IRS1 and type 2 diabetes mellitus: The water extract of Polygonati Rhizoma and Codonopsis Radix (PRCR), mainly the polysaccharide fraction, showed effective hypoglycemic effects through upregulation of the IRS1/PI3K/AKT signaling pathway and inhibition of IRS1 phosphorylation in the T2DM mouse model treated with PRCR extracts, as levels of total cholesterol, and triacylglycerol, alanine aminotransferase and aspartate aminotransferase were significantly reduced compared with the non-treated model group mice [112].