Photoprotective effect of red ginseng against ultraviolet radiation-induced chronic skin damage in the hairless mouse.

To evaluate the ability of red ginseng (RG) to protect the skin from photodamage, the gross and microscopic changes in the skin of hairless mice and RG-treated mice exposed chronically to UV were examined. The skin of the UV-irradiated mice showed characteristic signs of photoaging, such as deep wrinkles across the back, increased epidermal thickness, numerous cell infiltration, and many enlarged keratinizing cysts. The RG-treated mice showed a significantly decreased wrinkling score, minimal epidermal hyperplasia, slightly increased dermal cellularity and lack of proliferation of cysts. By week 22, 88.9% (i.p. with saline) or 60.0% (topical administration with cream base) of the UV-irradiated mice developed at least one tumor. RG delayed tumor onset significantly. RG was also effective in reducing the occurrence of UV radiation-induced skin tumors and reduced the number of tumors per mouse. After 22 weeks of treatment, 57.1% (i.p.) or 85.7% (topical administration) of the mice treated with RG were tumor-free. Tumor multiplicity was reduced by 89.3% (i.p.) or 92.2% (topical administration) in the RG treated groups. It is noted that skin that is chronically exposed to UV is subject to photoaging and photocarcinogenesis and the regular use of RG would prevent these photodamaging effects of UV. (c) 2008 John Wiley & Sons, Ltd.