SS-Lapachone

A naturally occurring quinone found in the bark of the Lapacho tree (Tabebuia avellanedae) . A novel DNA topoisomerase I inhibitor which unlike camptothecin does not stabilize the cleavable complex indicating a novel mode of action.1 Induces apoptosis in a number of cancer cell lines.2 In cancer cells overexpressing NAD (P) H:quinone oxidoreductase, reduction of -lapachone leads to futile cycling between quinone and hydroquinone forms3 resulting in the production of reactive oxygen species4. Suppresses radiation-induced activation of NFB.5