Penta-O-galloyl-β-D-glucose, a hydrolysable tannin from Radix Paeoniae Alba, inhibits adipogenesis and TNF-α-mediated inflammation in 3T3-L1 cells

Penta-O-galloyl-beta-D-glucose (PGG) was purified and identified from Radix Paeoniae Alba by HSCCC and HPLC/ESI-MS, and its inhibitory effects on adipogenesis and TNF-alpha-induced inflammation were assessed in 3T3-L1 cell line. The results showed that PGG dose-dependently reduced intracellular lipids accumulation, and this involved decrease the expression levels of major adipogenic markers, PPAR gamma, C/EBP alpha, through MAPKs inhibition. This was accompanied by a reduction of lipogenic genes, ACC, FAS, and SCD-1, involved in fatty acid synthesis. Furthermore, PGG also inhibited TNF-alpha-induced expression of inflammatory cytokines including IL-6 and MCP-1 in the matured 3T3-L1 adipocytes. The inhibitions were likely mediated by blocking the MAPKs and NF-kappa B activation. These findings highlighted that PGG could serve as a potent therapeutic agent for controlling obesity and obesity-related chronic inflammation.