The present work was performed to evaluate the effect of acidic‐extractable polysaccharides (AE‐PS) from fruit bodies of Cordyceps militaris on type 2 diabetes mellitus (T2DM) and its structural characteristics. The T2DM mice induced by high‐fat diet (HFD) and streptozotocin (STZ) were administered with 100 and 400 mg/kg AE‐PS for 4 weeks. Our work proved that AE‐PS decreased the levels of serum lipid, lipid peroxidation, and blood glucose; improved glucose and insulin resistance; enhanced antioxidant enzyme activities; and attenuated the injuries of the liver, kidney, and pancreas in T2DM mice. These results might offer references for the exploitation of AE‐PS as functional foods or natural drug source for preventing and treating HFD‐ and STZ‐induced T2DM. Moreover, gas chromatography (GC) results revealed that AE‐PS was heterogeneous and composed of fucose, ribose, arabinose, xylose, mannose, galactose, and glucose with mass percentages of 1.23%, 0.57%, 0.29%, 2.12%, 2.73%, 4.66%, and 88.4%, respectively. Fourier‐transform infrared (FTIR) and nuclear magnetic resonance (NMR) analysis indicated that AE‐PS was a pyran‐type polysaccharide with α‐ and β‐configurations.

PGPs from Pleurotus geesteranus enhanced hepatic functions by improving oxidative status via up-regulating Nrf2/HO-1 signalling pathways, and decreasing inflammation via down-regulating TLR4/NF-κB signalling pathways.

A polysaccharide named PFP-1 was isolated from the Pleurotus geesteranus fruiting body, and potential investigations on ameliorating oxidative stress and liver injury against alcoholic liver disease (ALD) were performed in mice. The animal studies demonstrated that PFP-1 had hepatoprotective effects by improving hepatocellular histopathology, modulating alcohol metabolisms and restoring the serum lipid levels. Besides, PFP-1 could attenuate oxidative stress and inflammatory responses by activating the Nrf2-mediated signal pathways and regulating the TLR4-mediated NF-κB signal pathways. The characterization indicated that PFP-1 was a typical pyranose-polysaccharide in a triple-helical conformation, which was linked by t-β-Glcp, 1,6-α-Glcp and 1,2,6-α-Galp. And the characteristic properties of higher water solubility and appropriate molecular weights contributed to the superior bioactivities. The results demonstrated that PFP-1 could be used as a supplement for alleviating alcohol-induced liver damage.