Optimization of the extract from flower of Citrus aurantium L. var. amara Engl. and its inhibition of lipid accumulation.

Flower of Citrus aurantium L. var. amara Engl. (CAVA) has been confirmed to have promising anti-obesity effects. However, the regulation of alkaloid extracts from flower of CAVA (Al) on lipid metabolism remain unknown. In this study, Al was optimized by ultrasound-assisted extraction using response surface methodology. The optimal conditions were ultrasonic time 72 min, ethanol concentration 78% and liquid/solid ratio 30 ml/g with the maximum alkaloid yield 5.66%. LC-MS assay indicated that the alkaloid compounds were enriched in Al after optimization. Nine alkaloid compounds were identified in Al by LC-MS assay and stachydrine, caffeine and cathine appeared as the major alkaloid compounds. Bioactivity assay showed that Al treatment significantly increased superoxide dismutase (SOD) activity, and reduced malonaldehyde (MDA) and reactive oxygen species (ROS) levels. Al administration also reversed oleic acid-induced hepatic steatosis in Hep G2 cells by inhibiting the expression of lipogenesis-signaling genes including fatty acid synthase (FAS), peroxisome proliferator-activated receptor subtype γ (PPARγ), uncoupling protein 2 (UCP2), and retinol binding protein (RBP4). However, OA-induced reduction of lipolysis-related gene carnitine palmitoyl transferase 1A (CPT1A) in Hep G2 cells was not improved by Al supplementation. Moreover, the increased SOD activity and decreased MDA and ROS contents were also observed in Caenorhabditis elegans by Al addition. Al intervention exhibited the ability to inhibit lipid accumulation in C. elegans by suppressing expression of lipid metabolism-related genes. These results suggested that the alkaloid extracts from the flower of CAVA showed great potential to regulate lipid metabolism. PRACTICAL APPLICATIONS: The extraction of alkaloid extracts from the flower of CAVA was optimized with a maximum yield of 5.66%. The regulatory effects and mechanisms of Al on lipid metabolism of Hep G2 cells and Caenorhabditis elegans were also investigated. More clinical studies are required to evaluate the potential of using alkaloids from the flower of CAVA as therapeutic agents against lipid metabolic disorders.

Molecular Imaging and In Situ Quantitative Profiling of Fatty Acid Synthase with a Chemical Probe.

Cancer cells rely on fatty acid synthase (FASN), a key enzyme for de novo biosynthesis of long chain fatty acids, to sustain their proliferative potential and drive invasion. Unfortunately, conventional FASN assays are technically inadequate for discerning otherwise elusive FASN activity in complex biological milieux, which has hindered progress in the functional study of FASN and development of its inhibitors. Here, we describe a chemical probe with unprecedented selectivity and sensitivity for the labeling of active FASN in living cells, thus demonstrating a new analytical modality for visualizing endogenous FASN activity and exploring opportunities for drug discovery.

The sheep (Ovis aries) muscle proteome: Decoding the mechanisms of tolerance to Seasonal Weight Loss using label-free proteomics.

Seasonal Weight Loss (SWL) is one of the most pressing issues in animal production in the tropics and Mediterranean. This work aims to characterize muscle proteome changes as a consequence of SWL in meat producing sheep, using a label-free proteomics approach. We compare three breeds: the Australian Merino (SWL susceptible), the Damara (SWL tolerant) and the Dorper (SWL intermediate tolerance). We identified 668 proteins of the sheep proteome, 95 with differential regulation. Also we observe that the more vulnerable to SWL a breed is, the more differential abundance proteins we find. Protein binding was the most frequently altered molecular function identified. We suggest 6 putative markers for restricted nutritional conditions independently of breed: ferritin heavy-chain; immunoglobulin V lambda chain; transgelin; fatty acid synthase; glutathione S-transferase A2; dihydrodiol dehydrogenase 3-like. Moreover, we suggest as related to SWL tolerance: S100-A10 Serpin A3-5-like and Catalase, subject however to necessary validation assays. The identification of SWL-tolerance related proteins using proteomics will lead to increased stock productivity of relevant interest to animal production, particularly if identified at the muscle level, the tissue of economic importance in meat production. BIOLOGICAL SIGNIFICANCE: Seasonal Weight Loss (SWL) is the most pressing issue in animal production in the tropics and the Mediterranean. To counter SWL, farmers often use animal breeds that have a natural ability to withstand pasture scarcity. Here we study the sheep muscle proteome at the muscle level, the tissue of economic importance in meat production. Furthermore, the identification of proteins that change their abundance in response to SWL using proteomics can contribute to increased stock productivity of relevant interest to animal production. We identified 668 proteins of the sheep proteome. We demonstrate that the following proteins are affected by restricted nutritional conditions: ferritin heavy chain; immunoglobulin V lambda chain; transgelin; fatty acid synthase; glutathione S-transferase A2; dihydrodiol dehydrogenase 3-like. Furthermore, S100-A10, Serpin A3-5-like and Catalase are proteins that changed their abundance in response to SWL. Nevertheless, it is important to highlight that Catalase values for the merino breed were close to significance and therefore catalase validation is of utmost importance.

Significantly increased monounsaturated lipids relative to polyunsaturated lipids in six types of cancer microenvironment are observed by mass spectrometry imaging.

Six different types of cancer (i.e., breast, lung, colorectal, esophageal, gastric, and thyroid cancer) have high rates of incidence or mortality worldwide. It has been shown that activation of de novo lipogenesis is an early and common event in the cancer microenvironment. In this study, we performed lipid imaging and profiling for 134 tissue samples from six different types of cancer using matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry, with 2,5-dihydroxybenzoic acid and 1,8-bis(dimethyl-amino)naphthalene as matrices in the positive and negative ion modes, respectively. Multivariate statistical analysis coupled with lipid distribution images revealed that significantly increased levels of monounsaturated fatty acids and monounsaturated phosphatidylcholines relative to polyunsaturated fatty acids and polyunsaturated phosphatidylcholines were observed in the cancer microenvironment compared with the adjacent normal tissue. The immunohistochemical assay indicated that fatty acid synthase, stearoyl-CoA desaturase-1, and choline kinase α were up-regulated in the cancer microenvironment compared with the adjacent normal tissue. Our findings suggest that de novo lipogenesis was activated in six types of cancer to promote a biosynthesis of lipids with monounsaturated acyl chains and to suppress a biosynthesis of polyunsaturated lipids in the cancer microenvironment.

Elevated expression of fatty acid synthase and nuclear localization of carnitine palmitoyltransferase 1C are common among human gliomas.

Fatty acid synthase (FASN) and carnitine palmitoyltransferase 1C (CPT1C), a brain-specific isoform of the CPT1 family, are upregulated in certain types of cancers, including gliomas. Acetyl-CoA carboxylase (ACC) catalyzes the carboxylation of acetyl-CoA to malonyl-CoA, the rate-limiting step in fatty acid synthesis, and its phosphorylated form inhibits lipid synthesis. We examined the expression and subcellular localization of these fatty acid metabolism-related molecules in human gliomas. We performed immunostaining of two glioma cell lines (U373MG and U87MG) and 41 surgical specimens of diffuse gliomas with various histological grades (21 with the isocitrate dehydrogenase 1(IDH1) R132H mutation and 20 without the mutation). In the cultured glioma cells, CPT1C and phosphorylated ACC (p-ACC) were mainly localized to the nuclei, whereas FASN localized to the cytoplasm. In the surgical specimens, most glioma tissues showed nuclear staining for CPT1C and p-ACC, and cytoplasmic staining for FASN, regardless of the genetic status of IDH1 and the histological grade. Therefore, elevated cytoplasmic expression of FASN and nuclear localization of CPT1C are common among human diffuse gliomas, which may be regulated by the differential phosphorylation status of ACC in the cellular compartment.

Fatty acid synthase overexpression in adult testicular germ cell tumors: potential role in the progression of non-seminomatous germ cell tumors.

Overexpression of fatty acid synthase (FASN), which is a key enzyme responsible for the endogenous synthesis of fatty acids, and its association with multistep progression have been demonstrated in various human malignant tumors. We aimed to clarify the potential role of FASN overexpression in the development and progression of adult testicular germ cell tumors (TGCTs). From the primary sites of a cohort of 113 TGCT cases, we obtained 221 histological components: 53 intratubular germ cell neoplasias, unclassified (IGCNUs), 84 seminomas, 32 embryonal carcinomas, seven choriocarcinomas, 21 yolk sac tumors, and 24 teratomas. Samples were analyzed for overexpression of FASN by immunohistochemistry. Intensities of immunoreactivity and the fraction of positive cells were classified into each four categories (intensity, 0 to 3; fraction, 0-10 % = 1, 11-50 % = 2, 51-80 % = 3, and >80 % = 4). The overall score was determined by multiplication of both scores and overall scores greater than 6 were considered FASN overexpression. On a component basis, FASN overexpression was detected in 8 % of seminomas but not in IGCNUs (0 %) and was detected frequently in non-seminomatous germ cell tumors (NSGCTs) (88 % of embryonal carcinomas, all choriocarcinomas, 81 % of yolk sac tumors, and 54 % of teratomas). There were no cases of a mixed tumor (i.e., a tumor with multiple histological components) that overexpressed FASN in seminoma components but not in co-existing NSGCT components, suggesting sequential progression. Our immunohistochemical data suggest that FASN overexpression occurs as a late event during the progression from IGCNUs/seminomas to NSGCTs.

Trans-chalcone and quercetin down-regulate fatty acid synthase gene expression and reduce ergosterol content in the human pathogenic dermatophyte Trichophyton rubrum.

BACKGROUND: Fatty acid synthase (FAS) is a promising antifungal target due to its marked structural differences between fungal and mammalian cells. The aim of this study was to evaluate the antifungal activity of flavonoids described in the scientific literature as FAS inhibitors (quercetin, trans-chalcone, ellagic acid, luteolin, galangin, and genistein) against the dermatophyte Trichophyton rubrum and their effects on fatty acid and ergosterol synthesis. METHODS: The antifungal activity of the natural products was tested by the microdilution assay for determination of the minimum inhibitory concentration (MIC). The effect of the compounds on the cell membrane was evaluated using a protoplast regeneration assay. Ergosterol content was quantified by spectrophotometry. Inhibition of FAS by flavonoids was evaluated by an enzymatic assay to determine IC50 values. Quantitative RT-PCR was used to measure transcription levels of the FAS1 and ERG6 genes involved in fatty acid and ergosterol biosynthesis, respectively, during exposure of T. rubrum to the flavonoids tested. RESULTS: The flavonoids quercetin and trans-chalcone were effective against T. rubrum, with MICs of 125 and 7.5 µg/mL for the wild-type strain (MYA3108) and of 63 and 1.9 µg/mL for the ABC transporter mutant strain (ΔTruMDR2), respectively. The MICs of the fluconazole and cerulenin controls were 63 and 125 µg/mL for the wild-type strain and 30 and 15 µg/mL for the mutant strain, respectively. Quercetin and trans-chalcone also reduced ergosterol content in the two strains, indicating that interference with fatty acid and ergosterol synthesis caused cell membrane disruption. The MIC of quercetin reduced the number of regenerated protoplasts by 30.26% (wild-type strain) and by 91.66% (mutant strain). Half the MIC (0.5 MIC) of quercetin did not reduce the number of regenerated wild-type fungal colonies, but caused a 36.19% reduction in the number of mutant strain protoplasts. In contrast, the MIC and 0.5 MIC of trans-chalcone and cerulenin drastically reduced protoplast regeneration in the two strains. The FAS1 gene was repressed in the presence of MICs of quercetin, trans-chalcone, fluconazole and cerulenin. The ERG6 gene was induced in the presence of MICs of fluconazole and cerulenin and was repressed in the presence of MICs of trans-chalcone and quercetin. Trans-chalcone and quercetin inhibited the enzymatic activity of FAS, with IC50 values of 68.23 and 17.1 µg/mL, respectively. CONCLUSION: Trans-chalcone and quercetin showed antifungal activity against T. rubrum, reducing ergosterol levels and modulating the expression of FAS1 and ERG6.

Milk fatty acid variability: effect of some candidate genes involved in lipid synthesis.

In this work, the genetic variation of milk FA was investigated in three different bovine breeds, the Jersey, the Piedmontese and the Valdostana, and at different lactation stages. All animals were genotyped for 21 Single Nucleotide Polymorphisms located within nine candidate genes involved in lipid synthesis: diacylglycerol acyltransferase 1 and 2 (DGAT1, 2); stearoyl-CoA desaturase (SCD); growth hormone receptor (GHR); fatty acid synthase (FASN); acyl-CoA dehydrogenase (ACAD); fatty acid binding protein (FABP4); lipoprotein lipase (LPL); and leptin gene (LEP). The highest milk-fat Jersey breed also showed the highest content of saturated FA. Throughout lactation, the breeds showed a similar variation in the FA, with a decrease in the short-chain, this was accompanied by a general increase in the long chain FA at the end of lactation. The increase in long chain saturated FA was particularly evident in the case of the Jersey. The effect of SCD gene on the C14 desaturation index was confirmed; the DGAT1 gene was polymorphic only in the Jersey breed, but its effect was confirmed only on milk fat content; three further potential candidate genes were identified: first, the FABP4 gene, which was found to influence medium and long chain FA in all the breeds, but not the desaturation indices; second, the FASN gene, which was found to influence the amount of PUFA in the Piedmontese and the Valdostana, and third, the LPL gene, which was found to affect fat content in the Piedmontese.

Expression status of fatty acid synthase (FAS) but not HER2 is correlated with the differentiation grade and prognosis of esophageal carcinoma.

BACKGROUND/AIMS: Fatty acid synthase (FAS) and human epidermal growth factor receptor 2 (HER2) are overexpressed in a series of cancers. However, few studies have investigated the potential role of FAS and HER2 in esophageal carcinoma. The aim of this study was to evaluate the expression of FAS and HER2 and the possible link between FAS/HER2 expression and the pathological prognostic variables. METHODOLOGY: The frequency of FAS and HER2 expression was determined immunohistochemically. The overall survival rate was analysed by the Kaplan-Meier method and the log-rank test using SPSS 17.0 software. RESULTS: The majority of the cases were esophageal squamous cell carcinomas (n=142). FAS and HER2 overexpression in the studied cases are 73.2% and 14.1%, respectively. There was a significant difference in FAS expression regarding tumor differentiation and FAS overexpression showed its prognostic value for patients with different tumor differentiation. Meanwhile, HER2 overexpression did not significantly relate to the clinicopathological characteristics of the tumors, with the only exception of the surgical margins. CONCLUSIONS: FAS and HER2 overexpression are common in esophageal carcinomas. FAS overexpression showed its prognostic value for esophageal carcinoma patients with different tumor differentiation, which lead us to consider FAS-inhibitors as potential candidates for target-based adjuvant therapies.

RETRACTED: Reversion of hepatic steatosis by exercise training in obese mice: the role of sterol regulatory element-binding protein-1c.

AIM: The dysregulation of regulatory element-binding protein-1c (SREBP-1c) is associated with hepatic steatosis. However, effects of exercise on SREBP-1c protein level in liver have not been investigated. Thus, in this study we investigated if reversion of the hepatic steatosis-induced by exercise training is related with levels of SREBP-1c. MAIN METHODS: Mice were divided into two groups: control lean mice (CT), fed on standard rodent chow, and obese mice (HF), fed on a high-fat diet for 2months. After this period obese mice were divided in two groups: obese mice and obese mice submitted to exercise (HF+EXE). The HF+EXE group performed a running program of 50min per day, 5days per week, for 8weeks. Forty-eight hours after the last exercise session, biochemical, immunoblotting, histology and immunohistochemistry analyses were performed. KEY FINDINGS: Livers of HF mice showed increased SREBP-1c, FAS (Fatty Acid Synthase), SCD1 (Stearoyl-CoA Desaturase1) and CPT1 (Carnitine Palmitoyl Transferase1) protein levels (3.4, 5.0, 2.6 and 2.9 times, respectively), though ACC (Acetyl-CoA Carboxilase) phosphorylation dropped 4.2 times. In livers of HF+EXE, levels of SREBP-1c, FAS, SCDI and CPTI decreased 2.1, 1.9, 1.8, and 2.7 times, respectively), while ACC phosphorylation increased 3.0 times. Lower SREBP-1c protein levels after exercise were confirmed also by immunohistochemistry. Total liver lipids content was higher in HF (2.2 times) when compared to CT, and exercise training reduced it significantly (1.7 times). SIGNIFICANCE: Our study allows concluding that the reduction in SREBP-1c protein levels is associated with steatosis reversion induced by exercise training.

Postweaning low-calcium diet promotes later-life obesity induced by a high-fat diet.

The aim of this study was to investigate the effects of a postweaning low-calcium diet on later obesity and explore the underlying mechanisms. Ninety-six male rats were weaned at 3 weeks of age, fed standard (STD: 0.50% calcium, n=48) and low-calcium (LC: 0.15% calcium, n=48) diets for 3 weeks, and then fed the standard diet for a 3-week washout period successively. Finally, the STD rats were divided into STD control and high-fat diet (HFD) groups, and the LC ones into LC control and LC+HFD (LCHF) groups. The STD and LC rats were fed the standard diet, while the HFD control and LCFD ones were fed a high-fat diet for 6 weeks to induce obesity. During the three feeding periods, adenosine-monophosphate-activated protein kinase (AMPK) and its responsive proteins phospho-acetyl-coA carboxylase, carnitine palmitoyltransferase 1 and uncoupling protein 3 were persistently down-regulated in the LC group (decreased by 18%, 24%, 18% and 20%, respectively) versus the STD group, and these effects were significantly more pronounced in the LCHFD group (decreased by 21%, 30%, 23% and 25%, respectively) than the HFD group by a later high-fat stimuli, causing more fat and body weight in adulthood. However, lipolysis enzymes, serum leptin, insulin and lipids were not significantly affected until the body weight and fat content changed at 15 weeks of age. The results suggest that the low-calcium diet after weaning promotes rat adult-onset obesity induced by high-fat diet, which might be achieved by programming expressions of genes involved in AMPK pathway.

Immunohistochemical expressions of fatty acid synthase and phosphorylated c-Met in thyroid carcinomas of follicular origin.

Thyroid carcinoma is the most common endocrine malignancy and the first cause of death among endocrine cancers. Fatty acid synthase (FASN) and c-Met are overexpressed in many types of human cancers. Recent studies have suggested a functional interaction between FASN and c-Met. However, their roles in thyroid carcinomas have not been fully investigated. In this study, we evaluated the expressions of FASN and phosphorylated (p)-c-Met by using immunohistochemistry in thyroid carcinomas of follicular origin, from 32 patients. The adjacent non-neoplastic thyroid tissue was also evaluated for comparison. Immunoreactive intensity and extensiveness were semi-quantified. The overexpression of FASN was observed in a subset of papillary thyroid carcinomas (PTC) including the classical type and tall cell, follicular, trabecular/insular and diffuse sclerosing variants, a subset of follicular thyroid carcinomas (FTC), and the PTC and FTC components in anaplastic thyroid carcinomas (ATC). No overexpression was observed in the ATCs per se and the columnar cell, solid, and cribriform variants of PTCs. All Hürthle cell variant FTCs and non-neoplastic Hürthle cells demonstrated positive staining for FASN while the non-neoplastic follicular cells without Hürthle cell change were negative. An association in overexpression between FASN and p-c-Met was observed in the majority of carcinomas as well as in the non-neoplastic Hürthle cells. In conclusion, overexpressions of FASN and p-c-Met were observed in a subset of thyroid carcinomas of follicular origin, which may be of values for targeted therapy and predicting prognosis while the positive immunostaining for these immunomarkers may be nonspecific for Hürthle cell thyroid carcinomas.

The combination of resveratrol and CLA does not increase the delipidating effect of each molecule in 3T3-L1 adipocytes.

INTRODUCTION: Trans-10, cis-12 conjugated linoleic acid (CLA) and resveratrol have been shown to reduce TG content in cultured 3T3-L1 adipocyte acting on different pathways. In recent years, the method of simultaneously targeting several signal transduction pathways with multiple natural products in order to achieve additive or synergistic effects has been tested. However, the combined effect of both molecules on lipid metabolism has not been described before. OBJECTIVE: The aim of the present work was to analyze the effect of the combination of trans-10, cis-12 CLA and resveratrol on TG accumulation as well as on FAS, HSL and ATGL expression in 3T3-L1 mature adipocytes, in order to assess a potential interaction between both molecules. METHODS: For this purpose, 3T3-L1 mature adipocytes were treated with the two molecules, both separately and combined, in 10 and 100 µM for 20 hours. TG content and FAS, ATGL and HSL expression were measured by spectrophotometry and Real Time RT-PCR respectively. RESULTS: Both doses of CLA and 100 M resveratrol decreased TG content in mature adipocytes. The combination of both molecules reduced TG accumulation to the same extent as each one separately. No change in FAS and HSL mRNA levels after CLA and resveratrol treatment was observed. ATGL was not modified by CLA but it was increased by resveratrol and by the combination. This combination did not increase the effect caused by resveratrol on its own. CONCLUSION: Lipolysis increase via ATGL is involved in the TG reduction induced by resveratrol and the combination of both molecules. The combination of these two molecules does not increase the efficacy of each molecule separately in mature adipocytes and thus it does not represent an advantage for obesity treatment or prevention.

Expression of fatty acid synthase (FASN) in oral nevi and melanoma.

OBJECTIVE: The aim of this study was to determine the expression of fatty acid synthase (FASN) in oral nevi and melanomas, comparing the results with correspondent cutaneous lesions. MATERIALS AND METHODS: Expression of FASN was evaluated by immunohistochemistry in 51 oral melanocytic lesions, including 38 intramucosal nevi and 13 primary oral melanomas, in 10 cutaneous nevi and in 14 melanomas. RESULTS: Fatty acid synthase was strongly expressed only in melanomas, either of the oral mucosa or cutaneous. On the other hand, most oral and cutaneous nevi were negative, with a few oral cases showing focal and weak expression. CONCLUSION: Fatty acid synthase is expressed in malignant melanocytes, and it can be a helpful marker to distinguish oral melanomas from oral melanocytic nevi.

Is there a role for fatty acid synthase in the diagnosis of prostatic adenocarcinoma?: A comparison with AMACR.

Our aim was to compare the usefulness of fatty acid synthase (FASn) with that of α-methylacyl coenzyme-A racemase (AMACR) in the diagnosis of prostatic adenocarcinoma. The expression of these 2 markers was compared in a tissue microarray containing 62 foci of benign glands and 36 foci of prostatic adenocarcinoma. Similar to AMACR, there was significantly higher FASn expression in adenocarcinoma compared with that in benign glands. The optimal accuracy rate and area under curve (AUC) by receiver operating characteristic analysis for FASn were not significantly different from those for AMACR (accuracy, 80% vs 87%; AUC, 0.942 vs 0.956; P for both, > .05). Moreover, in cases with coexistent malignant and benign glands on the same core, FASn could selectively distinguish a proportion of cases (17/21 [81%]) similar to using AMACR. We conclude that FASn may aid in the diagnosis of prostatic adenocarcinoma, at least to supplement AMACR as another positive marker of carcinoma and potentially increase diagnostic accuracy.

Alternation between dietary protein depletion and normal feeding cause liver damage in mouse

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The effect of frequent protein malnutrition on liver function has not been intensively examined. Thus, the effects of alternating 5 days of a protein and amino acid-free diet followed by 5 days of a complete diet repeated three times (3 PFD-CD) on female mouse liver were examined. The expression of carbonic anhydrase III (CAIII), fatty acid synthase (FAS), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and glutathione S-transferase P1 (GSTP1) in liver were assessed by proteomics, reverse transcriptase-polymerase chain reaction and Northern blotting. The activities of liver GSTs, glutathione reductase (GR) and catalase (CAT), as well as serum glutamic-oxaloacetic transaminase (SGOT) and glutamic-pyruvic transaminase (SGPT) were also tested. Additionally, oxidative damage was examined by measuring of protein carbonylation and lipid peroxidation. Liver histology was examined by light and electron microscopy. Compared with control mice, 3 PFD-CD increased the content of FAS protein (+90%) and FAS mRNA (+30%), while the levels of CAIII and CAIII mRNAs were decreased (−48% and −64%, respectively). In addition, 3 PFD-CD did not significantly change the content of GSTP1 but produced an increase in its mRNA level (+20%), while it decreased the activities of both CAT (−66%) and GSTs (−26%). After 3 PFD-CD, liver protein carbonylation and lipid peroxidation were increased by +55% and +95%, respectively. In serum, 3 PFD-CD increased the activities of both SGOT (+30%) and SGPT (+61%). In addition, 3 PFD-CD showed a histological pattern characteristic of hepatic damage. All together, these data suggest that frequent dietary amino acid deprivation causes hepatic metabolic and ultrastructural changes in a fashion similar to precancerous or cancerous conditions (AU)

Effect of dietary supplemental vitamin A concentration on performance, carcass merit, serum metabolites, and lipogenic enzyme activity in yearling beef steers.

A randomized complete block design experiment with 360 single-source black yearling steers (average BW = 316.1 +/- 9.1 kg) fed a 91% concentrate (steam-flaked corn base) diet was conducted to evaluate the effects of supplemental vitamin A (0, 1,103, 2,205, 4,410, or 8,820 IU/kg of dietary DM) on plasma and liver vitamin A and E concentrations, lipogenic enzyme activity, marbling score, and performance of yearling steers. Final BW (586, 580, 590, 585, and 584 kg for 0, 1,103, 2,205, 4,410, and 8,820 IU of supplemental vitamin A/kg of DM, respectively) did not differ (P = 0.39) among treatments. Feed efficiency, ADG, and daily DMI did not differ (P > 0.10) among treatments within each 28-d period or for the overall experiment. From d 57 to slaughter, average DMI (10.33, 10.28, 10.57, 9.75, and 10.22 kg/steer daily for 0, 1,103, 2,205, 4,410, and 8,820 IU of vitamin A/kg of DM, respectively) was less (P < 0.02) by steers receiving 4,410 IU of supplemental vitamin A/kg of dietary DM than for steers in the other treatments. Furthermore, DMI was greater (P = 0.06) for steers receiving 2,205 IU of supplemental vitamin A/kg of dietary DM than for steers receiving 8,820 IU of supplemental vitamin A/kg of DM. Marbling score, HCW, LM area, and 12th-rib fat thickness did not differ (P > 0.10) among treatments. Similarly, the percentage of carcasses grading >or=USDA Choice (62.6, 52.8, 64.0, 58.4, and 58.4% for 0, 1,103, 2,205, 4,410, and 8,820 IU of vitamin A/kg of DM, respectively), Select, or 0.10) among treatments. Except for d 56 (P = 0.050; r = 0.18 for liver retinol), no correlations (P > 0.10) between marbling score and any plasma or liver tissue retinol or alpha-tocopherol concentrations or vitamin A intake were found, and no differences (P > 0.10) in lipogenic enzyme activity were detected among treatments. Taken together with previous and concurrent research, results of this experiment suggest that vitamin A supplementation at a concentration up to twice the NRC recommendation has little effect on performance, marbling, or lipogenic enzyme activity in adipose tissue samples in yearling feedlot steers, and that 2,205 IU of supplemental vitamin A/kg of DM (20,000 IU/steer daily) or less is adequate to meet the vitamin A requirements of finishing beef cattle.

Effects of three different highly purified n-3 series highly unsaturated fatty acids on lipid metabolism in C57BL/KsJ-db/db mice.

Triglycerides (TG) consisting of highly purified (>97%) n-3 series highly unsaturated fatty acids, eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA), were administered to C57BL/KsJ-db/db mice for 4 weeks by pair-feeding to compare their effects on lipid metabolism and to evaluate the effects of DPA on lipid metabolism. The hepatic TG level and total amount was decreased by treatment with DHA and DPA compared to the control. The efficacy of DPA was greater than that of EPA, but less than that of DHA. In contrast, EPA had the greatest serum TG reducing effect. The hepatic cytosol fraction of the DHA-treated group contained the lowest fatty acid synthase (FAS) and malic enzyme (ME) activity levels. Furthermore, the DHA-treated group contained the highest serum adiponectin concentrations. These findings indicate that the strong hepatic TG-lowering effect of DHA is due to the suppression of TG synthesis. The same tendencies were observed in DPA-treated mice, and the effect was stronger than that observed in EPA-treated mice, but equivalent to that observed in DHA-treated mice. Based on these results, DPA possesses lipid metabolism-improving effects. The beneficial effects of DPA for lipid metabolism were not superior to those of EPA and DHA, and the effect was always intermediate between those of EPA and DHA.

Beneficiary effect of Tinospora cordifolia against high-fructose diet induced abnormalities in carbohydrate and lipid metabolism in Wistar rats.

High intake of dietary fructose has been shown to exert a number of adverse metabolic eff ects in humans and experimental animals. The present study was designed to investigate the eff ect of the aqueous extract of Tinospora cordifolia stem (TCAE) on the adverse eff ects of fructose loading toward carbohydrate and lipid metabolism in rats. Adult male Wistar rats of body weight around 200 g were divided into four groups, two of which were fed with starch diet and the other two with high fructose (66 %) diet. Plant extract of TC (400 mg/kg/day) was administered orally to each group of the starch fed rats and the highfructose fed rats. At the end of 60 days of experimental period, biochemical parameters related to carbohydrate and lipid metabolism were assayed. Hyperglycemia, hyperinsulinemia, hypertriglyceridemia, insulin resistance, and elevated levels of hepatic total lipids, cholesterol, triglycerides, and free fatty acids (p < 0.05) observed in fructose-fed rats were completely prevented with TCAE treatment. Alterations in the activities of enzymes of glucose metabolism (hexokinase, phosphofructokinase, pyruvate kinase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, and glucose-6-phosphate dehydrogenase) and lipid metabolism (fatty acid synthetase, lipoprotein lipase, and malic enzyme) as observed in the high fructose-fed rats were prevented with TCAE administration. In conclusion, our fi ndings indicate improvement of glucose and lipid metabolism in high-fructose fed rats by treatment with Tinospora cordifolia, and suggest that the plant can be used as an adjuvant for the prevention and/or management of insulin resistance and disorders related to it.

Evaluation of fatty acid synthase expression in oesophageal mucosa of patients with oesophagitis, Barrett's oesophagus and adenocarcinoma.

BACKGROUND AND AIM: To evaluate the expression of fatty acid synthase (FAS) in the oesophagitis-Barrett's oesophagus-oesophageal adenocarcinoma sequence compared with p53 and Ki67 expressions, retained for a long time reliable markers of oesophageal cells biological behaviour. METHODS: In Barrett's oesophagus, oesophagitis and oesophageal adenocarcinoma patients, biopsies were taken from pathologic sites of the mucosa for histological and immuno-histochemical detection of FAS, p53 and Ki67. FAS expression was positive, when a strong granular cytoplasmic staining was observed in oesophageal cells. Ki67 and p53 was defined positive, when nuclear staining was clearly detected at 10x magnification. RESULTS: A mild expression of FAS was found in 39% of patients with oesophagitis. The amount of FAS expression increased up to 70% in Barrett's oesophagus while this was present in all patients with oesophageal adenocarcinoma (p = 0.0001). In Barrett's oesophagus, p53 was mildly or intensely expressed in 77% and in 15% of cases, respectively, and mildly or intensely expressed in 33% and 67% of patients with oesophageal adenocarcinoma, respectively, (p = 0.0001). Ki67 was mildly expressed in 17% of oesophagitis cases and was absent in the majority of cases. In Barrett's oesophagus, a mild Ki67 expression was present in 46% of cases, and in oesophageal adenocarcinoma it was present prevalently in intense form (67%; p = 0.0001). CONCLUSIONS: The over-expression of p53, Ki67 and FAS in otherwise similar morphological groups may be useful to stratify patients into selected prognostic subgroups in order to achieve better clinical approaches.