The Buckwheat Iminosugar d-Fagomine Attenuates Sucrose-Induced Steatosis and Hypertension in Rats.

SCOPE: This study examines the long-term functional effects of d-fagomine on sucrose-induced factors of metabolic dysfunctions and explores possible molecular mechanisms behind its action. METHODS AND RESULTS: Wistar Kyoto rats are fed a 35% sucrose solution with d-fagomine (or not, for comparison) or mineral water (controls) for 24 weeks. The following are recorded: body weight; energy intake; glucose tolerance; plasma leptin concentration and lipid profile; populations of Bacteroidetes, Firmicutes, bacteroidales, clostridiales, enterobacteriales, and Escherichia coli in feces; blood pressure; urine uric acid and F2t isoprostanes (F2 -IsoPs); perigonadal fat deposition; and hepatic histology and diacylglycerols (DAGs) in liver and adipose tissue. d-Fagomine reduces sucrose-induced hypertension, urine uric acid and F2 -IsoPs (markers of oxidative stress), steatosis, and liver DAGs, without significantly affecting perigonadal fat deposition, and impaired glucose tolerance. It also promotes excretion of enterobacteriales generated by the dietary intervention. CONCLUSION: d-fagomine counteracts sucrose-induced steatosis and hypertension, presumably by reducing the postprandial levels of fructose in the liver.

Effects of combined D-fagomine and omega-3 PUFAs on gut microbiota subpopulations and diabetes risk factors in rats fed a high-fat diet.

Food contains bioactive compounds that may prevent changes in gut microbiota associated with Westernized diets. The aim of this study is to explore the possible additive effects of D-fagomine and ω-3 PUFAs (EPA/DHA 1:1) on gut microbiota and related risk factors during early stages in the development of fat-induced pre-diabetes. Male Sprague Dawley (SD) rats were fed a standard diet, or a high-fat (HF) diet supplemented with D-fagomine, EPA/DHA 1:1, a combination of both, or neither, for 24 weeks. The variables measured were fasting glucose and glucose tolerance, plasma insulin, liver inflammation, fecal/cecal gut bacterial subgroups and short-chain fatty acids (SCFAs). The animals supplemented with D-fagomine alone and in combination with ω-3 PUFAs accumulated less fat than those in the non-supplemented HF group and those given only ω-3 PUFAs. The combined supplements attenuated the high-fat-induced incipient insulin resistance (IR), and liver inflammation, while increasing the cecal content, the Bacteroidetes:Firmicutes ratio and the populations of Bifidobacteriales. The functional effects of the combination of D-fagomine and EPA/DHA 1:1 against gut dysbiosis and the very early metabolic alterations induced by a high-fat diet are mainly those of D-fagomine complemented by the anti-inflammatory action of ω-3 PUFAs.

Functional Effects of the Buckwheat Iminosugar d-Fagomine on Rats with Diet-Induced Prediabetes.

SCOPE: The goals of this work are to test if d-fagomine, an iminosugar that reduces body weight gain, can delay the appearance of a fat-induced prediabetic state in a rat model and to explore possible mechanisms behind its functional action. METHODS AND RESULTS: Wistar Kyoto rats were fed a high-fat diet supplemented with d-fagomine (or not, for comparison) or a standard diet (controls) for 24 weeks. The variables measured were fasting blood glucose and insulin levels; glucose tolerance; diacylglycerols as intracellular mediators of insulin resistance in adipose tissue (AT), liver, and muscle; inflammation markers (plasma IL-6 and leptin, and liver and AT histology markers); eicosanoids from arachidonic acid as lipid mediators of inflammation; and the populations of Bacteroidetes, Firmicutes, Enterobacteriales, and Bifidobacteriales in feces. It was found that d-fagomine reduces fat-induced impaired glucose tolerance, inflammation markers, and mediators (hepatic microgranulomas and lobular inflammation, plasma IL-6, prostaglandin E2 , and leukotriene B4 ) while attenuating the changes in the populations of Enterobacteriales and Bifidobacteriales. CONCLUSION: d-Fagomine delays the development of a fat-induced prediabetic state in rats by reducing low-grade inflammation. We suggest that the anti-inflammatory effect of d-fagomine may be linked to a reduction in fat-induced overpopulation of minor gut bacteria.

Mechanistically different effects of fat and sugar on insulin resistance, hypertension, and gut microbiota in rats.

Insulin resistance (IR) and impaired glucose tolerance (IGT) are the first manifestations of diet-induced metabolic alterations leading to Type 2 diabetes, while hypertension is the deadliest risk factor of cardiovascular disease. The roles of dietary fat and fructose in the development of IR, IGT, and hypertension are controversial. We tested the long-term effects of an excess of fat or sucrose (fructose/glucose) on healthy male Wistar-Kyoto (WKY) rats. Fat affects IR and IGT earlier than fructose through low-grade systemic inflammation evidenced by liver inflammatory infiltration, increased levels of plasma IL-6, PGE2, and reduced levels of protective short-chain fatty acids without triggering hypertension. Increased populations of gut Enterobacteriales and Escherichia coli may contribute to systemic inflammation through the generation of lipopolysaccharides. Unlike fat, fructose induces increased levels of diacylglycerols (lipid mediators of IR) in the liver, urine F2-isoprostanes (markers of systemic oxidative stress), and uric acid, and triggers hypertension. Elevated populations of Enterobacteriales and E. coli were only detected in rats given an excess of fructose at the end of the study. Dietary fat and fructose trigger IR and IGT in clearly differentiated ways in WKY rats: early low-grade inflammation and late direct lipid toxicity, respectively; gut microbiota plays a role mainly in fat-induced IR, and hypertension is independent of inflammation-mediated IR. The results provide evidence that suggests that the combination of fat and sugar is potentially more harmful than fat or sugar alone when taken in excess.

Peripheral T-cell lymphoma with follicular T-cell markers.

INTRODUCTION: Peripheral T-cell lymphomas (PTCLs) in western countries are uncommon tumors with unfavorable prognosis. They may be subclassified as anaplastic large-cell lymphomas (ALCLs), angioimmunoblastic-T-cell lymphomas (AITLs), or unspecified peripheral T-cell lymphomas (PTCLs-U). It has recently been demonstrated that AITLs originate from germinal center follicular helper T cells (TFH), whereas the normal counterparts of other PTCLs remain essentially unknown. The aim of this study was to establish whether other PTCL subgroups also express TFH cell markers. MATERIALS AND METHODS: One hundred forty-six PTCLs were analyzed for programmed death-1 (PD-1) expression in tissue microarrays using a new monoclonal antibody called NAT-105. PD-1-positive cases, which did not fulfill all the criteria for AITL, were further evaluated in whole-tissue sections for another 12 immunohistochemical markers, including the TFH cell markers CXCL13, CD10, and BCL6. Clonal Ig and T-cell receptor rearrangements and Epstein-Barr virus-encoded RNA expression were also evaluated. Morphologic, clinical, and follow-up data were reviewed. RESULTS: Twenty-five out of 87 non-AITL cases (28.75%) showed PD-1 immunostaining. CXCL13, BCL6, and CD10 expression was found in 24/25 (96%), 16/25 (64%), and 6/25 (24%) cases, respectively. All cases expressed at least 2 TFH cell markers. Moreover, 5 cases were positive for all 4 markers. Most cases (17/25, 68%) displayed some AITL-like features. Of the remainder, 1 was considered to be early AITL, 1 was diagnosed as ALCL-anaplastic lymphoma kinase-negative, and 4 of the other 6 PTCLs-U had morphology consistent with lymphoepithelioid (Lennert's) lymphoma. Three AITL-like cases showed IgH clonal rearrangement, 2 of which were associated with Epstein-Barr virus expression. Our series of patients did not differ significantly in their clinical presentation from most reported PTCL cases in the literature: 55% of them were alive and 35% were in complete remission after a median follow-up of 15 months after cyclophosphamide, dexorubicin, vincristine, and prednisone-based chemotherapy. CONCLUSIONS: TFH cell markers, especially PD-1, were expressed in a subset of PTCLs not classified as AITL, although most of them shared some morphologic features with AITL. This suggests that the spectrum of AITL may be wider than previously thought, possibly including cases of lymphoepithelioid (Lennert's) lymphoma. Additionally, the results suggest that a subgroup of PTCLs-U, distinct from AITL and including some cases denominated as ALCL, may also be derived from TFH cells, although they develop along a distinct pathogenic pathway.