Hexane Extract of Chloranthus japonicus Increases Adipocyte Differentiation by Acting on Wnt/β-Catenin Signaling Pathway

Chloranthus japonicus has been heavily investigated for the treatment of various diseases. This paper attempts to show that Chloranthus japonicus can modulate adipocyte differentiation of preadipocytes. To establish this, we investigated the effects of Chloranthus japonicus extract in peroxisome proliferator-activated receptor γ (PPARγ) expression, adipogenesis, and the underlying molecular mechanisms in C3H10T1/2 and 3T3-L1 cells. Our data showed that Chloranthus japonicus methanol extract increased lipid accumulation and promoted adipocyte differentiation. Further studies on the fractionation with various solvents led to the identification of Chloranthus japonicus hexane extract (CJHE) as the most potent inducer of adipocyte differentiation. CJHE consistently increased lipid accumulation and adipocyte marker expression including Pparγ and it acted during the early stages of adipocyte differentiation. Mechanistic studies revealed that CJHE and a Wnt inhibitor similarly stimulated adipogenesis and were active in Wnt-selective reporter assays. The effects of CJHE were inhibited by Wnt3a protein treatment and were significantly blunted in β-catenin-silenced cells, further suggesting that CJHE acted on Wnt pathways to promote adipogenesis. We also showed that Chloranthus japonicus extracts generated from different plant parts similarly promoted adipocyte differentiation. These results identified Chloranthus japonicus as a pro-adipogenic natural product and suggest its potential use in metabolic syndrome.