Effects of traditional herbal medicine, Hwaotang, on atherosclerosis using the spontaneous familial hypercholesterolemia model, Kurosawa and Kusanagi-hypercholesterolemic rabbits and the venous thrombosis rats.

Hwaotang (HOT), a traditional Korean medicinal formulation, is a dried decoctum of a mixture of seven herbal medicines, consisting of Angelica gigantis Radix, Rehmanniae Radix, Paeoniae Radix, Ciniamomi Cortex, Cnidii Rhizoma, Persicae Semen and Carthami Flos. In the present study, the inhibitory effects and anti thrombic properties of HOT on the progression of atherosclerotic lesions were studied using the spontaneous familial hypercholesterolemia (FH) model, Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits and rats. Changes in blood chemistry, pathology and low-density lipoprotein (LDL) oxidation were measured in a control and HOT group. In the control group, the area of atheromatous plaques of the aorta progressed between week 12 (36.65%) and week 14 (46.22%). This progression of atherosclerotic lesions did not occur in the HOT-treated group after 12 (24.24%) and 14 (23.34%) weeks. Antioxidative effects on LDL were seen in the HOT in weeks 12 and 14. HOT improved the hypercholesterolemia in the KHC rabbits. On the other hand, HOT and five of the seven herbs, except Cnidii Rhizoma and Carthami Flos, inhibited the endotoxin-induced hepatic venous thrombosis in high cholesterol diet-treated rats. However, Ciniamomi Cortex showed a very weak inhibitory effect on the endotoxin-induced hepatic venous thrombosis. The extract also inhibited the endotoxin-induced decrease in blood platelets and fibrinogen, and endotoxin-induced increase in fibrin degradation products (FDP) on disseminated intravascular coagulation in normal rats. In conclusion, these results suggest that HOT has inhibitory effects on the development of atheromatous plaque formation in spontaneous FH rabbits. It is also suggested that the antioxidative effects of HOT on LDL led to the beneficial effects observed in this study. The protection by HOT and its herbs on the artificially induced ischemic infarction might be related to their inhibitory effects on disseminated intravascular coagulation, platelet coagulation and thrombotic action. Copyright (c) 2005 John Wiley & Sons, Ltd.