Podophyllotoxin (Podofilox)

• non-alkaloid lignan toxin present in podophyllin, resin produced by the rhizomes of plants belonging to the genus Podophyllum, for which it and the aforementioned resin are named, as well as a number of other genera that I don't feel like listing since I'm pretty sure most of you don't care that much and I really, really want to avoiding bogging down my posts with boring information and hideously long-winded sentences
• plants containing lignans are commonly found in traditional medicine, making them interesting starting points for the development of new drugs
• the genus Podophyllum includes Podophyllum peltatum (American Mayapple), a perennial herb native to eastern North America that grows in colonies
  
• is used as a topic antiviral agent in the treatment of condyloma acuminatum (genital warts!) caused by human papilloma virus as well as other types of warts found on one's naughty bits
• has also been used in the treatment of psoriasis vulgaris and rheumatoid arthritis
• kills cancer cells but was found to be too toxic in mice in preclinical trials, the step in drug development when compounds are evaluated in animals before trying them out in humans
• inhibits the polymerization of tubulin -> prevents the formation of microtubules -> arrests the cell cycle in metaphase -> inhibits the growth of tumours
• etoposide, teniposide, and etopophos are anticancer drugs derived from podophyllotoxin that permanently inactivate DNA topoisomerase II, resulting in DNA strand breaks (i.e. damage) that eventually lead to cell death, but have no effects on the polymerization of tubulin
  

Gordaliza M et al. Podophyllotoxin: distribution, sources, applications and new cytotoxic derivatives. Toxicon. 2004 Sep 15;44(4):441-59.
http://en.wikipedia.org/wiki/Podophyllotoxin