Hepatotoxic plants Comfrey

Russian comfrey (Symphytum x uplandicum Nyman) is widely recommended as a medicinal herb and an item of human diet. A previous investigation of this species led to the isolation of three alkaloids which were not fully characterized (cf. Vol. 7, p. 57). Culvenor and co-workers have separated eight pyrrolizidine alkaloids from the leaves of this perennial plant by counter-current distribution.21 The known alkaloids echimidine (51), symphytine (52), lycopsamine (53), and intermedine (54) were present. In addition, four new alkaloids, i.e. 7-acetyl-lycopsamine (55), 7-acetylintermedine (56), symlandine (57), and uplandicine (58), were characterized by spectroscopic methods, and by hydrolysis. The total alkaloidal extract caused chronic hepatotoxic effects in rats, and the authors... 

Comfrey Symphytum officinale Anti-inflammatory gastritis diarrhea Hepatic veno-occlusive disease possible teratogen/carcinogen. (Note many other plants also contain hepatotoxic pyrrolizidine alkaloids-see Table 11-46). 

Substances toxic to all individuals are called toxic substances or toxins. Once a toxic substance has contacted the body it may have either acute (immediate) or chronic (long term) effects. Most of food-born toxins are substances with low acute toxicity (such as the pungent alkaloid piperine in black pepper), although some may present chronic effects, such as hepatotoxic pyrrohzidine alkaloids in plants (such as comfrey and coltsfoot species) or cause pathological changes to the respiratory system (e.g., tobacco smoke). 

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