CYTOTOXIC EFFECTS OF SINOCOCULINE

Three alkaloids, aknadinine, 1-nitroaknadinine and sinococuline, isola ted from Stephania sutchuenensis were studied for their effects on a f ibroblast cell line, eight tumour cell lines and a rat alveolar macrop hage culture. Sinococuline is an effective tumour cell growth inhibito r whereas the toxicity of aknadinine and 1-nitroaknadinine towards all tested cells is low. A dose-dependent decrease in cell viability and in the uptake of tritiated-thymidine, -leucine and -uridine by these c ells was observed when they were grown in the presence of sinococuline for 24 h. Exposure to sinococuline in vitro also altered the macropha ge function by reducing the production of tumour necrosis factor and r eactive nitrogen intermediates. Human leukaemic HL60 cells and mouse f ibroblast L929 cells were used to study the underlying mechanism of cy totoxicity and apoptosis seems to be the mode of death induced by sino coculine.