Exposure to aristolochic acid I is associated with poor prognosis of liver cancer patients.

The aristolochic acids (AAs), derived from Aristolochia and Asarum species used widely in herbal medicines, are closely associated with liver cancer. The major AA derivatives are aristolochic acid I (AAI) and II (AAII), which can bind DNA covalently to form AA-DNA adducts after metabolic activation in vivo. Among all these AA-DNA adducts, 7-(deoxyadenosine-N6-yl) aristolactam I (dA-AL-I) is the most abundant and persistent DNA lesion in patients. However, the direct evidence indicating AA exposure in human liver cancer is still missing. Here, we analyzed dA-AL-I adduct, the direct biomarker of AAI exposure, by ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-TQ/MS) in 209 liver cancer patients. Also, DNA samples from mice treated with/without AAI were used as positive and negative controls. dA-AL-I adduct was present in 110 of 209 (52.6%) patients, indicating that these patients were exposed to AAI prior to their clinical investigations and also had a worse prognosis. The relative high AA exposure rate and worse prognosis in our cohort of patients emphasize the significance to increase public awareness to avoid the use of herbal medicine containing AAs or their derivatives.