Pcynogenol Inhibits Adipogenesis and Simulate Antilipogenic Effect in 3T3‐L1 Adipocytes

Abstract

Pycnogenol(Pyc), standardized extracts from the bark of French maritime pine (Pinus pinaster Ait.), has a wild range of phamacological effects. To explore the possibility that Pyc might influence an adipocyte differentiation and lipolysis, this study investigated the effects of Pyc on the expression of adipokines and PPARγ, the effects of Pyc on the regulation of fatty acid metabolism, and the induction of apoptosis in the differentiated 3T3‐L1 cells. With Oil‐Red O staining, treatment of Pyc at concentration of 10–200 μg/ml significantly inhibited the cytoplasmic lipid accumulation and glucose uptake at day 9 after induction of differentiation. In addition, we measured the protein expression of adipokines and PPARγ during differentiation. As result, Pyc suppresses the adipogenesis at post stage during differentiation by inhibiting PPARγ and adiponectin expression, but not leptin. We demonstrated that Pyc blocks adipogenesis by suppression on the expression of adipogenic transcription factors and adipokines. Anti‐lipogenic effects of Pyc on differentiated 3T3‐L1 adipocytes were investigated. Pyc inhibited the cytoplasmic lipid accumulation and has synergistically increased the glucose uptake by 32.6% in the differentiated 3T3‐L1. Pyc increased glycerol release from differentiated 3T3‐L1 and also up‐regulated LPL and HSL mRNA expression to degrade cellular fatty acid. With 72hr treatment, Pyc induced the apoptosis by modulating Bax/Bcl‐2 ratio. Apoptosis may, at least in part, occur through caspase‐3 signaling pathway.