AIM: To study the effects of gypenosides (Gyp) on lymphocyte transformation and DNA polymerase I activity. METHODS: Lymphocyte transformation response was induced by concanavalin A and lipopolysaccharides respectively. The activity of DNA polymerase Il and DNA synthesis were assayed with TTP and [(3H)]TdR incorporation respectively in mixed lymphocyte culture test. RESULTS: Gyp 2.5 - 20 mg L(-1) enhanced splenic T- and B- cell transformation, increased the DNA synthesis and potentiated the activity of DNA polymerase I. However, Gyp > 40 mg L(-1) showed contrary effects. CONCLUSION: Gyp regulat...