BACKGROUND
Diabetes mellitus is postulated to be associated with increased oxidative stress and lipid peroxidation which may contribute to vascular complications. Recently ginseng (Panax) has been shown to have an antioxidant effect by enhancing nitric oxide synthesis in endothelial cells and by directly scavenging hydroxyl radicals. It is unknown whether ginseng might act as an antioxidant against lipid peroxidation in diabetes. METHODS: We studied the in vitro effect of red ginseng extract on lipid peroxidation employing phospholipid liposome and low-density lipoprotein (LDL) as a model system. To investigate the in vivo effect on lipid peroxidation in diabetes, we administered red ginseng extract (1 g/L in drinking water) to streptozotocin (STZ)- induced diabetic rats for 12 weeks and measured lipid peroxidation products in plasma, liver, kidneys and heart. RESULTS: The Fe(3+)- or Cu(2+)- mediated lipid peroxidation in phospholipid liposome and LDL, measured by the concentration of TBARS, was inhibited in the presence of red ginseng extract. MDA level in plasma measured by HPLC was higher in STZ-induced diabetic rats than in control rats. Plasma MDA level was lower by 41% in red ginseng-treated diabetic rats than in untreated diabetic rats. Tissue MDA levels measured by TBA method in liver, kidneys and heart were higher in STZ-induced diabetic rats than in control rats. In red ginseng-treated diabetic rats tissue MDA levels were lower by 14~30% than in untreated diabetic rats. CONCLUSION: We observed that red ginseng extract has an effect in inhibiting lipid peroxidation both in vitro and in STZ-induced diabetic rats. These results suggest that red ginseng might have a beneficial effect in diabetes as an antioxidant against lipid peroxidation and diabetic vascular complications.