Geiji-Bokryung-Hwan (GBH), a
drug preparation consisting of five herbs of Cinnamomi Ramulus (Geiji), Poria Cocos (Bokryun), Mountan Cortex Radicis (Mokdanpi), Paeoniae Radix (Jakyak) and Persicae Semen (Doin), is a traditional Korean herbal medicine that is widely used in the treatment of
atherosclerosis-related disorders. A water extract of GBH was found to scavenge
1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and inhibit
low-density lipoprotein (
LDL) oxidation more effectively than
probucol, a well-known commercially available
antioxidant. In order to evaluate the anti-atherogenic potential of this medication, New Zealand White (NZW) rabbits were fed a normal diet for 12 weeks, a high
cholesterol diet, a high
cholesterol diet containing 1%
probucol or a high
cholesterol diet containing 5% water-soluble extract of GBH. Both GBH and
probucol reduced plasma
cholesterol levels. LDLs from the GBH-treated group were more resistant to Cu(2+)-induced oxidation and contained more
vitamin E than LDLs from the high
cholesterol diet group. Endothelial damage, determined at week 6, was reduced by 55% in the GBH group (P<0.01). GBH treatment reduced an atherosclerotic area in the abdominal aorta by 58% (P<0.05) and
cholesterol deposition in the thoracic aorta by 55% (P<0.05). The severity of
atherosclerosis in the GBH group was significantly reduced after an adjustment using
cholesterol exposure as an index of the
cholesterol-lowering effect. On the other hand, diet-induced hyperlipidemic rabbits were given water extract of GBH in doses of 50 (Group B) and 200 mg/kg (Group C) and compared with controls (Group A). At 40 days after intervention in groups A, B and C, total and
LDL cholesterol levels were significantly lowered (P<0.01).
LDL/
high density lipoprotein (HDL) ratio was also significantly decreased (P<0.01). This study concludes that the reduction in
atherosclerosis by GBH relies not only on its
cholesterol-lowering effect but also more heavily on its
antioxidant potential, which prevents endothelial damage and inhibits
LDL oxidative modification in hypercholesterolemic animals.