Herbal Products Containing Aristolochic Acid and

Aristolochic acid nephropathy — a progressive form of renal inter-stitial fibrosis — was first reported in a group of young Belgian patients with end-stage renal disease in 1993 and was thought to be caused by the use of Chinese herbal medicines that contained aristolochic acid ( 1 – 3). Aristolochic acid has been shown to be as-sociated with urothelial cancer in studies of clinical cases around the world, in animal models, and by the detection of aristolochic acid – DNA adducts in kidney and ureteral tissues ( 4 – 6). In 2002, the International Agency for Research on Cancer classified herbal remedies that contain plant species of the genus Aristolochia, which contain a high level of aristolochic acid, as carcinogenic in humans (ie, group 1 carcinogens) ( 7). Consequently, many countries have since banned the use of herbs containing aristolochic acid, in