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Genistein can be used as a dietary additive to control fat deposition in animals, while its mechanism is poorly understood. In this study, a total of 144 male broilers were randomly divided into 4 groups. Birds were fed standard diets supplemented with 0, 50, 100 or 150 mg of genistein/kg from 21 to 42 d of age. Results showed that genistein treatment decreased the relative weight of abdominal fat and triglyceride contents in broiler chickens. Genistein downregulated hepatic lipid droplets accumulation and upregulated the activity of lipoprotein lipase and hepatic lipase and the concentration of adiponectin. Furthermore, the liver X receptor α, sterol regulatory element–binding protein 1c (SREBP-1c), acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS) mRNA expressions were decreased, whereas adiponectin receptor 2, peroxisome proliferator-activated receptor α, adipose triglyceride lipase, and carnitine palmitoyl transferase-I (CPT-I) mRNA abundances were increased in the liver of broilers treated with genistein. In addition, genistein increased the NAD+ concentration and NAD+/NADH ratio in the liver. Genistein increased estrogen receptor β (ERβ), forkhead box O1, nicotinamide phosphoribosyl transferase, sirtuin1 (SIRT1), phospho (p)-adenosine 5′-monophosphate-activated protein kinase (AMPK), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), p-ACC, and CPT-I protein levels, whereas the SREBP-1c and FAS levels were decreased. These data indicated that genistein might reduce fat accumulation in broiler chickens via activating the AMPK-SIRT1/PGC-1α signaling pathway. The activation of this signaling pathway might be achieved by its direct effect on improving the adiponectin secretion or its indirect effect on upregulation of ERβ expression level through paracrine acting of adiponectin.

Dehydroepiandrosterone (DHEA) has anti-inflammatory, anti-oxidant and immune-regulating properties, while the mechanism of DHEA actions remains unclear. The present study aims to investigate the effect and possible mechanism of DHEA on immune function of mice in vivo and in vitro. In vivo, a lipopolysaccharide (LPS)-induced experimental inflammation model was constructed to analyze the regulation of DHEA on anti-oxidative and immune function in ICR mice; In vitro, the effects of DHEA on the biological functions of lymphocytes and macrophages were studied. The results showed that DHEA increased the activity of total antioxidant capacity and superoxide dismutase, while it decreased the level of reactive oxygen species in LPS-induced mice. Meanwhile, DHEA increased the proportion of T lymphocytes and decreased that of B lymphocytes in primary cultured spleen lymphocytes, and markedly enhanced the Th1/Th2 ratio in spleen T lymphocytes. Furthermore, DHEA significantly increased the Th1 type cytokine (IL-2 and IFN-α) and decreased the Th2 type cytokine (IL-4 and IL-10) levels in LPS-induced mice or in primary cultured spleen T lymphocytes. In addition, DHEA improved the phagocytic ability, enhanced the NO production and increased the iNOS activity in peritoneal macrophages. Our data indicates that DHEA increases the macrophages function via improving NO content and up-regulating TNF-α expression levels; and it evoked a Th1 immuno-response and repressed a Th2 immuno-response through promoting a shift in Th1/Th2 balance toward Th1-dominant immunity in vivo and in vitro. These results provide substantial evidence on the mechanism of DHEA-mediated immune function and the efficient protection against infectious and inflammatory response in animals and humans.

The current research aimed to explore the impact of (-)-hydroxycitric acid (HCA) on fat metabolism and investigate whether this action of (-)-HCA was associated with modulation of glucose-6-phosphote isomerase (GPI) expression in chicken embryos. We constructed a recombinant plasmid (sh2-GPI) to inhibit GPI expression, and then embryos were treated with (-)-HCA. Results showed that (-)-HCA reduced lipid droplet accumulation, triglyceride content, and lipogenesis factors mRNA level and increased lipolysis factors mRNA expression, while this effect caused by (-)-HCA was markedly reversed when the chicken embryos were pretreated with sh2-GPI. (-)-HCA increased phospho (p)-acetyl-CoA carboxylase, enoyl-CoA hydratase short chain-1, carnitine palmitoyl transferase 1A, p-AMP-activated protein kinase, and peroxisome proliferators-activated receptor α protein expression, and this action of (-)-HCA also dispelled when the chicken embryos were pretreated with sh2-GPI. These data demonstrated that (-)-HCA decreased fat deposition via activation of the AMPK pathway, and the fat-reduction action of (-)-HCA was due to the increasing of GPI expression in chicken embryos.

This study aimed to investigate the effect of (-)-hydroxycitric acid ((-)-HCA) on lipid and glucose metabolism, and further analyzed these actions whether associated with modulation of aldehyde dehydrogenase 3 family member A2 (ALDH3A2) expression in chicken embryos. Results showed that (-)-HCA decreased triglyceride content and lipid droplet counts, while these effects induced by (-)-HCA were reversed in chicken embryos pre-transfected with sh4-ALDH3A2. (-)-HCA decreased malic enzyme, acetyl-CoA carboxylase, fatty acid synthase, and sterol regulatory element binding protein-1c mRNA level, while increased carnitine palmitoyl transferase 1A (CPT1A) and peroxisome proliferators-activated receptor α (PPARα) mRNA level; and the action of (-)-HCA on lipid metabolism factors had completely eliminated in embryos pre-transfected with sh4-ALDH3A2. Chicken embryos pre-transfected with sh4-ALDH3A2 had eliminated the increasing of serum glucose and hepatic glycogen content induced by (-)-HCA. (-)-HCA decreased phosphofructokinase-1 and increased G6P, fructose-1,6-bisphosphatase, phosphoenolpyruvate carboxykinase (PEPCK), and pyruvate carboxylase mRNA level in chicken embryos. Similarly, the effect of (-)-HCA on these key enzyme mRNA level was reversed in embryos pre-transfected with sh4-ALDH3A2. Furthermore, (-)-HCA increased PPAR-γ-coactivator-1α (PGC-1α), PPARα, hepatic nuclear factor-4A, PEPCK, and CPT1A protein level, and these actions of (-)-HCA disappeared in embryos pre-transfected with sh4-ALDH3A2. These results indicated that (-)-HCA reduced fat accumulation and accelerated gluconeogenesis via activation of PGC-1α signaling pathway, and these effects of (-)-HCA might associate with the increasing of ALDH3A2 expression level in chicken embryos.

Dehydroepiandrosterone (DHEA) is a popular dietary supplement that has anti-inflammatory, anti-oxidant and immune-regulating role; meanwhile, it also can effective in the protection of inflammation diseases such as inflammatory bowel disease (IBD), but the underlying mechanisms remain elusive. Here, we demonstrated that DHEA inhibits excessive inflammation response and enhances gut barrier function via activating the G protein-coupled receptor 30 (GPR30). GPR30-induced the ERK phosphorylation and p62 accumulation led to the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, which subsequently inhibited the reactive oxygen species (ROS) overproduction and finally alleviated the intestinal barrier dysfunction. Furthermore, DHEA blocked the p38-induced NLRP3 inflammasome activation in both LPS-stimulated colon epithelial cells and macrophages. In addition, in vivo results showed that DHEA and GPR30 agonist G1 attenuated inflammatory responses and gut barrier dysfunction in colitis mice, while the GPR30 specific inhibitor G15 abrogated these beneficial effects of DHEA. Cumulatively, our study unveiled that DHEA is an effective anti-inflammatory agent and suggested that GPR30 could as a potential target for the treatment of IBD.

Nonalcoholic fatty liver disease (NAFLD) is one of the most complex liver diseases in the world, which is characterized by hepatic steatosis, oxidative stress, inflammation, and apoptosis. (-)-Hydroxycitric acid [(-)-HCA] can regulate obesity in different animals, while whether this beneficial effect of (-)-HCA can alleviate the NAFLD and its mechanism is unclear. Hence, this study aimed to determine the potential actions and mechanisms of (-)-HCA on NAFLD in oleic acid (OA)-induced hepatocytes. We found that (-)-HCA effectively improved OA-induced hepatic steatosis by regulating the expression level of fat metabolism key factors, which was achieved by activating AMP-activated protein kinase (AMPK) signaling in hepatocytes. Importantly, activated AMPK alleviates mitochondrial disorder via the peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α)-nuclear transcription factor 1 (NRF-1)-mitochondrial transcription factor A (TFAM) pathway, then reduces reactive oxygen species production, and blocks the activation of p38 MAPK-NF-κB pathway in OA-induced hepatocytes. These results not only provide a theoretical basis for the occurrence and development of NAFLD but also offer compelling evidence for prevention of NAFLD supplemental with (-)-HCA.

Dehydroepiandrosterone (DHEA) is the major steroid hormone in humans and animals, which can regulate the body's inflammatory responses. However, the detail mechanism of this beneficial function is still poorly understood. The present study aimed to explore the anti-inflammation effect of DHEA and its underlying molecular mechanism in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The findings showed that DHEA significantly inhibited the inflammation-related mediators production and pro-inflammatory cytokines expression level. Further research found that DHEA obviously blocked the LPS-stimulated PI3K/AKT, MAPK and NF-κB activation in RAW 264.7 cells. Meanwhile, DHEA enhanced the autophagy-dependent Keap1 protein degradation, subsequently activated the Nrf2 pathway to alleviate the redox imbalance and inflammatory responses. In conclusion, our data demonstrated that DHEA suppresses inflammatory responses through the activation of Nrf2 and inhibition of NF-κB in LPS-stimulated macrophages.

(-)-Hydroxycitric acid [(-)-HCA] is widely used as a nutritional supplement to control body weight and fat accumulation in animals and humans, whereas the underlying biochemical mechanism is unclear. Broiler chicken was used as a model for studies of obesity due to its natural hyperglycemia and being insulin resistant. The current study aimed to obtain a systematic view of serum metabolites and hepatic proteins and well understand the mechanism of hepatic metabolic response to (-)-HCA treatment in chick embryos. The results showed that 22, 90, and 82 of differentially expressed proteins were identified at E14d, E19d, and H1d in chick embryos treated with (-)-HCA, respectively. Meanwhile, 5, 83, and 88 of serum metabolites significantly changed at E14d, E19d, and H1d in chick embryos after (-)-HCA treatment. Bioinformatics analysis showed that the key proteins and metabolites, which were significantly altered in chick embryos treated with (-)-HCA, were mainly involved in the citrate cycle, glycolysis/gluconeogenesis, fatty acid metabolism, and pyruvate metabolism. Our data indicated that (-)-HCA treatment might promote fat metabolism via regulating the key protein expression levels and metabolite contents in the citrate cycle, glycolysis/gluconeogenesis, and oxidative phosphorylation during chicken embryonic development. These results will deepen our understanding of the mechanism of fat reduction by (-)-HCA and provide substantial information for (-)-HCA as a nutritional supplement to control body weight gain and curb obesity-related diseases.

Dehydroepiandrosterone (DHEA) is commonly used as a nutritional supplement to control fat deposition, but the mechanism of this action is poorly understood. In this study, we demonstrated that DHEA increased phosphorylation of AMP-activated protein kinase (p-AMPK). Elevated p-AMPK levels resulted in reduced expression of sterol regulatory element binding protein-1c, acetyl CoA carboxylase, fatty acid synthase and enhanced expression of peroxisome proliferators-activated receptor α and carnitine palmitoyl transferase-I, ultimately leading to the reduction of lipid droplet accumulation in primary chicken hepatocytes. We found that DHEA activates the cyclic adenosine 3', 5'-monophosphate/protein kinase A - extracellular signal-regulated kinase 1/2 (cAMP/PKA-ERK1/2) signaling pathway, which regulates the conversion of DHEA into testosterone and estradiol by increasing the 17β-hydroxysteroid dehydrogenase and aromatase protein expression. Importantly, the fat-reducing effects of DHEA are more closely associated with the conversion of DHEA into estradiol than with the action of DHEA itself as an active biomolecule, or to its alternative metabolite, testosterone. Taken together, our results indicate that DHEA is converted into active hormones through activation of the cAMP/PKA-ERK1/2 signaling pathway; the fat-reducing effects of DHEA are achieved through its conversion into estradiol, not testosterone, and not through direct action of DHEA itself, which led to the activation of the p-AMPK in primary chicken hepatocytes. These data provide novel insight into the mechanisms underlying the action of DHEA in preventing fat deposition, and suggest potential applications for DHEA treatment to control fat deposition or as an agent to treat disorders related to lipid metabolism in animals and humans.

(−)-Hydroxycitric acid (HCA), a major component of Garcinia cambogia extracts, has been shown to suppress BW gain and fat accumulation in animals and humans. However, the mechanism remains unknown. In this study, gas chromatography-mass spectrometry was used to analyse serum metabolites, and principal component analysis and partial least-squares-discriminant analysis models were generated to analyse serum metabolite changes in broiler chickens after the administration of (−)-HCA at 0, 1000, 2000 and 3000 mg/kg diets for 28 days. Metabolites showing significant changes were screened by ‘variable importance in the projection’ plots. The results showed that 20 metabolites in the 1000 mg/kg (−)-HCA treatment group and 16 metabolites in 3000 mg/kg (−)-HCA treatment group were significantly altered. Metabolites pathway enrichment analysis indicated that these metabolites were mainly associated with metabolism of amino acids, protein synthesis, citric acid cycle, and uric acid and fatty acid synthesis. The data indicated that (−)-HCA promoted protein synthesis by regulating the metabolic directions of amino acids. At the same time, (−)-HCA treatment inhibited fatty acid synthesis by promoting the citric acid cycle, resulting in reduced cytosolic acetyl-CoA content in broiler chickens. The present study identified global changes in metabolites and analysed the main canonical metabolic pathways in broiler chickens supplemented with (−)-HCA. These results will deepen our understanding of the mechanism of (−)-HCA’s effects in animals.

This study was conducted to determine the impact of (−)-hydroxycitric acid ((−)-HCA) on biochemical indices and lipid metabolism parameters in chicken embryos. Two hundred and forty fertilized eggs were divided into six groups and injected with (−)-HCA at concentrations of 0, 0.1, 0.5, 1.0, 10.0 and 50 mg/kg (n = 40). After 19 days of incubation, serum and liver were collected for analysis of biochemical indices and lipid metabolism parameters. Results showed no significant differences on serum biochemical indices: 1–50 mg/kg (−)-HCA significantly increased serum glucose and hepatic glycogen contents (P

As the most important bioactive substance in Garcinia cambogia, (-)-hydroxycitric acid (HCA) is widely used in food additives to regulate obesity and diabetes in animals or humans, while the mechanism is poorly understood. The purpose of this study was to elucidate the regulatory effect and mechanism of (-)-HCA in regulating glucose and lipid metabolism in chicken primary hepatocytes. The results showed that (-)-HCA obviously decreased triglyceride content through inhibiting the fatty acid synthase protein level, and enhancing the protein level of phosphorylated acetyl CoA carboxylase, enoyl coenzyme A hydratase short chain 1 and carnitine palmitoyltransferase 1A in hepatocytes. Moreover, (-)-HCA markedly enhanced the protein level of phosphofructokinase-1, pyruvate dehydrogenase, succinate dehydrogenase A and complex IV, and which led to the enhancing of glucose uptake and catabolism in hepatocytes. Importantly, the regulation of (-)-HCA on these key factors associated with lipid and glucose metabolism in hepatocytes was mainly achieved through activation of AMP-activated protein kinase/peroxisome proliferator-activated receptor gamma coactivator 1α-nuclear respiratory factor 1 signaling pathway. These results convincingly demonstrated the mechanism of (-)-HCA's regulating on glucose and lipid metabolism, and provided a strategy in prevention of diseases associated with glycolipid metabolic abnormalities in animals, even in humans.

Dehydroepiandrosterone (DHEA) possess anti-inflammatory, anti-oxidant and immune-regulating function in animals and humans, but there is not enough information about the mechanisms underlying its beneficial effects. The present study investigated the effect and mechanism of DHEA in dextran sulfate sodium (DSS)-induced colitis mice. The findings showed that DHEA relieved the decreasing of body weight, the increasing of disease activity index, the enhancing of spleen weight, the shortening of colon length and the rising of myeloperoxidase activity; meanwhile, histopathological analysis showed that DHEA maintained a relatively intact structure of colon in DSS-induced colitis mice. DHEA decreased the malondialdehyde content, superoxide dismutase activity and inducible nitric oxide synthase protein level; meanwhile, DHEA also inhibited the secretion of tumor necrosis factor-α, interleukin-1β and interleukin-6 in DSS-induced colitis mice. Importantly, our results showed that DHEA blocked the activation of nuclear factor-kappa B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) pathways; and it inhibited the Nod-like receptor protein 3 inflammasome activation in DSS-induced colitis mice. Furthermore, DHEA markedly promoted the intestinal barrier function by up-regulation zonula occludens-1 expression level. The 16S rDNA gene sequencing demonstrated that DHEA decreased the Pseudomonas abundance in DSS-induced colitis mice. In conclusion, our data demonstrated that DHEA reduces oxidative damage through regulating antioxidant enzyme activity; inhibits pro-inflammatory cytokines production by blocking the activation of p38 MAPK and NF-κB signal pathway; protects colon barrier integrity via increasing tight junction protein expression and modulating gut microbiota taxa; all that finally alleviates DSS-induced experimental colitis in mice.

Dehydroepiandrosterone (DHEA), a critical metabolite in cholesterol metabolism, can regulate the inflammatory responses in humans or animals. However, the precise mechanisms of these beneficial actions remains poorly understood. Present study aims to clarify the anti-inflammatory function of DHEA and its possible mechanisms in the E. coli O157:H7-stimulated mice. The results indicated that DHEA reduced the mortality of mice and bacterial concentration in the peritoneal fluid in the E. coli-stimulated mice. DHEA increased the spleen index, the activity of lactate dehydrogenase and acid phosphatase; while it decreased the nitric oxide (NO) content and inducible nitric oxide synthase (iNOS) activity in mice. The mRNA levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and interferon gamma (IFN-γ) were decreased, whereas the interleukin-4 (IL-4) and interleukin-10 (IL-10) mRNA levels were increased in the E. coli-stimulated mice treated with DHEA. Moreover, DHEA treatment reversed the increasing of IFN-γ/IL-4 ratio in mice caused by E. coli infection. Importantly, DHEA blocked the nuclear translocation of p65 through down-regulation the IκB-α protein phosphorylation level in the mice stimulated with E. coli O157:H7. No statically changes were showed on the phospho (p)-ERK1/2 and p-JNK1/2 protein level, while DHEA significantly suppressed the p-p38 protein level in mice. The above results indicated that DHEA alleviated inflammatory responses by suppressing NO secretion and promoting Th2-associated anti-inflammatory cytokines production in mice; and this action might relate to the blocking of p38 MAPK and NF-κB signaling pathways activation. All the above results provide substantial information for understanding the anti-inflammatory function of DHEA and further support it as a potential immunomodulatory in prevention inflammatory and bacterial infection diseases.

As an important metabolite in cholesterol metabolism, dehydroepiandrosterone (DHEA) can modulate the immune function in animals and humans, but the underlying mechanism is still unclear. The present study investigated the effect and mechanism of DHEA's anti-inflammatory action in primary mice peritoneal macrophages infected with E. coli O157:H7. The finding showed that DHEA improved the phagocytic ability in E. coli O157:H7-infected macrophages. DHEA inhibited the cytokines (including tumor necrosis factor-α, interleukin-1β and interleukin-6) secretion in E. coli O157:H7-infected macrophages. The inducible nitric oxide synthase and cyclooxygenase-2 protein level were significantly decreased in E. coli O157:H7-infected macrophages treated with DHEA. In addition, DHEA markedly decreased the phospho (p)-p38 MAPK protein level in E. coli O157:H7-infected macrophages. Furthermore, DHEA prevented the nuclear translocation of NF-κB by decreasing of p-IκB-α protein level in E. coli O157:H7-infected macrophage; and these effects of DHEA were heightened when the cells were pre-treated with p38 MAPK inhibitor SB203580. Our data indicated that DHEA alleviates the pro-inflammatory mediator production in E. coli O157:H7-infected mice peritoneal macrophages; and this beneficial action associated with it prevents the activation of p38 MAPK and NF-κB signaling pathway.

(-)-Hydroxycitric acid (HCA) inhibits the deposition of fat in animals and humans, while the molecular mechanism is still unclear. The present study investigated the effect and mechanism of (-)-HCA's regulation of lipid, glucose, and energy metabolism in broiler chickens. The current results showed that (-)-HCA decreased the accumulation of lipid droplets and triglyceride content by reducing fatty acid synthase protein level and enhancing phosphorylation of acetyl-CoA carboxylase protein level. (-)-HCA accelerated carbohydrate aerobic metabolisms by increasing the activities of phosphofructokinase-1, pyruvate dehydrogenase, succinate dehydrogenase, and malate dehydrogenase. Furthermore, (-)-HCA increased adiponectin receptor 1 mRNA level and enhanced phospho-AMPKα, peroxisome proliferator-activated receptor gamma coactivator-1α, nuclear respiratory factor-1, and mitochondrial transcription factor A protein levels in broiler chickens. These data indicated that (-)-HCA reduced lipid droplet accumulation, improved glucose catabolism, and accelerated energy metabolism in broiler chickens, possibly via activation of adiponectin-AMPK signaling pathway. These results revealed the biochemical mechanism of (-)-HCA-mediated fat accumulation and the prevention of metabolic disorder-related diseases in broiler chickens.

// Xiao Ding 1 , Lei Yu 1 , Chongyang Ge 1 and Haitian Ma 1 1 Key Laboratory of Animal Physiology and Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China Correspondence to: Haitian Ma, email: // Keywords : dehydroepiandrosterone; oxidative damage; apoptosis; Leydig cells; Pathology Section Received : September 16, 2016 Accepted : January 07, 2017 Published : February 13, 2017 Abstract Dehydroepiandrosterone (DHEA) is widely used as a nutritional supplement due to its putative anti-aging properties. However, the effect of DHEA in Leydig cells, a major target cell of DHEA biotransformation in male, are not clear. The present study aimed to investigate the preventative effect of DHEA on oxidative damage and apoptosis after H 2 O 2 treatment in Leydig cells. The results showed that DHEA treatment attenuated the reduction of cell viability induced by H 2 O 2 . No differences were observed on the superoxide anion (O 2 - ) content, while DHEA treatment decreased reactive oxygen species (ROS) and hydroxyl radical (•OH) content in H 2 O 2 -treated Leydig cells. Pre-treatment with DHEA increased peroxidase (POD) activity and decreased glutathione peroxidase (GSH-Px) activity in H 2 O 2 -treated Leydig cell. DHEA treatment attenuated DNA damage as indicated by the decreasing of tail moment, comet length and olive tail moment. Total apoptosis ratio and early apoptosis ratio were significantly decreased in H 2 O 2 -treated Leydig cell that were pre-treatment with DHEA. DHEA treatment decreased Bax , capase-9 and capase-3 mRNA levels in H 2 O 2 -treated Leydig cells. Our results demonstrated that pre-treatment with DHEA prevented the Leydig cells oxidative damage caused by H 2 O 2 through increasing POD activity, which resulted in inhibition of •OH generation. Meanwhile, pre-treatment with DHEA inhibited H 2 O 2 -induced Leydig cells early apoptosis which mainly by reducing the pro-apoptotic protein Bax and caspases-9 , caspases-3 mRNA levels. This information is important to understand the molecular mechanism of anti-ageing effect and potential application in treatment of oxidative stress induced related diseases of DHEA.

(-)-Hydroxycitric acid (HCA), a major active ingredient of Garcinia Cambogia extracts, had shown to suppress body weight gain and fat accumulation in animals and humans. While, the underlying mechanism of (-)-HCA has not fully understood. Thus, this study was aimed to investigate the effects of long-term supplement with (-)-HCA on body weight gain and variances of amino acid content in rats. Results showed that (-)-HCA treatment reduced body weight gain and increased feed conversion ratio in rats. The content of hepatic glycogen, muscle glycogen, and serum T4 , T3 , insulin, and Leptin were increased in (-)-HCA treatment groups. Protein content in liver and muscle were significantly increased in (-)-HCA treatment groups. Amino acid profile analysis indicated that most of amino acid contents in serum and liver, especially aromatic amino acid and branched amino acid, were higher in (-)-HCA treatment groups. However, most of the amino acid contents in muscle, especially aromatic amino acid and branched amino acid, were reduced in (-)-HCA treatment groups. These results indicated that (-)-HCA treatment could reduce body weight gain through promoting energy expenditure via regulation of thyroid hormone levels. In addition, (-)-HCA treatment could promote protein synthesis by altering the metabolic directions of amino acids. Copyright © 2016 John Wiley & Sons, Ltd.

Dehydroepiandrosterone (DHEA) is a popular dietary supplement that has well-known benefits in animals and humans, but there is not enough information about the mechanisms underlying its effects. The present study aimed at investigating these mechanisms through in vitro experiments on the effects of DHEA on rat liver BRL-3A cells exposed to oxidative stress through H2O2. The findings showed that DHEA increased the antioxidant enzyme activity, decreased ROS generation, and inhibited apoptosis in H2O2-treated cells. These effects of DHEA were not observed when the cells were pretreated with known antagonists of sex hormones (Trilostane, Flutamide, or Fulvestrant). Furthermore, treatment with estradiol and testosterone did not have the same protective effects as DHEA. Thus, the beneficial effects of DHEA were associated with mechanisms that were independent of steroid hormone pathways. With regard to the mechanism underlying the antiapoptotic effect of DHEA, pretreatment with DHEA was found to induce a significant decrease in the protein expression of Bax and caspase-3 and a significant increase in the protein expression of PI3K and p-Akt in H2O2-treated BRL-3A cells. These effects of DHEA were abolished when the cells were pretreated with the PI3K inhibitor LY294002. No changes were observed on the p-ERK1/2, p-p38, and p-JNK protein levels in H2O2-induced BRL-3A cells pretreated with DHEA. In conclusion, our data demonstrate that DHEA protects BRL-3A cells against H2O2-induced oxidative stress and apoptosis through mechanisms that do not involve its biotransformation into steroid hormones or the activation of sex hormone receptors. Importantly, the protective effect of DHEA on BRL-3A cells was mainly associated with PI3K/Akt signaling pathways, rather than MAPK signaling pathways.

Dehydroepiandrosterone (DHEA) is widely used as a nutritional supplement, and administration of DHEA produces a number of beneficial effects in the elderly. Many researchers have suggested that DHEA exerts it function after conversion into more biologically active hormones in peripheral target cells. The actions of DHEA in Leydig cells, a major target cell of DHEA biotransformation in males, are not clear. The present study found that DHEA increased cell viability and decreased reactive oxygen species (ROS) and malondialdehyde contents in H2O2-induced Leydig cells. DHEA significantly increased the activities of superoxide dismutase, catalase and peroxidase, and decreased the DNA damage in H2O2-induced Leydig cells. Apoptosis was significant decreased in H2O2-induced Leydig cells after DHEA treatment. DHEA inhibited the loss of mitochondrial membrane potential (ΔΨm) and the upregulation of the caspase-3 protein level induced by H2O2 in Leydig cells. DHEA also reversed the decrease in PI3K and p-Akt protein levels induced by H2O2. These data showed that DHEA could ameliorate H2O2-induced oxidative damage by increasing anti-oxidative enzyme activities, which resulted in reduced ROS content, and decreased apoptosis, mainly by preventing the loss of ΔΨm and inhibiting caspase-3 protein levels via activation of PI3K/Akt signaling pathways. These results increase our understanding of the molecular mechanism of the anti-ageing effect of DHEA.

Background: Dehydroepiandrosterone decreases with age and this reduction has been shown to be associated with physical health in human. Some studies have suggested that the effects of DHEA are exerted after it is biotransformed into more biologically-active hormones in peripheral target cells. This study investigated the effects of DHEA on the testosterone biosynthesis and possible signaling pathway mechanism underlying these DHEA effects were also explored in primary rat Leydig cells. Methods: Primary Leydig cells were treated with DHEA and then detected testosterone content by RIA and steroidogenic enzymes, ERK1/2 signal pathway factors protein expression level by Western blot. Results: Incubation of primary Leydig cells with DHEA significantly increased testosterone content and 3β-HSD and 17β-HSD protein expression levels, while aromatase protein expression levels were decreased. Compared with the control group, p-ERK1/2 and p-CREB protein levels were significantly increased in DHEA-treated groups. Testosterone content was significantly decreased in the DHEA-treated group pre-incubated with U0126 (p-ERK1/2 inhibitor). Additionally, the rise in p-ERK1/2, 3β-HSD and 17β-HSD protein levels induced by DHEA was reversed when cells were pre-incubated with U0126. Interestingly, no significant difference was found in aromatase protein expression level in cells pretreated with U0126. Conclusion: These findings demonstrate that (a) exogenous DHEA might preferentially convert to testosterone rather than estradiol due to the up-regulation of 3β-HSD and 17β-HSD protein levels and the down-regulation of aromatase protein level in primary Leydig cells, and (b) the action of DHEA is at least partly associated with the elevation of p-ERK1/2 and p-CREB protein levels.

This study aimed to investigate the molecular mechanism of dehydroepiandrosterone (DHEA) rehabilitated BRL-3A cells oxidative stress damage induced by hydrogen peroxide (H2 O2 ). Results showed that DHEA reversed the decrease of cell viability and ameliorated nuclear chromatin damage in H2 O2 -induced BRL-3A cells. DHEA increased the activities of superoxide dismutase, catalase, peroxidase, and glutathione peroxidase, and decreased the reactive oxygen species (ROS) production in H2 O2 -induced BRL-3A cells. DHEA attenuated the protein damage and lipid peroxidation, and reduced the apoptosis in H2 O2 -induced BRL-3A cells. The mRNA levels of Bax, Caspase-9, and Caspase-3 were decreased, while the Bcl-2 mRNA level was increased in H2 O2 -induced BRL-3A cells treated with DHEA. Our results showed that DHEA treatment increased the PI3K and p-Akt protein levels, while decreased the Bax and capase-3 protein levels in H2 O2 -induced BRL-3A cells. However, the rise in PI3K and p-Akt protein levels, and the decrease in Bax and capase-3 protein levels induced by DHEA treatment were reversed when the cells pretreated with LY294002 (PI3K inhibitor). These results indicated that DHEA ameliorated H2 O2 -induced oxidative damage by increasing anti-oxidative enzyme activities and ameliorating the protein damage and lipid peroxidation in BRL-3A cells. In addition, DHEA decreased the apoptosis by inhibiting caspase-3 and Bax protein levels and this action mainly achieved via the activation of PI3K/Akt signaling pathways in H2 O2 -induced BRL-3A cells. These results provided substantial information for DHEA as a nutritional supplement to treat oxidative stress and it related diseases in animals and humans.

Metabolic disorder is a major health problem and is associated with a number of metabolic diseases. Due to native hyperglycaemia and resistance to exogenous insulin, chickens as a model had used in the studies of adipose tissue biology, metabolism and obesity. But no detailed information is available about the comprehensive changes of serum metabolites at different stages of chicken embryonic development. This study employed LC/MS-QTOF to determine the changes of major functional metabolites at incubation day 14 (E14d), 19 (E19d) and hatching day 1 (H1d), and the associated pathways of differential metabolites during chicken embryonic development were analysed using Metabolite Set Enrichment Analysis method. Results showed that 39 metabolites were significantly changed from E14d to E19d and 68 metabolites were significantly altered from E19d to H1d in chicken embryos. Protein synthesis was promoted by increasing the concentrations of L-glutamine and threonine, and gonadal development was promoted through increasing oestrone content from E14d to E19d in chicken embryos, which indicated that serum glutamine, threonine and oestrone contents may be considered as the candidate indicators for assessment of early embryonic development. 2-oxoglutaric acid mainly contributed to enhancing the citric cycle, and it plays an important role in improving the growth of chicken embryos at the late development; the decreasing of L-glutamine, L-isoleucine and L-leucine contents from E19d to H1d in chicken embryonic development implied their possible functions as the feed additive during early posthatch period of broiler chickens to satisfy the growth. These results provided insights into understand the roles of serum metabolites at different developmental stages of chicken embryos, it also provides available information for chicken as a model to study metabolic disease or human obesity.

To investigate the influence of dietary taurine and reduced housing density on hepatic functions in laying hens, green-shell laying hens were randomly assigned to 3 groups: a free-range group, a caged group with low-density, and a caged group with high-density. Each group was further divided into the control (C) and taurine-treatment (T) groups. All the test birds were fed the same basic diet, except that the T groups were supplemented with 0.1% taurine. After 15 d, sera and liver were aseptically collected. The results show that dietary taurine supplementation and reduced housing density significantly attenuated physiopathological changes in the liver. When compared with the free-range group, serum alanine aminotransterase and aspartate aminotransterase in the caged hens were significantly higher and were deceased by taurine (P0.05). Serum inducible nitric oxide synthase activity in caged hens was higher than that in free-range hens, and taurine reduced serum inducible nitric oxide synthase activities in the low-density group (P0.05). Nuclear factor-κB DNA-binding activity increased significantly in the high-density housing group when compared with the other 2 housing patterns and was decreased by taurine (P0.05). Taurine reduced the expression of tumor necrosis factor-α mRNA in all 3 rearing patterns, IL-4 mRNA expression in the high-density group, and IL-10 in the low-density group (P0.05). Malondialdehyde levels decreased in serum and liver from T groups and serum total antioxidation capability levels increased significantly (P0.05) in the low-density group. Dietary taurine supplementation decreased acetyl-CoA and sterol regulatory element-binding protein-1c mRNA expression in the high-density groups (P0.05). Taurine significantly increased lipoprotein lipase mRNA expression in the high-density group and peroxisome proliferator receptor mRNA expression both in the low- and high-density groups (P0.05). Taurine supplementation reduced total cholesterol levels in the low- and high-density groups, decreased triglyceride and low-density lipoprotein cholesterol levels in high-density groups, and increased high-density lipoprotein cholesterol levels in all 3 rearing patterns (P0.05). Our data demonstrate that dietary taurine and reduced housing density offer significant protection from hepatic damage in laying hens.

Mastitis, caused by mammary pathogenic bacteria which are frequent implications of Escherichia coli, is an important disease affecting women and dairy animals worldwide. The β-glucan binding of dectin-1 can induce its own intracellular signaling and can mediate a variety of cellular responses. This work was to investigate the effect of β-glucan on the lipopolysaccharide (LPS)-induced inflammatory response and related innate immune signaling in primary rat mammary epithelial cells. Cells were treated with serum-free medium added with a DMSO solution containing β-glucans at concentrations of 0, 1, 5, 25 μmol/L for 12h, and then exposed to 10 μg/mL LPS for 40 min. Moreover, cells were pretreated with BAY 11-7082 to inhibit NF-κB and then successively exposed to 5 μmol/L β-glucan, 10 μg/mL LPS, 5 μmol/L β-glucan and 10 μg/mL LPS, according to the specific experimental design. Normal control cultures contained an equal volume of DMSO, which was collected at the same time. After incubating rat mammary epithelial cells for 40 min with 10 μg/mL LPS, TLR4, MyD88 and NF-κB expression all increased (P

This study investigated the putative protective effects of supplemental 2-aminoethane sulfonic acid (taurine) and reduced housing density on renal function in laying hens. We randomly assigned fifteen thousand green-shell laying hens into three groups: a free range group, a low-density caged group, and a high-density caged group. Each group was further divided equally into a control group (C) and a taurine treatment group (T). After 15 d, we analyzed histological changes in kidney cells, inflammatory mediator levels, oxidation and anti-oxidation levels. Experimental data revealed taurine supplementation, and rearing free range or in low-density housing can lessen morphological renal damage, inflammatory mediator levels, and oxidation levels and increase anti-oxidation levels. Our data demonstrate that taurine supplementation and a reduction in housing density can ameliorate renal impairment, increase productivity, enhance health, and promote welfare in laying hens.

Background/Aims: (-)-Hydroxycitric acid (HCA) had been shown to suppress fat accumulation in animals and humans, while the underlying biochemical mechanism is not fully understood, especially little information is available on whether (-)-HCA regulates energy metabolism and consequently affects fat deposition. Methods: Hepatocytes were cultured for 24 h and then exposed to (-)-HCA (0, 1, 10, 50 µM), enzyme protein content was determined by ELISA; lipid metabolism gene mRNA levels were detected by RT-PCR. Results: (-)-HCA significantly decreased the number and total area of lipid droplets. ATP-citrate lyase, fatty acid synthase and sterol regulatory element binding protein-1c mRNA level were significantly decreased after (-)-HCA treatment, whereas peroxisome proliferator-activated receptor α mRNA level was significantly increased. (-)-HCA significantly decreased ATP-citrate lyase activity and acetyl-CoA content in cytosol, but significantly increased glucose consumption and mitochondrial oxygen consumption rate. (-)-HCA promoted the activity/content of glucokinase, phosphofructokinase-1, pyruvate kinase, pyruvate dehydrogenase, citrate synthase, aconitase, succinate dehydrogenase, malate dehydrogenase, NADH dehydrogenase and ATP synthase remarkably. Conclusions: (-)-HCA decreased lipid droplets accumulation by reducing acetyl-CoA supply, which mainly achieved via inhibition of ATP-citrate lyase, and accelerating energy metabolism in chicken hepatocytes. These results proposed a biochemical mechanism of fat reduction by (-)-HCA in broiler chickens in term of energy metabolism.

(-)-Hydroxycitric acid (HCA) suppresses fatty acid synthesis in animals, but its biochemical mechanism in poultry is unclear. This study identified the key proteins associated with fat metabolism and elucidated the biochemical mechanism of (-)-HCA in broiler chickens. Four groups (n = 30 each) received a diet supplemented with 0, 1000, 2000 or 3000 mg/kg (-)-HCA for 4 weeks. Of the differentially expressed liver proteins, 40 and 26 were identified in the mitochondrial and cytoplasm respectively. Pyruvate dehydrogenase E1 components (PDHA1 and PDHB), dihydrolipoyl dehydrogenase (DLD), aconitase (ACO2), a-ketoglutarate dehydrogenase complex (DLST), enoyl-CoA hydratase (ECHS1) and phosphoglycerate kinase (PGK) were upregulated, while NADP-dependent malic enzyme (ME1) was downregulated. Biological network analysis showed that the identified proteins were involved in glycometabolism and lipid metabolism, whereas PDHA1, PDHB, ECHS1, and ME1 were identified in the canonical pathway by Ingenuity Pathway Analysis. The data indicated that (-)-HCA inhibited fatty acid synthesis by reducing the acetyl-CoA supply, via promotion of the tricarboxylic acid cycle (upregulation of PDHA1, PDHB, ACO2, and DLST expression) and inhibition of ME1 expression. Moreover, (-)-HCA promoted fatty acid beta-oxidation by upregulating ECHS1 expression. These results reflect a biochemically relevant mechanism of fat reduction by (-)-HCA in broiler chickens.

Four hundred male chickens were selected to study the effects of pyruvate (Pyr), creatine pyruvate (CrPyr) and creatine (Cr) on the expression of hepatic mitochondrial and cytoplasm proteins associated with lipid and protein metabolism. Mitochondrial purification was accomplished using the two-step differential centrifugation and density gradient method, and the activities of organelle-specific marker enzymes were determined to assess the purity of the mitochondria. Proteins were extracted and fractionated by two-dimensional electrophoresis and the differential protein spots were assessed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. CrPyr reduced fatty acid accumulation by down-regulating adipose differentiation-related protein, inhibited ATP synthase expression, and reduced cholesteryl ester transfer protein (CETP) expression, thus reducing the levels of high density lipoprotein and triglycerol (TG) levels (thereby lowering fat and cholesterol deposition). CrPyr increased the expression of eukaryotic translation initiation factor (eIF) 2B, calreticulin (CRT) and eIF3a, thus promoting protein synthesis. CrPyr up-regulated the expression of fatty acid-binding proteins, CETP and apolipoprotein A-IV in cytoplasmic extracts, and these proteins accelerated the decomposition of fatty acids and TG, thus reducing fat deposition. In conclusion, CrPyr plays an important role in lipolysis and protein synthesis, and this effect was more pronounced than was the effect of Pyr and Cr.

Dehydroepiandrosterone (DHEA) is a precursor of the adrenocorticosteroid hormones that are common to all animals, including poultry. The study described herein was undertaken to investigate the effect of DHEA on lipid metabolism in broiler chickens during embryonic development and to determine the regulatory mechanisms involved in its physiological action. Treatment group eggs were injected with 50mg DHEA diluted in 50 μL dimethyl sulfoxide (DMSO) per kg, while control group eggs (arbor acres [AA] fertilized) were injected with 50 μL DMSO per kg prior to incubation. Liver samples were collected on days 9, 14 and 19 of embryonic development as well as at hatching. Extracted proteins were analyzed by two dimensional gel electrophoresis (2-DE) in combination with western blotting for specific anti-phosphotyrosine. The differential spots were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) or MALDI-TOF-TOF-MS. Peptide mass fingerprinting (PMF) of the differentially-expressed proteins were performed using the MASCOT, Prospector or proFound server. Thirty-seven proteins and twenty-two tyrosine phosphorylation proteins were successfully identified. All 37 proteins and 22 tyrosine phosphorylation proteins exhibited a significant volume difference from the control group. These results demonstrated that DHEA increased the expression and level of tyrosine phosphorylation and sulfotransferase proteins in broilers (at pI 5.9), therefore promoting the biotransformation of DHEA. The expression of apolipoproteinA-I was increased in the DHEA treatment group, which facilitated the conversion of cholesterol to cholesterol esters. Also, DHEA increased the expression of peroxiredoxin-6 and its tyrosine phosphorylation protein levels, thus enhancing its anti-oxidative activity. Furthermore, pyruvate dehydrogenase expression was decreased and the level of its tyrosine phosphorylation proteins increased in the DHEA treatment group. Take together, those data indicate that DHEA reduces the supply of acetyl-CoA by inhibiting the activity of its target enzyme (i.e., pyruvate dehydrogenase), thus affecting both protein synthesis and phosphorylation level and decreasing fat deposition in broiler chickens during embryonic development, which could reflect a physiologically-relevant DHEA fat-reduction mechanism in the broiler chicken.

The adrenals of humans and primates could secrete large amounts of dehydroepiandrosterone (DHEA) and its sulphate ester (DHEA-S) in the circulation, which act as precursors of active steroid hormones in a long series of peripheral target intracrine tissues. The marked decline of serum DHEA and DHEA-S concentrations with age in humans has been incriminated in the development of various pathologies. Therefore, this study aims to provide detailed information on the effects of the intraperitoneal injection of DHEA on circulating steroid hormones and their metabolites and their trade-off relationship over 24 h in male rats. In this study, 100 healthy adult male Sprague-Dawley (SD) rats were randomly divided into three groups: control, 25 mg kg(-1) DHEA-treated and 100 mg kg(-1) DHEA-treated. The animals were sacrificed at 0, 1.5, 3, 6, 12 or 24 h, and the samples were collected for subsequent analysis. Total cholesterol (TC) markedly decreased 3h after the administration of 100 mg kg(-1) DHEA, but markedly increased 12h after administration. The DHEA-S, progesterone (P), testosterone (T), oestradiol (E(2)), cortisol (Cor) and aldosterone (Ald) concentrations also markedly increased after DHEA administration, with serum DHEA-S, T, E(2) and Cor levels peaking at 1.5 h. Over time, steroid hormone levels were depressed, but serum Cor and Ald levels were markedly elevated relative to the control group at 24 h. Furthermore, DHEA treatment produced a significant increase in P450scc, 17beta-HSDIII, CYP17alpha and 3beta-HSD mRNA expression at 1.5 h, but a decided decrease in P450scc and StAR mRNA expression at 12 and 24 h, and CYP17alpha and 17beta-HSDIII expression at 12 h in the 100 mg kg(-1) DHEA group. In total, the results of the present study indicate that DHEA at high pharmacological doses may affect steroid through an effect on steroidogenic enzymes.

In order to investigate differences in fat metabolism during embryonic development, a comparative proteomics strategy was employed using Arbor Acres (AA) and San Huang (SH) broiler chickens with different growth and fat deposition characteristics. These birds were floor-reared and fed identical diets, and embryonic livers were collected from AA and SH chicken embryos on days 9, 14 and 19 of incubation and hatching. Proteins were extracted and fractionated by two-dimensional electrophoresis (2-DE), Neuhoff's colloidal Coomassie Blue G-250 staining was carried out, and stained gels were scanned and analyzed using PDQuest7.3 software (Bio-Rad). In-gel trypsin digestion of the differential protein spots and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) were subsequently assessed. Peptide mass fingerprinting of the differentially expressed proteins was performed using the server from MASCOT or either Prospector or ProFound, and 37 proteins were successfully identified. In the present study, embryo and liver weights showed a trend toward enhanced growth during embryonic development. Of the 37 identified differential proteins, phosphoenolpyruvate carboxykinase (PEPCK), apolipoprotein A-I (Apo A-I), fatty acid-binding protein (L-FABP) and 3-hydroxy-3-methylglutaryl-Coenzyme A synthase (HMG-CoA synthase) were up-regulated in SH chickens to a greater extent than they were in AA chickens. These observations suggest that the lipid metabolic proteins and enzymes are inherent characteristics that contribute to the apparent differences in fat deposition between the two strains.

Background Chicken as a delicious food for a long history, and it is well known that excess fat deposition in broiler chickens will not only induced metabolic diseases, but also lead to adverse effect in the consumer’s health. (−)-Hydroxycitric acid (HCA), a major active ingredient of Garcinia Cambogia extracts, had shown to suppress fat accumulation in animals and humans. While, the precise physiological mechanism of HCA has not yet been full clarified, especially its action in broiler chickens. Thus, this study aimed to assess the effect of (−)-HCA on lipid metabolism in broiler chickens. Methods A total of 120 1-day-old broiler chickens were randomly allocated to four groups, with each group was repeated three times with 10 birds. Birds received a commercial diet supplemented with (−)-HCA at 0, 1000, 2000 or 3000 mg/kg, respectively, for a period of 4 weeks ad libitum. Results Body weight (BW) in the 2000 and 3000 mg/kg (−)-HCA groups was significantly decreased (P < 0.05) than that in control group. A significantly decreased of serum triglyceride (TG) and density lipoprotein-cholesterol (LDL-C) content were observed in 3000 mg/kg (−)-HCA group (P < 0.05). Broiler chickens supplmented with 2000 and 3000 mg/kg (−)-HCA had pronouncedly higher hepatic lipase (HL) activity, hepatic glycogen and non-esterified fatty acid (NEFA) contents in liver (P < 0.05). Serum free triiodothyronine (FT3) and thyroxin (T4) contents were significantly higher in 3000 mg/kg (−)-HCA group (P < 0.05) compared with the control group. Supplemental (−)-HCA markedly decreased fatty acid synthase (FAS) and sterol regulatory element binding protein-1c (SREBP-1c) (P < 0.05) mRNA levels, while the mRNA abundance of adenosine 5′-monophosphate-activated protein kinaseβ2 (AMPKβ2) (P < 0.05) was significantly increased. In addition, ATP-citrate lyase (ACLY) mRNA level (P < 0.05) was significantly decreased in broiler chickens supplemented with 3000 mg/kg (−)-HCA. No differences was observed on carnitine palmitoyl transferase-I(CPT-I), while peroxisome proliferators-activated receptor α (PPARα) mRNA level (P < 0.05) was significantly increased in broiler chickens supplemented with 2000 and 3000 mg/kg (−)-HCA. Conclusions Supplemental (−)-HCA inhibited lipogenesis by inhibiting ACLY, SREBP-1c and FAS expression, and accelerated lipolysis through enhancing HL activity and PPARα expression, which eventually led to the reduced abdominal fat deposition in broiler chickens. Graphical abstract Mechanism of (−)-HCA effect on hepatic lipids metabolism.

Dehydroepiandrosterone (DHEA) has a fat-reducing effect, while little information is available on whether DHEA regulates glucose metabolism, which would in turn affect fat deposition. To investigate the effects of DHEA on glucose metabolism, rats were administered a high-fat diet containing either 0 (HCG), 25 (HLG), 50 (HMG), or 100 (HHG) mg·kg-1 DHEA per day via gavage for 8 weeks. Results showed that long-term administration of DHEA inhibited body weight gain in rats on a high-fat diet. No statistical differences in serum glucose levels were observed, whereas hepatic glycogen content in HMG and HHG groups and muscle glycogen content in HLG and HMG groups were higher than those in HCG group. Glucokinase, malate dehydrogenase and phosphofructokinase-2 activities in HMG and HHG groups, pyruvate kinase and succinate dehydrogenase activities in HMG group, and pyruvate dehydrogenase activity in all DHEA treatment groups were increased compared with those in HCG group. Phosphoenolpyruvate carboxykinase and glycogen phosphorylase mRNA levels were decreased in HMG and HHG groups, whereas glycogen synthase-2 mRNA level was increased in HMG group compared with those in HCG. The abundance of Glut2 mRNA in HMG and HHG groups and Glut4 mRNA in HMG group was higher than that in HCG group. DHEA treatment increased serum leptin content in HMG and HHG groups compared with that in HCG group. Serum insulin content and insulin receptor mRNA level in HMG group and insulin receptor substrate-2 mRNA level in HMG and HHG group were increased compared with those in HCG group. Furthermore, Pi3k mRNA level in HMG and Akt mRNA level in HMG and HHG groups were significantly increased than those in HCG group. These data showed that DHEA treatment could enhance glycogen storage and accelerate glucose catabolism in rats fed a high-fat diet, and this effect may be associated with the activation of PI3K/Akt-PFK-2 signaling pathway.

The aim of the present study was to identify the effects of dehydroepiandrosterone (DHEA) on hepatic lipid metabolism parameters and lipogenic gene mRNA expression in broiler chickens. A total of 72 1-day-old broiler chicks received a common basal diet with DHEA added at either 0 (control), 5 or 20 mg/kg feed. In the present study, the hepatic triglyceride (TG) concentration was significantly lower in male and female broilers that had bed administered DHEA than in control birds. In contrast, DHEA administration caused a marked rise in the hepatic non-esterified fatty acid (NEFA) concentration in both male and female broilers and also increased lipase (HL) activity in male broilers, while in female birds, no significant differences were observed in HL activity. The expression of peroxisome proliferators-activated receptor alpha (PPARalpha) and carnitine palmitoyl transferase I (CPTI) mRNA was decidedly enhanced following treatment with DHEA, and a similar tendency was also observed in the expression of acyl-Coenzyme A oxidase 1 (ACOX1). However, no significant differences were observed in the expression of either sterol regulatory element binding protein-1c (SREBP-1c) or acetyl CoA carboxylase (ACC) mRNA, except for a decline in the expression of ACC in females treated with 5 mg DHEA/kg. Numerous peroxisomes without a core and an increased number of peroxisomes were evident during morphological observations of broiler livers, in animals that had been treated with DHEA. Overall, the results of the present study indicated that DHEA accelerated lipid catabolism by direct regulation of hepatic lipid metabolism and by induction of relevant gene expression.

The aim of the current study was to evaluate the effect of chronic dehydroepiandrosterone (DHEA) administration on steroid hormones and antioxidant parameters in aged rats. To this end, three groups of Sprague-Dawley rats were compared: young (3 months of age) untreated; aged (19 months old) untreated; and aged rats treated with 20 mg/kg DHEA for 8 weeks. Major organs of aged rats in the untreated group demonstrated physiological atrophy, compared to those of young rats; this effect appeared to have been partially reversed by DHEA treatment. Testosterone and estradiol contents were significantly decreased and aldosterone significantly increased in aged untreated, compared to young untreated rats. Steroid hormone levels were obviously reversed, however, in aged rats treated with DHEA. Additionally, superoxide dismutase activity in serum, brain, heart, and liver was decreased, and maleic dialdehyde content in heart was markedly increased in untreated aged, compared to young, rats. Importantly, these changes in brain and heart of aged rats were reversed by DHEA treatment. Heme oxygenase mRNA levels were increased and inducible nitric oxide synthase mRNA levels decreased in aged, compared to young, rats; DHEA treatment appeared to reverse these changes. These results indicate that chronic DHEA administration may have effects on steroid hormone levels and antioxidant parameters in aged rats and result in postponement of the aging process.

Dehydroepiandrosterone (DHEA) is important for human health, especially for women. All estrogens and practically half of androgens are synthesized from DHEA in peripheral tissues. However, the mechanism and exact target tissues of DHEA biotransformation in the female are not fully clear. The present study showed that maximal content of androstenedione (AD) and testosterone (T) were observed at 3h after DHEA administration in female rats, which was 264% and 8000% above the control, respectively. Estradiol (E2) content significantly increased at 6h after DHEA administration, which was 113% higher than that in control group. Gavage with DHEA could significantly reduce 3β-hydroxysteroid dehydrogenase (3β-HSD) mRNA level at 3-12h and 17β-hydroxysteroid dehydrogenase (17β-HSD) mRNA level at 12h in ovary, while increasing aromatase mRNA levels at 6, 24, and 48 h. It is interesting that administration of DHEA caused a significant increase of 17β-HSD, 3β-HSD and aromatase mRNA levels in adrenal. The AD and T contents also markedly increased by 537% and 2737% after DHEA administration in ovariectomised rats, in company with a significant increase in 17β-HSD and 3β-HSD mRNA levels and decreased aromatase mRNA level in adrenal. However, DHEA administration did not restore the decreased E2, estrone (E1), and progesterone (P) caused by the removal of the ovaries in females. These results clearly illustrated that exogenous DHEA is preferentially converted into androgens in adrenal, while its conversion to estrogens mainly happens in the ovary through steroidogenic enzyme in female rats.

The effects of pyruvate (Pyr), creatine pyruvate (Cr-Pyr) and creatine (Cr) on lipid and protein metabolism were compared in broiler chickens. A total of 400 1-day-old male birds (Aconred) were allocated to four groups, each of which included four replicates (25 birds per replicate). Treatments consisted of unsupplemented basal diet (Control), basal diet containing 2% Pyr, basal diet containing 3% Cr and basal diet containing 5% Cr-Pyr. Cr-Pyr and Pyr significantly decreased the hepatic triglyceride and serum total cholesterol concentration (P < 0.01). Cr-Pyr markedly increased the serum non-esterified fatty acid and high-density lipoprotein cholesterol concentrations (P < 0.05), whereas the expression of carnitine palmitoyl transferase I (P < 0.05) and peroxisome proliferators-activated receptor-α (P < 0.01) mRNA in the liver were both decidedly enhanced in the Cr-Pyr group. The relative leg muscle weight was higher in the Cr-Pyr group than in the control group, whereas the serum uric acid content and hepatic glutamic-oxaloacetic transaminase activity were lower in the Cr-Pyr and Cr groups (P < 0.05), respectively. Muscle insulin-like growth factor I (P < 0.05) expression was enhanced, and the myostatin (P < 0.01) mRNA level was reduced in both the Cr-Pyr and Cr groups. In addition, Cr-Pyr did not alter body weight or the feed conversion ratio. These results indicate that, compared with Pyr and Cr alone, Cr-Pyr has a bifunctional role in broiler chickens, in that it influences both lipid and protein metabolism.

We previously demonstrated that exercise with an iso-caloric diet significantly reduced body weight and skin carcinogenesis in correspondence with lower plasma IGF-1 levels and IGF-1-dependent phospholipid signaling. This study was thus designed to test the hypothesis that IGF-1 reduction plays a causal role in exercise-induced phospholipid changes. SENCAR mice were randomly assigned to one of the following three groups for 12 weeks: ad libitum-fed sedentary control, exercise but pair-fed the amount of the control (PE), and PE with IGF-1 injection (PE+IGF-1). Treadmill exercise was conducted at 13.4 m/min for 90 min/d, 5 d/week. In the last two weeks IGF1 was i.p. injected (10 μg/g B.W.) twice per week. Both body weight and plasma IGF-1 levels were significantly reduced in PE mice when compared with the control. IGF-1 injection did not affect body weight, or the plasma levels of IGF-1 at the end of the experiment due to a rapid degradation with a half-life of 3.4 hrs. Of the 338 phospholipid species detected in the skin tissues by electron spray ionization tandem mass spectrometry, 21 were significantly changed in PE mice compared to control. Fourteen of the altered 21 species in PE mice were reversed by IGF-1 injection, including the most abundant phosphatidylinositol (PI) 38:4, a substrate for lipid PI3K signaling. Western Blot Analysis further showed the reduced PI3K, but not IGF-1R, in PE mice was also reversed by IGF-1 restoration. Overall, these data provided evidence that exercise-induced reduction of IGF-1 is required in mediating the alteration of phospholipid profile and PI-related PI3K signaling.

1. The aim of this study was to investigate the effect of maternal rearing on lipid metabolism and lipid metabolism-related gene expression in offspring broilers during embryonic development. 2. One hundred laying Sanhuang breeders were divided into two groups, and either floor-reared or cage-reared on the same diet. Liver and serum samples were extracted on days 14 and 19 of embryonic development and at hatching. The lipid metabolism related gene expressions of acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), malic enzyme (ME), apolipoprotein B100(apoB100), sterol regulating element binding protein (SREBP-1c), carnitine palmitoyltransferase (CPT-1) and peroxisome proliferators-activated receptor (PPARα) genes were determined using real time RT-PCR. 3. The results showed that embryonic weight, liver weight, serum and hepatic total cholesterol (TC) concentration and serum triglyceride (TG) content were not significantly different between the cage-reared group and the floor-reared group during embryonic development. However, embryonic weight, liver weight, serum and hepatic TC concentration and serum TG content in the cage-reared group were significantly higher than in the floor-reared group at hatching. 4. Hepatic ACC, FAS, SREBP-1c, ME and apoB genes expression were not significantly different between the cage-reared and the floor-reared groups during E9 and E14 development. Hepatic ME gene expression in the cage-reared group was higher than in the floor-reared group during E19 development. However, hepatic FAS, SREBP-1c, CPT-1 and PPARα gene expressions in the cage-reared group was higher than in the floor-reared group. 5. A change in the maternal regime could regulate lipid metabolism in offspring broilers during embryonic development, and especially at hatching.

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 100mg/kg diet. Eggs were collected after DHEA treatment and incubated at 37.5 degrees 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 20mg 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 20mg 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 100mg 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.

In order to identify the genes involved in the fatness variability, we studied the expression of several genes implicated in the hepatic lipid metabolism of broiler chickens with different fat deposition patterns during embryonic development. The mRNA expression of acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), malic enzyme (ME) and apolipoprotein B100 (apoB100) genes were determined using reverse transcriptase-polymerase chain reaction (RT-PCR). Samples of livers were collected from Arbor Acres (AA) and Sanhuang (SH) chickens on day 9, 14 and 19 of embryonic development as well as at hatching. This study showed that hepatic triglyceride (TG) level was found to increase suddenly during day 14 of embryonic development, to gradually increase thereafter, and to remain relatively constant at hatching. FAS gene expression in AA and SH broilers occurred prior to hatching and at hatching. The gene was expressed more in the former breed. ACC gene expression was observed beginning at the earlier development stage of days 9. No breed difference was observed in ME and apoB gene expression. This study indicated that the expression of lipogenic enzyme genes of the liver in broiler chickens exhibited scheduling during embryogenesis. The ACC gene started to express earlier than the FAS gene during embryonic development. This suggested that embryonic liver synthesized fatty acid, and breed difference was noticed prior to hatching.