title: Carcinogenic activity of Symphytum officinale.
abstract: The carcinogenicity of Symphytum officinale L., Russian comfrey, used as a green vegetable or tonic, was studied in inbred ACI rats. Three groups of 19--28 rats each were fed comfrey leaves for 480--600 days; four additional groups of 15--24 rats were fed comfrey roots for varying lengths of time. A control group was given a normal diet. Hepatocellular adenomas were induced in all experimental groups that received the diets containing comfrey roots and leaves. Hemangioendothelial sarcoma of the liver was infrequently induced.
mesh_terms: D000818:Animals; D002273:Carcinogens; D005260:Female; D006390:Hemangioendothelioma / Q000209:etiology / Q000473:pathology; D008113:Liver Neoplasms / Q000209:etiology / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000209:etiology* / Q000473:pathology; D019684:Magnoliopsida; D008297:Male; D009374:Neoplasms, Experimental / Q000209:etiology; D051381:Rats; D011912:Rats, Inbred ACI; D013997:Time Factors; D001749:Urinary Bladder Neoplasms / Q000209:etiology
chemical_list: D002273:Carcinogens