Differential expression of liver proteins in streptozotocin-induced diabetic rats in response to hypoglycemic mushroom polysaccharides

We investigated the influence of hypoglycemic fungal extracellular polysaccharides (EPS) on the differential expression of liver proteins in streptozotocin (STZ)-induced diabetic rats. The results of diabetic study revealed that orally administrated EPS exhibited an excellent hypoglycemic effect, lowering the average plasma glucose level in EPS-fed rats to 55.1% with enhanced glucose tolerance. In the next step, we analyzed the differential expression patterns of rat liver proteins from each group to discover potent candidates for diabetes-associated proteins. 34 proteins were upregulated and 35 proteins were downregulated upon diabetes induction. Surprisingly, the altered levels of most proteins in the diabetic group were fully or partially restored to those of the non-diabetic control group by EPS treatment. Although the molecular basis of protein modulation after EPS administration in diabetic rats was not verified, the results of the proteomic analysis provide impetus for further studies to identify reliable biomarkers for diabetic therapy.