Effect of 1,5-anhydro-D-fructose on the inhibition of adipogenesis in 3T3-L1 adipocytes.

1,5-Anhydro-D-fructose (1,5-AF) is a monosaccharide that shares a structural similarity to glucose. 1,5-AF is found in fungi, algae, Escherichia coli and rat liver and is produced by the degradation of starch and glycogen, which is catalyzed by the enzyme alpha-1,4-glucan lyase. However, the physiological role of 1,5-AF in mammalian tissues is not well understood. Here, we investigated the anti-obesity potential of 1,5-AF on adipogenesis in 3T3-L1 adipocytes. 1,5-AF caused a significant decrease in GPDH activity in 3T3-L1 preadipocytes and mature adipocytes without eliciting cytotoxicity, and inhibited cellular lipid accumulation through down-regulation of transcription factors such as PPARgamma and C/EBPalpha. 1,5-AF also induced dose-dependent phosphorylation of AMP-activated protein kinase (AMPK), a cellular energy sensor. However, the total AMPK protein content remained unchanged. Furthermore, 1,5-AF increased the levels of reactive oxygen species, an important upstream signal for AMPK activation in 3T3-L1 adipocytes. Our results show that 1,5-AF exerts anti-obesity action in vitro and suggest that 1,5-AF is potentially a novel preventative agent for obesity and other metabolic diseases.