title: Fighting fire with fire: poisonous Chinese herbal medicine for cancer therapy.
abstract: BACKGROUND
  Following the known principle of "fighting fire with fire", poisonous Chinese herbal medicine (PCHM) has been historically used in cancer therapies by skilled Chinese practitioners for thousands of years. In fact, most of the marketed natural anti-cancer compounds (e.g., camptothecin derivatives, vinca alkaloids, etc.) are often known in traditional Chinese medicine (TCM) and recorded as poisonous herbs as well. Inspired by the encouraging precedents, significant researches into the potential of novel anticancer drugs from other PCHM-derived natural products have been ongoing for several years and PCHM is increasingly being recognized as a gathering place for promising anti-cancer drugs. The present review aimed at giving a rational understanding of the toxicity of PCHM and, especially, providing the most recent developments on PCHM-derived anti-cancer compounds.
  
  
  METHODS
  Information on the toxicity and safety control of PCHM, as well as PCHM-derived anti-cancer compounds, was gathered from the articles, books and monographs published in the past 20 years.
  
  
  RESULTS
  Based on an objective introduction to the CHM toxicity, we clarified the general misconceptions about the safety of CHM and summarized the traditional experiences in dealing with the toxicity. Several PCHM-derived compounds, namely gambogic acid, triptolide, arsenic trioxide, and cantharidin, were selected as representatives, and their traditional usage and mechanism of anti-cancer actions were discussed.
  
  
  CONCLUSIONS
  Natural products derived from PCHM are of extreme importance in devising new drugs and providing unique ideas for the war against cancer. To fully exploit the potential of PCHM in cancer therapy, more attentions are advocated to be focused on their safety evaluation and mechanism exploration.
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau 999078, China.
authors.forename: Shengpeng
authors.initials: S
authors.lastname: Wang
authors.forename: Xu
authors.initials: X
authors.lastname: Wu
authors.forename: Miao
authors.initials: M
authors.lastname: Tan
authors.forename: Jian
authors.initials: J
authors.lastname: Gong
authors.forename: Wen
authors.initials: W
authors.lastname: Tan
authors.forename: Baolin
authors.initials: B
authors.lastname: Bian
authors.forename: Meiwan
authors.initials: M
authors.lastname: Chen
authors.forename: Yitao
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use*; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D029001:Herbal Medicine; D006801:Humans; D008516:Medicine, Chinese Traditional; D009369:Neoplasms / Q000188:drug therapy*; D008517:Phytotherapy; D010946:Plants, Medicinal; D011042:Poisons / Q000627:therapeutic use*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004365:Drugs, Chinese Herbal; D011042:Poisons