Abstract: AimTo study the effects of ginsenoside-Ro on cell proliferation and cytokine production in murine splenocytes. MethodsThe effect of ginsenoside-Ro on murine splenocytes proliferation was studied using ［³H］thymidine incorporation assay. Effects of ginsenoside-Ro on the production of cytokines interleukin-2 (IL-2), interferon-γ (IFN-γ) and interleukin-4 (IL-4) from murine splenocytes were detected by ELISA method. Effects of ginsenoside-Ro on mRNA level of Th1 cytokine IFN-γ and Th2 cytokine IL-4 were evaluated by reverse transcription polymerase chain reaction (RT-PCR) analysis. ResultsGinsenoside-Ro showed no mitogenic effect on unstimulated murine splenocytes. It enhanced the proliferation of Con A-induced murine splenocytes and the production of IL-2 at concentrations of 1-10 μmol·L^-1. Moreover, ginsenoside-Ro increased the production and expression of Th2 cytokine IL-4 and decreased the production and expression of Th1 cytokine IFN-γ in Con A-induced murine splenocytes at concentrations of 2-10 μmol·L^-1. ConclusionGinsenoside-Ro showed immunomodulatory effects by regulating the production and expression of Th1/Th2 cytokines in murine splenocytes.