Researchers in Taiwan have linked consumption two herbal products—Guan Mu Tong (Aristolochia manshuriensis) or Guang Fangchi (Aristolochia fangchi)—to an increased risk of developing end-stage renal disease (ESRD).
Guan Mu Tong and Guang Fangchi contain significant quantities of aristolochic acid, which is known to cause renal toxicities. In 2001, the FDA warned consumers to discontinue the use of botanical products containing aristolochic acid, noting that such products have been associated with permanent kidney damage, sometimes resulting in kidney failure requiring dialysis or kidney transplantation.
Prior to being prohibited in Taiwan on November 4, 2003, herbal products containing aristolochic acid were once widely prescribed in Taiwan, which has an extremely high incidence of ESRD, according to researchers.
The investigators, led by Jung-Der Wang, MD, and Ming-Nan Lai, MD, of the Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei City, noted that Xi Xin, an herbal product that contains some amount of aristolochic acid, still is widely prescribed in Asia, so they were concerned about the potential nephrotoxicity of its cumulative dosage.
The team studied 25,843 new cases of ESRD and 184,851 controls. After adjusting for known risk factors, cumulative doses of 61-100, 101-200, and more than 200 grams of Guan Mu Tong were associated with 47%, twofold, and sixfold increased risk of ESRD, respectively, the investigators reported in the American Journal of Kidney Diseases (2010;55:507-518). Cumulative doses of 61-100, 101-200, and more than 200 grams of Guang Fangchi were associated with a 60%, 62%, and twofold increased risk.
Dr. Wang’s team concluded that herbal products containing significant amounts aristolochic acid, including Guan Mu Tong and Guang Fangchi contributed to the high incidence and prevalence of CKD or ESRD in Taiwan from 1997-2002, which was the study’s period of observation.
They recommended universal surveillance of herbs or Chinese herbal products containing aristolochic acid to prevention ESRD.
The researchers noted that their population-based study is the first to document the dose-response relationship between Chinese herbal products and ESRD.