カキドウシ熱水抽出物による脂肪細胞分化への影響

抄録

The Glechoma hederacea subsp. Grandis is traditionally used for the treatment of asthma, colds and bronchitis, and is reportedly effective in promoting bile secretion and diuretic action and preventing diabetes. In this study, we investigated the effect of hot water extract of Glechoma on 3T3-L1 adipocyte differentiation. Oil Red O staining showed more neutral lipid droplets in 3T3-L1 adipocytes treated with the hot water extract of Glechoma. In addition to morphological change, the expression of CCAAT/enhancer-binding protein α, peroxisome proliferator activator γ2 (PPARγ2), adipogenic regulators at the intermediate stage of adipocyte differentiation and adipocyte protein 2, an adipocyte differentiation marker gene, was increased in cells treated with extract of Glechoma. PPARγ2, a ligand-activated transcription factor of a nuclear receptor, is known to normalize adipocyte functions and improve insulin sensitivity by promoting the differentiation of preadipocytes into small-sized adipocytes. Treatment with the hot water extract of Glechoma increased transcriptional activity of PPARγ, suggesting that Glechoma contains an active ingredient at least PPAR agonist. Our results demonstrate that the hot water extract of Glechoma could promote adipocyte differentiation in part through the activation of PPARγ. Taken together, Glechoma has the potential to improve insulin resistance and prevent the onset of type 2 diabetes.