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

Phellinus igniarius Polysaccharides Ameliorate Hyperglycemia by Modulating the Composition of the Gut Microbiota and Their Metabolites in Diabetic Mice

Gut microbiota dysbiosis has been reported as a risk factor in the development of type 2 diabetes mellitus (T2DM). Polysaccharides from Phellinus igniarius (P. igniarius) possess various properties that help manage metabolic diseases; however, their underlying mechanism of action remains unclear. Therefore, in this study, we aimed to evaluate the effect of P. igniarius polysaccharides (SH-P) on improving hyperglycemia in mice with T2DM and clarified its association with the modulation of gut microbiota and their metabolites using 16S rDNA sequencing and liquid chromatography-mass spectrometry. Fecal microbiota transplantation (FMT) was used to verify the therapeutic effects of microbial remodeling. SH-P supplementation alleviated hyperglycemia symptoms in T2DM mice, ameliorated gut dysbiosis, and significantly increased the abundance of Lactobacillus in the gut. Pathway enrichment analysis indicated that SH-P treatment altered metabolic pathways associated with the occurrence and development of diabetes. Spearman's correlation analysis revealed that changes in the dominant bacterial genera were significantly correlated with metabolite levels closely associated with hyperglycemia. Additionally, FMT significantly improved insulin sensitivity and antioxidative capacity and reduced inflammation and tissue injuries, indicating improved glucose homeostasis. These results indicate that the ameliorative effects of SH-P on hyperglycemia are associated with the modulation of gut microbiota composition and its metabolites.

Phellinus linteus polysaccharide extract improves insulin resistance by regulating gut microbiota composition

The hypoglycemic effect of Phellinus linteus polysaccharide extract (PLPE) has been documented in several previous studies, but the functional interactions among PLPE, gut microbiota, and the hypoglycemic effect remain unclear. We examined the regulatory effect of PLPE on gut microbiota, and the molecular mechanism underlying improvement of insulin resistance, using a type 2 diabetic rat model. Here, 24 male Sprague-Dawley rats were randomly divided into four groups that were subjected to intervention of saline (normal and model control group), metformin (120 mg/kg.bw), and PLPE (600 mg/kg.bw) by oral administration. After 8 weeks of treatment, PLPE increased levels of short-chain fatty acids (SCFAs) by enhancing abundance of SCFA-producing bacteria. SCFAs maintained intestinal barrier function and reduced lipopolysaccharides content in blood, thereby helping to reduce systemic inflammation and reverse insulin resistance. Our findings suggest that PLPE (in which polysaccharides are the major component) has potential application as a prebiotic for regulating gut microbiota composition in diabetic patients.

Hypoglycemic Effect of Ethanol and Ethyl Acetate Extract of Phellinus baumii Fruiting Body in Streptozotocin-Induced Diabetic Mice

We investigated hypoglycemic effect of ethanol (EtOH) and ethyl acetate extract acetate (AcOEt) extracts in streptozotocin- (STZ-) induced diabetic mice. Our data showed the maximum inhibitory effect on the fasting plasma glucose (FPG) level was detected in STZ-induced diabetic mice administered with 400 mg/kg AcOEt extract of P. baumii. A lower glycated albumin (GA) level and a higher insulin level were observed in 400 mg/kg AcOEt and EtOH extract groups. Moreover, 400 mg/kg AcOEt and EtOH extract exhibited a stronger effect on increasing size and cell number of islets. The insulin expression level of β-cells and integrated optical density (IOD) value were significantly increased by the administration of 400 mg/kg AcOEt and EtOH extracts. Taken together, AcOEt and EtOH extracts of P. baumii fruiting body exhibited considerable hypoglycemic effect on STZ-induced diabetic mice.