A graminan type fructan from Achyranthes bidentata prevents the kidney injury in diabetic mice by regulating gut microbiota.

Diabetic kidney disease (DKD) is the main cause of end-stage renal disease, and few therapeutic options are available. The root of Achyranthis bidentatae (AB) is commonly used for DKD treatment in Traditional Chinese medicine. However, its mechanisms are still unclear. Here, a graminan type fructan ABPW1 with molecular weight of 3998 Da was purified from AB. It was composed of ß-1,2-linked Fruf, ß-2,6-linked-Fruf and ß-1,2,6-linked-Fruf backbone, and terminated with T-Glcp and 2-Fruf residues. ABPW1 protected against kidney injuries and intestinal barrier disruption in Streptozotocin (STZ)/High fat diet (HFD) mice. It could modulate gut microbiota composition, evidenced by a rise in the abundance of Bacteroide and decreases of Rikenella, Alistipes, Laedolimicola and Faecalibaculum. ABPW1 intervention promoted short chain fatty acids (SCFAs) production in STZ/HFD mice, especially propionate and isobutyric acid. Antibiotic treatment further demonstrated the key role of gut microbiota in the renal protective action of ABPW1. In addition, in vitro simulated digestion and fermentation together with in vivo fluorescent labeling studies demonstrated ABPW1 was indigestible in upper digestive tract but could reach the colon and be degraded into SCFAs by gut microbiota there. Overall, these data suggested ABPW1 has the potential application on DKD prevention.

Characterization and comparison of polysaccharides from Achyranthes bidentata, Cyathula officinalis and Achyranthes aspera by saccharides mapping.

Although the roots of Achyranthes bidentata (AB), Cyathula officinalis (CO) and Achyranthes aspera (AA) are different drugs, they are always confused in clinical practice due to their similar chemical components and functions. As polysaccharides are abundant in these drugs, a systematic comparison of polysaccharides from AB, CO and AA is not only necessary to understand their similar but not identical functions, but also helpful for the quality control of them. In this study, polysaccharides from 22 batches of AB, CO and AA were compared with monosaccharide composition, molecular weight distribution and saccharide mapping. Polysaccharides of AB, CO and AA had similar monosaccharide compositions but their relative contents of fructose, glucuronic acid, galacturonic acid and glucose were significant different, and could be used as key markers to distinguish them. Results from molecular weight distribution and saccharide mapping showed polysaccharides from AB, CO and AA were mainly composed of fructans with ß-2,1 and ß-2, 6-D-fructosidic linkages, but their degree of polymerization were different. Meanwhile, pectins were also contained in these three drugs. AB is partial to immunomodulation while CO is partial to removing blood stasis. Fructans and pectins are the similar bioactive substance basis of AB, CO and AA whereas their structural difference might be contributed to the efficacy differentia of these three drugs. This study provides a better understanding on the profiles of polysaccharides from AB, CO and AA, further guiding their clinical usage and facilitating their quality control.

Structural characterisation of a water-soluble polysaccharide from tissue-cultured Dendrobium huoshanense C.Z. Tang et S.J. Cheng.

A water-soluble polysaccharide TC-DHPA4 with a molecular weight of 8.0 × 105 Da was isolated from tissue-cultured Dendrobium huoshanense by anion exchange and gel permeation chromatography. Monosaccharide analysis revealed that the homogeneous polysaccharide was made up of rhamnose, arabinose, mannose, glucose, galactose and glucuronic acid with a molar ratio of 1.28:1:1.67:4.71:10.43:1.42. The sugar residue sequence analysis based on the GC-MS files and NMR spectra indicated that the backbone of TC-DHPA4 consisted of the repeated units:→6)-ß-Galp-(1→6)-ß-Galp-(1→4)-ß-GlcpA-(1→6)-ß-Glcp-(1→6)-ß-Glcp-(→. The sugar residue sequences ß-Glcp-(1→)-α-Rhap-(1→3)-ß-Galp-(1→, ß-Glcp-(1→4)-α-Rhap-(1→3)-ß-Galp-(1→, ß-Galp-(1→6)-ß-Manp-(1→3)-ß-Galp-(1→, and α-l-Araf-(1→2)-ß-Manp-(1→3)-ß-Galp-(1→ were identified as the branches attached to the C-3 position of (1→6)-linked galactose in the backbone.