Publications (2)3.96 Total impact
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Article: Polysaccharide isolated from Triticum aestivum stimulates insulin release from pancreatic cells via the ATP-sensitive K+ channel.
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ABSTRACT: Traditional natural plants have been used throughout the world for their antidiabetic effects. The aim of the present study was to investigate the stimulating activity of a polysaccharide extract derived from T. aestivum sprout (TASP) on insulin secretion in vitro using the RIN-5F pancreatic β-cell line and rat pancreatic islets. In these experiments, TASP (0.1 to 2 mg/ml) augmented glucose-stimulated insulin secretion in a dose-dependent manner in the presence of a stimulatory glucose concentration (16.7 mM), but not of a basal concentration (1.1 mM). Although TASP failed to enhance the high K+-induced insulin secretion, the insulinotropic effect of TASP was significantly inhibited by diazoxide, an opener of ATP-sensitive K+ channel blocking insulin release. TASP potentiated the insulin secretion induced by other secretagogues, such as IBMX and tolbutamide. Moreover, glucose-derived blood insulin levels were significantly elevated by oral administration of TASP to mice, similarly to antidiabetic drugs. We also demonstrated that TASP significantly increased glucose-induced 45Ca2+ uptake and proinsulin mRNA expression in rat islets. Overall, our results suggest that TASP has a stimulating effect on insulin secretion and production in pancreatic β-cells via K+ channel closure and calcium influx. These results suggest that TASP may be useful as a candidate for the therapy of diabetes mellitus.International Journal of Molecular Medicine 05/2012; 29(5):913-9. · 1.98 Impact Factor -
Article: Deoxyschisandrin inhibits H2O2-induced apoptotic cell death in intestinal epithelial cells through nuclear factor-kappaB.
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ABSTRACT: Oxidative stress is a pathogenesis for a typical inflammatory intestinal disease known as ulcerative colitis (UC) characterized by erosion and mucosal ulceration. For the treatment of UC, many kinds of traditional Asian medical plants have been used. Schisandra chinensis fruits (SC) are known to possess anti-ulcer, anti-hepatotoxic and anti-neurotoxic activity. However, its mechanism is still unknown. In the present study, we investigated the cytoprotective effect of deoxyschisandrin, a lignan compound comprised of SC fruits, on H2O2-induced apoptotic cell death in human intestinal epithelial cells (HCT116). In flow cytometry assay using Annexin V and propidium iodide, deoxyschisandrin inhibited H2O2-induced apoptotic cell death. To further evaluate the apoptotic signaling by H2O2, we detected caspase-3 activation using cleavage of pro-caspase-3. Deoxyschisandrin inhibited H2O2-induced caspase-3 activation by blocking cleavage of pro-caspase-3. Furthermore, it has been reported that oxidative stress by H2O2 induces an activation of nuclear factor-kappaB (NF-kappaB). In our results, H2O2 stimulated the degradation of IkappaBalpha, inhibitor of NF-kappaB, in a concentration-dependent manner. On the contrary, deoxyschisandrin inhibited H2O2-stimulated degradation of IkappaBalpha and activation of NF-kappaB by blocking translocation of NF-kappaB to the nucleus. Therefore, we suggest that deoxyschisandrin inhibits H2O2-induced apoptotic cell death.International Journal of Molecular Medicine 09/2010; 26(3):401-6. · 1.98 Impact Factor
