AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was dete...AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was detected under optical microscopy and with colorimetric assay and gel electrophoresis.The activities of glutathione peroxidase and superoxide dismutase,total antioxidant capacity,and content of malondialdehyde in serum and tissue slices of pancreas were examined after 60 d to determine the effect of COSs in streptozotocin-induced diabetes in rats. RESULTS:COSs can prohibit the apoptosis of pancreatic islet cells.All concentrations of COSs can improve the capability of total antioxidant capacity and activity of superoxide dismutase and decrease the content of malondialdehyde drastically.Morphological investigation in the pancreas showed that COSs have resulted in the reduction of islets,loss of pancreatic cells,and nuclear pyknosis of pancreatic cells. CONCLUSION:COSs possess various biological activities and can be used in the treatment of diabetes mellitus.展开更多
Glutathione （GSH） is a tripeptide that constitutes one of the main intracellular reducing compounds. The normal content of GSH in the intestine is essential to optimize the intestinal Ca2＋ absorption. The use of GS...Glutathione （GSH） is a tripeptide that constitutes one of the main intracellular reducing compounds. The normal content of GSH in the intestine is essential to optimize the intestinal Ca2＋ absorption. The use of GSH depleting drugs such as DL-buthionine-S,R-sulfoximine, menadione or vitamin K3, sodium deoxycholate or diets enriched in fructose, which induce several features of the metabolic syndrome, produce inhibition of the intestinal Ca2＋ ab-sorption. The GSH depleting drugs switch the redox state towards an oxidant condition provoking oxida-tive/nitrosative stress and inflammation, which lead to apoptosis and/or autophagy of the enterocytes. Either the transcellular Ca transport or the paracellular Ca route are altered by GSH depleting drugs. The gene and/or protein expression of transporters involved in the transcellular Ca2＋ pathway are decreased. The favonoids quercetin and naringin highly abrogate the inhibition of intestinal Ca2＋ absorption, not only by restoration of the GSH levels in the intestine but also by their anti-apoptotic properties. Ursodeoxycholic acid, melatonin and glutamine also block the inhibition of Ca2＋ transport caused by GSH depleting drugs. The use of any of these antioxidants to ameliorate the intestinal Ca2＋ absorption under oxidant conditions associated with different pathologies in humans requires more investigation with regards to the safety,pharmacokinetics and pharmacodynamics of them.展开更多
基金Supported by The National Scientific Research Fund of China(2008JK007)the National Key Research and Development Program of China for the Tenth Five-Year Plan,No.2006BAD06A14
文摘AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was detected under optical microscopy and with colorimetric assay and gel electrophoresis.The activities of glutathione peroxidase and superoxide dismutase,total antioxidant capacity,and content of malondialdehyde in serum and tissue slices of pancreas were examined after 60 d to determine the effect of COSs in streptozotocin-induced diabetes in rats. RESULTS:COSs can prohibit the apoptosis of pancreatic islet cells.All concentrations of COSs can improve the capability of total antioxidant capacity and activity of superoxide dismutase and decrease the content of malondialdehyde drastically.Morphological investigation in the pancreas showed that COSs have resulted in the reduction of islets,loss of pancreatic cells,and nuclear pyknosis of pancreatic cells. CONCLUSION:COSs possess various biological activities and can be used in the treatment of diabetes mellitus.
文摘Glutathione （GSH） is a tripeptide that constitutes one of the main intracellular reducing compounds. The normal content of GSH in the intestine is essential to optimize the intestinal Ca2＋ absorption. The use of GSH depleting drugs such as DL-buthionine-S,R-sulfoximine, menadione or vitamin K3, sodium deoxycholate or diets enriched in fructose, which induce several features of the metabolic syndrome, produce inhibition of the intestinal Ca2＋ ab-sorption. The GSH depleting drugs switch the redox state towards an oxidant condition provoking oxida-tive/nitrosative stress and inflammation, which lead to apoptosis and/or autophagy of the enterocytes. Either the transcellular Ca transport or the paracellular Ca route are altered by GSH depleting drugs. The gene and/or protein expression of transporters involved in the transcellular Ca2＋ pathway are decreased. The favonoids quercetin and naringin highly abrogate the inhibition of intestinal Ca2＋ absorption, not only by restoration of the GSH levels in the intestine but also by their anti-apoptotic properties. Ursodeoxycholic acid, melatonin and glutamine also block the inhibition of Ca2＋ transport caused by GSH depleting drugs. The use of any of these antioxidants to ameliorate the intestinal Ca2＋ absorption under oxidant conditions associated with different pathologies in humans requires more investigation with regards to the safety,pharmacokinetics and pharmacodynamics of them.
