ascorbic-acid and galangin

To examine the effect of galangin on hyperglycemia-mediated oxidative stress in streptozotocin (STZ)-induced diabetic rats.. Diabetes was induced by intraperitoneal administration of low-dose STZ (40 mg/kg body weight (BW)) into male albino Wistar rats. Galangin (8 mg/kg BW) or glibenclamide (600 µg/kg BW) was given orally, once daily for 45 days to normal and STZ-induced diabetic rats.. Diabetic rats showed significantly increased levels of plasma glucose, thiobarbituric acid reactive substances, lipid hydroperoxides, and conjugated dienes. The levels of insulin and non-enzymatic antioxidants (vitamin C, vitamin E, reduced glutathione) and the activity of enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase (GST)) were decreased significantly in diabetic control rats. These altered plasma glucose, insulin, lipid peroxidation products, enzymatic and non-enzymatic antioxidants ions were reverted to near-normal level after the administration of galangin and glibenclamide.. The present study shows that galangin decreased oxidative stress and increased antioxidant status in diabetic rats, which may be due to its antidiabetic and antioxidant potential.

Topics: Animals; Antioxidants; Ascorbic Acid; Diabetes Mellitus, Experimental; Flavonoids; Hyperglycemia; Lipid Peroxidation; Male; Oxidation-Reduction; Oxidative Stress; Random Allocation; Rats; Rats, Wistar; Streptozocin; Vitamin E

The formation of complexes of metal ions with the flavonoids quercetin (L1), rutin (L2), galangin (L3) and catechin (L4) has been investigated by UV-visible spectroscopy. The antioxidant activities of the compounds were evaluated by using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicalscavenging method. In this work, we have shown that the complexed flavonoids are much more effective free radical scavengers than the free flavonoids. We suggest that the higher antioxidant activity of the complexes is due to the acquisition of additional superoxide dismutating centers. Radical scavenging activities of the compounds were also investigated from an electrochemical point of view. There is a relationship between the logarithm of the antioxidant activity (represented by EC50) and the oxidation potential. The synergic effect of the complexes and ascorbic acid were studied by [13C]-NMR analyses. The results show that ascorbic acid can protect flavonoids from oxidative degradation, and reveal antioxidant synergies between ascorbic acid and the compounds.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Catechin; Drug Synergism; Flavonoids; Free Radical Scavengers; Magnetic Resonance Spectroscopy; Metals; Oxidation-Reduction; Picrates; Quercetin; Reactive Oxygen Species; Rutin; Superoxide Dismutase