Abstract: This study aimed to observe the effect of sea cucumber cerebroside on the proliferation and differentiation of 3T3- L1 preadipocytes and to explore the underlying mechanism. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was used to explore the effect of cerebroside on the proliferation of preadipocytes. 3T3-L1 preadipocytes were induced into mature adipocytes by the traditional cocktail method, and oil red O staining and triglyceride content of mature adipocytes were used to evaluate whether sea cucumber cerebroside could change lipid accumulation in adipocytes. The mRNA expression levels of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein alpha (C/EBPα) genes and those associated with the Wnt/β-catenin signaling pathway were measured by reverse transcription real-time polymerase chain reaction (qRT-PCR). The transfer of β-catenin protein to the nucleus was measured by Western blotting. Sea cucumber cerebroside could significantly inhibit the proliferation and differentiation of 3T3-L1 preadipocytes without cytotoxicity (P < 0.01). The results of qRT-PCR showed that the expression of PPARγ and C/EBPα genes and those associated with the Wnt/β-catenin signaling pathway were significantly inhibited by sea cucumber cerebroside. Western blotting results showed that sea cucumber cerebroside could significantly increase the content of β-catenin protein in nuclei (P < 0.01). In conclusion, sea cucumber cerebroside can inhibit the proliferation and differentiation of 3T3-L1 preadipocytes. The mechanism is related to the transcription factors PPARγ, C/EBPα and the Wnt/β-catenin signaling pathway.

Key words: sea cucumber cerebroside, 3T3-L1 preadipocyte, differentiation, Wnt/β-catenin