Chronic ginseng consumption attenuates age-associated oxidative stress in rats.

The antioxidant properties of North American ginseng (Panax quinquefolium) were investigated in young and old rats fed a ginseng-supplemented diet for 4 mo. Female Fischer 344 rats at 4 (Y, n = 38) or 22 (O, n = 25) mo of age were randomly divided into three groups and fed either a AIN-93G formula-based control diet (C) or a diet containing 0.5 g/kg (low dose, L) or 2.5 g/kg (high dose, H) dry ginseng power for 4 mo. Oxidant generation, measured with 2'7'-dichlorofluorescin (DCFH), was significantly lowered with ginseng feeding in the homogenates of heart, soleus, and the deep portion of vastus lateralis muscle (DVL) (P < 0.05) in both Y and O rats, and the effects were dose dependent. Superoxide dismutase activity was elevated in heart and DVL of H rats, and in soleus of L rats (P < 0.05). H rats showed higher glutathione peroxidase activity in DVL and soleus muscle (P < 0.05), and elevated citrate synthase activity in the heart of both age groups and DVL of Y rats (P < 0.05). Neither the H nor L diet affected age-dependent lipid peroxidation in the heart or muscle, but protein carbonyl content was attenuated with the H diet in the heart (P < 0.05) and with both the L and H diets in DVL (P < 0.01). We conclude that ginseng supplementation can prevent age-associated increase in oxidant production and oxidative protein damage in rats. These protective effects are explained in part by elevated antioxidant enzyme activities in the various tissues.