Anthocyanins from Purple Corn Ameliorated Tumor Necrosis Factor‐α‐Induced Inflammation and Insulin Resistance in 3T3‐L1 Adipocytes via Activation of Insulin Signaling and Enhanced GLUT4 Translocation

Scope The aim was to compare the effect of an anthocyanin‐rich extract from purple corn pericarp (PCW) and pure anthocyanins on adipogenesis, inflammation, and insulin resistance in 3T3‐L1 adipocytes on basal and inflammatory conditions. Methods and results Preadipocytes (3T3‐L1) were treated during differentiation with or without PCW. Differentiated adipocytes were treated either individually or in combination with tumor necrosis factor α (TNF‐α) and PCW, or pure C3G, Pr3G, P3G. PCW reduced preadipocyte differentiation (IC50 = 0.4 mg/mL). PCW and pure anthocyanins including C3G reduced fatty acid synthase enzymatic activity. PCW reduced TNF‐α‐dependent inflammatory status increasing adiponectin (39%), and decreasing leptin (−79%). PCW and C3G increased glucose uptake and reduced reactive oxygen species generation in insulin resistant adipocytes. An increase in phosphorylation was observed in AKT, IKK, and MEK, and a decrease in IRS and mTOR activating the insulin receptor‐associated pathway. PCW (7.5‐fold) and C3G (6.3‐fold) enhanced GLUT4 membrane translocation compared to insulin resistant adipocytes. Conclusion Anthocyanins from colored corn prevented adipocyte differentiation, lipid accumulation, and reduced PPAR‐γ transcriptional activity on adipocytes in basal conditions. Ameliorated TNF‐α‐induced inflammation and insulin resistance in adipocytes via activation of insulin signaling and enhanced GLUT4 translocation suggesting a reduced hyperglycemia associated with the metabolic syndrome.