IRS1 and brain disorder: Although the underlying mechanisms remain to be elucidated, these antidiabetic effects of these herbal supplements may be through increasing glucose uptake and improving insulin sensitivity in peripheral tissues, as well as improving glycogen synthesis in the liver, restoring pancreatic islets dysfunction, slowing down gastric emptying rates, and improving diabetic renal and brain disorders, via multiple signaling pathways, including those of the PPARs, AMPK, PI3K/IRS-1, RBP4-GLUT4, and Nrf2 pathways [37].