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Query: UMLS:C0000737 (abdominal pain)
 31,184 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The development of herbal medicine has follow in line with increased popular interest in ecology. Emphasis has been placed on the safety of natural herbs in contrast with the risks involved with "classical" medicines. But recent publications have revealed that several herbal medicines are toxic for the liver. For example, in France we have observed cases of hepatitis after ingestion of germander (Teucrium chamaedrys). Clinicians should also be aware of other well documented toxic effects of herbs used in popular medicines in Africa, Asia or Central America. The toxicity of pyrrolizidine alkaloids was recognized over 40 years ago. More than 300 plant species, including Heliotropium, Crotalaria, Senecio and Symphytum, are implicated. In Africa or Central America, intoxication is sometimes endemic since these plants are often used for making tea. In Western countries, cases of herb-induced hepatitis have been observed after use of preparations containing Symphytum or Chinese herbs. Pyrrolizidine alkaloids cause obstruction of the hepatic venous system and can lead to hepatonecrosis. Clinical manifestations include abdominal pain, ascitis, hepatomegaly and raised serum transaminase levels. Prognosis is often poor with death rates of 20 to 30% being reported. Atractylis gummifera is another example of herbal toxicity. Twenty-six species of this plant are used for medicinal purposes or for chewing gum. Intoxication usually occurs in the spring and is related to chewing the roots of these plants. Severe hepatocellular lysis may occur less than 24 hours after ingestion. Clinical manifestations are related to the induced hypoglycemia and neurovegetative disorders or subsequent renal failure. These compounds have an inhibitor effect on the Krebs cycle and can lead to severe or fatal liver failure. Other similar cases of fatal liver accidents have been reported after ingesting Callilepis laureola, a herb used by the Zoulous in Natal for medicinal purposes or after use of products containing extracts of Teucrium chamaedrys, which was nevertheless authorized in France in 1986 for use in preparations for weight loss. These examples emphasize the importance of remembering that herbal medicine is not harmless. Faced with the extensive distribution of many herbal preparations and the risk of self-medication, consumers and clinicians alike should be increasingly vigilant with these potentially hepatotoxic products.
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PMID:[Liver involvement in the course of phytotherapy]. 807 73

Herbal medication has gathered increasing recognition in recent years with regard to both treatment options and health hazards. Pyrrolizidine alkaloids have been associated with substantial toxicity after their ingestion as tea and in the setting of contaminated cereals have led to endemic outbreaks in Jamaica, India and Afghanistan. In Western Europe, comfrey has been applied for inflammatory disorders such as arthritis, thrombophlebitis and gout and as a treatment for diarrhoea. Only recently was the use of comfrey leaves recognized as a substantial health hazard with hepatic toxicity in humans and carcinogenic potential in rodents. These effects are most likely due to various hepatotoxic pyrrolizidine alkaloids such as lasiocarpine and symphytine, and their related N-oxides. The mechanisms by which toxicity and mutagenicity are conveyed are still not fully understood, but seem to be mediated through a toxic mechanism related to the biotransformation of alkaloids by hepatic microsomal enzymes. This produces highly reactive pyrroles which act as powerful alkylating agents. The main liver injury caused by comfrey (Symphytum officinale) is veno-occlusive disease, a non-thrombotic obliteration of small hepatic veins leading to cirrhosis and eventually liver failure. Patients may present with either acute or chronic clinical signs with portal hypertension, hepatomegaly and abdominal pain as the main features. Therapeutic approaches include avoiding intake and, if hepatic failure is imminent, liver transplantation. In view of the known serious hazards and the ban on distributing comfrey in Germany and Canada, it is difficult to understand why comfrey is still freely available in the United States.
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PMID:The efficacy and safety of comfrey. 1127 98