Regulatory Effect of Fresh Rehmanniae Radix Extract on the in Vitro Production of Proinflammatory Cytokines in Pristane-Induced Lupus Mice

Fresh Rehmanniae radix is known as a traditional medicine with anti-inflammatory and antioxidant activities. However, whether Rehmanniae radix attenuates autoimmune inflammation in lupus models characterized by T cell-dependent autoimmune disease including overproduction of proinflammatory cytokines, loss of T cell tolerance, and B cell hyperactivity remains unclear. We investigated the effect of fresh Rehmanniae radix methanol extracts (RGMeOH) on the in vitro overproduction of proinflammatory cytokines by immune cells from pristaneinduced lupus BALB/c mice. These results showed that RGMeOH remarkably attenuated Con A-increased overproduction of proinflammatory cytokines, such as IL-2, IFN-${\gamma}$, IL-6 and IL-10 by splenocytes from pristaneinduced lupus mice. RGMeOH greatly reduced LPS-induced production of TNF-${\alpha}$ by splenic macrophages from pristane-induced lupus mice, while significantly enhanced LPS-induced production of IL-10 but did not alter IL-6 by splenic macrophages and splenocytes. These findings suggest that RGMeOH may ameliorate lupus systemic inflammatory autoimmunity via down-regulation of TNF-${\alpha}$ and T cell-dependent cytokine production.