Anthocyanins ameliorate palmitate-induced inflammation and insulin resistance in 3T3-L1 adipocytes

Increased adiposity has been associated with adipose tissue low-grade inflammation leading to insulin resistance. Adipocyte differentiation inhibitors are expected to be effective in preventing obesity and related diseases. Anthocyanins (ACNs) are associated to enhanced adipocyte function and protection from metabolic stress. Herein, we evaluated the in vitro protective effects of an ACN rich extract against palmitic acid (PA)-induced hypertrophy, inflammation, and insulin resistance in 3T3-L1 adipocytes. ACN extract pretreatment reduces lipid accumulation and peroxisome proliferators-activated receptor-γ protein levels induced by PA. In addition, PA induces inflammation with activation of NF-κB pathway, whereas ACN extract pretreatment dose-dependently inhibited this pathway. Furthermore, adipocyte dysfunction associated with hypertrophy induces insulin resistance by affecting phosphatidylinositol 3-kinase-protein kinase B/Akt axis, GLUT-1, and adiponectin mRNA levels. ACN extract pretreatment reverts these effects induced by PA and moreover was able to induce insulin pathway with levels higher than insulin control cells, supporting an insulin sensitizer role for ACNs. This study demonstrates a prevention potential of ACNs against obesity comorbidities, due to their protective effects against inflammation/insulin resistance in adipocytes. In addition, these results contribute to the knowledge and strategies on the evaluation of the mechanism of action of ACNs from a food source under basal and insulin resistance conditions related to obesity.