Irniine, a pyrrolidine alkaloid, isolated from Arisarum vulgare can induceapoptosis and/or necrosis in rat hepatocyte cultures

The effects of irniine, a pyrrolidine alkaloid extracted from the tubers of Arisarum vulgare, on rat hepatocyte primary cultures and rat liver epithel ial cell line (RLEC) were studied. Cytotoxicity was first evaluated by LDH release, MTT and NR tests and MDA production, while cellular alterations we re visualized by electron microscopy and DNA gel-electrophoresis. In hepato cyte and RLEC cultures, a major toxicity appeared at 40 mu M of irniine and was demonstrated by an increase in LDH release and decreases in MTT reduct ion and NR uptake while concentrations lower than 40 mu M did not induce si gnificant changes in these parameters. However, we observed an increase in MDA production at 30 mu M Important alterations of the nuclei and mitochond ria were also Visualized by electron microscopy in cells treated with 50 mu M. Using DNA gel-electrophoresis, we demonstrated that irniine at 40 and 5 0 mu M induced DNA damage. All together these results demonstrate that: (1) Irniine induces a significant hepatotoxicity, (2) Irniine toxicity is not mediated by a metabolic derivative since RLEC, which do not contain a monoo xygenase system, were also affected by this compound. (3) Irniine induces a significant DNA damage and oxidative stress which leads to cell death by n ecrosis and/or by apoptosis. Moreover, our data suggest that the alkaloid i rniine contained in A. vulgare may be involved in the toxic symptoms observ ed after medicinal use or consumption of the plant, tubers as food both by humans and animals, (C) 2000 Elsevier Science Ltd. All rights reserved.