5 research outputs found

    The starburst-active galactic nucleus connection in the merger galaxy Mrk 938: An infrared and X-ray view

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    Mrk 938 is a luminous infrared (IR) galaxy in the local Universe believed to be the remnant of a galaxy merger. It shows a Seyfert 2 nucleus and intense star formation according to optical spectroscopic observations. We have studied this galaxy using new Herschel far-IR imaging data in addition to archival X-ray, UV, optical, near-IR and mid-IR data. Mid- and far-IR data are crucial to characterize the starburst contribution, allowing us to shed new light on its nature and to study the coexistence of active galactic nuclei (AGN) and starburst activity in the local Universe. The decomposition of the mid-IR Spitzer spectrum shows that the AGN bolometric contribution to the mid-IR and total IR luminosity is small [Lbol(AGN)/LIR ? 0.02], which agrees with previous estimations. We have characterized the physical nature of its strong IR emission and constrained it to a relatively compact emitting region of ?2 kpc. It is in this obscured region where most of the current star formation activity is taking place as expected for luminous IR galaxies. We have used Herschel imaging data for the first time to constrain the cold dust emission with unprecedented accuracy. We have fitted the integrated far-IR spectral energy distribution and derived the properties of the dust, obtaining a dust mass of 3 × 107 M . The far-IR is dominated by emission at 35 K, consistent with dust heated by the ongoing star formation activityThanks to F. Schweizer for kindly providing the optical image of Mrk 938, to J. Gallimore for providing the MIPS SED data, and to H. Krimm and W. Baumgartner for the analysis of the BAT ob- servations. PE, AA-H and MP-S acknowledge support from the Spanish Plan Nacional de Astronom ́ıa y Astrof ́ısica under grant AYA2009-05705-E. AA-H and MP-S acknowledge support under grant AYA2010-21161-C02-01. MP-S acknowledges support from the CSIC under grant JAE-Predoc-2007. AMP-G acknowledges support by the Spanish Plan Nacional de Astronom ́ıa y Astrof ́ısica under the grant AYA2008-06311-CO2-01. CRA acknowledges fi- nancial support from STFC (ST/G001758/1) and from the Span- ish Ministry of Science and Innovation (MICINN) through project Consolider-Ingenio 2010 Programme grant CSD2006-00070: First Science with the GTC. MP acknowledges Junta de Andaluc ́ıa and Spanish Ministry of Science and Innovation through projects PO8- TIC-03531 and AYA2010-15169. PACS has been developed by a consortium of institutes led by MPE (Germany) and including UVIE (Austria); KU Leuven, CSL, IMEC (Belgium); CEA, LAM (France); MPIA (Germany); INAF- IFSI/OAA/OAP/OAT, LENS, SISSA (Italy) and IAC (Spain). This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI/INAF (Italy) and CICYT/MCYT (Spain). SPIRE has been developed by a consortium of institutes led by Cardiff University (UK) and including University of Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, University of Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, University of Sus- sex (UK) and Caltech, JPL, NHSC, University of Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC (UK) and NASA (USA). This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Labo- ratory, California Institute of Technology, under NASA contract 1407

    Spirulina platensis improves insulin sensitivity and reduces hyperglycemia-mediated oxidative stress in fructose-fed rats

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    Oxidative stress, hyperglycemia and insulin resistance are hallmarks of diabetes mellitus. The present study aimed to assess the antidiabetic activity of a local strain of Spirulina platensis produced at Pahou (Benin), known as “Spiruline Dou Bogan” (SPD), in fructose-fed rats.  Glucose metabolism impairment was induced by feeding 8g/kg, body weight (bw), fructose solution orally to Sprague Dawley rats (n = 8) for 56 days, treated with SPD (18.75; 37.5 and 75 mg/kg, bw), and analyzed for plasma blood glucose, serum biochemistry and the markers of oxidative stress (Ferric Reducing Antioxidant Power Assay (FRAP), Malondialdehyde (MDA), Reduced glutathione (GSH), DPPH radical scavenging assay. SPD concentrations, given orally for 42 days, significantly reversed the elevations in plasma blood glucose, MDA, and the reduction in kidneys glutathione activity. Oral administration of 18.75, 37.5, and 75 mg/kg doses of SPD also lowered serum Aspartate Aminotransferase (ASAT), Alanine Aminotransferase (ALAT), Triglycerides and Creatinine levels. SPD 75 mg/kg treatment in particular has significantly decreased serum Triglycerides level and increased HDL-Cholesterol levels, reversing the atherogenic potential of 56 days fructose administration. The consumption of S. platensis produced locally in Benin as a food supplement, easily accessible for low-income populations, may be helpful in the prevention and management of type 2 diabetes. Keywords: Oxidative stress; Spirulina platensis; hyperglycemia; insulin resistance, fructose die

    A 90-Day Oral Toxicity of Hydroethanolic Root Extract of Carissa spinarum in Wistar Rats

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    Background. Herbal medication is a worldwide and ancient practice, mostly in developing countries, where a large part of the population is involved in this practice. Hence, studies must be conducted to evaluate their safety and efficiency to avoid or prevent toxicological risks due to their usage. In Togo, Carissa spinarum is a medicinal plant belonging to Apocynaceae family, used as an aphrodisiac or to heal some ailments including malaria, sickle cell anemia, hypertension, pain, and asthma. Notwithstanding its several ethnomedicinal benefits, just a few toxicological data associated with its chronic use are available. Objective. Therefore, this study aims to assess the toxicity of an ethanolic root extract of Carissa spinarum in Wistar rats. Methods. The 90-day oral toxicity process following OECD TG 408 guidelines is used. Male Wistar rats received Carissa spinarum root hydroethanolic extract at 500 and 1000 mg/kg for 90 days by oral gavage. Body weight changes, hematological and blood biochemical parameters, organ weight changes, malondialdehyde as a lipoperoxidation marker expressed according to tissue proteins, and histopathology of vital organs were assessed. Results. No signs of toxicity or mortality were observed during the 90 days experiment. Hematological parameters have not shown any treatment-related abnormalities. According to biochemical parameters, an increase in the chloride ion level was observed at 1000 mg/kg p<0.01. There was no significant difference between the treated groups and the control group concerning the malondialdehyde concentration, body weight, and organ relative weight. No changes in necropsy and histopathology of vital organs associated with extract treatment were observed. Conclusion. The results indicated that an ethanolic root extract of Carissa spinarum does not cause adverse effects, which can lead to Wistar rats’ death after 90-day oral administration at 500 and 1000 mg

    Ethnopharmacological Survey on Medicinal Plants Used by Traditional Healers in Central and Kara Regions of Togo for Antitumor and Chronic Wound Healing Effects

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    Cancer is an emerging public health problem in sub-Saharan Africa. Several medicinal plants are used by traditional healers to treat tumors. In Togo, there are no recorded data for these plants but traditional healers claim to cure tumors with some success. So, information on medicinal plants used to cure human tumors and cancer could be of great importance for their widespread use and scientific validation. The present ethnopharmacological survey aims to record information on antitumor plants in central and Kara regions of Togo. Semistructured validated questionnaires were administered to fifty-seven traditional healers specialized in tumor management in 7 prefectures of Togo. Good practices and know-how were recorded. Quantitative ethnobotanical tools were used to analyze and summarize the data collected. 85 recipes of medicinal plants for tumors management are provided. In the local dialect, 78.95% of traditional healers do not have a clear tumor designation and 29.90% find that the causes of tumors remain unknown. According to 48.78% of traditional healers, the diagnosis of tumors in patients is made in the hospital. The types of tumors frequently treated are those of the breast (43.75%) and the lung (16.67%). The seventy listed medicinal plants belong to thirty-nine families, the most represented being Rubiaceae (17.95%), Caesalpiniaceae (12.82%), Fabaceae (10.26%), and Annonaceae (7.69%). The ten most cited species were Xylopia aethiopica, Aframomum melegueta, Khaya senegalensis, Parkia biglobosa, Piliostigma thonningii, Blighia sapida, Vitellaria paradoxa, Adansonia digitata, Annona muricata, and Parinari curatellifolia. Most of the recipes are prepared as decoction (40%) and administered orally (54.12%). Both regions of our study have a wealth of medicinal plants, and traditional healers would use their local knowledge in the management of various tumors and chronic wounds
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