Product samples were tested for Salmonella, metals, furans, pesticides, antibiotics, mycotoxins, rodenticides, nephrotoxins (such
as aristolochic acid, maleic acid, paraquat, ethylene glycol, diethylene glycol, toxic hydrocarbons, melamine and related triazines) and were screened for other chemicals and poisonous compounds.
But in 2013, researchers found that a compound in the plants, known
as aristolochic acid, seems to cause a specific DNA mutation.
Genomic sequencing experts at Johns Hopkins partnered with pharmacologists at Stony Brook University to reveal a striking mutational signature of upper urinary tract cancers caused by
aristolochic acid, a plant compound contained in herbal remedies used for thousands of years to treat a variety of ailments such
as arthritis, gout and inflammation.