Toxic Relationships Between Your Liver and Herbs
Herbal medicines continue to be increasingly popular therapies for many illnesses and conditions. More than two decades ago, we published one of our first articles on herbal medicine in the Inside Tract® newsletter.1 Since then, we have written about herbal supplements, Traditional Chinese Medicine, and other herbal remedies, including the popular herb, medical cannabis.
Herbal therapies, or treatments with plant-derived compounds, are formally known as phytomedicines. Some herbal therapies have shown promising results to treat gastrointestinal (GI) diseases and disorders. However, many do not have enough evidence to support their use, and this is often due to barriers in clinical trials and research. Many studies also fail to detect serious adverse events because of small sample sizes and confounding factors. However, due to their popularity and use, researchers have been able to gather and analyze a growing body of literature on their associated risks and side effects.2
In this article, we cover a few herbal medicines that studies have found to be associated with, or cause, herbal hepatotoxicity. Hepatotoxicity, or toxic hepatitis, is when serious liver damage occurs and it is often due to the intake of, or exposure to, certain medications, herbal supplements, chemicals and solvents, and alcohol.
Regulations
Health Canada regulates the sale and marketing of natural health products, which includes herbal medicines.3 Natural health products must follow licensing and labelling requirements and they need clinical trial data or published studies to support their claims for health benefits. Those items with a Natural Product Number (NPN) or Homeopathic Medicine Number (HMN) on its label show that Health Canada has reviewed and approved the item for sale.
A recent report from the Office of the Auditor General of Canada concluded that there are major gaps in Health Canada’s regulation of natural health products, such as routine inspection of manufacturing sites, monitoring of products for adverse events, and inability to enforce mandatory recalls of products that present serious health risks.4 As a result, please consult your treating physician if you are currently taking or planning to take herbal medicines.
In most cases of toxic liver damage, discontinuing herbal medicine may resolve your symptoms. Researchers warn that prolonged intake, especially in large amounts, may increase your risk of serious liver damage that can lead to the need for liver transplantation and even death.
Herbs Associated with Liver Damage
| Herb | Use | Research Findings |
| Atractylis gummifera5 | fever, constipation, nausea, ulcers, and drowsiness; children consume its fluid extracts as chewing gum | • associated with liver failure • immediate side effects include acute hepatitis, nausea, headache, and abdominal pain |
| Chaparral (Larrea tridentata) | common cold, bone and muscle pain, snake bites, weight loss, skin disorders, and antioxidant properties | • also known as ‘creosote bush’ or ‘greasewood’ • reports dating back to the 1990s on cases of liver damage |
| Germander (Teucrium chamaedrys) | weight loss and diarrhea | • a 600 to 1600 milligrams/per day dose for two months often led to the development of hepatitis • continued treatment can lead to cirrhosis |
| Greater Celandine (Chelidonium majus) | irritable bowel syndrome | • therapeutic benefits have not been tested in randomized clinical trials • several reports of hepatotoxicity |
| Herbs containing pyrrolizidine alkaloids (Heliotropium, Senecio, Symphytum (Comfrey), and Crolataria) | dietary supplement6 | • fluid accumulation in the abdomen (ascites), which can lead to liver cirrhosis • prolonged use may lead to chronic or acute liver failure • known as ‘Senecio disease’ in South Africa • Canada and Germany have banned the sale of products with comfrey |
| Kava root or kava kava (Piper methysticum rhizome) | anxiety disorders and depression | • potential therapeutic effectiveness found from randomized controlled trials for the treatment of anxiety • associated with liver damage and liver failure, transplantation, and even death |
| Ma Huang (Ephedra sinica) | weight loss | • acute hepatitis after three weeks of intake |
| Pennyroyal (Menta pulegium and Hedeoma pulegoides) | induces uterine bleeding, which can cause an abortion7 | • may cause intoxication • used as a flea pesticide • associated with acute liver failure and death |