Advances in the Research on Safety of Traditional Medicine Containing Heavy Metals

Traditional medicines containing heavy metals have a long history of clinical application in China. The "harmful elements" in such medicines include copper, lead, mercury, arsenic, and cadmium, etc, with potential toxicities mainly on liver, kidney, and brain. These toxicities are related to their species and valence, and are also closely related to their preparation and compatibility detoxification methods. The technical difficulty in safety control research of heavy metal-containing traditional medicines lies in the development of detection methods for extremely small amounts and different forms of heavy metal compounds in organisms. The key problems in the present study of heavy metal-containing traditional medicines are the one-sided evaluation as replacing medicinal standards with food standards, replacing content of chemical species with total metal elements, and replacing the remedy part with exogenous heavy metal contamination. The key scientific issues should be deeply investigated for the safety control of heavy metal-containing traditional medicines including the in vivo metabolism and toxicity mechanisms of heavy metal compounds, curative effect and risk evaluation, safety assessment and standards formulation, etc. It is particularly necessary to strengthen the fundamental research on the valence state and the pharmacokinetics of heavy metals with different valence states. This paper reviews the research progress on the safety of heavy metalcontaining traditional medicines and aims to provide ideas for the safety control study of heavy metal components in traditional medicines.