7-o-galloyl-d-sedoheptulose and Body-Weight

7-O-Galloyl-D-sedoheptulose (GS) is the bioactive polyphenol isolated from the low-molecular-weight fraction of Corni Fructus (Cornus officinalis Sieb. et Zucc.). The present study was conducted to examine whether GS has an ameliorative effect on the liver of type 2 diabetic db/db mice. GS (20 or 100 mg/kg body weight/day, per os) was administered every day for 6 weeks to db/db mice, and its effect was compared with vehicle-treated db/db and m/m mice. The administration of GS decreased the elevated serum glucose, leptin, insulin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), resistin, and hepatic functional parameters, and reduced the increased fluorescent advanced glycation endproducts (AGEs) and reactive oxygen species in the liver. The db/db mice exhibited the up-regulation of receptor for AGEs (RAGE) and AGE-related proteins; however, GS treatment significantly reduced those expressions. Moreover, the augmented expressions of oxidative stress- and inflammation-related proteins, phospho-extracellular-signal regulated kinase 1/2, phospho-c-Jun N-terminal kinase, nuclear factor-kappa B, activator protein-1, monocyte chemotactic protein-1, intracellular adhesion molecule-1, TNF-α, and IL-6, were down-regulated by GS administration. Hematoxylin-eosin staining showed that the increased hepatocellular damage in the liver of db/db mice improved with GS administration. The present results support the evidence for GS ameliorating hepatic damage through the RAGE-mediated inflammation pathway.

Topics: Animals; Biomarkers; Body Weight; Cornus; Diabetes Mellitus, Type 2; Drinking; Eating; Glycation End Products, Advanced; Heptoses; Liver; Male; Mice; Organ Size; Oxidative Stress; Polyphenols; Receptor for Advanced Glycation End Products

The aim of the present study was to evaluate the beneficial effects of 7-O-galloyl-D-sedoheptulose (GS), isolated from Corni Fructus, on hepatic and renal lipid metabolisms and advanced glycation endproduct formation followed by oxidative stress and inflammation using type 2 diabetic mice. GS was orally administered to db/db mice at doses of 20 and 100 mg/kg body weight per day for 8 weeks, and its effects were compared with those of the vehicle in db/db and m/m mice. The serum, hepatic, and renal biochemical factors, and protein expressions related to lipid metabolism, inflammation, advanced glycation endproducts, and their receptors, were measured. After 8 weeks of GS treatment, elevation of serum adiponectin as well as an improvement of hepatic and renal functional parameters was shown in db/db mice, and significant reductions of lipids in serum, liver, and kidney were observed according to the down-regulation of sterol regulatory element-binding protein-1. Moreover, GS inhibited oxidative stress and advanced glycation endproduct formation and their receptor expressions in the liver and kidney of db/db mice. These results suggest that GS could effectively inhibit advanced glycation endproduct formation caused by oxidative stress and/or dyslipidemia in the liver and kidney of db/db mice. Furthermore, the augmented expression of nuclear factor-kappa B p65 and its related inflammatory protein expressions were down-regulated in GS-treated groups. In conclusion, GS could have hepato- and reno-protective effects against abnormal lipid metabolism and the reactive oxygen species-related formation of advanced glycation endproducts with inflammation in type 2 diabetes.

Topics: Animals; Biomarkers; Body Weight; Cholesterol; Diabetes Mellitus, Type 2; Drinking; Gene Expression Regulation; Glucose; Hematologic Tests; Heptoses; Kidney; Liver; Male; Mice; Organ Size; Oxidative Stress; Triglycerides

Diabetes is the leading cause of end-stage renal failure, since glucose-dependent metabolic factors are synergistically activated within the diabetic kidney. Accordingly, in Japan, there is much debate over the health benefits of natural therapies to reduce these risk factors. In our previous study, we reported that Cornus officinalis SIEB. et ZUCC. possessed an antidiabetic effect via ameliorating glucose-mediated metabolic disorders as well as aminoguanidine, an inhibitor of advanced glycation endproduct (AGE) formation, with a renoprotective effect. The aim of the present study was to investigate the effect of 7-O-galloyl-D-sedoheptulose (GS) against diabetic oxidative stress and AGE formation. Streptozotocin-induced diabetic rats were orally administered GS for 20 d, and the changes in serum glucose levels, as well as those of body weight every 10 d were evaluated. In addition, glucose, fluorescent AGE, methylglyoxal, glycolaldehyde (GA), and immunoblotting analyses for heme oxygenase-1, receptor for AGE, N(epsilon)-(carboxymethyl)lysine, N(epsilon)-(carboxyethyl)lysine, and GA-pyridine were performed in the kidney at the end of the experiment. The results obtained in this study demonstrated that 20 d of treatment with GS had beneficial effects on hypoglycemic and renal metabolic abnormalities, including renal glucose, oxidative stress, and AGE formation. Together, our data help to elucidate its potential therapeutic value against diabetic kidney disease.

Topics: Aldehydes; Animals; Antioxidants; Blood Glucose; Blotting, Western; Body Weight; Cornus; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Glucose; Glycation End Products, Advanced; Heme Oxygenase-1; Heptoses; Kidney; Kidney Function Tests; Male; Oxidative Stress; Pyruvaldehyde; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances