Anti-Adipogenic Activity of Secondary Metabolites Isolated from Smilax sieboldii Miq. on 3T3-L1 Adipocytes.

Smilax sieboldii , a climbing tree belonging to Smilacaceae, has been used in traditional oriental medicine for treating arthritis, tumors, leprosy, psoriasis, and lumbago. To evaluate the anti-obesity effects of S. sieboldii (Smilacaceae), we screened methylene chloride (CH 2 Cl 2 ), ethyl acetate (EtOAc), aqueous-saturated n -butanol, and ethanol (EtOH) extracts of the whole plant at various concentrations to inhibit adipogenesis in adipocytes. The 3T3-L1 cell line with Oil red O staining with the help of fluorometry was used as an indicator of anti-obesity activity. Bioactivity-guided fractionation of the EtOH extract and subsequent phytochemical investigation of the active CH 2 Cl 2 - and EtOAc-soluble fractions resulted in the isolation of 19 secondary metabolites ( 1 - 19 ), including a new α-hydroxy acid derivative ( 16 ) and two new lanostane-type triterpenoids ( 17 and 18 ). The structures of these compounds were characterized using various spectroscopic methods. All the isolated compounds were screened for adipogenesis inhibition at a concentration of 100 μM. Of these, compounds 1 , 2 , 4 - 9 , 15 , and 19 significantly reduced fat accumulation in 3T3-L1 adipocytes, especially compounds 4 , 7 , 9 , and 19 , showing 37.05 ± 0.95, 8.60 ± 0.41 15.82 ± 1.23, and 17.73 ± 1.28% lipid content, respectively, at a concentration of 100 μM. These findings provide experimental evidence that isolates from S. sieboldii extracts exert beneficial effects regarding the regulation of adipocyte differentiation.