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Radix Ginseng
in the body’s own defences against exogenous stress factors and noxious
chemicals (31). Secondly, the drug promotes an overall improvement in
physical and mental performance (30–33).
Treatment of cultured mammalian cells, isolated organs, and animal
models (primarily mice and rats) with Radix Ginseng before or during
exposure to physical, chemical, or psychological stress increased the ability
of the respective model systems to resist the damaging effects of various
stressors (31). These results were demonstrated in cases of radiation
poisoning (34–36), viral infection and tumour load (37, 38), alcohol or carbon
tetrachloride poisoning (39–41), oxygen deprivation and hypobaric
pressure (42, 43), light or temperature stress, emotional stress, and electrical
shock or restricted movement (44, 45, 46). The mechanism by which
the drug exerts its activity is most likely through the hypothalamus–pituitary–adrenal
axis (47–49) and through its immunostimulant effect (50).
Intraperitoneal administration to rats of ginseng saponin fractions or
the ginsenosides Rb 1
, Rb 2
, Rc, Rd, and Re elevated serum levels of adrenocorticotropic
hormone (ACTH) and corticosterone (51, 52). Pretreatment
with dexamethasone, which blocks hypothalamus and pituitary
functions, prevented ginseng saponin-mediated release of ACTH and
corticosterone, and thereby demonstrated that the increase in serum corticosterone
by ginseng occurs indirectly through release of ACTH from
the pituitary (51, 52).
The immunomodulatory activity of ginseng appears to be at least partly
responsible for its adaptogenic effect (50, 53, 54). Alcohol extracts of
Radix Ginseng stimulated phagocytosis in vitro, were mitogenic in cultured
human lymphocytes, stimulated the production of interferon, and
enhanced the activity of natural killer cells (55, 56). Intraperitoneal administration
of an extract of the drug to mice stimulated cell-mediated
immunity against Semliki Forest virus, elevated antibody levels against
sheep red blood cells and natural killer cells (57), and stimulated the production
of interferon (58).
Improvement in physical and mental performance has been observed
in mice and rats after oral or intraperitoneal administration of the drug
(59–63). Oral administration of ginseng saponin fractions to mice increased
endurance and prolonged swimming time in swimming tests (63).
However, two studies concluded that ginseng had no positive effects on
the physical performance in mice and rats (64, 65). The adaptogenic effects
of Radix Ginseng are generally attributed to the ginsenosides (66,
67). The ginsenosides have been shown to alter mechanisms of fuel homeostasis
during prolonged exercise, by increasing the capacity of skeletal
muscle to oxidize free fatty acids in preference to glucose for cellular en-
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