Gallotannin derivatives from mango (Mangifera indica L.) suppress adipogenesis and increase thermogenesis in 3T3-L1 adipocytes in part through the AMPK pathway

Expansion of adipose tissue in obesity is associated with dysregulation of adipokines, which can lead, to longterm metabolic disorders. Gallotannin derivatives from mango possess anti-inflammatory activities, but their potential role in lipid metabolism is not well investigated. In this study, 3T3-L1 preadipocytes were differentiated into adipocytes and treated with mango polyphenols (MG), or pyrogallol (PG) for 6 days. The antiadipogenic activity of PG was demonstrated by reduced number of lipid droplets and expressions of adipogenic markers, such as peroxisome proliferator-activated receptor gamma (PPAR gamma) and CCAAT/enhancer binding protein alpha (C/EBP alpha). In mature adipocytes, PG promoted adipocyte browning and increased the expressions of uncoupling protein 1 (UCP1) and sirtuin 1 (Sirt1). Knockdown of AMP-activated protein kinase (AMPK) alpha 1 with siRNA partially abolished the effect of PG on adipogenesis. Results indicate that gallotannin derivatives modulate lipid metabolism, at least in part, though the AMPK pathway, and possess potential to prevent obesity-related conditions.