| 1. |
- Persson, Ingrid, et al.
(författare)
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Effect of Vaccinium myrtillus and Its Polyphenols on Angiotensin-Converting Enzyme Activity in Human Endothelial Cells
- 2009
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 57:11, s. 4626-4629
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates if the connection between Vaccinium myrtillus and angiotensin-converting enzyme (ACE) might be an explanation of the pharmacological effects on circulation. Cultured endothelial cells from human umbilical veins were incubated with bilberry 25E extract. The main anthocyanidins combined in myrtillin chloride and separately in cyanidin, delphinidin, and malvidin, respectively, were examined concerning their effects on ACE. After 10 min of incubation with bilberry 25E, a significant, dose-dependent inhibition of ACE activity was seen, and after incubation with myrtillin chloride a significant inhibition was seen. No effect was seen with the anthocyanidins. The effect seems to be dependent on this specific mixture of anthocyanins in the bilberry. V. myrtillus may thus have the potential to prevent and protect against cardiovascular diseases.
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| 2. |
- Persson, Ingrid, et al.
(författare)
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Effects of green tea, black tea and rooibos on angiotensin-converting enzyme activity in healthy volunteers
- 2009
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Ingår i: in Planta Medica(ISSN 0032-0943). ; , s. 1030-1030
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Konferensbidrag (refereegranskat)abstract
- Tea has been reported to reduce cardiovascular mortality, but the mechanisms behind are largely unknown. The aim of this project was to investigate the effect of green tea (Japanese Sencha), black tea (Indian Assam B.O.P.) and Rooibos on angiotensin-converting enzyme and nitric oxide. Seventeen healthy volunteers received a single oral dose of either 400 ml green tea, black tea or Rooibos tea in a randomized three-phase cross over study. ACE activity and NO concentration were measured (at 0, 30, 60 and 180 minutes) in all phases. ACE activity was analysed with a commercial radioenzymatic assay. Nitrite was analysed as a marker of NO concentration. In addition ACE genotype was determined using a PCR method. Oral intake of a single dose of Rooibos significantly inhibited ACE activity, p<0.01 after 30 min and p<0.05 after 60 min. A significant inhibition of ACE activity was seen with green tea for the ACE genotype II (p<0.05), 30 minutes after intake of the tea and for the ACE genotype ID (p<0.05), 60 minutes after intake. A significant inhibition of ACE activity was also seen with Rooibos for the ACE genotype II (p<0.05), 60 minutes after intake. No significant effect on NO concentration was seen.
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| 3. |
- Persson, Ingrid, 1951-, et al.
(författare)
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Tea flavanols inhibit angiotensin-converting enzyme activity and increase nitric oxide production in human endothelial cells
- 2006
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Ingår i: Journal of Pharmacy and Pharmacology (JPP). - : Oxford University Press (OUP). - 0022-3573 .- 2042-7158. ; 58:8, s. 1139-1144
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Tidskriftsartikel (refereegranskat)abstract
- A diversity of pharmacological effects on the cardiovascular system have been reported for Camellia sinensis: antioxidative, antiproliferative and anti-angiogenic activity, and nitric oxide synthase activation. The purpose of this study was to investigate if the connection between tea and angiotensin-converting enzyme (ACE) and nitric oxide (NO) might be an explanation of the pharmacological effects of tea on the cardiovascular system. Cultured endothelial cells from human umbilical veins (HUVEC) were incubated with extracts of Japanese Sencha (green tea), Indian Assam Broken Orange Pekoe (black tea) and Rooibos tea, respectively. The main flavanols and purine alkaloids in green and black tea were examined for their effects on ACE and NO. After incubation with green tea, black tea and Rooibos tea for 10 min, a significant and dose-dependent inhibition of ACE activity in HUVEC was seen with the green tea and the black tea. No significant effect on ACE was seen with the Rooibos tea. After 10-min incubation with (-)-epicatechin, (-)- epigallocatechin, (-)-epicatechingallate and (-)-epigallocatechingallate, a dose-dependent inhibition of ACE activity in HUVEC was seen for all four tea catechins. After 24-h incubation, a significantly increased dose-dependent effect on NO production in HUVEC was seen for the green tea, the black tea and the Rooibos tea. After 24-h incubation with (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechingallate and (-)-epigallocatechingallate, a dose-dependent increased NO production in HUVEC was seen. In conclusion, tea extracts from C. sinensis may have the potential to prevent and protect against cardiovascular disease. © 2006 The Authors.
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| 4. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Life cycle assessment of Biodiesel - Hydrotreated oil from rape, oil palm or Jatropha
- 2008
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Ingår i: Annual Poster Exhibition at the Department of Chemical and Biological Engineering, Chalmers University of Technology, Mars 6th, 2008, Göteborg, Sweden.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- There is a need for fuels based on renewable resources that have acceptable emission profiles and that are functional for truck engines used in heavy vehicles. Volvo has participated in the CONCAWE/EUCAR/JRC WTW study, which analyzed a number of candidate fuels, several process routes to produce each fuel as well as different raw material choices. However, the CONCAWE study did not include any second generation hydrogenated vegetable oil type biodiesel. In the present study, Volvo and Chalmers investigate and benchmark hydrogenated vegetable oils. Different production routes from different proposed raw materials are investigated using life cycle assessment modeling. Raw materials considered are oil from rape seed (grown in Germany), palm oil (grown in Malaysia) and oil from the fruits of Jatropha curcas (grown in India). The raw material is converted into hydrogenated oil at a production site in northern Europe and used at the European market. Results regarding life cycle global warming potential and energy use are presented.
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| 5. |
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| 6. |
- Björkqvist, Maria, et al.
(författare)
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Role of gastrin in the development of gastric mucosa, ECL cells and A-like cells in newborn and young rats
- 2002
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Ingår i: Regulatory Peptides. - 1873-1686. ; 108:2-3, s. 73-82
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Tidskriftsartikel (refereegranskat)abstract
- Histamine-producing ECL cells and ghrelin-producing A-like cells are endocrine/paracrine cell populations in the acid-producing part of the rat stomach. While the A-like cells operate independently of gastrin, the ECL cells respond to gastrin with mobilization of histamine and chromogranin A (CGA)-derived peptides, such as pancreastatin. Gastrin is often assumed to be the driving force behind the postnatal development of the gastric mucosa in general and the ECL cells in particular. We tested this assumption by examining the oxyntic mucosa (with ECL cells and A-like cells) in developing rats under the influence of YF476, a cholecystokinin-2 (CCK2) receptor antagonist. The drug was administered by weekly subcutaneous injections starting at birth. The body weight gain was not affected. Weaning occurred at days 1522 in both YF476-treated and age-matched control rats. Circulating gastrin was low at birth and reached adult levels 2 weeks after birth. During and after weaning (but riot before), YF476 greatly raised the serum gastrin concentration (because of abolished acid feedback inhibition of gastrin release). The weight of the stomach was unaffected by YF476 during the first 2-3 weeks after birth. From 4 to 5 weeks of age, the weight and thickness of the gastric mucosa were lower in YF476-treated rats than in controls. Pancreastatin-immunoreactive cells (i.e. all endocrine cells in the stomach) and ghrelin-immunoreactive cells (A-like cells) were few at birth and increased gradually in number until 6-8 weeks of age (control rats). At first, YF476 did not affect the development of the pancreastatin-immunoreactive cells, but a few weeks after weaning, the cells were fewer in the YF476 rats. The ECL-cell parameters (oxyntic mucosal histamine and pancreastatin concentrations, the histidine decarboxylase (HDC) activity, the HDC mRNA levels and serum pancreastatin concentration) increased slowly until weaning in both YF476-treated and control rats. From then on, there was a further increase in the ECL-cell parameters in control rats but not in YF476 rats. The postnatal development of the ghrelin cells (i.e. the A-like cells) and of the A-like cell parameters (the oxyntic mucosal ghrelin concentration and the serum ghrelin concentrations) was not affected by YF476 at any point. We conclude that gastrin affects neither the oxyntic mucosa nor the endocrine cells before weaning. After weaning, CCK2 receptor blockade is associated with a somewhat impaired development of tire oxyntic mucosa and the ECL cells. While gastrin stimulation is of crucial importance for the onset of acid secretion during weaning and for the activation of ECL-cell histamine formation and secretion, the mucosal and ECL-cell growth at this stage is only partly gastrin-dependent. In contrast, the development of the A-like cells is independent of gastrin at all stages. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 7. |
- Bresell, Anders, et al.
(författare)
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Bioinformatic and enzymatic characterization of the MAPEG superfamily
- 2005
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Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 272:7, s. 1688-1703
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Tidskriftsartikel (refereegranskat)abstract
- The membrane associated proteins in eicosanoid and glutathione metabolism (MAPEG) superfamily includes structurally related membrane proteins with diverse functions of widespread origin. A total of 136 proteins belonging to the MAPEG superfamily were found in database and genome screenings. The members were found in prokaryotes and eukaryotes, but not in any archaeal organism. Multiple sequence alignments and calculations of evolutionary trees revealed a clear subdivision of the eukaryotic MAPEG members, corresponding to the six families of microsomal glutathione transferases (MGST) 1, 2 and 3, leukotriene C4 synthase (LTC4), 5-lipoxygenase activating protein (FLAP), and prostaglandin E synthase. Prokaryotes contain at least two distinct potential ancestral subfamilies, of which one is unique, whereas the other most closely resembles enzymes that belong to the MGST2/FLAP/LTC4 synthase families. The insect members are most similar to MGST1/prostaglandin E synthase. With the new data available, we observe that fish enzymes are present in all six families, showing an early origin for MAPEG family differentiation. Thus, the evolutionary origins and relationships of the MAPEG superfamily can be defined, including distinct sequence patterns characteristic for each of the subfamilies. We have further investigated and functionally characterized representative gene products from Escherichia coli, Synechocystis sp., Arabidopsis thaliana and Drosophila melanogaster, and the fish liver enzyme, purified from pike (Esox lucius). Protein overexpression and enzyme activity analysis demonstrated that all proteins catalyzed the conjugation of 1-chloro-2,4-dinitrobenzene with reduced glutathione. The E. coli protein displayed glutathione transferase activity of 0.11 µmol·min−1·mg−1 in the membrane fraction from bacteria overexpressing the protein. Partial purification of the Synechocystis sp. protein yielded an enzyme of the expected molecular mass and an N-terminal amino acid sequence that was at least 50% pure, with a specific activity towards 1-chloro-2,4-dinitrobenzene of 11 µmol·min−1·mg−1. Yeast microsomes expressing the Arabidopsis enzyme showed an activity of 0.02 µmol·min−1·mg−1, whereas the Drosophila enzyme expressed in E. coli was highly active at 3.6 µmol·min−1·mg−1. The purified pike enzyme is the most active MGST described so far with a specific activity of 285 µmol·min−1·mg−1. Drosophila and pike enzymes also displayed glutathione peroxidase activity towards cumene hydroperoxide (0.4 and 2.2 µmol·min−1·mg−1, respectively). Glutathione transferase activity can thus be regarded as a common denominator for a majority of MAPEG members throughout the kingdoms of life whereas glutathione peroxidase activity occurs in representatives from the MGST1, 2 and 3 and PGES subfamilies.
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| 8. |
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| 9. |
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| 10. |
- Davidsson, Pia, 1962, et al.
(författare)
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Clinical mass spectrometry in neuroscience. Proteomics and peptidomics.
- 2003
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Ingår i: Cellular and molecular biology (Noisy-le-Grand, France). - 0145-5680 .- 1165-158X. ; 49:5, s. 681-8
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Forskningsöversikt (refereegranskat)abstract
- In this review we discuss the merits and drawbacks with the use of proteomic and peptidomic strategies for identification of proteins and peptides in their multidimensional interactions in complex biological processes. The progress in proteomics and peptidomics during the last years offer us new challenges to study changes in the protein and peptide synthesis. These strategies also offer new tools to follow post-translational modifications and other disturbed chemical processes that may be indicative of pathophysiological alteration(s). Furthermore these techniques can contribute to improvements in the diagnosis and therapy of neurodegenerative diseases, such as Alzheimer's disease, and psychiatric diseases, as depression and post traumatic stress disorders. We also consider different practical aspects of the applications of mass spectrometry in clinical neuroscience, illustrated by example from our laboratories. The new proteomic and peptidomic strategies will further enable the progress for clinical neuroscience research.
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