TNF and diabetes mellitus: Furthermore, total saponins from Dioscorea nipponica, down regulated NF-κβ and up-regulate protein expression of IRS-1, GLUT-4, p-AKT, and p-AMPK; and decreased gene expression of TNF-α, IL-6, PEPCK, and G6Pase and GSK-3 in liver (Yu et al., 2015), implicating the plant extracts potential for pre-diabetic and diabetes treatment.