Triptolide has long been used as an ingredient in Chinese herbal therapy. The source of the chemical, a plant commonly referred to as lei gong teng or “thunder god vine,” has proven to work both as an anti-inflammatory and as an anti-tumor drug. Precisely how triptolide functions, was unknown, but a recent article in Nature now illuminates its mechanism of action.
Triptolide irreversibly binds to the XPB protein, a subunit of the transcription factor TFIIH. THe XPB protein is involved in unwinding DNA. Binding of triptolide to XPB inhibits transcription (the copying of DNA into RNA), and may also prevent a type of DNA repair (nucleotide excision repair). The latter would trigger an accumulation of genetic mistakes, which would signal the body to target affected cells for elimination. Furthermore, triptolide appears to enhance the anti-cancer function of DNA-damaging drugs such as cisplatin and may be useful as a new type of cancer drug.
Top