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Altenhofen D, da Luz G, Frederico MJS, Venzke D, Brich M, Vigil S, Fröde TS, Linares CEB, Pizzolatti MG, Silva FRMB. Bis-Pyrano Prenyl Isoflavone Improves Glucose Homeostasis by Inhibiting Dipeptidyl Peptidase-4 in Hyperglycemic Rats. J Cell Biochem 2016; 118:92-103. [PMID: 27238050 DOI: 10.1002/jcb.25614] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 05/26/2016] [Indexed: 12/25/2022]
Abstract
Isoflavones widely distributed in plants prevent diabetes. This study investigated the in vivo and in vitro effect of 3',4'-dihydroxy-6″,6″,6″',6″'-tetramethylbis(pyrano[2″,3″:5,6::2″',3″':7,8]isoflavone (bis-pyrano prenyl isoflavone) on glucose homeostasis in hyperglycemic rats. The ethyl acetate fraction from aerial parts of Polygala molluginifolia that contain isoflavones was assayed on glucose tolerance, on in vitro maltase activity and on protein glycation. The isoflavone bis-pyrano prenyl isolated from this fraction was investigated on glucose homeostasis. The in vivo action of the isoflavone exhibits an anti-hyperglycemic effect by improving glucose tolerance, augmenting the liver glycogen, inhibiting maltase activity, and stimulating glucagon-like peptide-1 (GLP-1) and insulin secretion. The in vitro isoflavone inhibits dipeptidyl peptidase-4 (DPP-4) activity since the glucose tolerance was improved in the presence of the isoflavone as much as sitagliptin, an inhibitor of DPP-4. However, the co-incubation with isoflavone and sitagliptin exhibited an additive anti-hyperglycemic action. The isoflavone increased the GLP-1 faster than the positive hyperglycemic group, which shows that the intestine is a potential target. Thus, to clarify the main site of action in which isoflavone improves glucose balance, the in vitro mechanism of action of this compound was tested in intestine using calcium influx as a trigger for the signal pathways for GLP-1 secretion. The isoflavone stimulates calcium influx in intestine and its mechanism involves voltage-dependent calcium channels, phospholipase C, protein kinase C, and stored calcium contributing for GLP-1 secretion. In conclusion, the isoflavone regulates glycaemia by acting mainly in a serum target, the DPP-4 inhibitor. Furthermore, the long-term effect of isoflavone prevents protein glycation. J. Cell. Biochem. 118: 92-103, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Delsi Altenhofen
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Cx. Postal 5069, CEP: 88040-970, Florianópolis, Santa Catarina, Brazil
| | - Gabrielle da Luz
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Cx. Postal 5069, CEP: 88040-970, Florianópolis, Santa Catarina, Brazil
| | - Marisa Jádna Silva Frederico
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Cx. Postal 5069, CEP: 88040-970, Florianópolis, Santa Catarina, Brazil
| | - Dalila Venzke
- Departamento de Química, Centro de Ciências Físicas e Matemáticas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, CEP: 88040-900, Florianópolis, Santa Catarina, Brazil
| | - Mayara Brich
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Cx. Postal 5069, CEP: 88040-970, Florianópolis, Santa Catarina, Brazil
| | - Silvana Vigil
- Departamento de Análises Clínicas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, CEP: 88040-900, Florianópolis, Santa Catarina, Brazil
| | - Tania Silvia Fröde
- Departamento de Análises Clínicas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, CEP: 88040-900, Florianópolis, Santa Catarina, Brazil
| | - Carlos Eduardo Blanco Linares
- Departamento de Ciências da Saúde, Centro de Ciências da Saúde, Universidade Regional Integrada do Alto Uruguai e da Missões, Campus Frederico Westphalen, Frederico Westphalen, Rio Grande do Sul, Brazil
| | - Moacir Geraldo Pizzolatti
- Departamento de Química, Centro de Ciências Físicas e Matemáticas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, CEP: 88040-900, Florianópolis, Santa Catarina, Brazil
| | - Fátima Regina Mena Barreto Silva
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Cx. Postal 5069, CEP: 88040-970, Florianópolis, Santa Catarina, Brazil
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Lucas ML, Morrison JD. An investigation into the relationship between small intestinal fluid secretion and systemic arterial blood pressure in the anesthetized rat. Physiol Rep 2015; 3:3/5/e12407. [PMID: 26019291 PMCID: PMC4463835 DOI: 10.14814/phy2.12407] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The effects of changes in the steady level of diastolic blood pressure on fluid flux across the jejunum has been investigated in the anesthetized rat during perfusion with a nutrient-free and Na+-free solution. Diastolic blood pressure was manipulated by intravenous infusions, during the jejunal perfusions, of vasodilators (vasoactive intestinal polypeptide, acetyl-β-methylcholine, and phentolamine) and a vasoconstrictor (arginine vasopressin), each of which acts through a different cellular mechanism. The outcome was that fluid flux was related by a parabolic relationship with diastolic blood pressure in which net secretion occurred over the range 40–100 mmHg, whereas net absorption was recorded at diastolic pressures exceeding 100 mmHg and below 40 mmHg. Against a background of normal absorption promoted by perfusion with 145 mmol L−1 Na+/5 mmol L−1 glucose solution, reductions in diastolic blood pressure markedly reduced the mean rate of fluid absorption by 58% overall, whereas the rate of glucose absorption remained unchanged. Our results were explained on the basis that vasodilatation led to increased capillary pressure and then to net filtration of fluid from the mesenteric capillary bed. Experiments in which Escherichia coli heat-stable toxin was added to the jejunal perfusate confirmed the absence of a secretory response, which was consistent with the absence of effect of the toxin on diastolic blood pressure.
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Affiliation(s)
- Michael L Lucas
- School of Life Sciences, University of Glasgow, West Medical Building, Glasgow, G12 8QQ, U.K
| | - James D Morrison
- School of Life Sciences, University of Glasgow, West Medical Building, Glasgow, G12 8QQ, U.K
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