Methylene Chloride Fraction of Saururus chinensis Inhibits Adipocyte Differentiation in 3T3-L1 Cells and Reduces Lipid Accumulation in High-Fat Diet-Fed C57BL/6 Mice

The aerial parts of Saururus chinensis (Lour.) Baill., known for its rich lignan content and diverse pharmacological activities such as anti-inflammatory and anticancer effects, has not been extensively explored for its potential in preventing obesity. In this study, we investigated the inhibitory effect of methylene chloride fraction of S. chinensis (MCSC) on adipocyte differentiation using experimental models. Furthermore, we conducted a comprehensive chemical analysis employing HPLC and LC-ESI/MS to identify and characterize the main compounds responsible for these effects. MCSC significantly inhibited preadipocyte differentiation, accompanied by down-regulation of target genes involved in lipid synthesis and storage. This anti-adipogenic effect was mediated by the inhibition of CCAAT/enhancer binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ) expression. In a mouse model, oral administration of MCSC resulted in reduced body weight and adipose tissue weight, along with improvements in serum lipid profiles in high-fat diet-induced C57BL/6 obese mice. Active ingredients were identified as manassantin A and manassantin B through comparison of their spectrometric features with previously reported data. This evidence suggests that MCSC could be a potential candidate for the treatment and prevention of obesity-associated diseases.