In vitro treatment of chicken peripheral blood lymphocytes, macrophages, and tumor cells with extracts of Korean medicinal plants.

A variety of different medicinal plants have traditionally been used in Asian cultures as medicinal plants to enhance immunity and treat cancers. However, limited information exists on the underlying mechanisms responsible for these immune enhancing properties. The current investigation was conducted to examine the effects of methanol extracts of 3 Korean indigenous plants (dandelion root, mustard leaf, and safflower leaf) on various in vitro parameters of innate immunity (peripheral blood lymphocyte proliferation, nitric oxide production by macrophages, and free radical scavenging activity) and tumor cell growth. All plant extracts inhibited tumor cell growth and exerted antioxidant effects compared with vehicle controls. In addition, safflower leaf extract stimulated lymphocyte proliferation and mustard leaf induced nitric oxide production. These results demonstrate, for the first time, that traditional Korean medicinal plant extracts are effective in enhancing innate immunity and suppressing tumor cell growth.