Lysine-orotate potentiates the toxicity of an extract of the mushroom Amanita phalloides

Upon simultaneous administration lysine-orotate increases (about 40-fold) the toxicity in mice of a crude Amanita phalloides extract. This effect, though less prominent, is also observed if these two compounds are injected 1 hr apart. The potentiating effect of lysine-orotate is dose dependent and neither L-lysine nor orotic acid exert any effect on the toxicity of the crude A. phalloides extract. Lysine-orotate increases the toxicity of amatoxins (alpha-amanitin) only, not affecting the toxicity of phalloidins. Thin layer chromatography on silica gel plates and column chromatography on Sephadex LH-20 has proven the formation of a relatively stable complex of amanitin and lysine-orotate. The results demonstrate that lysine-orotate should not be used as a hepatoprotective agent in cases of Amanita intoxication.