Synergistic effects of the alkaloid sinomenine in combination with the immunosuppressive drugs tacrolimus and mycophenolic acid

The alkaloid sinomenine extracted from the medicinal plant Sinomenium acutu m is used in China for the treatment of various rheumatic diseases, It has immunomodulatory properties in a cardiac allograft transplantation model. I ts antiproliferative effect on human mononuclear cells in combination with different immunosuppressive drugs was further analysed in vitro. Sinomenine dose-dependently attenuated thymidine incorporation, interleukin-2 synthes is, and cell cycle progression of activated T-lymphocytes. Cell proliferati on was synergistically decreased by addition of sinomenine together with su boptimal concentrations of the established immunosuppressive drugs tacrolim us or mycophenolic acid, respectively.