Structural features and hypoglycaemic effects of Cynomorium songaricum polysaccharides on STZ-induced rats

Abstract A water-soluble polysaccharide isolated from Cynomorium songaricum which is a traditional Chinese food was purified by Ultrahydrogel 500 gel filtration chromatography. The structural characterisation and hypoglycaemic activity of the purified polysaccharide fraction (CSPA) were evaluated. CSPA (Mw of 1.394 × 105 Da) was a heteropolysaccharide consisting of Ara, Glu and Gal. The conformation of CSPA was characterised as a compact chain of sphere-like structure in aqueous solution with a df value of 2.86. Linkage analysis and NMR (1D and 2D) revealed the presence of the following unit: → 3 ) - α - araf - ( 1 → 3 ) - α - d - glcp - ( 1 → 4 ) - α - d -Gal p A6Me- ( 1 → . Pharmaceutical experiments showed that the administration of CSPA could significantly decrease blood glucose levels, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, blood urea nitrogen, creatinine activities, and effectively increase serum insulin level and the content of liver glycogen in streptozotocin-induced diabetic rats. Histopathology studies showed that the reduced islet cells were restored to near normal upon treatment with CSPA. The results suggest CSPA could be considered as a potential candidate for developing a new anti-diabetic agent.