Serum metabolome analysis reveals medicinal fungi Phellinus igniarius ameliorated type 2 diabetes mellitus indications in rats via modulation of amino acid and carbohydrate metabolism

Medicinal fungi Phellinus igniarius exhibited hypoglycemic effects; however, the protective mechanisms of P. igniarius on type 2 diabetes are not yet fully understood. Herein, the anti-diabetic effect of P. igniarius was investigated via gas chromatography–mass spectrometry (GC/MS)-based metabolome analysis. The rats were divided into normal group; model group; positive group; and groups treated with low, medium, and high dose of P. igniarius. After the treatments, a significant decrease in blood glucose concentration was observed. The levels of total cholesterol and triglyceride were dramatically decreased, whereas the level of insulin was increased. Multivariate statistical analysis revealed 31 differential endogenous metabolites between model group and normal group. A total of 14, 28, and 31 biomarkers were identified for low, medium, and high dose of P. igniarius treated groups, respectively. Twenty-one of the biomarkers were validated by using standard substances. The linear correlation coefficients ranged from 0.9990 to 1.0000. The methodology exhibited good repeatability, recoveries, and stability. The major intervened metabolic pathways covered glyoxylate and dicarboxylic acid metabolism; alanine, aspartate, and glutamate metabolism; and glycine, serine, and threonine metabolism. Our metabolome analysis has provided insights into the underlying mechanism of P. igniarius on type 2 diabetes.