Inhibitory effects of compounds isolated from roots of Cynanchum wilfordii on oxidation and glycation of human low-density lipoprotein (LDL)

Low-density lipoprotein (LDL) modification such as oxidation and glycation has been known to play a significant role in the initiation and progression of atherosclerosis. The inhibitors on LDL modification have been emerged as a new strategy to be a supplement for prevention of atherosclerosis. In an effort to discover inhibitors on LDL modification from natural products, phytochemical investigation on Cynanchum wilfordii roots were performed, leading to isolation of acetophenones (1-6) including a new one (1) and nine pregnane-type steroids (7-15). The structure of the compound 1 was determined by analysis of 1D and 2D NMR spectral data analysis. All the isolated compounds were evaluated for their inhibitory activities against LDL modification. Among them, compounds 2 and 5 strongly inhibited LDL oxidation and glycation. These results suggest that compounds 2 and 5 from C. wilfordii may provide potential protective effects against atherosclerosis via inhibition of LDL oxidation and glycation.