Fucoidans from Thelenota ananas with 182.4 kDa Exhibited Optimal Anti-Adipogenic Activities by Modulating the Wnt/β-Catenin Pathway

In this study,fucoidans were extracted from the sea cucumber Thelenota ananas(Ta-FUCs)by enzymatic degradation.Four products with molecular weights of 1380.3,524.0,182.4,and 110.3 kDa were obtained,and the Ta-FUC showing optimal anti-adipogenic activities was determined.Results of MTT and Oil red O staining analyses showed that the Ta-FUCs inhibited the proliferation and differentiation of 3T3-L1 adipocytes.Futhermore,Ta-FUCs significantly downregulated the key transcriptional factors,such as SREBP-1c,PPARγ,and C/EBPαof adipocytes.The Ta-FUCs also activated Wnt/β-catenin pathway-related genes,such asβ-catenin,LRP5,and FrZ.The Ta-FUCs suppressed lipid accumulation in 3T3-L1 adipocytes possibly by decreasing the expression of genes ACC,FAS,ME,GPAT,DGAT,and PILN,which are important in the synthesis of fatty acids and triglycerides;and by increasing the expression of genes PPARα,CPT-1α,and ACOX,which are crucial in fatty acidβ-oxidation.The anti-adipogenic activities initially increased and then declined with decreasing molecular weight.Among the Ta-FUCs,the 182.4 kDa Ta-FUC exhibited optimal bioactivities.This study reports for the first time that Ta-FUCs can prevent obesity by regulating the differentiation and lipid accumulation of adipocytes.