Investigation of the Renal Protective Effect of Combined Dietary Polyphenols in Streptozotocin-Induced Diabetic Aged Rats.

Natural polyphenols are widely reported to have a large range of pharmacological properties, especially antioxidant activities and free radical scavenging capacities. In this study, we investigate the effects of naringin, chlorogenic acid, and quercetin mixtures (NCQ) on renal fibrosis in streptozotocin (STZ)-induced diabetic aged rats and its underlying mechanisms for ten consecutive weeks. The oxidative defense system in the kidneys of treated rats was found to be improved. Several biomarkers were investigated including the blood urea nitrogen, creatinine, and uric acid. Moreover, antioxidant parameters were evaluated and we found that superoxide dismutase, catalase, glutathione peroxidase, Na+-K+-ATPase activities, the nitric oxide production, the protein carbonyl, the advanced oxidation protein products, lipid peroxidation, and reduced glutathione levels were all significantly balanced and close to control values. In addition, NCQ restored renal injuries and fibrosis as assessed by histological method and molecular biology investigation of the matrix metalloproteinase, the transforming growth factor-beta TGF-ß, the tumor necrosis factor TNFα, and p53 expression. Our study proposes the NCQ combination as potential plant-derived bioactive compounds to prevent diabetic nephropathy.

New Isoflavones with Antioxidant Activity Isolated from Cornulaca monacantha.

In the course of phytochemical and chemotaxonomical investigations of Cornulaca monacantha (Amaranthaceae), two new isoflavones, 3-(2-hydroxyphenyl)-5,7-dimethoxy-6-(methoxymethyl)-4H-1-benzopyran-4-one (1) and 7-hydroxy-3-(4-hydroxyphenyl)-5-methoxy-6-(methoxymethyl)-4H-1-benzopyran-4-one (2) were isolated from the fresh aerial parts of C. monacantha among with three known compounds named vanillic acid (3), N-cis-feruloyltyramine (4) and N-trans-feruloyltyramine (5). Their structures were elucidated by means of spectroscopic methods including one- and two-dimensional NMR and HR-ESI-MS techniques. The isolated compounds exhibited interesting antioxidant activity determined by DPPH, ABTS and TAC tests.