American ginseng supplementation induces an oxidative stress in postmenopausal women.
OBJECTIVE
To determine whether American ginseng (Panax Quinquefolium) confers antioxidant protection to postmenopausal women at rest and after a mild aerobic exercise session.


METHODS
In this double-blinded parallel study, 12 female subjects (age range 55-75) consumed two capsules, containing 500 mg of dry American ginseng whole-root powder, everyday for 4 months, whereas 13 female control subjects of the same age range consumed two placebo capsules. Before and after the supplementation regimen each subject performed 30 minutes of treadmill walking on a 5% grade incline at an estimated 60% of VO(2)max.


RESULTS
Ginseng supplementation had no effect on heart rate, blood pressure, plasma blood glucose, or lactate concentration at rest or immediately after exercise tests. The ginseng supplemented group displayed a higher resting plasma glutathione disulfide (GSSG) concentration and lower glutathione (GSH):GSSG ratio, as well as a lower resting total antioxidant content (TAC). Plasma GSSG concentration decreased, whereas the GSH:GSSG ratio and TAC increased after exercise in all subjects. Furthermore, plasma malondialdehyde and urine 8-hydroxydeoxyguanosine concentrations were elevated in the ginseng-supplemented group. Erythrocyte superoxide dismutase and GSH reductase activities were increased after ginseng supplementation. The 30-minute treadmill walking, however, did not alter these changes.


CONCLUSIONS
These data suggest that chronic American ginseng supplementation at the given dose can cause an oxidative stress in postmenopausal women, as reflected by the elevated oxidative damage markers and the increased erythrocyte antioxidant enzyme activity.
Dickman
Jonathan R
JR
Department Of Kinesiology, University Of Wisconsin - Madison, Madison, Wisconsin, USA.
Koenig
Ryan T
RT
Ji
Li Li
LL
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000975:Antioxidants / Q000378:metabolism*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D019587:Dietary Supplements; D004311:Double-Blind Method; D004912:Erythrocytes / Q000201:enzymology / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005260:Female; D005978:Glutathione / Q000097:blood*; D019803:Glutathione Disulfide / Q000097:blood*; D005980:Glutathione Reductase / Q000097:blood; D006801:Humans; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D018384:Oxidative Stress; D005894:Panax / Q000009:adverse effects*; D028321:Plant Preparations / Q000009:adverse effects*; D018517:Plant Roots; D017698:Postmenopause; D013482:Superoxide Dismutase / Q000097:blood; D016138:Walking
D000975:Antioxidants; D028321:Plant Preparations; D008315:Malondialdehyde; D000080242:8-Hydroxy-2'-Deoxyguanosine; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D003849:Deoxyguanosine; D005978:Glutathione; D019803:Glutathione Disulfide