Inonotus obliquus polysaccharide ameliorates serum profiling in STZ-induced diabetic mice model

Background Diabetes mellitus is a systemic disease mainly caused by the disorder of metabolism, which has become huge threat to human health. Polysaccharides are the main active substance from Inonotus obliquus (I. obliquus) with hypoglycemic effect. This study aims to evaluate the hypoglycemic activity and investigate the molecular mechanism of I. obliquus polysaccharide (IOP) in streptozotocin (STZ)-induced diabetic mice using metabolomics based on UPLC-Q-Exactive-MS method. Results The results showed that the oral administration of IOP in high dose (1.2 g/kg) can significantly reduce the blood glucose with 31% reduction comparing with the diabetic model and relieve dyslipidemia in diabetic mice. By UPLC-Q-Exactive-MS method and multivariate statistical analysis, a total of 15 differential metabolites were identified, including 4 up-regulated and 11 down-regulated biomarkers, of which l -tryptophan, l -leucine, uric acid, 12-HETE, arachidonic acid, PC(20:1(11Z)/14:1(9Z)) and SM(d18:0/24:1(15Z)) were exhibited an important variation, as the potential biomarkers in diabetes. Pathway analysis indicated that phenylalanine, tyrosine and tryptophan biosynthesis and arachidonic acid metabolism were prone to interference in diabetes. Moreover, leucine and proline were reversed and phytosphingosine was further reduced in diabetic mice under the intervention of IOP. Conclusion IOP has predominant hyperglycemic effect on STZ-induced diabetic mice via ameliorating serum profiling.