Characterization and renal protective effect of a polysaccharide from Astragalus membranaceus

Abstract

A water-soluble polysaccharide named as APS was isolated from the roots of Astragalus membranaceus by hot water extraction, anion-exchange and gel-permeation chromatography and tested for its renal protective effect. Its structural characteristics were investigated by FTIR, AMLC, NMR spectroscopy, GLC-MS, methylation analysis, periodate oxidation and Smith degradation. Based on the data obtained, APS was found to be an α-(1→4)-d-glucan, with a single α-d-glucose at the C-6 position every nine residue, on average, along the main chain. The glucan has a weight-average molecular weight of about 3.6 × 104 Da. 24 h Urine protein quantification and morphological observation revealed that APS significantly decreased the proteinuria and morphological changes on glomerulonephritis rats induced by cationic Bovine Serum Albumin (C-BSA), indicating APS could have a possible glomerulonephritis therapeutic potential. © 2009 Elsevier Ltd. All rights reserved.