Hydroxytyrosol prevents metabolic impairment reducing hepatic inflammation and restoring duodenal integrity in a rat model of NAFLD

The potential mechanisms of action of polyphenols in nonalcoholic fatty liver disease (NAFLD) are overlooked. Here, we evaluate the beneficial therapeutic effects of hydroxytyrosol (HT), the major metabolite of the oleuropein, in a nutritional model of insulin resistance (IR) and NAFLD by high-fat diet. Young male rats were divided into three groups receiving (1) standard diet (STD; 10.5% fat), (2) high-fat diet (HFD; 58.0% fat) and (3) HFD + HT (10 mg/kg/day by gavage). After 5 weeks, the oral glucose tolerance test was performed, and at 6th week, blood sample and tissues (liver and duodenum) were collected for following determinations. The HT-treated rats showed a marked reduction in serum AST, ALT and cholesterol and improved glucose tolerance and insulin sensitivity, reducing homeostasis model assessment index. HT significantly corrected the metabolic impairment induced by HFD, increasing hepatic peroxisome proliferator-activated receptor PPAR-α and its downstream-regulated gene fibroblast growth factor 21, the phosphorylation of acetyl-CoA carboxylase and the mRNA carnitine palmitoyltransferase 1a. HT also reduced liver inflammation and nitrosative/oxidative stress decreasing the nitrosylation of proteins, reactive oxygen species production and lipid peroxidation. Moreover, HT restored intestinal barrier integrity and functions (fluorescein isothiocyanate-dextran permeability and mRNA zona occludens ZO-1). Our data demonstrate the beneficial effect of HT in the prevention of early inflammatory events responsible for the onset of IR and steatosis, reducing hepatic inflammation and nitrosative/oxidative stress and restoring glucose homeostasis and intestinal barrier integrity.     

Lipoic acid effects on established atherosclerosis

AimsAlpha-lipoic acid (LA) is a commonly used dietary supplement that exerts anti-oxidant and anti-inflammatory effects in vivo and in vitro. We investigated the mechanisms by which LA may confer protection in models of established atherosclerosis.Main methodsWatanabe heritable hyperlipidemic (WHHL) rabbits were fed with high cholesterol chow for 6 weeks and then randomized to receive either high cholesterol diet alone or combined with LA (20 mg/kg/day) for 12 weeks. Vascular function was analyzed by myography. The effects of LA on T cell migration to chemokine gradients was assessed by Boyden chamber. NF-κB activation was determined by measuring translocation and electrophoresis migration shift assay (EMSA).Key findingsLA decreased body weight by 15 ± 5% without alterations in lipid parameters. Magnetic Resonance Imaging (MRI) analysis demonstrated that LA reduced atherosclerotic plaques in the abdominal aorta, with morphological analysis revealing reduced lipid and inflammatory cell content. Consistent with its effect on atherosclerosis, LA improved vascular reactivity (decreased constriction to angiotensin II and increased relaxation to acetylcholine and insulin), inhibited NF-κB activation, and decreased oxidative stress and expression of key adhesion molecules in the vasculature. LA reduced T cell content in atherosclerotic plaque in conjunction with decreasing ICAM and CD62L (l-selectin) expression. These effects were confirmed by demonstration of a direct effect of LA in reducing T cell migration in response to CCL5 and SDF-1 and decreasing T cell adhesion to the endothelium by intra-vital microscopy.SignificanceThe present findings offer a mechanistic insight into the therapeutic effects of LA on atherosclerosis.     

Carnosine ameliorates cognitive deficits in streptozotocin-induced diabetic rats: Possible involved mechanisms

Diabetic patients are at increased risk to develop cognitive deficit and senile dementia. This study was planned to assess the benefits of chronic carnosine administration on prevention of learning and memory deterioration in streptozotocin (STZ)-diabetic rats and to explore some of the involved mechanisms. Rats were divided into 5 groups: i.e., control, carnosine100-treated control, diabetic, and carnosine-treated diabetics (50 and 100 mg/kg). Carnosine was injected i.p. at doses of 50 or 100 mg/kg for 7 weeks, started 1 week after induction of diabetes using streptozotocin. Treatment of diabetic rats with carnosine at a dose of 100 mg/kg at the end of the study lowered serum glucose, improved spatial recognition memory in Y maze, improved retention and recall in elevated plus maze, and prevented reduction of step-through latency in passive avoidance task. Furthermore, carnosine at a dose of 100 mg/kg reduced hippocampal acetylcholinesterase (AChE) activity, lowered lipid peroxidation, and improved superoxide dismutase (SOD) activity and non-enzymatic antioxidant defense element glutathione (GSH), but not activity of catalase. Meanwhile, hippocampal level of nuclear factor-kappaB (NF-κB), tumor necrosis factor α (TNF-α), and glial fibrillary acidic protein (GFAP) decreased and level of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase 1 (HO-1) increased upon treatment of diabetic group with carnosine at a dose of 100 mg/kg. Taken together, chronic carnosine treatment could ameliorate learning and memory disturbances in STZ-diabetic rats through intonation of NF-κB/Nrf2/HO-1 signaling cascade, attenuation of astrogliosis, possible improvement of cholinergic function, and amelioration of oxidative stress and neuroinflammation.     

Astaxanthin reduces hepatic lipid accumulations in high-fat-fed C57BL/6J mice via activation of peroxisome proliferator-activated receptor (PPAR) alpha and inhibition of PPAR gamma and Akt

We have previously reported that astaxanthin (AX), a dietary carotenoid, directly interacts with peroxisome proliferator-activated receptors PPARα and PPARγ, activating PPARα while inhibiting PPARγ, and thus reduces lipid accumulation in hepatocytes in vitro. To investigate the effects of AX in vivo, high-fat diet (HFD)-fed C57BL/6J mice were orally administered AX (6 or 30 mg/kg body weight) or vehicle for 8 weeks. AX significantly reduced the levels of triglyceride both in plasma and in liver compared with the control HFD mice. AX significantly improved liver histology and thus reduced both steatosis and inflammation scores of livers with hematoxylin and eosin staining. The number of inflammatory macrophages and Kupffer cells were reduced in livers by AX administration assessed with F4/80 staining. Hepatic PPARα-responsive genes involved in fatty acid uptake and β-oxidation were upregulated, whereas inflammatory genes were downregulated by AX administration. In vitro radiolabeled assays revealed that hepatic fatty acid oxidation was induced by AX administration, whereas fatty acid synthesis was not changed in hepatocytes. In mechanism studies, AX inhibited Akt activity and thus decreased SREBP1 phosphorylation and induced Insig-2a expression, both of which delayed nuclear translocation of SREBP1 and subsequent hepatic lipogenesis. Additionally, inhibition of the Akt-mTORC1 signaling axis by AX stimulated hepatic autophagy that could promote degradation of lipid droplets. These suggest that AX lowers hepatic lipid accumulation in HFD-fed mice via multiple mechanisms. In addition to the previously reported differential regulation of PPARα and PPARγ, inhibition of Akt activity and activation of hepatic autophagy reduced hepatic steatosis in mouse livers.     

Oral Angiotensin-(1–7) prevented obesity and hepatic inflammation by inhibition of resistin/TLR4/MAPK/NF-κB in rats fed with high-fat diet

Obesity is characterized by a pro-inflammatory state commonly associated with type 2 diabetes and fat-liver disease. In the last few years, different studies pointed out the role of Angiotensin (Ang)-(1–7) in the metabolic regulation. The aim of the present study was to evaluate the effect of oral-administration of Ang-(1–7) in metabolism and inflammatory state of high-fat feed rats. Twenty-four male Sprague Dawley rats were randomized into three groups: High Fat Diet (HFD); Standard Diet (ST); High Fat Diet + Angiotensin-(1–7) [HFD + Ang-(1–7)]. Glycemic profile was evaluated by glucose tolerance and insulin sensitivity tests, plasmatic glucose and insulin. Cholesterol, HDL and triglycerides analyses presented lipidic profile. RT-PCR evaluated mRNA expression to ACE, ACE2, resistin, TLR4, IL-6, TNF-α and NF-κB genes. The main results showed that oral Ang-(1–7) decreased body weight and abdominal fat-mass. In addition, HFD + Ang-(1–7) treated rats presented enhanced glucose tolerance, insulin-sensitivity and decreased plasma-insulin levels, as well as a significant decrease in circulating lipid levels. These alterations were accompanied by a marked decreased expression of resistin, TLR4, ACE and increased ACE2 expression in liver. Furthermore, Ang-(1–7) decreases phosphorylation of MAPK and increases NF-κB expression. These alterations diminished expression of interleukin-6 and TNF-α, ameliorate inflammatory state in liver. In summary, the present study showed that oral-treatment with Ang-(1–7) in high-fat feed rats improved metabolism down-regulating resistin/TLR4/NF-κB-pathway.     

Nobiletin improves obesity and insulin resistance in high-fat diet-induced obese mice

Nobiletin (NOB) is a polymethoxylated flavone present in citrus fruits and has been reported to have antitumor and anti-inflammatory effects. However, little is known about the effects of NOB on obesity and insulin resistance. In this study, we examined the effects of NOB on obesity and insulin resistance, and the underlying mechanisms, in high-fat diet (HFD)-induced obese mice. Obese mice were fed a HFD for 8 weeks and then treated without (HFD control group) or with NOB at 10 or 100 mg/kg. NOB decreased body weight gain, white adipose tissue (WAT) weight and plasma triglyceride. Plasma glucose levels tended to decrease compared with the HFD group and improved plasma adiponectin levels and glucose tolerance. Furthermore, NOB altered the expression levels of several lipid metabolism-related and adipokine genes. NOB increased the mRNA expression of peroxisome proliferator-activated receptor (PPAR)-γ, sterol regulatory element-binding protein-1c, fatty acid synthase, stearoyl-CoA desaturase-1, PPAR-α, carnitine palmitoyltransferase-1, uncoupling protein-2 and adiponectin, and decreased the mRNA expression of tumor necrosis factor-α and monocyte chemoattractant protein-1 in WAT. NOB also up-regulated glucose transporter-4 protein expression and Akt phosphorylation and suppressed IκBα degradation in WAT. Taken together, these results suggest that NOB improves adiposity, dyslipidemia, hyperglycemia and insulin resistance. These effects may be elicited by regulating the expression of lipid metabolism-related and adipokine genes, and by regulating the expression of inflammatory makers and activity of the insulin signaling pathway.     

Inhibition of myeloid differentiation factor-2 attenuates obesity-induced cardiomyopathy and fibrosis

Obesity causes cardiovascular diseases, including cardiac hypertrophy and remodeling, via chronic tissue inflammation. Myeloid differentiation factor-2 (MD2), a binding protein of lipopolysaccharide, is functionally essential for the activation of proinflammatory pathways in endotoxin-induced acute inflammatory diseases. Here we tested the hypothesis that MD2 plays a central role in obesity-induced cardiomyopathy. Wildtype or MD2 knockout mice were fed with a high fat diet (HFD) or normal diet (Control) for total 16 weeks, and MD2 inhibitor L6H21 (20 mg/kg) or vehicle (1% CMC-Na) were administered from the beginning of the 9th week. HFD induced significant weight gain and cardiac hypertrophy, with increased cardiac fibrosis and inflammation. L6H21 administration or MD2 knockout attenuated HFD-induced obesity, inflammation and cardiac remodeling. In vitro exposure of H9C2 cells to high lipids induced cell hypertrophy with activated JNK/ERK and NF-κB pathways, which was abolished by pretreatment of MD2 inhibitor L6H21. Our results demonstrate that MD2 is essential to obesity-related cardiac hypertrophy through activating JNK/ERK and NF-κB-dependent cardiac inflammatory pathways. Targeting MD2 would be a therapeutic approach to prevent obesity-induced cardiac injury and remodeling.     

Altered cellular redox status,sirtuin abundance and clock gene expression in a mouse model of developmentally primed NASH

BackgroundWe have previously shown that high fat (HF) feeding during pregnancy primes the development of non-alcoholic steatohepatits (NASH) in the adult offspring. However, the underlying mechanisms are unclear.AimsSince the endogenous molecular clock can regulate hepatic lipid metabolism, we investigated whether exposure to a HF diet during development could alter hepatic clock gene expression and contribute to NASH onset in later life.MethodsFemale mice were fed either a control (C, 7% kcal fat) or HF (45% kcal fat) diet. Offspring were fed either a C or HF diet resulting in four offspring groups: C/C, C/HF, HF/C and HF/HF. NAFLD progression, cellular redox status, sirtuin expression (Sirt1, Sirt3), and the expression of core clock genes (Clock, Bmal1, Per2, Cry2) and clock-controlled genes involved in lipid metabolism (Rev-Erbα, Rev-Erbβ, RORα, and Srebp1c) were measured in offspring livers.ResultsOffspring fed a HF diet developed NAFLD. However HF fed offspring of mothers fed a HF diet developed NASH, coupled with significantly reduced NAD⁺/NADH (p < 0.05, HF/HF vs C/C), Sirt1 (p < 0.001, HF/HF vs C/C), Sirt3 (p < 0.01, HF/HF vs C/C), perturbed clock gene expression, and elevated expression of genes involved lipid metabolism, such as Srebp1c (p < 0.05, C/HF and HF/HF vs C/C).ConclusionOur results suggest that exposure to excess dietary fat during early and post-natal life increases the susceptibility to develop NASH in adulthood, involving altered cellular redox status, reduced sirtuin abundance, and desynchronized clock gene expression.     

Heat shock protein-27 attenuates foam cell formation and atherogenesis by down-regulating scavenger receptor-A expression via NF-κB signaling

Previously, we showed an inverse correlation between HSP27 serum levels and experimental atherogenesis in ApoE^?/? mice that over-express HSP27 and speculated that the apparent binding of HSP27 to scavenger receptor-A (SR-A) was of mechanistic importance in attenuating foam cell formation. However, the nature and importance of the interplay between HSP27 and SR-A in atheroprotection remained unclear. Treatment of THP-1 macrophages with recombinant HSP27 (rHSP27) inhibited acLDL binding (? 34%; p < 0.005) and uptake (? 38%, p < 0.05). rHSP27 reduced SR-A mRNA (? 39%, p = 0.02), total protein (? 56%, p = 0.01) and cell surface (? 53%, p < 0.001) expression. The reduction in SR-A expression by rHSP27 was associated with a 4-fold increase in nuclear factor-kappa B (NF-κB) signaling (p < 0.001 versus control), while an inhibitor of NF-κB signaling, BAY11-7082, attenuated the negative effects of rHSP27 on both SR-A expression and lipid uptake. To determine if SR-A is required for HSP27 mediated atheroprotection in vivo, ApoE^?/? and ApoE^?/? SR-A^?/? mice fed with a high fat diet were treated for 3 weeks with rHSP25. Compared to controls, rHSP25 therapy reduced aortic en face and aortic sinus atherosclerotic lesion size in ApoE^?/? mice by 39% and 36% (p < 0.05), respectively, but not in ApoE^?/?SR-A^?/? mice. In conclusion, rHSP27 diminishes SR-A expression, resulting in attenuated foam cell formation in vitro. Regulation of SR-A by HSP27 may involve the participation of NF-κB signaling. Lastly, SR-A is required for HSP27-mediated atheroprotection in vivo.     

Hepatoprotective effect of cryptotanshinone from Salvia miltiorrhiza in d-galactosamine/lipopolysaccharide-induced fulminant hepatic failure

Cryptotanshinone from Salvia miltiorrhiza Bunge was investigated for hepatoprotective effects in d-galactosamine (GalN)/lipopolysaccharide (LPS)-induced fulminant hepatic failure. Cryptotanshinone (20 or 40 mg/kg) was orally administered 12 and 1 h prior to GalN (700 mg/kg)/LPS (10 μg/kg) injection. The increased mortality and TNF-α levels by GalN/LPS were declined by cryptotanshinone pretreatment. In addition, cryptotanshinone attenuated GalN/LPS-induced apoptosis, characterized by the blockade of caspase-3, -8, and -9 activation, as well as the release of cytochrome c from the mitochondria. In addition, cryptotanshinone significantly suppressed JNK, ERK and p38 phosphorylation induced by GalN/LPS, and phosphorylation of TAK1 as well. Furthermore, cryptotanshinone significantly inhibited the activation of NF-κB and suppressed the production of proinflammatory cytokines. These findings suggested that hepatoprotective effect of cryptotanshinone is likely associated with its anti-apoptotic activity and the down-regulation of MAPKs and NF-κB associated at least in part with suppressing TAK1 phosphorylation.     

VBP15: Preclinical characterization of a novel anti-inflammatory delta 9,11 steroid

Δ9,11 modifications of glucocorticoids (21-aminosteroids) have been developed as drugs for protection against cell damage (lipid peroxidation; lazaroids) and inhibition of neovascularization (anecortave). Part of the rationale for developing these compounds has been the loss of glucocorticoid receptor binding due to the Δ9,11 modification, thus avoiding many immunosuppressive activities and deleterious side effect profiles associated with binding to glucocorticoid and mineralocorticoid receptors. We recently demonstrated that anecortave acetate and its 21-hydroxy analog (VBP1) do, in fact, show glucocorticoid and mineralocorticoid receptor binding activities, with potent translocation of the glucocorticoid receptor to the cell nucleus. We concluded that Δ9,11 steroids showed novel anti-inflammatory properties, retaining NF-κB inhibition, but losing deleterious glucocorticoid side effect profiles. Evidence for this was developed in pre-clinical trials of chronic muscle inflammation. Here, we describe a drug development program aimed at optimizing the Δ9,11 chemistry. Twenty Δ9,11 derivatives were tested in in vitro screens for NF-κB inhibition and GR translocation to the nucleus, and low cell toxicity. VBP15 was selected as the lead compound due to potent NF-κB inhibition and GR translocation similar to prednisone and dexamethasone, lack of transactivation properties, and good bioavailability. Phamacokinetics were similar to traditional glucocorticoid drugs with terminal half-life of 0.35 h (mice), 0.58 h (rats), 5.42 h (dogs), and bioavailability of 74.5% (mice), and 53.2% (dogs). Metabolic stability showed ?80% remaining at 1 h of VBP6 and VBP15 in human, dog, and monkey liver microsomes. Solubility, permeability and plasma protein binding were within acceptable limits. VBP15 moderately induced CYP3A4 across the three human hepatocyte donors (24–42%), similar to other steroids. VBP15 is currently under development for treatment of Duchenne muscular dystrophy.     

Oleanolic acid,a natural triterpenoid improves blood glucose tolerance in normal mice and ameliorates visceral obesity in mice fed a high-fat diet

Excess visceral adiposity may predispose to chronic diseases like hypertension and type 2 diabetes with a high risk for coronary artery disease. Adipose tissue secreted cytokines and oxidative stress play an important role in chronic disease progression. To combat adiposity, plant-derived triterpenes are currently receiving much attention as they possess antioxidant and anti-inflammatory properties and the ability to regulate glucose and lipid metabolism. In the search for potential antiobese compounds from natural sources, this study evaluated the effects of oleanolic acid (OA), a pentacyclic triterpene commonly present in fruits and vegetables, in glucose tolerance test and on high-fat diet (HFD)-induced obesity in mice. Adult male Swiss mice treated or not with OA (10 mg/kg) were fed a HFD during 15 weeks. Sibutramine (SIB) treated group (10 mg/kg) was included for comparison. Weekly body weights, food and water consumption were measured, and at the end of study period, the levels of blood glucose and lipids, plasma hormone levels of insulin, ghrelin and leptin, and the visceral abdominal fat content were analysed. Mice treated with OA and fed a HFD showed significantly (p < 0.05) improved glucose tolerance, decreased body weights, visceral adiposity, blood glucose, plasma lipids relative to their respective controls fed no OA. Additionally, OA treatment, while significantly elevating the plasma hormone level of leptin, decreased the level of ghrelin. However, it caused a greater decrease in plasma amylase activity than lipase. Sibutramine-treated group also manifested similar effects like OA except for blood glucose level that was not different from HFD control. These findings suggest that OA ameliorates visceral adiposity and improves glucose tolerance in mice and thus has an antiobese potential through modulation of carbohydrate and fat metabolism.     

Expression of IL-32 modulates NF-κB and p38 MAP kinase pathways in human esophageal cancer

BackgroundEsophageal cancer is the seventh leading cause of cancer death in males in USA, and there is a strong link has been demonstrated between inflammation and esophageal cancer, interleukin (IL)-32 is a recently described pro-inflammatory cytokine characterized by the induction of nuclear factor NF-κB activation, the p38MAPK also plays an important role in key cellular processes related to inflammation and cancer. We investigated whether the IL-32 expression may be involved in esophageal carcinogenesis through modulates the activity of NF-κB and p-p38 MAPK.MethodMalignant esophageal tissue and blood samples were obtained from 65 operated untreated patients, normal samples was obtained from 35 patients operated for other reasons as control. IL-32 expression visualized by immunohistochemistry, Real time RT–PCR for IL-32 mRNA expression, NF-κB phosphorylation and phosphorylated p38mapk were analyzed by immunoblotting, ELISA for further detection IL-32 and cytokines (TNF-α, IL-1β, IL-6 and IL-8) concentration in the patient’s sera.ResultsIL-32 expression was increased in immunohistochemical staining for malignant esophageal tissue and it’s correlated with the relative expression level of IL-32 mRNA P = 0.007, the P-NF-κB level elevated in tumor tissue compared with control and no difference in the total NF-κB level P = 0.003 while the IL-32 up-regulated the P-pNF-κB in the esophageal tumor P = 0.005. There is increase in p-p38MAPK activation underlying IL-32 expression in tumor P = 0.004, but no change in total p38 MAPK in malignant esophagus. The plasma level of IL-32 expression was increased in malignant esophageal patients P = 0.01, with increased in the levels of the cytokines TNF-α, IL-6, and IL-1β P<0.05.ConclusionsUnderstanding the pathway of IL-32 expression to stimulate the secretion cytokines via the activation of NF-κB and up-regulation of p-p38MAPK may or may not prove to be a therapeutic target, or a biomarker, and future studies will finally answer this hypothesis generated.     

The modulation of hepatic adenosine triphosphate and inflammation by eicosapentaenoic acid during severe fibrotic progression in the SHRSP5/Dmcr rat model

AimsEicosapentaenoic acid (EPA) can ameliorate certain liver lesions involved in non-alcoholic steatohepatitis (NASH). A previous study has found that stroke-prone spontaneously hypertensive 5/Dmcr (SHRSP5/Dmcr) rats fed a high fat-cholesterol (HFC) diet developed fibrotic steatohepatitis with histological similarities to NASH. This study evaluated the potential effects and mechanisms of action of EPA supplementation using this rodent model.Main methodsMale rats were randomly assigned to groups that were fed with either the stroke-prone (SP) diet or HFC diet with or without EPA for 2, 8 and 14 weeks, respectively. The liver histopathology, biochemical features, mRNA and protein levels, and nuclear factor-κB (NF-κB) DNA binding activity were determined.Key findingsThe SP diet-fed rats presented normal livers. Conversely, the HFC diet-fed rats developed microvesicular/macrovesicular steatosis, inflammation, ballooning degeneration and severe fibrosis. At 2 weeks, the administration of EPA inhibited hepatic inflammatory recruitment by blocking the phosphorylation of inhibitor of κB-α (IκBα), which antagonizes the NF-κB activation pathway. The dietary supplementation of EPA for 8 weeks ameliorated hepatic triglyceride accumulation and macrovesicular steatosis by inhibiting the HFC diet-induced decrease in the protein levels of enzymes involved in fatty acid β-oxidation including carnitine palmitoyltransferase 1, very long chain acyl-CoA dehydrogenase and peroxisomal bifunctional protein. Although the administration of EPA elicited no histologically detectable effects on severe fibrosis at 14 weeks, it restored an HFC diet-induced decline in hepatic adenosine triphosphate (ATP) levels and suppressed ballooning degeneration, suggesting that EPA may inhibit HFC diet-induced ATP loss and cell death.SignificanceInitial amelioration of the inflammation and steatosis in the rats after EPA supplementation indicates a possibility to treat steatohepatitis. Additionally, this study provides new insights into the roles of EPA in hepatic ATP depletion and subsequent hepatocellular injury during severe fibrosis.     

Effects of maternal treatment of dehydroepiandrosterone (DHEA) on serum lipid profile and hepatic lipid metabolism-related gene expression in embryonic chickens

Over the last decade, much evidence emerged to suggest that alterations in maternal diets during pregnancy may irreversibly affect aspects of physiological and biochemical functions in the fetus. To explore the effects of maternal dietary treatments with dehydroepiandrosterone (DHEA) on lipid metabolism in the embryo, we investigated serum lipid profile and hepatic lipid metabolism-related gene expression in the maternal and embryonic chicken. Sixteen-week-old pullets were allocated into 3 groups (n = 30), and after laying, they were provided with a commercial diet supplemented with DHEA at 0, 20 or 100 mg/kg diet. Eggs were collected after DHEA treatment and incubated at 37.5 °C and a relative humidity of 60%. Blood and liver samples were collected from hens and embryonic chickens. DHEA treatment resulted in decreased body weight and increased relative liver weight in both maternal and embryonic chickens, while the concentrations of blood triglyceride (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and non-esterified fatty acid (NEFA) were significantly lower in the 20 mg DHEA/kg group as compared to the control group during embryonic development. The expression of acetyl CoA carboxylase (ACC) and carnitine palmitoyl transferase I (CPTI) gene was also reduced following treatment with 20 mg DHEA/kg at hatching. However, blood TC, and hepatic fatty acid synthase (FAS) and hydroxy methylglutaryl-CoA reductase (HMGR) gene expression were significantly up-regulated in the 100 mg DHEA/kg group during embryonic development and hatching. Overall, the results of this study indicate that maternal dietary treatment with DHEA regulates serum lipid metabolism and hepatic gene expression.     

Organoselenium (Sel-Plex diet) decreases amyloid burden and RNA and DNA oxidative damage in APP/PS1 mice

To evaluate potential antioxidant characteristics of organic selenium (Se), double knock-in transgenic mice expressing human mutations in the amyloid precursor protein (APP) and human presenilin-1 (PS1) were provided a Se-deficient diet, a Se-enriched diet (Sel-Plex), or a control diet from 4 to 9 months of age followed by a control diet until 12 months of age. Levels of DNA, RNA, and protein oxidation as well as lipid peroxidation markers were determined in all mice and amyloid β-peptide (Aβ) plaques were quantified. APP/PS1 mice provided Sel-Plex showed significantly (P < 0.05) lower levels of Aβ plaque deposition and significantly decreased levels of DNA and RNA oxidation. Sel-Plex-treated mice showed no significant differences in levels of lipid peroxidation or protein oxidation compared to APP/PS1 mice on a control diet. To determine if diminished oxidative damage was associated with increased antioxidant enzyme activities, brain glutathione peroxidase (GSH-Px), glutathione reductase, and glutathione transferase activities were measured. Sel-Plex-treated mice showed a modest but significant increase in GSH-Px activity compared to mice on a normal diet (P < 0.5). Overall, these data suggest that organic Se can reduce Aβ burden and minimize DNA and RNA oxidation and support a role for it as a potential therapeutic agent in neurologic disorders with increased oxidative stress.     

Sexual dimorphism,weight gain and glucose intolerance in a B- and T-cell deficient mouse model

BackgroundEstrogen is thought to aid maintenance of insulin sensitivity potentially through modulation of a counter-regulatory mechanism that interferes with the contribution of adaptive and innate immune systems to visceral fat deposition. We evaluated the impact of estrogen on long-term high fat diet (HFD) intake in B- and T-cell deficient and immunocompetent animals comparatively.MethodsA total of 16 BALB and 16 SCID mice, 8 of each sex and strain, were randomized to receive low fat diet, 4.1% fat or HFD, 35% fat, such that there was a group of both each sex and each strain receiving each diet. Biweekly levels of adiponectin, leptin and insulin levels were assessed and a glucose tolerance test (GTT) was performed after 13 weeks.ResultsUnlike their male counterparts, HFD-fed SCID females neither gained weight, nor became insulin resistant. Meanwhile, in the HFD-fed BALB groups both males and females gained weight similarly, but remarkable sexual dimorphism was nonetheless observed. The females had notable higher adiponectin levels as compared to males (10–60 μg/mL vs. 6–10 μg/mL respectively) causing the adiponectin-to-leptin (A/L) ratio to reach 80 one week after HFD initiation. The A/L dropped to 10, still higher than males, by week 13, but dropped to 2 by the end of the study in agreement with inverse insulin trends. None of the HFD-fed female groups developed insulin resistance (IR) by week 13, while all male counterparts had. Similar results were observed in the HFD-fed SCID groups whereby the females did not develop IR and had a higher A/L; however, adiponectin levels were comparable between groups (5–11 μg/mL).ConclusionsThe present study provides lacking evidence indicating that estrogen may be sufficient to prevent weight gain and development of glucose intolerance in high-fat fed B- and T-cell deficient mice.     

Alpha-lipoic acid attenuates methionine choline deficient diet-induced steatohepatitis in C57BL/6 mice

AimsNon-alcoholic steatohepatitis (NASH) is a liver disease that causes fat accumulation, inflammation and fibrosis. Increased oxidative stress contributes to hepatic inflammation and fibrosis by upregulation of Cytochrome P450 2E1 (CYP2E1), endoplasmic reticulum (ER) stress and mitogen-activated protein kinase (MAPK) activity. This study examined whether alpha-lipoic acid (ALA), a naturally occurring thiol antioxidant, prevents steatohepatitis through the inhibition of several pathways involved in hepatic inflammation and fibrosis.Main MethodsC57BL/6 mice were fed an MCD diet with or without ALA for 4 weeks. Liver sections from mice on control or MCD diets with or without ALA were stained with hematoxylin-eosin, oil red O, and anti-4-HNE antibody. The effects of ALA on methionine-choline deficient MCD-diet induced plasma AST and ALT as well as tissue TBARS were measured. The effects of ALA on CYP2E1 expression, ER stress, MAPK levels, and NF-κB activity in MCD diet-fed mice liver were measured by northern and western blot analysis.Key findingsDietary supplementation with ALA reduced MCD diet-induced hepatic lipid accumulation, hepatic inflammation, TBARS, 4-HNE, and plasma ALT and AST levels. These effects were associated with a reduced expression of CYP2E1 and reduced ER stress and MAPK and NF-κB activity.SignificanceTaken together, the results of the present study indicate that ALA attenuates steatohepatitis through inhibition of several pathways, and provide the possibility that ALA can be used to prevent the development and progression of non-alcoholic fatty liver disease in patients who have strong risk factors for NASH.     

1,8-cineole (eucalyptol) ameliorates cerulein-induced acute pancreatitis via modulation of cytokines,oxidative stress and NF-κB activity in mice

AimsAcute pancreatitis (AP) is an inflammatory condition wherein pro-inflammatory mediators, oxidative stress, and NF-κB signaling play a key role. Currently, no specific therapy exists and treatment is mainly supportive and targeted to prevent local pancreatic injury and systemic inflammatory complications. This study was aimed to examine whether 1,8-cineole, a plant monoterpene with antioxidant and anti-inflammatory properties could ameliorate cerulein-induced acute pancreatitis.Main methodsAP was induced in Swiss mice by six one hourly injections of cerulein (50 μg/kg, i.p.). 1,8-cineole (100, 200 and 400 mg/kg, p.o.) was administered 1 h prior to first cerulein injection, keeping vehicle and thalidomide treated groups as controls. Blood samples were taken 6-h later to determine serum levels of amylase and lipase, and cytokines. The pancreas was removed for morphological examination, myeloperoxidase (MPO) and malondialdehyde (MDA) assays, reduced glutathione (GSH) levels, and for nuclear factor (NF)-κB immunostaining.Key findings1,8-cineole effectively reduced the cerulein-induced histological damage, pancreatic edema and NF-κB expression, levels of MPO activity and MDA, and replenished the GSH depletion. Cerulein increased serum levels of amylase and lipase, and pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 were also decreased by 1,8-cineole pretreatment, similar to thalidomide, a TNF-α inhibitor. The anti-inflammatory IL-10 cytokine level was, however, enhanced by 1,8-cineole.SignificanceThese findings indicate that 1,8-cineole can attenuate cerulein-induced AP via an anti-inflammatory mechanism and by combating oxidative stress. Further studies are needed to clearly elucidate its benefits in patients on acute pancreatitis.