3,3′,4,5′-Tetramethoxy-trans-stilbene improves insulin resistance by activating the IRS/PI3K/Akt pathway and inhibiting oxidative stress

The potential anti-diabetic effect of resveratrol derivative, 3,3′,4,5′-tetramethoxy-trans-stilbene (3,3′,4,5′-TMS) and its underlying mechanism in high glucose (HG) and dexamethasone (DXMS)-stimulated insulin-resistant HepG2 cells (IR-HepG2) were investigated. 3,3′,4,5′-TMS did not reduce the cell viability of IR-HepG2 cells at the concentrations of 0.5–10 µM. 3,3′,4,5′-TMS increased the potential of glucose consumption and glycogen synthesis in a concentration-dependent manner in IR-HepG2 cells. 3,3′,4,5′-TMS ameliorated insulin resistance by enhancing the phosphorylation of glycogen synthase kinase 3 beta (GSK3β), inhibiting phosphorylation of insulin receptor substrate-1 (IRS-1), and activating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in IR-HepG2 cells. Furthermore, 3,3′,4,5′-TMS significantly suppressed levels of reactive oxygen species (ROS) with up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) expression. To conclude, the beneficial effect of 3,3′,4,5′-TMS against insulin resistance to increase glucose consumption and glycogen synthesis was mediated through activation of IRS/PI3K/Akt signaling pathways in the IR-HepG2 cells, accomplished with anti-oxidative activity through up-regulation of Nrf2.University of Macau | Ref. SRG2019-00154-ICMSUniversity of Macau | Ref. MYRG2019-00157-ICMSUniversity of Macau | Ref. MYRG2018-00169-ICMSScience and Technology Development Fund | Ref. 0117/2020/AScience and Technology Development Fund | Ref. SKL-QRCM(UM)-2020–2022Science and Technology Development Fund | Ref. 0098/2020/AMinisterio de Ciencia e Innovación | Ref. RYC2020-030365-