Inhibitory Effect of Methanolic Extract of Black Garlic on Adipogenesis in 3T3-L1 Adipocytes

Black garlic (also called aged garlic) is produced from fresh garlic and used as a food ingredient and functional food. The aim of this work was to study the effects of different solvent (water, methanol, and ethanol) extracts of black garlic (WEBG, MEBG, and EEBG) on inhibition of adipogenesis in 3T3-L1 adipocytes. The results demonstrated that MEBG has the most prominent inhibitory effects on cell numbers, intracellular triglycerides, and glycerol-3-phosphate dehydrogenase activity in 3T3-L1 adipocytes. MEBG significantly up-regulated the protein expression of adiponectin, as well as down-regulated the protein expression of fatty acid synthase in 3T3-L1 adipocytes. Real-time RTPCR analyses of 3T3-L1 adipocytes exposed to MEBG showed that MEBG decreases the expressions of lipogenic genes (PPARγ, C/EBPα, FAS, aP2, and ACC) and adipokines (leptin and resistin), and increases the expressions of PGC-1α and adiponectin. These results demonstrated that MEBG efficiently inhibits adipogenesis in 3T3-L1 adipocytes.