Aronia melanocarpa anthocyanin extracts are an effective regulator of suppressor of cytokine signaling 3-dependent insulin resistance in HepG2 and C2C12 cells

Abstract

Insulin resistance (IR) is involved in the development of type 2 diabetes mellitus (T2DM). Plant anthocyanins can attenuate IR, but the related mechanisms are still incompletely understood. We found that Aronia melanocarpa anthocyanin extracts (AMAE) could improve glucose uptake by upregulating glucose transporter-4, enhance insulin action in IR HepG2 and C2C12 cells, increase IRS-1 and p-GSK-3β (Ser9) levels, and decrease p-IRS-1 (Ser307) and GSK-3β levels, thereby promoting glycogen synthesis. Suppressor of cytokine signaling 3 (SOCS3), a negative regulator of insulin signaling, was reduced by AMAE after palmitic acid induction. Importantly, siSOCS3 transfection significantly amplified the insulin-sensitizing effects of AMAE. These findings indicated that AMAE could enhance insulin sensitivity and glycogen synthesis in IR HepG2 and C2C12 cells by downregulating SOCS3. This research was conducive to supplement the molecular mechanisms of AMAE alleviating IR, providing support for application of A. melanocarpa anthocyanins in the prevention and treatment of T2DM.