IRS1 and Insulin resistance: Therefore, the ability of berberine to protect experimental animals with type 2 diabetes mellitus from insulin resistance is due to the regulation of the expression of cAMP, PKA, PPM1B, PPARγ, LRP1, GLUT4, NF-B p65, JNK, IKKβ, IRS-1, IRS -2, PI3K, and AKT in the heart [315].