Ultraviolet (UV) light is electromagnetic radiation with a wavelength from 400 nm to 10 nm (shorter than that of visible light but longer than X-rays). UV radiation is present in sunlight, and is produced by electric arcs and specialized lights such as mercury-vapor lamps, tanning lamps, and black lights.

Ultraviolet radiation can cause chemical reactions, and the impact of ultraviolet radiation on human health has implications for the risks and benefits of sun exposure. Overexposure to UV radiation not only can cause sunburn but also some forms of skin cancer like malignant melanoma. In 2011, UV is classified into class I carcinogen.

Ginsenoside Re is found in ginseng, and it can change into protopanaxatriol (PPT), the active form of ginsenosides, in the body. The latest reseach showed that ginsenoside Re can protect cells from UV injury and prevent malignant transformation of cells. The research was published on the journal “Lishizhen Medicine and Materia Medica Research, 2013(08)” .

The study used a UV-sensitive human cells (Rsa cells) to test the Re effect on the cell viability under UV exposure. Results showed UV reduced cell proliferation and the activity of antioxidant SOD in the cell, in a dose-dependent manner. However, the addtion of 50ug/ml Re greatly recovered the SOD activity and restored the growth capacity as well. Moreover, the apoptosis induced by UV exposure was halted after Re intervention.

Taken together, PPT-type ginsenoside Re can protect human cells from UV injury, and increased SOD level and cell viability could be responsible for Re’s beneficial effect.