In vitro Effects of Methanol Extracts of Korean Medicinal Fruits (Persimmon, Raspberry, Tomato) on Chicken Lymphocytes, Macrophages, and Tumor Cells

A variety of fruits have traditionally been used in Asian cultures to enhance resistance to diseases and treat cancers. However, limited information exists on the underlying mechanisms responsible for these effects. The present investigation was conducted to examine the ability of three Korean indigenous fruits (persimmon, raspberry and tomato) to stimulate lymphocyte proliferation and macrophage nitric oxide production as parameters of innate immunity, and to inhibit tumor cell growth. In vitro co-culture of chicken spleen lymphocytes with methanol extracts of persimmon (Diospyros kaki) or tomato (Lycopersicon esculentum) induced greater cell proliferation compared with cells treated with the vehicle control. Stimulation of chicken macrophages with extracts of persimmon or raspberry (Rubus crataegifolius), but not tomato, stimulated robust nitric oxide production to levels similar to that produced by interferon-g. All fruit extracts uniformly inhibited the growth chicken tumor cells in vitro. These results provide a rational basis for future studies investigating the effects of medicinal fruits on innate immunity and carcinogenesis in humans and animals.