Herbal medicines are often taken by those who want to improve health using more natural methods than pharmaceuticals. Many have been used since ancient times, particularly in Traditional Chinese Medicine (TCM). However, like drugs, herbal preparations also have risks as they can cause health problems rather than help. The FDA has recently updated a warning about the ingredient Aristolochic acid which has been shown can lead to kidney failure and upper urinary tract cancer.
The botanical Aristolochia spp and other plants in the Aristolochiaceae family contain Aristolochic acid which, in small amounts, could be used for years without any apparent adverse events. However, long-term use or high doses are potentially nephrotoxic (damaging to the kidneys) and the damage could be occurring without symptoms until the effects are serious and irreversible.
Dr. Arthur Grollman MD, Distinguished Professor of Pharmacological Sciences at Stony Brook University School of Medicine, have been studying patients in Croatia, Bosnia and Serbia who have an unusual kidney disease known as Balkan endemic nephropathy. This disease is characterized by progressive kidney failure, frequently coupled with the development of urothelial cell carcinoma (UUC), a type of bladder cancer that starts in the cells lining the bladder. If this cancer is not treated early, it can spread to nearby organs and other parts of the body.
Dr. Grollman and his team extracted DNA from tumors of 67 UUC patients and detected a metabolite of aristolochic acid bound to DNA in the kidney cortex. The aristolactam(AL)-DNA adducts cause alterations in the properties of genomic DNA. While 70% of the endemic UUC patients had this finding, 94% of those also carried a “fingerprint” mutation in TP53, making them genetically susceptible to many forms of cancer.
The exposure to toxic aristolochic acid came from wheat grown in the region where the patients were tested. Aristolochia clematitis is also popularly known as “birthwort” and was baked into bread.
“Implications of these results go beyond the population of those exposed in the Balkans,” says Dr. Grollman in the journal Kidney International, “as millions of people worldwide are at risk for developing diseases due to aristolochic acid exposure from traditional remedies prepared from Aristolochia herbs.” For example, Aristolochic acid may be present in dietary supplements that can be purchased globally. Consumers should look for the ingredients "Aristolochia," "Bragantia" or "Asarum" on the label of suspected aristolochic acid-containing products.
The FDA first warned the US public about Aristolochic acid in May of 2000, listing 16 products to avoid including Rheumixx (PharmaBotanixx), BioSlim Doctor’s Natural Weight Loss System Slim Tone Formula (Thane International), and Prostatin (Herbal Doctor Remedies). This list was most recently updated and expanded as of October 12, 2011. Examples of some Chinese medicines know to contain the potential carcinogen include Dang Gui Si Ni, Du Hou Ji Sheng Tang, and Chuam Xiong Cha Tiao Wan. A full list can be viewed at www.accessdata.fda.gov.
Study Source Reference: Kidney International , (9 November 2011) | doi:10.1038/ki.2011.371