We conducted this study to isolate novel anti-hyperlipidemic agents derived from natural marine products. To accomplish this, we investigated the effects of ethanolic (EtOH) extracts of Ecklonia stolonifera and its phlorotannin constituents,
eckol and
dieckol, on serum
lipid levels in rats with
hyperlipidemia that was induced by a high-
cholesterol diet or
poloxamer 407. Treatment with the EtOH extracts of E. stolonifera and its phlorotannin-rich
ethyl acetate (EtOAc) and
n-butanol (n-BuOH) fractions induced a significant reduction in
triglycerides (TG), total
cholesterol (TC), and
low-density lipoprotein-cholesterol (
LDL-C) levels, as well as a significant increase in the
high-density lipoprotein-cholesterol (HDLC) level in hyperlipidemic rats. However, treatment with the water (H(2)O) fraction did not exert any significant effects on the serum levels of hyperlipidemic rats. In addition,
eckol and
dieckol isolated from the active EtOAc fraction induced a significant reduction in serum TG, TC, and
LDL-C levels, as well as in the atherogenic index (A.I.). Furthermore, treatment with
dieckol induced a greater decrease in the serum TG, TC, and
LDL-C levels of hyperlipidemic rats than
eckol or
lovastatin, as well as an increase in the serum HDL-C levels. Taken together, these results suggest that phlorotannins such as
eckol and
dieckol have the potential for use for the prevention of hyperlipidemic
atherosclerosis.