had significantly lower hemoglobin and hematocrits in the blood and significantly lower tissue iron in the liver and spleen. Hepatic hepcidin and BMP6 mRNA levels were also strongly down-regulated in the ID group. Developmental iron deficiency significantly increased iron transporters divalent metal transporter 1 (DMT1) and ferroportin (FPN) in the duodenum, but decreased DMT1 in the liver. Dietary iron repletion restored the levels of hemoglobin and hematocrit to a normal range, but the tissue iron levels and hepatic hepcidin mRNA levels were significantly lower than those in the CON group. Both FPN and DMT1 protein levels in the liver and in the duodenum were not different between the IDR and the CON. By contrast, DMT1 in the spleen was significantly lower in the IDR, compared to the CON. The splenic FPN was also decreased in the IDR more than in the CON, although the difference did not reach statistical significance. CONCLUSIONS: Our findings demonstrate that iron transporter proteins in the duodenum, liver and spleen are differentially regulated during developmental iron deficiency. Also, post-weaning iron repletion efficiently restores iron transporters in the duodenum and the liver but not in the spleen, which suggests that early-life iron deficiency may cause long term abnormalities in iron recycling from the spleen.

Association between Dietary Patterns and Atopic Dermatitis in Relation to GSTM1 and GSTT1 Polymorphisms in Young Children.

Previous research suggests the association of glutathione S-transferase (GST) gene polymorphisms or diet, but no interactions between these factors in atopic dermatitis (AD). We conducted a community-based case-control study including 194 AD and 244 matched non-AD preschoolers. Glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) present/null genotypes were evaluated uisng a multiplex PCR method. We measured dietary intakes by a validated food frequency questionnaire and constructed three dietary patterns such as "traditional healthy", "animal foods", and "sweets" diets. In stratified analyses by GST genotypes, the "traditional healthy" diet and reduced AD showed association only in the GSTM1-present group (odd ratio (OR) 0.31, 95% confidence interval (CI) 0.13-0.75). A similar pattern of the association existed in the combined GSTM1/T1 genotype that indicated the inverse association between the "traditional healthy" diet and AD in the double GSTM1/T1-present genotype group (OR 0.24, 95% CI 0.06-0.93). Results from the multiplicative test analyses showed that the "traditional healthy" diet on reduced AD was significant or borderline significant in the GSTM1-present group (OR 0.71, 95% CI 0.54-0.92 vs. GSTM1-null group) or the GSTM1/T1 double present group (OR 0.63, 95% CI 0.39-1.03 vs. GSTM1/T1 double null group). These findings demonstrate that the present type of GSTM1 may increase susceptibility to the potential effect of the "traditional healthy" diet on AD.

Arctiin inhibits adipogenesis in 3T3-L1 cells and decreases adiposity and body weight in mice fed a high-fat diet.

BACKGROUND/OBJECTIVES: The purpose of this study was to examine the effects and associated mechanisms of arctiin, a lignan compound found in burdock, on adipogenesis in 3T3-L1 cells. Also, the effects of arctiin supplementation in obese mice fed a high-fat diet on adiposity were examined. MATERIALS/METHODS: 3T3-L1 cells were treated with arctiin (12.5 to 100 µM) during differentiation for 8 days. The accumulation of lipid droplets was determined by Oil Red O staining and intracellular triglyceride contents. The expressions of genes related to adipogenesis were measured by real-time RT-PCR and Western blot analyses. For in vivo study, C57BL/6J mice were first fed either a control diet (CON) or high-fat diet (HF) to induce obesity, and then fed CON, HF, or HF with 500 mg/kg BW arctiin (HF + AC) for four weeks. RESULTS: Arctiin treatment to 3T3-L1 pre-adipocytes markedly decreased adipogenesis in a dose-dependent manner. The arctiin treatment significantly decreased the protein levels of the key adipogenic regulators PPARγ and C/EBPα, and also significantly inhibited the expression of SREBP-1c, fatty acid synthase, fatty acid-binding protein and lipoprotein lipase. Also, arctiin greatly increased the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target phosphorylated-acetyl CoA carboxylase. Furthermore, administration of arctiin significantly decreased the body weight in obese mice fed with the high-fat diet. The epididymal, perirenal or total visceral adipose tissue weights of mice were all significantly lower in the HF + AC than in the HF. Arctiin administration also decreased the sizes of lipid droplets in the epididymal adipose tissue. CONCLUSIONS: Arctiin inhibited adipogenesis in 3T3-L1 adipocytes through the inhibition of PPARγ and C/EBPα and the activation of AMPK signaling pathways. These findings suggest that arctiin has a potential benefit in preventing obesity.

The changes of zinc transporter ZnT gene expression in response to zinc supplementation in obese women.

Obesity is associated with an alteration in zinc metabolism. This alteration may be associated with changes in gene expression of zinc transporters. In this study, we examined the leukocyte expression of zinc transporter ZnTs in response to zinc supplementation in young obese women. Thirty-five young obese women (BMI ≥ 25 kg/m(2)), aged 18-28 years, were randomly assigned to two groups: a placebo group or a zinc group (30 mg zinc/day for 8 weeks). Usual dietary zinc intake was estimated from 3-day diet records. Serum zinc and urinary zinc concentrations were measured by atomic absorption spectrometry. Messenger RNA (mRNA) levels of leukocyte ZnT transporters were examined using quantitative real-time PCR. Expression levels of two ZnT transporters, ZnT1 and ZnT5, in obese women, increased significantly after zinc supplementation. At the end of the study, mRNA levels of ZnT1 and ZnT5 showed no correlation with serum zinc or urinary zinc concentration in obese women. In addition, a further study was conducted to identify whether the association between the gene expression levels of leukocyte ZnT1 and ZnT5 and dietary zinc intake remained consistent in 216 healthy young adults aged 20-29 years. A positive correlation between ZnT1 and dietary zinc intake (r = 0.181, P = 0.089) was also observed in healthy men although the significance was marginal. Taken together, these results show that the gene expression levels of ZnT1 and ZnT5 may be changed by zinc intake, suggesting that zinc supplementation could potentially restore ZnT transporter expression in obese women with altered zinc metabolism.

The alteration of zinc transporter gene expression is associated with inflammatory markers in obese women.

Obesity, a chronic inflammatory state, is associated with altered zinc metabolism. ZnT and Zip transporters are involved in the regulation of zinc metabolism. This study examined the relationships among obesity, zinc transporter gene expression, and inflammatory markers in young Korean women. The messenger RNA (mRNA) levels of leukocyte zinc transporters between obese (BMI = 28.3 ± 0.5 kg/m(2), n = 35) and nonobese (BMI = 20.7 ± 0.2 kg/m(2), n = 20) women aged 18-28 years were examined using quantitative real-time polymerase chain reaction. Inflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-6, were measured in serum by enzyme immunoassay. ZnT1 and Zip1 were the most abundantly expressed zinc transporters in leukocytes. The mRNA levels of many zinc transporters (ZnT4, ZnT5, ZnT9, Zip1, Zip4, and Zip6) were significantly lower in obese women, and expression of these genes was inversely correlated with BMI and body fat percentage. In addition, inflammatory markers (CRP and TNF-α) were significantly higher in obese women. The mRNA levels of ZnT4, Zip1, and Zip6 were inversely correlated with CRP (P < 0.05), and mRNA levels of ZnT4 and ZnT5 were inversely correlated with TNF-α (P < 0.05). In standardized simple regression models, levels of TNF-α and CRP were negatively associated with mRNA levels of zinc transporters such as ZnT4, ZnT5, Zip1, and Zip6 (P < 0.05). These results suggest that the expression of zinc transporters may be altered in obese individuals. Changes in zinc transporters may also be related to the inflammatory state associated with obesity.

Salty taste acuity is affected by the joint action of αENaC A663T gene polymorphism and available zinc intake in young women.

Salty taste perception affects salt intake, of which excess amounts is a major public health concern. Gene polymorphisms in salty taste receptors, zinc status and their interaction may affect salty taste perception. In this study, we examined the relationships among the α-epithelial sodium channel (αENaC) A663T genotype, zinc intake, and salty taste perception including salty taste acuity and preference in healthy young adults. The αENaC A663T genotype was determined by the PCR-restriction fragment length polymorphism in 207 adults. Zinc intake was examined by one 24-h recall and a two-day dietary record. Salty taste acuity and preference were determined by measuring the salty taste recognition threshold and the preferred salinity of beansprout soup, respectively. Men had significantly higher thresholds and preferences for salty taste than women did (p < 0.05). In women, the salty taste threshold was significantly lower in the highest tertile of available zinc intake than in the lowest tertile (12.2 mM and 17.6 mM, respectively, p = 0.02). Interestingly, a significant inverse association between available zinc intake and salty taste threshold was found only in women with αENaC AA homozygotes (ß = -0.833, p = 0.02), and no such association was found in T663 allele carriers. The salty taste preference was not associated with the αENaC A663T genotype or available zinc intake in either sex. In conclusion, our data suggest that gene-nutrient interactions between the αENaC A663T genotype and available zinc intake play a role in determining the salty taste acuity in young women.

Inhibitory effect of a Cirsium setidens extract on hepatic fat accumulation in mice fed a high-fat diet via the induction of fatty acid ß-oxidation.

Cirsium setidens is a perennial medicinal herb that is rich in flavonoids. We investigated in this study the effect of a C. setidens ethanol extract (CSE) on the development of nonalcoholic fatty liver in mice fed a high-fat diet (HF). C57BL/6J mice were fed either a control diet (CON) or HF for 8 weeks, and then fed CON, HF, or HF with 100 mg/kg of BW CSE (HF+CSE) for an additional 7 weeks. The final body weight and adipose tissue weight of the mice in the HF+CSE group were significantly lower than those in the HF group. CSE also markedly diminished both the lipid droplets in the liver tissues and decreased the hepatic and serum triglycerides (TG) concentrations. CSE strongly increased the hepatic mRNA levels of carnitine palmitoyltransferase (CPT1) and medium-chain acyl-CoA dehydrogenase (MCAD), the fatty acid ß-oxidation enzymes. The hepatic levels of phosphorylated-AMP-activated protein kinase (AMPK) were significantly higher in the HF+CSF group than in the HF group. These results suggest that CSE inhibited hepatic fat accumulation by up-regulating the expression of the fatty acid ß-oxidation genes.

Lancemaside A isolated from Codonopsis lanceolata and its metabolite echinocystic acid ameliorate scopolamine-induced memory and learning deficits in mice.

The rhizome of Codonopsis lanceolata (family Campanulaceae), which contains lancemaside A as a main constituent, has been used as herbal medicine to treat inflammation, insomnia, and hypomnesia. Lancemaside A and echinocystic acid, which is its metabolite by intestinal microflora, potently inhibited acetylcholinesterase activity in a dose-dependent manner, with IC50 value 13.6 µM and 12.2 µM, respectively. Its inhibitory potency is comparable with that of donepezil (IC50=10.9 µM). Lancemaside A and echinocystic acid significantly reversed scopolamine-induced memory and learning deficits on passive avoidance task. Lancemaside A orally administered 5h before treatment with scopolamine reversed scopolamine-induced memory and learning deficits more potently than one orally administered 1h before. Echinocystic acid more potently reversed it than lancemaside A. Lancemaside A and echinocystic acid significantly reversed scopolamine-induced memory and learning deficits on the Y-maze and Morris water maze tasks. Lancemaside A and echinocystic acid also increased the expression of brain-derived neurotrophic factor (BDNF) and phosphorylated cAMP response element binding protein (p-CREB). Based on these findings, orally administered lancemaside A may be metabolized to echinocystic acid, which may be absorbed into the blood and ameliorate memory and learning deficits by inhibiting AChE activity and inducing BDNF and p-CREB expressions.

High carbohydrate intake was inversely associated with high-density lipoprotein cholesterol among Korean adults.

The traditional Asian diet, which is characterized as being high in carbohydrate with an abundance of vegetables, may be beneficial for preventing metabolic syndrome abnormalities within the Asian population. However, the prevalence of metabolic syndrome is increasing in Asian countries. This study explored the association between dietary carbohydrates and low high-density lipoprotein cholesterol (HDL-C) prevalence, one of the abnormalities of metabolic syndrome in Korean adults. We used the data from the Fourth Korea National Health and Nutrition Examination Survey and evaluated a total of 9947 Korean adults older 20 years. To measure carbohydrate quality and quantity, total carbohydrate intake (g/d), percentage of energy from carbohydrate, glycemic index, and glycemic load were divided into quintiles. Mean levels of HDL-C significantly decreased across the quintiles for all types of dietary carbohydrate intake except glycemic index after adjusting for potential variables in both men and women. Odds ratios for having low HDL-C in the highest quintile were 1.66 (95% confidence interval, 1.24-2.22) for total carbohydrate, 1.34 (1.02-1.75) for percentage of energy from carbohydrate, and 1.54 (1.17-2.03) for glycemic load in men as compared with the second quintile as a reference. Odds ratio for low HDL-C was 1.38 (1.12-1.71) for percentage of energy from carbohydrate in women. In conclusion, our study indicates that low HDL-C is associated with high carbohydrate intake without regard to energy or fat intake. Further studies would be necessary to optimize carbohydrate intake quantitatively on dyslipidemia for Asian population.

Apo-10'-lycopenoic acid, a lycopene metabolite, increases sirtuin 1 mRNA and protein levels and decreases hepatic fat accumulation in ob/ob mice.

Lycopene has been shown to be beneficial in protecting against high-fat diet-induced fatty liver. The recent demonstration that lycopene can be converted by carotene 9',10'-oxygenase into a biologically active metabolite, ALA, led us to propose that the function of lycopene can be mediated by ALA. In the present study, male ob/ob mice were fed a liquid high-fat diet (60% energy from fat) with ALA supplementation (ALA group, 240 µg · kg body weight(-1) · d(-1)) or without ALA supplementation as the control (C group) for 16 wk. Steatosis, SIRT1 expression and activity, genes involved in lipid metabolism, and ALA concentrations in the livers of mice were examined. The results showed that ALA supplementation resulted in a significant accumulation of ALA in the liver and markedly decreased the steatosis in the ALA group without altering body and liver weights compared to the C group. The mRNA and protein levels of hepatic SIRT1 were higher in the ALA group compared to the C group. SIRT1 activity also was higher in the ALA group, as indicated by the lower levels of acetylated forkhead box class O1 protein levels. In addition, the mRNA level of acetyl CoA carboxylase 1 was significantly lower in the ALA group than in the C group. Because SIRT1 plays a key role in lipid homeostasis, the present study suggests that the lycopene metabolite, ALA, protects against the development of steatosis in ob/ob mice by upregulating SIRT1 gene expression and activity.

Cytochrome P450 2E1 inhibition prevents hepatic carcinogenesis induced by diethylnitrosamine in alcohol-fed rats.

Chronic alcohol ingestion increases hepatic cytochrome P450 2E1 (CYP2E1), which is associated with hepatocarcinogenesis. We investigated whether treatment with chlormethiazole (CMZ), a CYP2E1 inhibitor, protects against alcohol-associated hepatic carcinogenesis in rats. Rats were fed either an ethanol liquid diet or a non-ethanol liquid diet, with or without CMZ for one and ten months. A single intraperitoneal injection of diethylnitrosamine (DEN, 20 mg/kg) was given to initiate hepatic carcinogenesis. CYP2E1 expression, inflammatory proteins, cell proliferation, protein-bound 4-HNE, etheno-DNA adducts, 8-hydroxy-2'-deoxyguanosine (8-OHdG), retinoid concentrations, and hepatic carcinogenesis were examined. Ethanol feeding for 1 month with DEN resulted in significantly increased hepatic CYP2E1 levels and increased nuclear accumulation of NF-κB protein and TNF-α expression, which were associated with increased cyclin D1 expression and p-GST positive altered hepatic foci. All of these changes induced by ethanol feeding were significantly inhibited by the one month CMZ treatment. At 10-months of treatment, hepatocellular adenomas were detected in ethanol-fed rats only, but neither in control rats nor in animals receiving ethanol and CMZ. The 8-OHdG formation was found to be significantly increased in ethanol fed animals and normalized with CMZ treatment. In addition, alcohol-reduced hepatic retinol and retinoic acid concentrations were restored by CMZ treatment to normal levels in the rats at 10 months of treatment. These data demonstrate that the inhibition of ethanol-induced CYP2E1 as a key pathogenic factor can counteract the tumor-promoting action of ethanol by decreasing TNF-α expression, NF-κB activation, and oxidative DNA damage as well as restoring normal hepatic levels of retinoic acid in DEN-treated rats.

Diet-induced obesity leads to decreased hepatic iron storage in mice.

An increased risk of iron deficiency has been reported in obese individuals. We investigated hepatic iron status and serum levels of both adipokines and inflammatory markers in obese mice to test the hypothesis that high-fat-diet (HFD)-induced obesity leads to reduced iron storage associated with inflammation. Four-week-old C57BL mice were fed a HFD containing 60% energy from fat for 16 weeks and were compared with mice on a control diet with 10% energy from fat. The HFD group had significantly higher levels of leptin (43.7 ng/mL in control, n = 16 vs 104.3 ng/mL in HFD, n = 17; P < .001) and significantly lower amounts of high-molecular-weight adiponectin (4.80 µg/mL in control, n = 16 vs 3.67 µg/mL in HFD, n = 18; P = .002) compared with the control group. Higher serum amyloid A levels in the HFD group (60.4 µg/mL in control, n = 17 vs 117.9 µg/mL in HFD, n = 18; P < .001) suggest inflammation in the HFD-induced obese animals. The HFD group had lower hepatic nonheme iron (3.12 µg/mg protein in control, n = 17 vs 0.869 µg/mg protein in HFD, n = 16; P < .001). Expression of hepcidin messenger RNA (mRNA) was only 54% of the control levels in HFD mice (P = .016). However, the ratio of hepcidin mRNA expression to nonheme iron was 2.5-fold higher in the HFD compared with the control animals. Hepcidin is a homeostatic regulator of iron metabolism that restricts intestinal iron absorption and is also known as a mediator of inflammation. Increased serum amyloid A levels and a higher ratio of hepatic hepcidin mRNA expression to nonheme iron suggest that lower hepatic iron status in obese animals might be associated with inflammation.

Long-term ethanol consumption promotes hepatic tumorigenesis but impairs normal hepatocyte proliferation in rats.

Chronic and excessive alcohol consumption has been related to an increased risk of several cancers, including that of the liver; however, studies in animal models have yet to conclusively determine whether ethanol acts as a tumor promoter in hepatic tumorigenesis. We examined whether prolonged alcohol consumption could act as a hepatic tumor promoter after initiation by diethylnitrosamine (DEN) in a rat model. Male Sprague-Dawley rats were injected with 20 mg DEN/kg body weight 1 wk before introduction of either an ethanol liquid diet or an isoenergic control liquid diet. Hepatic pathological lesions, hepatocyte proliferation, apoptosis, PPARα and PPARγ, and plasma insulin-like growth factor 1 (IGF-1) levels were assessed after 6 and 10 mo. Mean body and liver weights, plasma IGF-1 concentration, hepatic expressions of proliferating cellular nuclear antigen and Ki-67, and cyclin D1 in ethanol-fed rats were all significantly lower after 10 mo of treatment compared with control rats. In addition, levels of hepatic PPARγ protein, not PPARα, were significantly higher in the ethanol-fed rats after prolonged treatment. Although ethanol feeding also resulted in significantly fewer altered hepatic foci, hepatocellular adenoma was detected in ethanol-fed rats at 10 mo, but not in control rats given the same dose of DEN. Together, these results indicate that chronic, excessive ethanol consumption impairs normal hepatocyte proliferation, which is associated with reduced IGF-1 levels, but promotes hepatic carcinogenesis.

Vitamin E supplementation does not prevent ethanol-reduced hepatic retinoic acid levels in rats.

Chronic, excessive ethanol intake can increase retinoic acid (RA) catabolism by inducing cytochrome P450 2E1 (CYP2E1). Vitamin E (VE) is an antioxidant implicated in CYP2E1 inhibition. In the current study, we hypothesized that VE supplementation inhibits CYP2E1 and decreases RA catabolism, thereby preventing ethanol-induced hepatocyte hyperproliferation. For 1 month, 4 groups of Sprague-Dawley rats were fed a Lieber-DeCarli liquid ethanol (36% of the total energy) diet as follows: either ethanol alone (Alc group) or ethanol in combination with 0.1 mg/kg body weight of all-trans-RA (Alc + RA group), 2 mg/kg body weight of VE (Alc + VE group), or both together (Alc + RA + VE group). Control rats were pair-fed a liquid diet with an isocaloric amount of maltodextrin instead of ethanol. The ethanol-fed groups had 3-fold higher hepatic CYP2E1 levels, 50% lower hepatic RA levels, and significantly increased hepatocyte proliferation when compared with the controls. The ethanol-fed rats given VE had more than 4-fold higher hepatic VE concentrations than the ethanol-fed rats without VE, but this did not prevent ethanol induction of CYP2E1, lower hepatic retinoid levels, or hepatocellular hyperproliferation. Furthermore, VE supplementation could not prevent RA catabolism in liver microsomal fractions of the ethanol-fed rats in vitro. These results show that VE supplementation can neither inhibit ethanol-induced changes in RA catabolism nor prevent ethanol-induced hepatocyte hyperproliferation in the rat liver.

Association of glutathione-S-transferase polymorphisms with atopic dermatitis risk in preschool age children.

BACKGROUND: Glutathione S-transferase (GST) enzymes are critical for detoxifying reactive oxygen species (ROS) and their products which have been implicated in the pathology of inflammatory diseases such as atopic dermatitis (AD). METHODS: We investigated the effects of genetic polymorphisms of GST on the risk of AD in preschool age children. Biomarkers for oxidative stress were also evaluated with respect to GST genotype. RESULTS: The GSTP1 Val105 allele was significantly associated with an increased risk of AD [odds ratio (OR)=1.62, p<0.05]. The combination of the GSTP1 Val105 allele and the GSTT1 null genotype further increased this risk by 2.3-fold (p<0.01). No association was observed for the GSTM1 null or GSTT1 null genotype alone. In children with AD, blood total antioxidant capacity was significantly less (p<0.001), while malondialdehyde was higher (p=0.12). Children with the GSTP1 Val105 allele had significantly lower concentrations of erythrocyte glutathione compared to GSTP1 ILE/ILE homozygotes (P=0.03). CONCLUSIONS: Our study suggests that the GSTP1 Val105 allele is an important determinant of susceptibility to AD in preschool age children and increased oxidative stress may play a role in the pathogenesis of AD.

Investigation of the MALDI process used to characterize self-assembled monolayers of alkanethiolates on gold.

In this work, we investigated the surface processes involved in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS), which produce intact characteristic ions, typically in disulfide form, from self-assembled monolayers (SAMs) of alkanethiolates on gold. For the study, SAMs decorated with peptides and a THAP matrix were employed. Using two-laser MS, it was previously found that irradiation with a UV laser gave rise to the direct desorption of SAM molecules from alkanethiol SAMs on gold, producing disulfide species in vacuum. However, a closer examination of this study suggests that the MALDI process in which the matrix is used may not be the case. Instead, the results indicate that the treatment of the matrix solution is responsible for the characteristic ion formation in MALDI MS. We propose that the matrix solution dissolves alkanethiolate molecules from SAMs, leading to the generation of characteristic disulfide species in the solution. The disulfides are then cocrystallized with matrix molecules and subsequently detected by MALDI MS. Because MALDI MS is a powerful tool for biopolymers with high molecular weights, it has been successfully applied to SAMs presenting large biomolecules. This understanding of the MALDI process in the surface MS of alkanethiol SAMs on gold may allow advances in the biomolecular application of SAMs in combination with mass spectrometric analysis.