PREVENTION OF DAMAGE FROM TOXINS
Ginseng extract has been shown to be beneficial in the prevention and treatment of testicular damage induced by environmental pollutants. Dioxin is one of the most potent toxic environmental pollutants. Exposure to dioxin either in adulthood or during late fetal and early postnatal development causes a variety of adverse effects on the male reproductive system. The chemical decreases spermatogenesis and the ability to conceive and carry a pregnancy to full term. Pretreatment with 100 or 200 mg/kg ginseng aqueous extract intraperitoneally for 28 days prevented toxic effects of dioxin in guinea pigs. There was no loss in body weight, testicular weight or damage to spermatogenesis. In guinea pigs Panax ginseng also improves the survival and quality of sperm exposed dioxin.
Ginseng is traditionally used to treat anaemia. The total saponin fraction, and specifically Rg1 and Rb1, have been shown to promote haemopoiesis by stimulating proliferation of human granulocyte-macrophage progenitors.
In vitro studies did not find various extracts of ginseng to be particularly potent antioxidants against several different free radicals. However, animal models have demonstrated effects in type 2 diabetes, particularly for the leaf, which may suppress lipid peroxidation in diabetic rats. Ginseng extract has also been shown to protect muscle from exercise-induced oxidative stress in animal studies.
Whether these effects are directly due to the antioxidant activity of ginseng components or secondary to other mechanisms, such as blood glucose regulation, is unclear. Additionally ginseng compounds may require in vivo conversion to active metabolites in order to exert their full effects.
Ginsenosides have been demonstrated to have anti-allergic activity in vitro. One of the metabolites, 20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol, was found to inhibit beta-hexosaminidase release from rat basophil leukaemia cells and potently reduce passive cutaneous anaphylaxis reaction. The inhibitory activity of protopanaxadiol was more potent than that of disodium cromoglycate, an antiallergic drug. The compound stabilised membranes but had no effect on hyaluroni-dase and did not scavenge free radicals. These results suggest that the anti-allergic action of protopanaxadiol originates from its cell membrane-stabilising activity and that the ginsenosides are prod rugs with anti-allergic properties.
Ginsenoside Rb2 has been reported to improve wound healing. It is believed that ginsenoside Rb2 enhances epidermal cell proliferation by enhancing the expressions of protein factors related to cell proliferation, such as epidermal growth factor and fibronectin (and their receptors), keratin and collagenase. Ginsenoside Re may also enhance tissue regeneration by inducing angiogenesis.
In an animal model of acne, ginseng extracts reduced the size of comedones by altering keratinisation of the skin and desquamating horny cells in comedones. In a study of experimentally induced hyperkeratosis, ginseng reduced the accumulation of lipids in the epidermis by regulating enzymes associated with epidermal metabolism.