Lapachol is a naturally occurring naphthoquinone compound derived from the inner bark of the Tabebuia tree, traditionally used in South American herbal medicine. Its use in the context of leukemia is primarily supported by early scientific interest stemming from in vitro and animal studies. Research in the 1970s and 1980s demonstrated that lapachol exhibited cytotoxic effects against several cancer cell lines, including leukemia cells, suggesting potential anti-leukemic properties. Mechanistically, lapachol is believed to interfere with cellular metabolism, inhibit topoisomerase enzymes, and induce apoptosis in malignant cells. However, subsequent studies also documented significant toxicity, particularly hepatotoxicity and anticoagulant effects, in animal models and initial human trials, which limited further development as an anti-cancer agent.

Clinical evidence for lapachol's efficacy in leukemia is extremely limited. There are no robust, well-controlled human clinical trials demonstrating its benefit in leukemia patients. Additionally, due to safety concerns, its investigation in humans has largely ceased. Despite the promising preclinical data, the lack of translational success and considerable risk profile have prevented its adoption in mainstream oncology. In summary, while there is some scientific rationale and preliminary laboratory evidence for lapachol’s use in leukemia, the overall quality and quantity of the evidence are low, and it is not currently recommended as a treatment for leukemia.